UNITED STATES DEPARTMENT OF COMMERCE

National Oceanic and At mospheric Administration

NATIONAL MARINE FISHERIES SERVICE Northwest Region 7600 Sand Point Way N.E., Bldg. 1
Seattle, WA 98115

Refer to NMFS No:

2011/06017 July 10, 2012

Christine B. Reichgott Unit Manager Environmental Review & Sediment Management U.S. Environmental Protection Agency, Region 10 1200 Sixth Avenue, Suite 900 Seattle, Washington 98101-3140

Re: Endangered Species Act Biological Opinion and Magnuson-Stevens Fishery Conservation and Management Act Esse ntial Fish Habitat Response for the Environmental Protection Agency Designati on of the North and South Yaquina River Ocean Disposal Material Dredged Site s, Pacific Ocean, Li ncoln County, Oregon

Dear Ms. Reichgott:

The enclosed document contains a biological opi nion (opinion) prepared by the National Marine Fisheries Service (NMFS) pursuant to section 7(a)(2) of the Endangered Species Act (ESA) on the effects of Environmental Protection Agency ’s (EPA) designation of the North and South Yaquina River Ocean Disposal Material Dredge d Sites (ODMD) under their authority found in section 102(c) of the Marine Protection, Research and Sanctuaries Act, as amended (MPRSA), 33 U.S.C. §§ 1401 to 1445 near the mouth of the Yaquina River, Lincoln County, Oregon. Included in this designation is the adoption of a Site Management and Mo nitoring Plan (SMMP).

In this opinion, NMFS concludes that the proposed action is not likely to adversely affect five species of Chinook salmon, two species of coho salm on, four species of mari ne turtles, Southern Resident killer whales ( Orcinus orca ) eastern distinct population segment (DPS) Steller sea lions ( Eumotopias jubatus ), and five other species of marine ma mmals. All of these species are listed under the Endangered Species Act.

The NMFS also concluded that the proposed acti on is not likely to jeopardize the continued existence of Oregon Coast coho salmon ( Oncorhynchus kisutch ), southern DPS North American green sturgeon ( Acipenser medirostris ), southern DPS Pacific eulachon ( Thaleichthys pacificus ),

or result in the destruction or adverse modification of designated critical habitat for southern DPS North American green sturgeon.The adverse effects identified in this opinion th at NMFS is reasonably cert ain will occur are the

result of the indirect effects of subsequent Federal actions carri ed out by the United States Army Corps of Engineers (Corps) a nd other entities carrying out dredging and disposal. The EPA expects the ODMD sites will be used in the futu re for disposal of material dredged by other public or private entities ( e.g. the U.S. Coast Guard, Port of Yaquina, Port of Toledo) in

accordance with section 103 of th e MPRSA. These disposals woul d require section 103 permits (which could be multiple year authorizations up to 7 years) from the Regulatory Branch of the Corps and EPA concurrence. Individual permits are publicly noticed and require other Federal consultations ( e.g. ESA, EFH) and authorizations ( e.g. water quality certification). The EPA’s

action here does not authorize a nd will not itself result in dispos al of any dredged materials.

Therefore, although NMFS anticipates indirect effects from EPA’ s action, it does not anticipate any take will be caused by the site designation and adoption of the SMMP. Any further analysis of the effects of disposal of dredged material at the disposal site and issu ance of an incidental take statement will be prepared when the dis posal permit is requested by the action agency.

This document also includes the results of our anal ysis of the action’s like ly effects on essential fish habitat (EFH) pursuant to section 305(b) of the Magnuson-Ste vens Fishery Conservation and Management Act (MSA), and includes two c onservation recommendations to avoid, minimize, or otherwise offset potential a dverse effects on EFH. These c onservation recommendations are

not a subset of the ESA take statement’s terms and conditions. Section 305(b) (4) (B) of the MSA requires Federal agencies to provide a deta iled written response to NMFS within 30 days after receiving these recommendations.

If the response is inconsiste nt with the EFH conservation r ecommendations, the Federal action agency must explain why the recommendations will not be followed, including the scientific justification for any disagreemen ts over the effects of the acti on and the recommendations. In response to increased oversigh t of overall EFH program effectiveness by the Office of Management and Budget, NMFS established a quar terly reporting requirement to determine how many conservation recommendations are provided as part of each EFH consultation and how many are adopted by the action agency. Therefore, we request that in your statutory reply to the EFH portion of this consultation, you clea rly identify the number of conservation recommendations accepted.

Please direct questions regard ing this opinion to Jeff Young, fi shery biologist in the Oregon Coast Branch of the Oregon State Habitat Office, at 541.957.3389.

Sincerely,

William W. Stelle, Jr. Regional Administrator

cc: Bridgette Lohrman, EPA Kate Groth, Corps

## Endangered Species Act Biological Opinion

and Magnuson-Stevens Fishery Cons ervation and Management Act

Essential Fish Ha bitat Response

for the

EPA Designation of the North and South Yaquina River Ocean Dis posal Material Dredged Sites Pacific Ocean, Lincoln County, Oregon

NMFS Consultation Number: 2011/06017

Federal Action Agency: U.S. Environmental Protection Agency

Affected Species and Determinations:

ESA-Listed Species ESA

Status Is the action likely to adversely affect this species or its

critical habitat? Is the Action likely to jeopardize this species? Is the action likely to destroy or adversely modify critical habitat for this species?
Oregon Coast coho salmon T Y N N
Southern DPS green sturgeon T Y N N

Southern DPS Pacific eulachon T Y N N
Southern Oregon/Northern California

Coast coho salmon T N N N

Lower Columbia R. Chinook salmon T N N N
Upper Columbia R. Chinook salmon T N N N
Upper Willamette R. Chinook salmon T N N N
Snake R. spr/sum Chinook Salmon T N N N

Snake R. fall Chinook salmon T N N N

Eastern DPS Stelle r sea lion T N N N

Blue whale E N N N/A

Sei whale E N N N/A
Sperm whale E N N N/A

Fin whale E N N N/A
Humpback whale E N N N/A

Southern Resident Killer Whale E N N N

Green turtle T N N N

Leatherback turtle E N N N
Loggerhead turtle T N N N
Olive Ridley turtle E N N N/A

Fishery Management Plan that Describes EFH in the

Action Area Would the acti on adversely

affect EFH? Are EFH conservation recommendations provided?

Pacific Coast salmon Y Y
Coastal pelagics species Y Y
Pacific Coast groundfish Y YConsultation Conducted By: National Mari ne Fisheries Service Northwest Region

Issued by: ___________________ William W. Stelle, Jr. Regional Administrator

Date: July 10, 2012-iTABLE OF CONTENTS

1. INTRODUCTION ............................................................................................................... ....... 1 1.1 Background ................................................................................................................ ........... 1 1.2 Consultation History ...................................................................................................... ....... 1 1.3 Proposed Action ........................................................................................................... ......... 2

1.4 Action Area ............................................................................................................... ............ 6

2. ENDANGERED SPECIES ACT BIOLOGICAL OPINION AND INCIDENTAL TAKE

STATEMENT ..................................................................................................................... ............ 9 2.1 Introduction to the Biological Opinion ................................................................................. 9 2.2 Rangewide Status of the Speci es and Critical Habitat ........................................................ 11 2.2.1 Status of the Species ................................................................................................ 12

2.2.2 Status of the Critical Habitat .................................................................................... 24

2.3 Environmental Baseline .................................................................................................... .. 26 2.4 Effects of the Action on the Species and Designated Critical Habitat ............................... 33

2.4.1 Effects to the Environment ...................................................................................... 33 2.4.2 Effects to ESA-listed species ................................................................................... 37

2.4.3 Effects to Critical Habitat ........................................................................................ 50

2.5 Cumulative Effects......................................................................................................... ..... 52 2.6 Integration and Synthesis ................................................................................................. ... 52 2.6.1 ESA-listed Species ................................................................................................... 52

2.6.2 Critical Habitat ........................................................................................................ . 53

2.7 Conclusion ................................................................................................................ .......... 53

2.8. Incidental Take Statement ................................................................................................ .. 53

2.8.1 Amount or Extent of Take ....................................................................................... 54

2.9. Conservation Recommendations ....................................................................................... 54

2.10 Reinitiation of Consultation ............................................................................................. . 55 2.11 “Not Likely to Adversely Affect” Determinations ........................................................... 55 2.11.1 ESA-listed Fish Species ......................................................................................... 55

2.11.2 ESA-listed Marine Mammals ................................................................................ 56

2.11.3 ESA-listed Marine Turtles ..................................................................................... 57

2.11.4 Leatherback Sea Turtle Desi gnated Critical Habitat ............................................. 58

3. MAGNUSON-STEVENS FISHERY CONS ERVATION AND MANAGEMENT ACT ...... 58 3.1 Essential Fish Habitat Affected by the Project ................................................................... 58

3.2 Adverse Effects on Essential Fish Habitat .......................................................................... 60

3.3 Essential Fish Habitat Conservation Recommendations .................................................... 61 3.4 Statutory Response Requirement ........................................................................................ 61 3.5 Supplemental Consultation ................................................................................................. 62 4. DATA QUALITY ACT DOCUMENTATION AND PRE-DISSEMINATION REVIEW .... 62

5. LITERATURE CITED ........................................................................................................... .. 64-iiLIST OF ACRONYMS

BA Biological Assessment BRT Biological Recovery Team CFR Code of Federal Regulations Corps U.S. Army Corps of Engineers DPS Distinct Population Segment DQA Data Quality Act

EFH Essential Fish Habitat EPA U.S. Environmental Protection Agency ESA Endangered Species Act ESU Evolutionarily Significant Unit FR Federal Register GLOBEC Global Ocean Ecosystem Dynamics

HAPC Habitat Area of Particular Concern

ITS Incidental Take Statement LAA Likely to Adversely Affect

LCR Lower Columbia River MPRSA Marine Protection, Research and Sanctuaries Act MSA Magnuson-Stevens Fishery and Conservation Management Act NLAA Not Likely to Adversely Affect

NMFS National Marine Fisheries Service OC Oregon Coast TRT Technical Recovery Team ODMD Ocean Disposal Material Dredged PAH Polycyclic Aromatic Hydrocarbons PCB Polychlorinated biphenyls PCE Primary Constituent Elements PFMC Pacific Fishery Marine Council

SEF Sediment Evaluation Framework SL Screening Level SMMP Site Management and Monitoring Plan SONCC Southern Oregon/Northern California Coast

SR Snake River SVOC Semi-volatile Organic Compounds TBT Organotins TOC Total Organic Carbon TSS Total Suspended Solids UCR Upper Columbia River UWR Upper Willamette River VSP Viable Salmonid Population-1- 1. INTRODUCTION

This Introduction section provides information rele vant to the other sectio ns of this document and is incorporated by reference into Sections 2 and 3 below.

1.1 Background

The biological opinion (opinion) portion of this document was prepared by the National Marine Fisheries Service (NMFS) in accordance with sec tion 7(b) of the Endangered Species Act (ESA) of 1973, as amended (16 U.S.C. 1531, et seq .), and implementing regulations at 50 CFR 402.

The NMFS also completed an essential fish ha bitat (EFH) consultation. It was prepared in accordance with section 305(b )(2) of the Magnuson-Stevens Fishery Conservation and Management Act (MSA) (16 U.S.C. 1801, et seq .) and implementing regulations at 50 CFR 600.

The opinion and EFH conservation recommendations are both in compliance with section 515 of the Treasury and General Government A ppropriations Act of 2001 (Public Law 106-5444) (“Data Quality Act”) and underw ent pre-dissemination review.

1.2 Consultation History

The NMFS received a letter and a biological as sessment (BA) on December 22, 2011, from the U.S. Environmental Protection Agency Region 10 (EPA) requesting formal consultation and informal consultation for ESA-listed species and cr itical habitats that may be affected by the EPA’s proposed designation of two dredged mate rial disposal sites in the Pacific Ocean

northwest and southwest of the mouth of the Ya quina River. The EPA determined the proposed action was likely to adversely aff ect Oregon Coast (OC) coho salmon ( Oncorhynchus kisutch ).

Additionally, EPA determined that the proposed action may affect, but was not likely to adversely affect (NLAA) the following species: (1) Lower Columbia River (LCR) Chinook salmon ( O. tshawytscha ); (2) Upper Willamette River (UWR) Chinook salmon ( O

. tshawytscha ); (3) Snake River (SR) spring/summer run Chinook salmon ( O

. tshawytscha ); (4) southern distinct population segment (DPS) North American gree n sturgeon (hereafter referred to ‘green sturgeon’) ( Acipenser medirostris ); (5) southern DPS Pacific eu lachon (hereafter referred to as ‘eulachon’) ( Thaleichthys pacificus ); (6) Southern Reside nt killer whales ( Orcinus orca ); (7) eastern DPS Steller sea lions ( Eumotopias jubatus ); (8) blue whales ( Balaenoptera

musculus ); (9) fin whales ( B. physalus ); (10) humpback whales ( Megaptera novaengliae ); (11) sei whales ( B. borealis ); (12) sperm whales ( Physeter macrocephalus ); (13) leatherback sea turtles ( Dermochelys coriacea ); (14) loggerhead sea turtles ( Caretta caretta ); (15) green sea turtles ( Chelonia mydas ); and (16) olive ridley sea turtles ( Lepidochelys olivacea ). The EPA also determined that the proposed action is NLAA de signated critical habita t for leatherback sea turtles and designated critical habitat for green sturgeon.

After reviewing information provided by the EPA, NMFS has determined that SR fall-run and Upper Columbia River (UCR) Chinook salmon ( O. tshawytscha ) also potentially occur in the-2- action area and may be affected by the proposed action. Therefore, NMFS will include these species in this opinion.

The EPA included an EFH assessment in the cons ultation request package and determined that the effects of the proposed action may advers ely affect EFH designated for Pacific Coast groundfish, coastal pelagic species, and Pacific salmon. A complete record of this consultation is on file at the Oregon Coast Branch of the Oregon State Habitat Office in Roseburg, Oregon.

1.3 Proposed Action

“Action” means all activities or programs of any kind authorize d, funded, or carried out, in whole or in part, by Federal agenci es. Interrelated actions are those th at are part of a larger action and depend on the larger action for their justification. In terdependent actions are those that have no independent utility apart from the action under consideration.

The proposed action is the EPA’s designation of the Yaquina River north and south Ocean Disposal Material Dredged (ODMD) sites und er section 102(c) of the Marine Protection, Research and Sanctuaries Act, as amended (MPRSA), 33 U.S.C. §§ 1401 to 1445. The proposed

north site is located 1.7 nautical miles northwest of Yaquina Bay and the south site is about 2 nautical miles southwest of the bay. Both ODMD sites are 4,000 feet wide by 6,500 feet long, about 597 acres each, and their depths range from 112 to 152 feet. Included in this designation is the adoption of a Site Management and Mon itoring Plan (SMMP). Prior to the proposed designation, three sites, the interim, adjusted, and drop zone of the north site (authorized for use under section 103 of MPRSA in 2001), were used fo r disposal of dredged material (Figure 1). The interim and adjusted sites were determined inadequate to continue to receive disposed

material. Use of the north site expired at the end of the 2011 dre dge season and is unavailable for future dredge seasons unless designated as pr oposed in the EPA’s current designation action (EPA 2011).

The SMMP has been prepared jointly by EPA, an d the U.S. Army Corps of Engineers (Corps) (Portland District), and describes management and monitoring requirements for EPA-designated ODMD sites located offshore from Yaquina Bay, Oregon. This SMMP supersedes all previous SMMPs for the Yaquina River ODMD sites. Pe riodic review and updating of the SMMP will occur on a minimum 10-year schedule. All permits or other authorizations to use the Yaquina

River ODMD sites shall be conditioned as necess ary to assure consistency with this SMMP.

MPRSA 102(c)(3)(E) requires that the management plan include c onsideration of the anticipated use of the site. Disposal activities associated with dredging are not conducted by the EPA, are subject to subsequent consulta tion, and are therefore not part of the EPA’s proposed action. However, disposal would not be able to occur bu t for EPA’s designation of this disposal site, so

it constitutes an interrelated action that must be analyzed along with the proposed action. The EPA expects the Corps will be the primary and regular user of the Yaquina River ODMD sites proposed for designation for dispos al of dredged material remove d from the Federal navigation project. A summary of the Yaqui na River Federal navigation proj ect is included in the SMMP. Recent (last ten years) volumes of dredged materi al disposed of at the north ODMD site have averaged 217,379 cubic yards (cy) with a ra nge from 320,455 cy in 2003 to 161,678 cy in 2009.-3- Only material from Corps Federal projects has b een disposed of in the ocean, except when Port of Toledo disposed of 3,000 cy in 2010. The EPA expects the ODMD sites will be used in the future for disposal of material dredge d by other public or private entities ( e.g. the U.S. Coast Guard, Port of Newport, Port of Toledo) in accordance with Sec tion 103 of the MPRSA.

Disposal Capacity: Based on sediment FATE modeling, EPA expects each proposed ODMD site to have the capacity to receive approximat ely, on average, 310,000 cy of dredged material annually for 20 years (or 6.2 million cubic yards (m cy) each) without impacting the present wave

climate 1

.

The type of dredge used to gath er the material to be disposed influences the dimensions of the individual and cumulative dump mounds at the disposal sites. No specific disposal technique is required at the Yaquina River ODMD sites. For the hopper dredges that commonly work in the Yaquina River, such as the Corps’ multiple bottom door hopper dredge Yaquina , each load would produce a thinner deposit than the split hull contract ho pper dredges typically used by private entities at any given water depth. Material discharged from a split-hull barge is typically more consolidated than material discharged from a multiple bottom-door hopper dredge. Only hopper dredges can be used at the Yaquina Rive r entrance channel dredging site due to waves and currents. Clamshell dredges with barges can be used at estuary dredgi ng sites such as South Beach Marina and Yaquina Ri ver (including Depot Slough).

1 The long-term statistical characterization of the behavior of waves in the ocean.-4- Figure 1. The EPA’s proposed Yaquina Bay no rth and south ODMD site locations.-5- The EPA and the Corps will closely monitor and document disposal volumes and placement, to verify uniform placement, and to assess dispersi ve capability of disposed material (EPA and Corps 2011a). Adverse sea and weather conditio ns limit dredging and disposal to a period typically from June 1 to October 31. Even during the dredging season, storm events can restrict disposal events. Environmental restrictions may be imposed on disposal. In the event that new information or monitoring results reveal the need for any additional restrictions, disposal activities will be scheduled to avoid unacceptabl e adverse effects (EPA and Corps 2011a). The EPA identified that ocean disposal in the proposed sites would occu r for 6 days in April or May

and then from June 15 to October 31. The EPA also identified three dredging sites of Yaquina Bay that would likely co ntribute to the amount of dredged material disposed at the EPA’s proposed ODMD sites and they include the Yaqu ina River entrance channel, South Beach Marina, and the Yaquina Rive r (including Depot Slough) (EPA and Corps 2011b). Thirty-two days of dredging were identified for the Yaqui na Bay entrance channel and 30 days for the marina and Yaquina River. 2 The total volume of dredged material estimated to be placed within Yaquina ODMD sites for the next 20 years wa s 6.2 million cubic yards (or 310,000 cy/yr). The maximum volumes that the Corps would dredge a nd dispose of from the entrance channel, South Beach Marina, and the Yaquina River (inclu ding Depot Slough) are 370,000 cy, 25,000 cy, and 100,000 cy, respectively. The NMFS will use these as the proposed maximum volumes (EPA and Corps 2011b) when conducting our effects anal ysis. Dredging would occur annually for the

entrance channel and South Beach Marina and Ya quina River are dredged every 5 to 8 years. The proposed maximum volume of 495,000 cy of di sposed dredged material is the proposed amount that the EPA expects could occur in any one year. 2 The number of disposal trips per year will vary depending on the volume of material and disposal tactic. Based on the average volume of dredged material disposed of by the Yaqui na hopper dredge (800 cy), the maximum number of disposal events that could occur when 495,000 cy of material is dredged is 619. For this proposed action and analysis, the EPA estimated the maximum volume (495,000 cy) of disposed material and number of disposal events (619) in any one year, which would include the Corps’ anticipated disposal activities a ssociated with the Fede ral navigation project and all other entities (Corps, U.S. Coast Guard, private users, etc.) that may dispose at the proposed ODMD sites. 3

Operation of the sites . The EPA and Corps’ environmental assessment (EPA and Corps 2011b) described the sizing of the proposed Ya quina Bay north and south ODMD sites. The proposed north and south sites have been size d to provide sufficient capacity to accommodate material dredged from the Yaquina Federal naviga tion project, as well as material from other projects. The size of the north and south ODMD sites was modeled based on the requirement to provide at least 20 years of disposal capacity per site, without the sites accumulating dredged material to a height that coul d potentially amplify waves. Mana gement of material placement resulting from monitoring as described in the SMMP will assure that the wave climate will not be significantly affected and navi gational safety not compromised.

2 Number of days identified in NMFS biological opinion issued to the Corps on May 28, 2010 for the Corps Maintenance Dredging Program for the Oregon Coastal Projects (NMFS No.: 2009/01756).

3 E-mail from Bridgette Lohrman (EPA) to Jeff Young (NMFS) reporting on the EPA’s proposed maximum volume of disposed material per year and the number of disposal events per year associated w ith that volume (February 16, 2012).-6- The Yaquina Bay north and south ODMD sites w ill operate under a uniform placement strategy. Uniform placement means the spreading of disposal activities within the site s, rather than spot dumping. Uniform placement at each site is expected to result in relatively uniform dispersal and accumulation of dredged materials on the ocean bo ttom. To achieve uniform placement and site management objectives described in the SMMP, ODMD site management will include establishing cells in each site to ensure uniform placement, minimize the accumulation of material and avoid excessive or persistent m ounding. This will be established using an ODMD site disposal placement grid. This placement grid consists of 32 cells that are 700 feet by 700 feet and establish the release point for each load of dredged material. Dump plans will be developed and may be adjusted during each disposal season to utilize different portions or cells within the sites to achieve uniform placement and mi nimize mounding (EPA and Corps 2011b – Appendix B). There will be a preference for use of the north ODMD site if capacity exists. At some time, disposal may be alternated, as necessary, between the two sites to allow for maximum usage and minimal impact. The north site is anticipated to receive more frequent initial use, but this may change as conditions warrant. The proposed act ion specifies there will be a preference for disposal at the north ODMD s ite, but both ODMD sites could be used in a single dredging

season. 4

The NMFS relied on the foregoing description of th e proposed action, includi ng all stated impact reduction measures, to complete th is consultation. To ensure that this consultation remains valid, NMFS requests that the action agen cy or applicant keep NMFS informed of any changes to the proposed action.

1.4 Action Area

“Action area” means all areas to be affected directly or indirectly by the Federal action and not merely the immediate area involved in the action (50 CFR 402.02).

The EPA’s proposed north and south ODMD sites for designation are located approximately 1.7

and 2.0 nautical miles northwest and southwes t of Yaquina Bay’s entrance (Figure 1). The proposed Yaquina ODMD sites have the following corner coordinates (North American Datum [NAD] 1983).

Proposed North Yaquina ODMD Site Proposed South Yaquina ODMD Site 44° 38‘ 17.98 N, 124° 07‘ 25.95 W 44° 36‘ 04.50 N, 124° 07‘ 52.66 W 44° 38‘ 12.86 N, 124° 06‘ 31.10 W 44° 35‘ 59.39 N, 124° 06‘ 57.84 W 44° 37‘ 14.33 N, 124° 07‘ 37.57 W 44° 35‘ 00.85 N, 124° 08‘ 04.27 W 44° 37‘ 09.22 N, 124° 06‘ 42.73 W 44° 34‘ 55.75 N, 124° 07‘ 09.47 W

Dimensions: 4,000 feet wide Dimensions: 4,000 feet wide 6,500 feet long 6,500 feet long Depth Range: 112 to 152 feet Depth Range: 112 to 152 feet

4 E-mail from Bridgette Lohrman, EPA, to Jeff Young, NMFS (reporting on the potential use of both proposed disposal sites in any one dredging season) (April 5, 2012).-7- Each of the proposed ODMD sites occupies 597 acres. The action ar ea includes both ODMD sites and the rectangular area within the corner coordinates, the exte nt of sediment drift, and the

water column from the water surface to the ocean floor. The EPA included a 500-foot buffer within the sites, in which disposal will not occu r in order to keep disposed material inside the designated area. However, long-term modeling of sediment disposal showed the sediment mound extending outside of the site boundaries (EPA and Corps 2011d). Thus, NMFS includes an

additional 500 feet around the site boundaries to account for sediment dispersion outside EPA’s proposed boundaries. The total action area as described by NMFS is approximately 1,722 acres located outside the mouth of the Yaquina River at the two sites (Figure 1). Disposal of material at the proposed north and south ODM D sites is an indirect effect of site designation and the most likely aquatic impacts of disposal (suspended sediments, physical dist urbance, and benthic effects) would be limite d to this action area.

Based on information provided by the EPA and developed during consultation, NMFS determined that the proposed action is likely to adversely affect (LAA) OC coho salmon, green sturgeon, and eulachon and is NLAA all other speci es that may occur in the action area (Table 1). The NMFS also determined that the proposed action is NLAA critical habitat designated for green sturgeon and leatherback sea turtles ( Dermochelys coriacea ). Critical habitat has not been designated or proposed for any othe r species within the action area.-8- Table 1. Federal Register notices for final rules that list threatened and endangered species, designate critical habitats , or apply protective regulations to listed species considered in this consultation. Listing status: “T” means lis ted as threatened under the ESA; “E” means listed as endangered; “P” means proposed.

Species Listing Status Critical Habitat Protective Regulations

Marine and Anadromous Fish

Chinook salmon ( Oncorhynchus tshawytscha )

Lower Columbia River T 6/28/2005; 70 FR 37160 9/02/05; 70 FR 52630 6/28/05; 70 FR 37160
Upper Willamette River T 6/28/2005; 70 FR 37160 9/02/05; 70 FR 52630 6/28/05; 70 FR 37160
Upper Columbia River spring-run E 6/28/2005; 70 FR 37160 9/02/05; 70 FR 52630 ESA section 9 applies
Snake River spring/summer run T 6/28/2005; 70 FR 37160 10/25/99; 64 FR 57399 6/28/05; 70 FR 37160

Snake River fall-run T 6/28/2005; 70 FR 37160 12/28/93; 58 FR 68543 6/28/05; 70 FR 37160

Coho salmon ( O. kisutch )

Oregon Coast 6/20/2011; 76 FR 35755 2/11/08; 73 FR 7816 2/11/08; 73 FR 7816
S. Oregon / N. California Coasts T 6/28/2005; 70 FR 37160 5/5/99; 64 FR 24049 6/28/05; 70 FR 37160
Southern DPS green sturgeon ( Acipenser

medirostris ) T 4/07/2006; 71 FR 17757 10/09/09; 74 FR 52300 6/02/10; 75 FR 30714

Southern DPS eulachon ( Thaleichthys pacificus ) T 3/18/2010; 75 FR 13012 P 01/05/11; 76 FR 515 Not applicable

Marine Mammals

Eastern DPS Steller sea lion ( Eumetopias jubatus ) T 5/5/1997; 63 FR 24345 8/ 27/93; 58 FR 45269 11/26/90; 55 FR 49204

Blue Whale ( Balaenoptera musculus ) E 12/02/1970; 35 FR 18319 Not appl icable ESA section 9 applies

Fin whale ( Balaenoptera physalus ) E 12/02/1970; 35 FR 18319 Not appl icable ESA section 9 applies

Humpback whale ( Megaptera novaeangliae ) E 12/02/1970; 35 FR 18319 Not appl icable ESA section 9 applies

Southern Resident killer whale ( Orcinus

orca ) E 11/18/2005; 70 FR 69903 11/29/06; 71 FR 69054 ESA section 9 applies

Sei whale ( Balaenoptera borealis ) E 12/02/1970; 35 FR 18319 Not appl icable ESA section 9 applies
Sperm whale ( Physeter macrocephalus ) E 12/02/1970 Not applicable ESA section 9 applies

Marine Turtles

Green turtle ( Chelonia mydas ) ET 7/28/1978 43 FR 32800 9/02/1998; 63 FR 46693 ESA section 9 applies

Leatherback turtle ( Dermochelys coriacea ) E 6/02/70 ; 39 FR 19320 3/23/79; 44 FR 17710

1/26/2012 77 FR 4170 ESA section 9 applies
Loggerhead turtle ( Caretta caretta ) T 7/28/78; 43 FR 32800 Not applicable 07/28/1978; 32800
Olive ridley turtle ( Lepidochelys olivacae ) ET 7/28/78; 43 FR 32800 Not appli cable ESA section 9 applies-9- 2. ENDANGERED SPECIES ACT BIOLOGICAL OPINION AND INCIDENTAL TAKE

STATEMENT

The ESA establishes a national program for cons erving threatened and endangered species of fish, wildlife, plants, and the habitat on which they depend. Section 7(a)(2) of the ESA requires Federal agencies to consult with the U.S. Fish and Wildlife Service, NMFS, or both, to ensure that their actions are not likely to jeopardize th e continued existence of endangered or threatened species or adversely modify or destroy their desi gnated critical habitat. Section 7(b)(3) requires that at the conclusion of consultation, the Serv ice provide an opinion st ating how the agencies’ actions will affect listed species or their critical habitat. If incidental take is expected, Section 7(b)(4) requires the prov ision of an incidental take statemen t (ITS) specifying the impact of any incidental taking, and including reasonable and prudent measures to minimize such impacts.

2.1 Introduction to the Biological Opinion

Section 7(a)(2) of the ESA requires Federal agenci es, in consultation with NMFS, to insure that their actions are not likely to jeopardize the continued existenc e of endangered or threatened species, or adversely modify or destroy their de signated critical habitat. The jeopardy analysis

considers both survival and rec overy of the species. The adverse modification analysis considers the impacts to the conservation value of the designated critical habitat.

“To jeopardize the continued existence of a liste d species” means to engage in an action that would be expected, directly or indirectly, to reduce apprec iably the likelihood of both the survival and recovery of a listed species in th e wild by reducing the reproduction, numbers, or

distribution of that species (50 CFR 402.02).

This opinion does not rely on the regulatory defi nition of “destruction or adverse modification” of critical habitat at 50 CFR 402.02. Instead, we have relied upon the statutor y provisions of the ESA to complete the following analysis with respect to critical habitat. 5

We will use the following approach to determ ine whether the proposed action described in Section 1.3 is likely to jeopardize listed species or destroy or a dversely modify critical habitat:

 Identify the rangewide status of the species and critical hab itat likely to be adversely affected by the proposed action . This section describes the current status of each listed species and its critical habitat relative to the conditions needed for recovery. For listed salmon and steelhead, NMFS has developed specif ic guidance for analyzing the status of the listed species’ component populations in a “viable salmonid populations” paper (VSP; McElhany et al . 2000). The VSP approach consid ers the abundance, productivity, spatial structure, and diversity of each popul ation as part of the overall review of a species’ status. For listed salm on and steelhead, the VSP criter ia therefore encompass the species’ “reproduction, numbers, or distribution” (50 CF R 402.02). In describing the range-wide status of listed species, we rely on viability assessments and criteria in

5 Memorandum from William T. Hogarth to Regional Administrators, Office of Protected Resources, NMFS (Application of the “Destruction or Adverse Modification” Standard Under Section 7(a)(2) of the Endangered Species Act) (Nov ember 7, 2005).-10- technical recovery team documents and recove ry plans, where availa ble, that describe how VSP criteria are applie d to specific populations, major population groups, and species. We determine the rangewide status of critical habitat by examining the condition of its physical or biological features (also ca lled “primary constituent elements” or PCEs in some designations) – which were identified when the critical habitat was designated. Species and critical habitat stat us are discussed in Section 2.2.

 Describe the environmental bas eline for the proposed action . The environmental baseline includes the past and present impacts of Federa l, state, or private actions and other human

activities in the action area . It includes the anticipated impacts of proposed Federal projects that have already undergone formal or early se ction 7 consultation and the impacts of state or private actions that ar e contemporaneous with the consultation in process. The environmental baseline is discussed in Section 2.3 of this opinion.

 Analyze the effects of the proposed actions . In this step, NMFS considers how the proposed action would affect the species’ re production, numbers, and distribution or, in the case of salmon and steelhead, their VSP characteristics. NMFS also evaluates the proposed action’s effects on critical habita t features. The effects of the action are described in Section 2.4 of this opinion.

 Describe any cumulative effects. Cumulative effects, as defined in NMFS’ implementing regulations (50 CFR 402.02), are the effects of future stat e or private activities, not involving Federal activities, th at are reasonably certain to occur within the action area.

Future Federal actions that are unrelated to the proposed action are not considered because they require separate section 7 cons ultation. Cumulative effects are considered in Section 2.5 of this opinion.

 Integrate and synthesize the above factors to assess the risk that the proposed action poses to species and critical habitat. In this step, NMFS adds the effects of the action (Section 2.4) to the environmental baseline (Section 2.3) and the cumulative effects (Section 2.5) to assess whether the action could reasonably be expected to: (1) appreciably reduce the likelihood of both survival and recovery of the species in the wild by reducing its numbers, reproduction, or dist ribution; or (2) reduce the value of designated or proposed critical habitat fo r the conservation of the species. These

assessments are made in full consideration of th e status of the species and critical habitat (Section 2.2). Integration and synthesis occurs in Section 2.6 of this opinion.

 Reach jeopardy and adverse modification conclusions . Conclusions regarding jeopardy

and the destruction or adverse modification of critical habitat are presented in Section 2.7. These conclusions flow from the logic and rationale presented in the Integration and Synthesis section (2.6).

 If necessary, define a reasonable and prudent alternative to the proposed action. If, in completing the last step in the analysis , NMFS determines that the action under consultation is likely to jeopardize the continue d existence of listed sp ecies or destroy or adversely modify designated critical habitat, NMFS must identify a reasonable and-11- prudent alternative (RPA) to the action. The RPA must not be likel y to jeopardize the

continued existence of ESA-lis ted species nor adversely modi fy their designated critical

habitat and it must meet ot her regulatory requirements.

In this opinion, NMFS concludes that the pr oposed action is NLAA the following ESA-listed species:

1. Lower Columbia River (LCR) Chinook salmon

2. Upper Columbia River (UCR) Chinook salmon

3. Upper Willamette River (UWR) Chinook salmon

4. Snake River (SR) spring/summer Chinook salmon

5. SR fall Chinook salmon

6. LCR coho salmon

7. Southern Oregon Northern Califor nia Coasts (SONCC) coho salmon

8. Eastern DPS Steller sea lions

9. Blue whales

10. Fin whales

11. Humpback whales

12. Southern Residentkiller whales

13. Sei whales

14. Sperm whales

15. Green turtles

16. Leatherback turtles

17. Loggerhead turtles

18. Olive ridley sea turtles

The NMFS also concludes that the proposed ac tion is NLAA green sturgeon and leatherback turtle designated critical ha bitat. See Section 2.11 for disc ussion of NLAA determinations.

2.2 Rangewide Status of the Species and Critical Habitat

The summaries that follow descri be the status of the ESA-liste d species, and their designated critical habitats, that occur w ithin the geographic area of this proposed action and are considered in this opinion. More detailed information on the status and trends of th ese listed resources, and their biology and ecology, can be found in the listing regulations a nd critical habitat designations published in the Federal Register (Table 1, above).

Climate change is likely to play an increasingl y important role in dete rmining the abundance of ESA-listed species, and the quality and function of designated critical ha bitats, in the Pacific Northwest. These changes will not be spatially homogeneous across the Pacific Northwest. Areas with elevations high enough to maintain temperat ures well below freezing fo r most of the winter and early spring would be less affected. Low-lying areas that historically have received scant precipitation contribute little to total streamfl ow and are likely to be more affected.

During the last century, average regional air temp eratures increased by 1.5°F, and increased up to 4°F in some areas (USGCRP 2009). Warming is likely to continue duri ng the next century as-12- average temperatures increase a nother 3°F to 10°F (USGCRP 2009). Overall, about one-third of

the current cold-water fish habitat in the Paci fic Northwest is likely to exceed key water temperature thresholds by the e nd of this century (USGCRP 2009).

Precipitation trends during the next century are less certain than for temperature but more precipitation is likely to occu r during October through March and less during summer months, and more of the winter precipitation is likely to fall as rain rather than snow (ISAB 2007, USGCRP 2009). Where snow occurs, a warmer clim ate will cause earlier runoff so stream flows in late spring, summer, and fall will be lowe r and water temperatures will be warmer (ISAB 2007, USGCRP 2009).

Higher winter stream flows increase the risk th at winter floods in sensitive watersheds will damage spawning redds and wash away incubati ng eggs (USGCRP 2009). Earlier peak stream flows will also flush some young salmon and steelhead from rivers to estuaries before they are physically mature, increasing stress and the ri sk of predation (USGCRP 2009). Lower stream flows and warmer water temperatures during su mmer will degrade summer rearing conditions, in part by increasing the prevalence and virulence of fish diseas es and parasites (USGCRP 2009). Other adverse effects are likely to include a ltered migration patterns, accelerated embryo development, premature emergence of fry, variati on in quality and quantity of tributary rearing habitat, and increased competition and predati on risk from warm-water, non-native species (ISAB 2007).

The earth’s oceans are also warming, with consid erable interannual and inter-decadal variability superimposed on the longer-term trend (Bindoff et al . 2007). Historically, warm periods in the

coastal Pacific Ocean have coin cided with relatively low abundances of salmon and steelhead, while cooler ocean periods have coincided with relatively high abundances (Scheuerell and Williams 2005, Zabel et al . 2006, USGCRP 2009). Ocean conditions adverse to salmon and steelhead may be more likely under a warming climate (Zabel et al . 2006).

2.2.1 Status of the Species

Climate change, as described in S ection 2.2, is likely to adversely affect the size and distribution of populations of ESA-listed anadro mous fish in the Pacific Nort hwest. The size and distribution of the populations considered in this opinion generally have declined over the past few decades due to natural phenomena and human activity, including the operation of hydropower systems, over-harvest, hatcheries, and habita t degradation. Enlarged populations of terns, seals, sea lions, and other aquatic predators in the Pacific Northwest have been iden tified as factors that may be limiting the productivity of some Pacific sa lmon and steelhead populations (Ford 2011).

2.2.1.1 Oregon Coast Recovery Domain

The OC recovery domain includes OC coho salmon, green sturgeon, and eulachon, covering Oregon coastal streams south of the Columbia River and north of Cape Blanco. Streams and

rivers in this area drain west into the Pacific Oc ean, and vary in length from less than a mile to more than 210 miles in length.-13- OC coho salmon . This species includes population of OC coho salmon in Oregon coastal

streams south of the Columbia River and north of Cape Blanco. The Cow Creek hatchery stock (South Umpqua population) is managed as an integr ated program and is included as part of the evolutionarily significant unit (ESU) because th e original brood stock was founded from the local natural origin population and natural origin coho salmon have been incorporated into the brood stock on a regular basis. OC coho salmon were first listed in February 2008. As part of a legal settlement agreement in 2008, NMFS complete d a new status review for the ESU. In 2011, NMFS issued a final rule re-promulgating th e threatened listing fo r OC coho salmon (USDC 2011).

The OC-technical recovery team (TRT) id entified 56 populations; 21 independent and 35 dependent. The dependent populations were depe ndent on strays from other populations to maintain them over long periods. The TRT also identified 5 biogeographic stratum (Table 2) (Lawson et al. 2007). Independent populations are populations that historically would have had a high likelihood of persisting in isolation from neighboring populations for 100 years and are rated as functionally independent and poten tially independent. De pendent populations historically would not have had a high likelihood of persisting in isolation for 100 years. These populations relied upon periodic immigration from other populations to maintain their

abundance.-14- Table 2. OC coho salmon populations. Dependen t populations (D); functionally independent (FI); and potentiall y independent (PI) (McElhany et al. 2000,

Lawson et al. 2007).

Stratum Population Type Stratum Population Type

North

Coast Necanicum PI

Mid-Coast (cont.) Alsea FI Ecola D Big (Alsea) D Arch Cape D Vingie D

Short Sands D Yachats D

Nehalem FI Cummins D Spring D Bob D

Watseco D Tenmile D

Tillamook FI Rock D Netarts D Big (Siuslaw) D

Rover D China D Sand D Cape D
Nestucca FI Berry D

Neskowin D Sutton D

Mid-Coast Salmon PI Siuslaw FI

Devils D Lakes Siltcoos PI

Siletz FI Tahkenitch PI

Schoolhouse D Tenmile PI
Fogarty D Umpqua Lower Umpqua FI Depoe D Middle Umpqua FI Rocky D North Umpqua FI Spencer D South Umpqua FI

Wade D

Mid-South

Coast Threemile D

Coal D Coos FI Moolack D Coquille FI Big (Yaquina) D Johnson D Yaquina FI Twomile D

Theil D Floras PI

Beaver PI Sixes PI

Wainwright et al. (2008) determined that the weakest st ratum of OC coho salmon were in the North Coast and Mid-Coast of Oregon, which had only “low” certainty of being persistent. The strongest stratum was the Lakes and Mid-South Coast, which had “high” certainty of being persistent. To increase certaint y that the ESU as a whole is pe rsistent, they recommended that

restoration work should focus on t hose populations with low persistenc e, particularly those in the North Coast, Mid-Coast, and Umpqua stratum.

A 2010 biological recovery team (BRT) (Stout et al. 2011) noted significant improvements in hatchery and harvest practices have been made. However, harvest and hatchery reductions have changed the population dynamics of the ESU. It has not been demonstrated that productivity during periods of poor marine survival is now ad equate to sustain the ESU. Recent increases in adult escapement do not provide strong eviden ce that the century-long downward trend has changed. The ability of the OC coho salmon ESU to survive another pr olonged period of poor marine survival remains in question.

Current concerns for spatial structure focus on th e Umpqua River. Of the four populations in the Umpqua stratum, two, the North Umpqua and Sout h Umpqua, were of particular concern. The North Umpqua is controlled by Winchester Dam and has historically been dominated by-15- hatchery fish. Hatchery influence has recently be en reduced, but the natural productivity of this population remains to be demonstrated. The S outh Umpqua is a large, warm system with degraded habitat. Spawner distribution appears to be seriously restricted in this population, and it is probably the most vulnerable of any populatio n in this ESU to increased temperatures. Current status of diversity shows improvement through the waning effects of hatchery fish on populations of OC coho salmon. In a ddition, recent efforts in severa l coastal estuaries to restore

lost wetlands should be be neficial. However, diversit y is lower than it was historically because of

the loss of both freshwater and tidal habitat loss coupled with the restri ction of diversity from very low returns over the past 20 years.

The BRT concluded that there is a moderate certa inty of ESU persistence over the next 100 years and a low-to-moderate certainty that the ESU is sustainable for the foreseeable future, assuming no future trends in factors affecting the ESU. The NMFS issued a final determination to retain the ESA listing status, effective June 20, 2011. Thus, the February 2008 critical habitat designation and 4(d) regulations remain in effect (USDC 2011).

Limiting factors and threats to the OC coho salmon ESU include (Stout et al. 2011, NOAA Fisheries 2011):

 Degraded freshwater habitat: Floodplain conn ectivity and function, channel structure and complexity, riparian areas and large wood s upply, stream substrate, stream flow, and water quality have been degraded because of cumulative impacts of agriculture, forestry, in-stream mining, dams, road cros sings, dikes, levees, etc.

 Fish passage barriers that limit access to spawning and rearing habitats.

 Adverse climate, altered past ocean/marine productivity, and curre nt ocean ecosystem conditions have favored competitors and pred ators and reduced salmon survival rates in freshwater rivers and lakes, estu aries, and marine environments.

Mid-Coast Stratum . The mid-coast stratum of OC coho salmon consists of Salmon, Siletz, Yaquina, Alsea, and Sius law rivers and Beaver Creek i ndependent populations. Adult OC coho salmon from all mid-coast populations a nd juveniles from Yaqui na, Alsea and Siuslaw rivers and Beaver Creek populations will occur in the action area with individuals from Yaquina and Alsea rivers and Beaver Creek populations occurring most frequent ly. The Siletz, Yaquina, Alsea, and Siuslaw rivers populations are all fu nctionally independent po pulations, whereas the

Salmon River and Beaver Creek populations are potentially i ndependent populations. Weitkamp and Neely (2002) showed that adult OC coho salmon from the Salmon River hatchery were recovered as far south as Monterey Bay, Californi a with the majority of recoveries occurring in the northern and central Oregon Coast recovery ar eas (including the action area outside Yaquina Bay). Run-timing for adult OC coho salmon is Sept ember to January with a peak in November –

December. Juvenile OC coho salmon of the mid-coast populations outmigrate beginning in

March until the end of June. Estimates of adult OC coho spawners returning to the mid-coast populations show considerable vari ability in the annual abundance fr om year to year (Figure 2).-16- Figure 2. Estimated abundance of wild adult OC coho salmon spawners by population in the OC mid-coast stratum 1995 to 2010 (ODFW 2011).

The number of OC coho salmon juvenile outmig rants from the mid-coast populations has not been studied to provide a reliab le estimate by direct sampling. However, one can estimate it by dividing the number of returning adults by marine survival. The Oregon Department of Fish and Wildlife (ODFW) (2012) estimated marine surviv al of OC coho salmon from sub-populations in the Siletz, Yaquina, and Alsea populations of OC coho salmon from 1995 to 2007. Marine survival rates of the overall populations are likelysimilar to those estimated for the relative subpopulation. Estimated marine survival averag ed (from 1995 to 2007) 4.1% for Siletz (range, 0.6% to 7.4%), 10.1% for Yaquina (range, 1.3% to 22.6%), and 4.2% for Alsea (range, 0.7% to 9.2%) populations of OC coho salmon. The Salm on River, Beaver Creek, and Siuslaw River populations marine survival rates are likely similar to those of th e Siletz and Alsea. Therefore, NMFS used the ODFW (2012) estimated marine surv ival values for their respective populations and 4.15% (average for Siuslaw and Alsea popul ations) for the Salmon, Beaver Creek, and Siuslaw populations to back-calculate and estimate the number of smolts for each population. The number of out migrants estimated by this b ack calculation for each population is shown in Figure 3. While this extrapolat ion is not optimal, NMFS considers this the best available information and is adequate for use in the analysis portion of this opinion.

Estimated adult spawner abundances for the mid-co ast stratum populations appear to have been the highest in the last four to five years with the lowest abundances occurring in the late 1990s. The TRT estimated potential historical abundance for adult spawners for the Salmon, Siletz, Yaquina, Alsea, and Siuslaw rivers and Beaver Creek populations. The potential historical abundance of adult spawners was 17,000; 122,000; 122,000; 163,000; 267,000; and 27,000, respectively (Lawson et al . 2007). The potential historical abunda nce of juvenile smolts in the Yaquina and Alsea rivers and Beaver Creek populations was 1,217,000; 1,628,000; and 265,000; respectively (Lawson et al . 2007). Even with the considerable variability in adult return 0 10000 20000 30000 40000 50000 60000 Salmon Siletz Yaquina Beaver Cr. Alsea Siuslaw-17- estimates from year-to-year, the abundance leve ls in the Umpqua populations since 1995 are low compared to historical abundance levels.

Figure 3. Estimated number of OC coho salmon smolts by population from back calculation in the OC mid-coast stratum, 1995 to 2010.

In 2008, the Oregon and Northern California Co asts TRT developed a biological recovery criteria report for the OC coho salmon ESU. The primary purpose of this report was to assess the progress of recovery of the OC coho salmon ESU. The biological recovery criteria developed are framed within the context of a Decision Suppor t System (DSS) that is organized into two categories; persistence and sustainability. A pers istence analysis assesses the ability of the ESU to persist (i.e. not go extinct) over a 100-year ti me frame. A sustainabilit y analysis assesses the ability of the ESU to maintain its genetic le gacy and long-term adaptive potential for the foreseeable future (Wainwright 2008). In develo ping the criteria, the TRT explained a system where a persistence or sustainability value of 1 would indicate complete confidence that the ESU will persist or sustain itself for the next 100 years; a value of -1 would indicate complete certainty of failure of a populati on to persist or sustain itself; and a value of 0 would indicate no certainty of persistence, sustainabi lity, or extinction. The BRT (Stout et al . 2011) conducted updated persistence and sustainabi lity analyses for the populations in the OC coho salmon ESU.

Results of the BRT’s persistence a nd sustainability analyses in Stout et al . 2011 showed that persistence values in the north coast populations ranged from -1. 00 in the Salmon to 0.79 in the Beaver Creek population. Sustainability values ranged from -1.00 in the Salmon to 0.56 in the Beaver Creek population (Table 3). 0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000 Salmon Siletz Yaquina Beaver Cr. Alsea Siuslaw-18- Table 3. Persistence and sustainabili ty values for the mid-coas t populations identified in

Stout et al . 2011.

Population Population

Persistence Population Sustainability Population Condition (Persistence) 3 Population Condition (Sustainability) 3

Salmon -1.00 -1.00 Certain failure of this population to persist Certain failure of this population to sustain itself Siletz 0.34 0.38 Moderate certainty for this population to persist Moderate certainty for this population to sustain itself Yaquina 0.47 0.54 Moderate to high certainty for this population to persist Moderate to high certainty for this population to

sustain itself Beaver Cr. 0.79 0.56 High certainty for this population to persist High certainty for this population to sustain itself Alsea -0.03 0.13 Low certainty of failure of this population to persist Low certainty for this population to sustain itself Siuslaw 0.17 0.35 Low to moderate certainty for this population to persist Moderate certainty for this population to sustain itself

The ODFW identified stream comp lexity and water quality as the top two limiting factors for the Siletz, Yaquina, Alsea, and Si uslaw populations of OC coho sa lmon and spawning gravel and stream complexity for the Beaver Creek population (ODFW 2007).

Southern DPS green sturgeon . Green sturgeon is a widely distributed and marineoriented species found in the nearshore waters from Baja California to Canada (NMFS 2008a). There are two distinct population segments de fined for green sturgeon – a northern DPS with spawning populations in the Klamath and Rogue rive rs and a southern DPS that spawns in the Sacramento River (NMFS 2008b). The southern D PS includes all spawning populations of green sturgeon south of the Eel River in California, of which only the Sacramento River currently contains a spawning population. McLa in (2006) noted that green stur geon were first determined to occur in Oregon and Washington waters in the late 1950s when tagged San Pablo Bay green sturgeon were recovered in the Co lumbia River estuary (CDFG 2002).

The green sturgeon BRT convened a status review update in November 2004 (BRT 2005). The majority of the BRT concluded that green st urgeon is likely to become endangered in the foreseeable future and only one member conclude d that the southern DPS is not in danger of extinction or likely to become endangered in the foreseeable future. Weighing heavily on this decision was the fact that only one population of spawning adults (Sacramento River) remains. The BRT felt that the blockage of green sturge on spawning from what we re certainly historic spawning areas above Shasta Dam and the accomp anying decrease in spawning area with the loss of the Feather River spawning area make green sturgeon in the southern DPS at risk of

extinction in the foreseeable future.

Green sturgeon estuarine/marine di stribution and the seasonality of estuarine use range-wide are largely unknown. Green sturgeon are known to congr egate in coastal wate rs and estuaries, including estuaries of non-natal rivers to feed. Informati on from fisheries-dependent sampling suggests that green sturgeon only occupy large estuaries during th e summer and early fall in the-19- northwestern United States. Green sturgeon are known to enter Washington estuaries during summer (Moser and Lindley 2007). Co mmercial catches of green st urgeon peak in October in the Columbia River estuary, and records from other estuarine fisheries (Willapa Bay and Grays Harbor, Washington) support the idea that green sturgeon are only present in these estuaries from June until October (Moser and Lindley 2007) . Conducting feeding studies on green sturgeon have proven difficult. In additi on to various invertebrates, green sturgeon appear to be opportunistic foragers and feed on various fish species, such as lingcod (Dumauld et al . 2008), herring (Erickson and Hightower 2007), sand lace, and anchovies (97 FR 52084). Lindley et al

. (2008) described ocean migration of green sturge on and the months in which tagged fish passed hydrophone arrays (Figure 4). It is unknown which individuals ta gged during thei r study were southern DPS green sturgeon. However, those capt ured and tagged in the California waters were most likely, but not definitely, southern DPS. Typically gree n sturgeon migrate north after leaving their natal sp awning rivers (Israel et al . 2009), further supporting th at these were likely from the southern DPS. Mature green sturgeon may spawn every two to four years or possibly even less frequently. Lindley et al . (2008) revealed green sturgeon make rapid, long-distance seasonal migrations along the continental shelf between central California and central British Columbia. During the northern migration th e fish approached 0.25 body lengths per second (BL/s). The overall maximum mi gration rate observed was 36 m iles per day, but there were a range of migrations rates obs erved and included some as slow as 0.3 miles per day.-20- Figure 4. From Lindley et al . (2008) – detectio ns of pinger-tagged green sturgeon by hydrophone arrays along the West Coast of North America (n = total number of unique fish observed at each location. Bar height indicates the number of unique fish observed per day.

Yaquina River/Bay . Telemetry data have confirmed the presence of green sturgeon in Yaquina Bay that were tagged in the Sacramen to River (Figure 4) (74 FR 1954; October 9, 2009). Emmet et al . (1991) reports that green sturgeon (of undetermined DPS) are common in Yaquina Bay, most likely using the bay as over-su mmering habitat, though to a lesser extent than Winchester Bay and Coos Bay. In a summary of 4 years of attempted data collection (2000 to 2004), no green sturgeon were captured in Yaqui na Bay. However, during the same period, 24 green sturgeon were captured and tagged in the ocean just off-shore from Yaquina Bay (Farr et
al . 2001, Farr and Rein 2002, Farr and Rein 2003, Fa rr and Kern 2004). Green sturgeon have not been observed upstream of the head of tide of the Yaquina River. According to ODFW sport catch data, green sturgeon were caught by recr eational fisherman in Yaquina Bay and River 17 out of the last 27 years (Table 4). Sport catches ranged from 0 to 26 in 1988. The ODFW also-21- reported 21 fish caught in 1988 and 24 in 2007. Wh ether sport caught green sturgeon reported by

ODFW were from the southern or northern DPS is unknown.

Table 4. Expanded catch of green sturgeon in the Yaquina Bay and River 1986 – 2010 (ODFW 2008 and ODFW 2011).

Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total

1986 0 0 0 0 0 0 0 0 0 0 0 0 0

1987 0 0 0 0 0 0 0 0 0 0 0 0 0

1988 0 0 0 0 0 0 0 0 0 0 0 0 26

1989 0 0 0 0 0 0 0 0 0 0 0 0 21

1990 0 0 0 0 0 0 0 0 0 0 0 0 3

1991 0 0 0 0 0 0 0 0 0 0 0 0 13

1992 0 0 0 0 0 0 0 0 0 0 0 0 16

1993 0 0 0 0 0 0 0 0 0 0 0 0 16

1994 0 0 0 0 0 0 0 0 0 0 0 0 0

1995 0 0 0 0 0 0 0 0 0 0 0 0 0

1996 0 0 0 3 0 3 0 0 0 0 0 0 6

1997 4 4 0 7 0 4 0 0 0 0 0 0 19

1998 4 0 0 0 0 0 0 0 0 0 0 4 8

1999 0 0 11 0 0 0 6 0 0 0 0 0 17

2000 4 0 0 0 0 0 0 0 0 0 0 0 4

2001 0 0 0 0 10 3 0 0 0 0 0 0 13

2002 0 0 0 0 0 0 0 3 0 0 0 0 3

2003 0 0 0 0 0 0 0 3 0 0 0 0 3

2004 0 0 0 0 0 0 0 0 0 0 0 0 0

2005 0 0 0 4 0 0 0 0 0 0 0 0 4

2006 0 4 0 0 0 0 0 0 0 0 0 0 4

2007 0 0 0 0 14 5 0 5 0 0 0 0 24

2008 0 0 0 0 0 0 0 0 0 0 0 0 0

2009 0 0 0 0 0 0 0 0 0 0 0 0 0

2010 0 0 0 0 0 0 0 0 0 0 0 0 0

Eulachon . The southern DPS of eulachon extend s from the Skeena River in British

Columbia south to the Mad River in Northern California (inclusive). In the portion of the species’ range that lies south of the U.S.–Canada border, most eulachon production originates in

the Columbia River basin. In the Columbia Rive r basin, the major and most consistent spawning runs return to the mainstem of the Columbia River and the Cowlitz River. Spawning also occurs in the Grays, Elochoman, Kalama, Lewis, and Sa ndy rivers. Adult eulachon have been recorded

at several locations on the Wash ington and Oregon coasts, and th ey were previously common in Oregon’s Umpqua River and the Klamath River in northern California. R uns occasionally occur in many other rivers and streams, although these te nd to be erratic, appearing in some years but-22- not others, and appearing only rarely in some river systems (Hay and McCarter 2000, Willson et
al . 2006, Gustafson et al . 2010). Core populations for this sp ecies include the Fraser River, Columbia River, and (histo rically) the Klamath River.

Eulachon eggs are broadcast over an d attach to a variety of subs trates from sand to pea-sized gravel. Newly hatched young are carried to the sea with the current and widely dispersed by

estuarine and ocean currents. After three to five years at sea, they return as adults to spawn. Marine migrations of eulachon are largely unkno wn; however, it appears that there is spatial

structure to the distributions of fish from different rivers. Beacham et al . (2005) estimated proportional composition of three marine-caugh t samples from Nootka Sound, Chatham Sound, and Queen Charlotte Sound in Canada. Using deoxyribonucleic acid ( DNA) analysis Beacham et
al . (2005) determined that significant portions of the Nootka Sound and Queen Charlotte Sound samples consisted of eulachon from the Columbia River. This suggests that eulachon migrate large distances from their natal streams during th e ocean residence portion of their life cycle.

Eulachon have been observed as bycatch in th e west coast pink shrimp fisheries (Barraclough 1964) and groundfish surveys (Weinberg et al . 1994, Wilkins et al. 1998, Shaw et al . 2000, Weinberg et al . 2002) up and down the west coast of the U.S. and Canada. The amount of eulachon bycatch in these fisheries and surveys s eems to indicate that th e distribution of these organisms overlap in the ocean. Barraclough (1964) describes the depth range at which eulachon were caught as bycatch in mid-wate r trawls and pink shrimp trawls from 72 feet to 630 feet. Hay and McCarter (2000) showed th e offshore distribution of eulachon in British Columbia as determined in research trawl surveys, which i ndicate that most eulachon were taken at around 328 feet, although some were taken as deep as 1,640 feet and some less than 33 feet. Groundfish surveys (Weinberg et al . 1994, Wilkins et al. 1998, Shaw et al . 2000, Weinberg et al . 2002) occurred at depths of 180 f eet to 600 feet along the continental shelf. In 2002, the NMFS

Northwest Fisheries Science Cent er conducted trawl surveys along the west coast. During these surveys, eulachon were captured at two survey sta tions at Heceta Head and one survey station at Newport near the action area. Th e trawl in these surveys covered depths from 0 to 59 feet (NWFSC 2002).

There are few direct estimates of eulachon abundance. In most areas of the southern DPS, escapement counts or estimates of spawning-stoc k biomass are unavailable. When available,

catch statistics from commercial or recreational eulachon fisheries have been used as proxies of relative abundance. However, infe rring population status or even tr ends from yearly changes in catch statistics requires assumptions that are seldom met including consistent fishing effort and efficiency, the relationship of the harvested porti on to the total abundance of the stock, that catch represents a random sample of the entire population, etc. Howeve r, the combination of catch

records and anecdotal information indicate that eulachon were presen t in large annual runs in the past and that significant dec lines in abundance have occurr ed over the last 20-30 years (Gustafson et al . 2010). Of the four components of species viability criteria, abundance of the

eulachon has declined to historic al low levels, productivity is of concern due to climate change, diversity is limited to a single ag e class, and spatial structure is declining as runs sizes dwindle throughout their range (Drake et al. 2008).-23- The Columbia River and its tributaries support th e largest known eulachon run. Although direct estimates of adult spawning-st ock abundance are unavailable, r ecords of commercial fishery landings begin in 1888 and continue as a nearly uninterrupted data set to 2010 (Gustafson et al

. 2010). Historic commercial ca tch levels were typically more than 500 metric tons, 6 and occasionally exceeded 1,000 metric tons, fr om about 1915 to 1992. In 1993, the catch level began to decline; it averaged less than five metric tons from 2005 through 2008 (Gustafson et al

. 2010). Some of this pattern is due to fishery restrictions, which were put in place in response to the sharp decline in abundance. Persistent low returns and landings of eu lachon in the Columbia River from 1993 to 2000 prompted the states of Oregon and Washington to adopt a Joint State Eulachon Management Plan (WDFW and ODFW 2001). All eulachon fisheries in Washington and Oregon were closed in 2011. Similar declines in eulachon abundance ha ve occurred in the

Fraser and other coastal British Columbia ri vers (Hay and McCarter 2000, Moody 2008). No long-term monitoring program for eulachon exists in Northern California, but large spawning aggregations of eulachon we re regularly report ed in the Klamath River (Fry 1979, Moyle et al

. 1995, Larson and Belchik 1998, Moyle 2002, Hamilton et al . 2005). Although NMFS is reasonably confident that eulachon have declined substantially in the Klam ath River, it is also clear that they have not been absent from this area in recent years. In particular, recent reports

from Yurok Tribal fisheries bi ologists note a few eulachon being caught incidentally in other

fisheries on the Klamath in 2007 and 2011—thus de monstrating that eula chon still enter the

Klamath River in low numbers. Eulachon numbers are at, or near, historically low levels throughout the range of the southern DPS.

There are no direct estimates of productivity for any eulachon populations within the southern DPS. However, the ability of the Columbia River eulachon stock to respond rapidly to the good ocean conditions of the late 1999–early 2002 period il lustrates the species’ resiliency (Gustafson

et al . 2010). This resiliency buffers the species ag ainst future environmental perturbations. The productivity potential or intrinsic ra te of increase of eulachon (Musick et al . 2000), as indicated by life history characteris tics such as low age-at-maturity, sm all body size, and planktonic larvae, likely confer some resilience to extinction risk as they retain the ability to rapidly respond to favorable ocean conditions (Gustafson et al . 2010). However, there are no empirical or theoretical grounds to conclude that a species with high fecundity is more resilient to extinction than a species with lower fecundity (Sadovy 2001, Reynolds et al . 2005).

There is currently little information availabl e about eulachon distribution and spawning in Yaquina Bay/River. However, the information that is available (Willson et al . 2006, Emmett et
al . 1991, Monaco et al . 1990, Borgerson et al . 1991) appears to suggest that eulachon occur in Yaquina Bay on an infrequent basis and in small numbers.

The primary limiting factors responsible for the decline of the southern DPS of eulachon are changes in ocean conditions due to climate change (Gustafson et al . 2010, Gustafson et al

. 2011), particularly in the southern portion of its range wher e ocean warming trends may be the most pronounced and may alter prey, spawning, a nd rearing success. Addi tional factors include climate-induced change to freshwater habitats, dams, and water diversions (particularly in the

6 The U.S. ton is equivalent to 2,000 pounds and the metric ton is equivalent to 2,204 pounds.-24- Columbia and Klamath Rivers where hydropower generation and flood control are major activities), and bycatch of eulachon in commercial fisher ies (NOAA Fisheries 2011).

Other limiting factors include (Gustafson et al . 2010, Gustafson et al . 2011):

 adverse effects related to dams and water diversions

 artificial fish passage barriers

 increased water temperatures, insufficient streamflow

 altered sediment balances

 water pollution

 over-harvest

 predation

2.2.2 Status of the Critical Habitat

Climate change, as described in Section 2.2, is likely to adversel y affect the quality and function of designated critical habitats in the Pacific Northwest. The condition of critical habitats considered in the opinion generally declined during the era of European settlement due to depletion of cold water habitat and other variat ions in quality and quant ity of spawning, rearing and migration habitats associated with developm ent of riverine and estuarine areas (Ford 2011).

Green sturgeon critical habitat . For freshwater rivers north of and including the Eel River, the areas upstream of the head of the tide were not consid ered part of the geographical area occupied by the southern DPS. However, the critical habitat designa tion recognizes not only the importance of natal habitats, but of habitats throughout their range. Critical habitat has been designated in coastal U.S. marine waters within 60 fathoms depth from Monterey Bay, California (including Monterey Bay), north to Cape Flattery, Washington, in cluding the Strait of Juan de Fuca, Washington, to its United States boundary; th e Sacramento River, lower Feather River, and lower Yuba River in California; the Sacr amento-San Joaquin Delta and Suisun, San Pablo, and San Francisco bays in Califor nia; the lower Columbia River es tuary; and certain coastal bays and estuaries in California (Humboldt Bay), Oregon (Coos Bay, Winchester Bay, Yaquina Bay, and Nehalem Bay), and Washington (Willapa Ba y and Grays Harbor) and freshwater (USDC 2009). Table 5 below delineates PCEs for green sturgeon.-25- Table 5. PCEs of critical habitat designated fo r green sturgeon and corresponding species life history events.

Primary Constituent Elements Species Life History Event Site Type Site Attribute

Freshwater riverine system Food resources Migratory corridor Sediment quality Substrate type or size Water depth

Water flow Water quality -Adult spawning -Embryo incubation, growth and development -Larval emergence, growth and development -Juvenile metamorphosis, growth and development

Estuarine areas Food resources Migratory corridor Sediment quality

Water flow Water depth Water quality -Juvenile growth, development, seaward migration -Subadult growth, development, seasonal holding, and movement

between estuarine and marine areas -Adult growth, development, seasonal holding, movements between estuarine and marine areas, upstream spawning movement, and seaward post-spawning movement

Coastal marine

areas Food resources Migratory corridor Water quality -Subadult growth and development, movement between estuarine and marine areas, and migration between marine areas -Adult sexual maturation, growth and development, movements between estuarine and marine areas, migration between marine areas, and spawning migration

The green sturgeon critical habita t analytical review team identif ied several activities that may threaten the PCEs in coastal bays and estuar ies and may necessitate the need for special management considerations or protection. The a pplication of pesticides may adversely affect prey resources and water quality within the ba ys and estuaries, as well as the growth and reproductive health of green sturgeon through bioaccumulation. Other activities of concern include those that may disturb bo ttom substrates, adversely affect prey resources, or degrade water quality through re-suspensi on of contaminated sediments. Of particular concern are activities that affect prey resources. Prey reso urces can be affected by: commercial shipping and activities generating point source pollution and n on-point source pollution that can discharge

contaminants and result in bioaccumulation of c ontaminants in green sturgeon; disposal of dredged materials that can bury pr ey resources; and bottom trawl fisheries that can disturb the bottom (but may result in beneficial or adverse effects on prey resources for green sturgeon). In addition, petroleum spills from commercial ship ping activities and proposed alternative energy hydrokinetic projects may affect water quality or hinder the migration of green sturgeon along the coast (USDC 2009).

Critical habitat is designated fo r green sturgeon that includes th e action area. The PCEs consist of physical and biological features identified as essentia l to the conservation of green sturgeon in documents that designated critical habitat. The PCEs present in the action area consist of those necessary for life stages of green sturgeon that oc cupy coastal marine areas (Table 5) and include forage, safe passage, and water quality. The NM FS identified nearshore ocean habitat in the action area as high conservation valu e habitat due to the role this habitat provides for migration

and connection between the northern estuaries and the southern spawning habitat (NMFS 2008b).-26- 2.3 Environmental Baseline

The “environmental baseline” includes the past and present impacts of all Federal, state, or private actions and other human activities in th e action area, the anticipated impacts of all proposed Federal projects in the action area that have already unde rgone formal or early section 7 consultation, and the impact of state or privat e actions which are contemporaneous with the consultation in process (50 CFR 402.02).

The action area is in the Pacific Ocean offshore of the mouth of Yaquina Bay (Figure 1) and covers approximately 1,194 acres. There are two components of the action area, a north and

south ODMD site. Environmental conditions were described in the BA (EPA 2011). Each of the proposed ODMD sites is approximately 597 acres (6,500-feet long by 4,000-feet wide). Based on sediment FATE modeling NMFS added 500 feet around each site for sediment dispersion making the affected area for each site approxim ately 861 acres. Ocean depths range from 112 to

152 feet. The north and south ODMD sites are located on the continen tal shelf where the sediment cover is sand extending seaward from land for over 10 nautical miles.

The Yaquina Bay zone of siting feasibility (ZSF) is characterized primarily by fine sand with exposed rock outcroppings. To the north of the Sec tion 103 disposal site, ther e exists a large area of seabed rock exposure. These seabed rock outcroppings contribute co arser sediment to the nearshore area as rock surfaces are eroded by wave action.

Ocean water circulation near the proposed nor th and south Yaquina ODMD sites is directly influenced by larger-scale region al currents and weather patterns in the northwestern Pacific Ocean. During winter, strong low-pressure system s with winds and waves predominantly from

the southwest contribute to st rong northward currents . During summer, high-pressure systems dominate and waves and winds are commonly from the north. Along the Oregon Coast, there is a southerly wind in summer that creates a mass tran sport of water offshore resulting in upwelling of cold, nutrient-rich bottom water nearshore.

Disposal history . Yaquina River enters the Pacific Ocean near the city of Newport, Oregon, approximately 115 miles south of the Colu mbia River. The Corps has been responsible for maintenance of navigable wa terways of the north Pacific coast since 1871. The need for improved navigation controls in the Yaquina Bay estuary bega n with the founding of the port city at Yaquina. Congress author ized dredging in the bay in 1919.

Historic offshore disposal (pre-1977) . Prior to the Interim Site receiving designation in 1977, the Corps had historically used the same general area as the proposed ODMD sites for dredged material disposal si nce at least 1916. Approximately 200,000 cy annually were dredged from 1919 to 1968. The Corps records of dredgi ng from 1959 to 1969 (excluding 1968) show that 247,737 cy (Table 6) was fairly typical of quantitie s removed (Percy et al. 1974). Interim site designations in 1977 were an attempt by EPA to document and establish coordinates for historically used Corps disposal sites.

Offshore disposal (1977 – 2000) . In January 1977, the Interim Site received its interim designation when EPA issued final Ocean Du mping Regulations (40 CFR 228). Between 1977-27- and 1985, material was placed in the Interim Site. Due to increased mounding at the Interim Site and its potential advers e effect on navigation safety, in 1986 the Corps selected an alternate ODMD site under its Section 103 authority, the 1986 nearshore Section 103 s ite (see Figure 1). From 1986-2000, dredged material was placed in the nearshore Section 103 site. Due to mounding, the nearshore Section 103 site was expa nded in 1998 to include the outer two-thirds of the EPA Interim Site; material wa s placed in this expanded area in 1999.

Offshore disposal (2001 – Present) . In 2001, the Corps, under its Section 103 authority, selected two new ODMD sites (North Site and Sout h Site) for the disposal of dredged material. The EPA concurred in a July 19, 2001 letter for th e first 5-year period. The North Site was first used in 2001 and expired in 2006 with an option for an additional 5 years. The EPA issued a second Section 103 concurrence letter dated Apri l 27, 2007 for continued use of the North Site.

This allowed use of the North Site until the end of the 2011 dredging season.

Between 2001 and 2009, the Corps placed all dredged ma terial in the northern half of the Section 103 North Site. In 2009 and 2010, material from Depot Slough was dredged by clamshell and barged to the North Site. Also, the Corps placed a portion of the material from the Yaquina Bay federal project in the southern half of the North Site. The Corps, in 2011, placed all dredged

material in the southern half of the North site. No material has been placed in the South Site as of the end of the 2011 dredging season.-28- Table 6. Volume of dredged material plac ed at Yaquina Bay ODMD sites.

ODMDS Location Year Total (cy) Annual Average at Site (cy)

Interim Site 1928-1940* 1,040,000

252,379 1941-1967* 5,400,000
1968-1981* 6,440,000
1982 331,180
1983 453,319
1984 670,773
1985 302,764
Interim Site Total 14,638,036

Nearshore Section

103 Site 1986 242,468

310,240 1987 537,843
1988 324,519
1989 333,807
1990 216,696
1991 316,956
1992 321,652
1993 358,407
1994 206,971
1995 393,641
1996 314,636
1997 370,000
1998 351,000
1999 260,000
2000 105,000
Section 103 Site Total 4,653,596

North ODMDS 2001 198,284

217,379 2002 179,427
2003 320,455
2004 241,293
2005 282,596
2006 223,150
2007 192,352
2008 175,031
2009 161,678
2010 199,524
North ODMDS Total 21,465,422
*Volumes are approximate

Sediments . Classification of bottom sediments in the action area using high-resolution

side-scan sonar showed that the action area botto m consists primarily of fine sand (EPA and Corps 2011b). There is almost a complete lack of finer silts and clays offshore of Yaquina Bay until silt appears at a depth of 300 feet. This lack of silt or clay is likely due to the high wave energy regime. Summer wave c onditions produce bottom ripples to depths over 300 feet while winter storm waves can produce ripp les to over 600 feet (Komar et al . 1972 as cited in EPA and Corps 2011b).-29- In June 2008, the EPA collected 18 sediment sa mples at the Yaquina 103 north and south sites for physical and chemical analysis. Samples were analyzed for grain si ze, total solids, total organic carbon (TOC), metals, organotin (TBT), semi-volatile compounds (SVOCs), polychlorinated biphenyls (PCBs ), and polycyclic aromatic hydr ocarbons (PAHs). Samples were characterized by whether or not disposal of dred ged materials had previously occurred at the sample location. Those samples taken where dispos al of dredged material from Yaquina Bay has occurred were from the north site drop zone and those taken where no disposal has occurred (background stations) were from the southern part of the north site, those within the south site, and those outside of the proposed ODMD sites.

Physical analyses . Physical analyses showed primarily medium sand with little variation. The percent sand was essentially the same at the north site drop zone as that of the background stations, (97.8% to 99.7% in th e north site drop zone as comp ared to 96.6% to 99.5% in the background stations [EPA and Corps 2011c]) as was the mean percent sand at 98.6% and 98.3%, respectively. Mean grain sizes at the north site drop zone were more consistent than those at the background stations, ranging 0.195 millimeters (mm) to 0.213 mm in the north site drop zone and 0.171 mm to 0.308 mm in the background stations (EPA and Corps 2011c).

Chemical analyses . The EPA analyzed the 2008 samples for metals, TBT, SVOCs, PCBs,

and PAHs. Metals concentrations detected in all samples were below sediment evaluation framework (SEF) (SEF 2009) screening limits (SLs) and were comparable between the north site drop zone and back ground stations. The EPA di d not detect antimony, cadmium, cobalt, copper, mercury, selenium, and thallium at any of the sa mpling stations. No TBT, PCBs, or pesticides were detected at any sampling station. All dete cted concentrations of SVOCs (including PAHs) in the north site drop zone and background stat ions were below SEF SL s. Laboratory reporting limits for the following compounds exceeded the SE F SLs, however, none were detected above reporting limits in any samples: 2,4-dimethylphenol , dieldron, heptachlor, hexachlorobenzene, hexachlorobutadiene, and n-nitr osodiphenylamine. The sediments in the north site drop zone stations do not appear to have been negativel y impacted by dredged material disposal (EPA Corps 2011c).

Physical and chemical evaluation sampling wa s performed by the Corps at Yaquina Bay and South Beach Marina in 1980, 1986, 1990, 1991, 1995, 2000, 2005, and 2010 (these reports are available at http://www.nwp.usace.army.mil/envir onment/sediment.asp). Potential sources of contaminants to the Federal navigation cha nnel are logging, wood processing, fish processing and urban runoff. Over the years, sediment st udies have shown sediment is typically below screening levels for contaminants of concern. Consequently, sedime nt has been acceptable for inwater ocean disposal. In July of 2010, eight sediment sample s were taken from Yaquina Bay as follows: (1) Two from the Yaquina Bay entrance ch annel; (2) four from the federal navigation (Yaquina River) channel; and (3) three from the South Beach Marina. The Corps conducted physical analyses on all samples. Based upon grai n size and sample location, 5 out of the 9 samples were subjected to chemical analyses . Sampling and analyses of sediments were conducted in accordance with the SEF (2009).-30- Physical analyses . The overall mean grain size for th e samples taken from Yaquina Bay was 72% sand. The mean grain size for the federa l navigation channel (Yaquina River from the entrance channel to the turning basin) was 94% sand and 45% sand in th e South Beach Marina.

Chemical analyses . Five of the nine samples were subjected to chemical analyses. Sediment samples from Yaquina Bay were analy zed for metals, TOC, pesticides, PCBs, phenols, phthalates, miscellaneous extractables, PAHs and TBT and all tested well below SEF SLs. Thus, the sediment analyzed from the 2010 samples was de termined to meet the guidelines established in SEF (2009) for unconfined in-water pla cement without further characterization.

Water quality . The EPA (2011) reported that Water quality throughout th e action area is typical for Oregon nearshore marine waters. Water column chemistry and physical characteristics offshore of the Yaquina River were studied in 1980 (F uhrer and Rinella 1982). All parameters measured were well within norma l ranges expected for nearshore ocean waters and met the state’s water quality standards. Speci fic information pertaining to total suspended solids (TSS) was not provided in the BA. Typical TSS values in waters of the West Coast shelf ranged from 0 to 10 milligrams per liter (mg/l) with the 50 th percentile of 4.0 mg /l. These values represent data from the 2003 sampling of 137 sta tions from California, Oregon, and Washington collected during an ecological condition cruise (Nelson et al . 2008).

Mounding . In general, Pacific Northwest ocean dumping sites are dispersive. However, mounds (and potential navigation hazards) develop when more material is placed in discrete locations than the ocean has capability to disper se before the next disposal event. Current understanding and experience indicate generally slow dispersion from mounds at ocean depths greater than 59 feet, w ith dispersion steadily decreasing wi th increasing depth. Much higher dispersion rates have been observe d within nearshore areas with depths shallower than 59 feet.

Between 2001 and 2009, all dredged material was pl aced in the northern half of the proposed

north ODMD site. Maximum mound height in 2007 reached five feet, while in 2008, it reached six feet and in 2009, the maximum mound height reached ten feet re lative to July 2001. Portions

of the north half of the north site have mounde d 10-12 feet above the 20 01 baseline bathymetry. The southern half of the proposed north ODMD site has areas that have not changed in depth and some areas that have accreted up to 2 feet. This accretion can be attributed to disposal during the 2009 dredging season and severe storms rearranging the seafloor sediments.

Biotic community . Studies along the coast have demonstrated summer chlorophyll a (chl)

concentration is related to winter river out flow and continental shelf widths (Chase et al. 2007). The winter river flows carry iron into the ocean which is later brought back into the shallows with the summer upwelling, thus fue ling phytoplankton production. Chase et al. (2007) presented chl concentrations from the sea-viewin g-wide-field-of-sensor (SeaWiFS) satellite data and the study area included this action area. Ba sed on this SeaWiFS data presented in Chase et
al. (2007), chl concentrations are likely moderate ly high in a narrow bandwidth along the Oregon

Coast nearshore. The action area chl concentrations from this satellite data presentation appear comparable to other northern waters due to bein g in the vicinity of the Yaquina River. The influence of the Yaquina River and the subse quent ocean upwelling that bring the iron-rich nutrients back into the shallower water provid e the basis for a rich phytoplankton community.-31- Surface water chl concentrations along the West Coast shelf ranged from 0 to 28 micrograms per liter ( μ g/L). The 50 th percentile of area sampled ha d a chl concentration of 3.9 μ g/L, while the

90 th percentile had a chl concentration of 14.5 μ g/L. These values represent data from the 2003 sampling of 187 stations from California, Oregon, and Washi ngton collected during a cruise to assess ecological conditions along the West Coast shelf (Nelson et al. 2008).

Bi et al. (2008) used increasing concentrations of chl as an indicator of primary production coupled with decreasing water depths to classi fy yearling coho salmon habitat quality. In their 2007 study (Bi et al. 2007), the foundation of their 2008 pape r, they relied on low-zero catch probability as an indicator of habitat use; that is, they used fish sampling data and the presence or absence of yearling coho salmon to indicate habitat use and prefe rred quality. Given habitat use, they used step-wise regression to assess habita t condition indicators. The probability of having a zero-catch (of yearling coho salmon) decreased with increasing chl concentration an d decreasing water depth. Based on the Chase et al. (2007) chl data presentati on, the action area has chl concentrations comparable to northern Or egon and Washington waters. In general chl concentrations are likely lower and less widely distributed than the areas off the Washington coast (Bi et al. 2008). Additional environmental factors, as yet not understood, also determine yearling coho salmon abundance (Bi et al. 2008).

In the 2008 paper, Bi et al . characterized yearling coho salmon habitat as favorable, potentially favorable, or unfavorable based on the water de pth, chl, and coho salmon yearling abundance. Based on combining predictive habitat modeli ng and yearling coho salmon sampling data the

researchers classified these habi tats and presented abundance estim ates. Large variability exists with these data and the subseque nt abundance estimates. Year to year variation in predicting the location of these three habitat catego ries also varies significantly (Bi et al . 2008). It is likely the action area is favorable or pot entially favorable habitat base d on the water depth and chl concentrations, but the habitat quality will vary from year to year as observed with these studies. Some years the action area may even be unfavorable depending on upwelling.

Keister and Peterson (2003) pr ovided a discussion of the z ooplankton community found off the central Oregon Coast (along the New port hydrographic line). They indi cate in their study that the zooplankton community is influenced strongly by seasonal variations in wind and current patterns. During late spring and summer, north westerly winds set up equatorward flow and coastal upwelling. Northwesterly winds dominate from April/May-September where periodic relaxations or southwesterly stor ms rapidly affect the hydrography of nearshore areas. Offshore, about 19 miles, conditions are less variab le. Boreal neritic copepods such as Pseudocalanus

mimus

, Calanus marshallae

, Centropages abdominalis

, Acartia longiremis , and Acartia

hudsonica dominate the coastal plan kton during summer (Peterson and Miller 1977). In early fall, winds reverse and upwelling ceases; during autumn and winter, winds are predominantly southwesterly, the Davidson Current flows polewar d, and offshore surface waters are transported onshore. In winter, the coastal zooplankton is populated by warm-wat er species such as

Mesocalanus tenuicornis

, Paracalanus parvus

, Ctenocalanus vanus , Clausocalanus spp.

, Acartia tonsa , and Corycaeus anglicus (Peterson and Miller 1977). Th e action area is within the continental shelf depths, so it will be assumed the area is pr oductive yearling coho salmon and juvenile and adult eulachon habitat when ocean conditions are optimal.-32- The EPA (2011) provided results from field surveys conducted at or near the proposed ODMD sites in March 1984, May 1986, October 1989, May 1999, September 1999, June 2000, September 2000, June 2008, and August 2008. Domi nant species and groups included gammaridean amphipods, sand dollars Dendraster eccentricus, surface-dwelling gastropods

Olivella spp., and various species of polychaete worms. The benthic invertebrate fauna densities and diversities collected during these studies were typical of the nearshore sandy substrate along the Oregon coast (EPA 2011).

The most recent data collection efforts to desc ribe benthic infauna densities and diversities occurred in June and August 2008. The dominate sp ecies from the June 2008 efforts were the polychaetes Chaetozone nr . setosa

, Magelona sacculata

, Nephtys caecoides, Onuphis iridescens

, Spio filicornis, and Spiophanes bombyx ; the crustaceans Anchicolurus occidentalis and

Eohaustorius estuarius ; and the miscellaneous phylum neme rtinea. The number of polychaetes, specifically Spiophanes bombyx at a count of 3,313, far exceeded the number of other individual organisms. In August 2008 the dominate species were the polychaetes Magelona sacculata, Spio filicornis and Spiophanes bombyx ; the mollusca Siliqua sp. juvenile (razor clam); the crustacea Anchicolurus occidentalis, Diastylopsis dawsoni and Photis sp. indeterminate; and the miscellaneous phylum nemertinea. As in June, the count of Spiophanes bombyx exceeded the

number of other indi vidual organisms.

To further describe the benthi c infauna baseline, EPA (2011) br oke the data from June and August 2008 into four groups based on their similar ities in relative impact from disposal of dredged material and includes: (1) North ODMD site drop zone; (2) southern part of north ODMD site; (3) south ODMD site; and (4) outside proposed ODMD sites. EPA (2011) considered the latter three groups baseline sta tions because they were relatively unimpacted by disposal at the time these data were collect ed. After comparing the number of species and

individuals between the four s ites (number of species and individuals we re lower in North ODMD site drop zone than baseline stations), EPA (2011) stated that there appears to be a decrease in the numbers of species and indivi duals in response to disposal. This difference indicates a potential effect from dispos al of dredged materi al at the location.

The EPA (2011) stated that these studies cons istently found the benthic community to be dominated by mobile organisms that are ad apted to a sandy environment. This benthic community provides an important link in the mari ne food web. These organisms serve as a direct food source for other benthic organisms and demersal fishes. They also play an active role in the breakdown of organic debris and th e tube-building species help st abilize the marine sediments. Many of the benthic species in th is study are able to survive in this dynamic environment being either very mobile or being able to react both to natural or anthropogenic perturbations. They readily recolonize in disturbed areas.

Demersal fish and epibenthic species captured by otter trawl in the vicinity of the proposed Yaquina north and south ODMD sites included seve ral commercially important species, such as sole, flounder, and Dungeness crab. The trawl sa mples denote the nearshore area as a nursery ground with an abundant food source. Most of the species encountered in the trawl samples were

benthic feeders that inhabit areas where there tends to be abunda nt food and fewer predators. The-33- majority of the fish (75%) captured in the trawls were juveniles. However, larger fish have the ability to avoid the trawl net a nd so may have been under-repres ented in the species captured.

The action area is in the nears hore area of the Pacific Ocean o ff the Yaquina River. The action area supports anadromous salmonids including OC coho salmon, winter steelhead, and springand fall-run Chinook salmon, as well as a variety of other pelagic and demersal fish species. The action area lies approximately 2.3 m iles offshore from the mouth of the Yaquina River; therefore use of this area by all of these an adromous salmonid species is mu ch more likely than most other

areas of the Pacific Ocean. OC coho salmon marine survival in the Pacific Ocean has been positively correlated with the strength of co astal upwelling during the summer of smolt outmigration and in turn this influences primary and secondary production (Pearcy 1992). As previously noted, the summer upwe lling provides the nutrients to fuel primary and secondary production that in turn determines habitat qual ity in the form of av ailable yearling OC coho salmon forage (Bi et al . 2008, Chase et al. 2007). Based on available information regarding general water quality conditions, water dept hs, and primary and secondary production, the baseline conditions of the action area provide, at a minimum, sufficient conditions to support coho salmon. The habitat quality of these conditions varies from year to year depending on the large scale ocean dynamics that determine nutri ent upwelling and water quality conditions. Far

fewer studies have occurred to link ocean c onditions with marine survival, growth, and production of green sturgeon and eulachon, therefor e it is assumed fact ors influencing these parameters are also based on large-scale forces.

2.4 Effects of the Action on the Speci es and Designated Critical Habitat

“Effects of the action” means the di rect and indirect effects of an action on the species or critical habitat, together with the effect s of other activities that are inte rrelated or interdependent with that action, that will be added to the environmental baseline (50 CFR 402.02). Indirect effects are those that are caused by the proposed action and are later in time, but still are reasonably certain

to occur.

Section 1.3 of this opinion describe s subsequent dredging and dispos al by the Corps and all other

entities as an interrela ted action, which NMFS must consider along with the effects of EPA’s proposed action. Subsequent dredging and disposal ac tions also constitute indirect effects of the proposed action, since they are reas onably certain to occur. Therefore, the proposed action will have the following indirect eff ects: (1) Increased suspended sedi ment (fine-grained materials); (2) mounding; (3) reduced forage; (4) chemical contamination/exposure for OC coho salmon, green sturgeon, and their forage; and (5) coarse-g rained materials in the water column. The EPA identifies the potential use of both the north and south ODMD sites in any single dredging season; therefore the proposed action will potentially affect 1, 722 acres of the Pacific Ocean each dredging season.

2.4.1 Effects to the Environment

Water quality – suspended fine-grained solids . Interrelated actions of the proposed

action will increase TSS within the water column repeatedly each dredging season. Based on the EPA’s proposed action, a maximum of 495,000 cy of dr edged material could be disposed of at-34- the Yaquina ODMD sites in any one year. 2 The total number of loads of dredged material disposed at the sites that could occu r in any single dredging season is 619. 2 Each time the hopper dredge carries the materials out to the site and disposes of these materials, TSSs will increase. Disposal material is comprised of fine-grained material and larger , coarse-grained material. Finegrain suspended sediments could remain elevated in the area for longer periods than the actual release of dredged material. Exposure to suspen ded sediment plumes from dredged material disposal will probably be on th e order of minutes to hours in duration (Wilber and Clarke 2001). The BA concluded the dredged disposal material is comprised of sandy material; most of the

material will leave the water colu mn rapidly. EPA (2011) stated dred ge material will settle from

the water column within 5 to 30 minutes, due to the relativ e density of the sandy dredged material and dispersive water column currents. The duration of the suspended sediment plume and the dispersion of this plume are dependent on variables such as ocean currents, size composition of the disposal materials, wave ac tion, and dredge ship speed and disposal rate. Approximately 1,722 acres of the Pacific Ocean could be exposed annually to elevated suspended sediment plumes over the course of the 20 years of disposal operations.

Suspended sediment at moderate levels, can re duce primary and secondary productivity, and at high levels can injure or kill adult and juvenile fish, and interfere with feeding (Bjornn and Reiser 1991, Servizi a nd Martins 1991, Spence et al. 1996). The NMFS anticipates suspended sediment will dissipate due to currents and wave action within a few hours. The NMFS is reasonably certain increases in suspended sediment levels will exceed 17 mg/l concentrations for the majority of the discharge field. The suspe nded sediment plume will be spread by the wave

and ocean currents relative to the release lo cation. The NMFS is reasonably certain the suspended sediment plume will dissipate to concentrations that are immeasurable and undetectable against background within 500 feet of the proposed boundaries of the ODMD sites within a few hours of disposal. The area will receive dredged material 619 times per year. Reduced primary production in the action area is not reasonably certain to occur due to the resulting duration (hours), concen tration, and small areal coverage of the increased suspended

sediment concentrations which result in minimal effects to primary production.

Elevated chemical contaminants . The EPA’s proposed action includes the adoption and implementation of the SMMP that requires any propos ed sediments for disposal to adhere to the procedures approved by Corps and EPA 1991 a nd SEF 2009. Only clean sediment may be disposed of at the site. The Corps conducts se diment sampling and analysis for the coastal projects, including Yaquina Bay, on a five-yea r cycle. The Corps conducted physical and chemical analyses at Yaquina Bay a nd South Beach Marina in 1980, 1986, 1990, 1991, 1995, 2000, 2005, and 2010. Chemical analyses have shown that the sediment is typically below screening levels for contaminan ts of concern that includes me tals, PAHs, and other compounds described in section 2.3 (Envir onmental baseline) of this opi nion. Results for the 2010 study are

summarized in EPA 2011. The results for 2010 were c onsistent with historical data. Material represented by these samples was determined to be suitable for unconfin ed, in-water placement

without further characterization. Trace concentrations of various heavy metals, PAHs and other compounds will occur with the sediments, but the concentrations will not exceed those harmful to organisms in the action area.-35- Mounding . Past disposal of dredge d materials at the interim site, the nearshore section 103 site, and the drop zone of th e northern portion of the north ODMD site have created mounds on the ocean floor. Section 2.3 (Environmental base line) describes mounding that has occurred at the north ODMD site. The proposed action is to designate the north and south ODMD sites so that disposal of similar volu mes of material may continue.

Disposal capacity . Based on sediment FATE modeling, the EPA expects that the north and south ODMD sites will have capacity suffi cient to receive, on average, 310,000 cy of material over a 20 year period (total capacity = 6.2 mcy) without impa cting the present wave climate. The Yaquina north and south ODMD sites are relatively deep (112 feet to 152 feet) which removes material from the Newport litto ral cell. Material may be re-suspended and brought into the littoral cell only on extreme stor m events. In an annual assessment conducted by the Corps, they indicated to the EPA that the Yaquina north ODMD site is behaving as expected and will be able to receive dredged material fo r at least another 10 years. The Yaquina south ODMD site has not yet been used for disposal of dredged material a nd would have 20 years capacity (EPA 2011).

The EPA’s and Corps’ EA (2011b) described the potential depositional thickness and areal coverage for different dredge ships. The estimat ed areal coverage of a mound resulting from a single load placed by the Westport (a Corps dredge ship) in 100 feet water depth is about 21 acres with maximum mound height of 0.22 feet; however 90% of the mounded area is less than 0.10 feet (1.2 inches). The estimated areal cove rage of a mound resul ting from a single load placed by the Yaquina in 100 feet water depth is about 17 acres with maximum mound height of 0.12 feet; however 90% of the mounded area is less than 0.07 feet (0.84 inches). The Westport’s dump footprint is larger aerially and thicker than the Yaquina’s dump footprint. The Yaquina’s footprint is more uniform in terms of depositional thickness.

Section 2.3 (Environmental baseli ne) of this opinion describes mounding of sediment that has occurred at the Yaquina north ODM D site due to disposal of dr edged material. There has been no mounding as a result of dis posal activities at the south ODMD site. Based on modeling conducted by the Corps presented in EPA and Corps (2011d), the seafloor at the proposed

ODMD sites can accrete 14 feet of material wi thout altering the wave climate. The Corps’ modeling also showed that using the grid placemen t system for disposal in one site during one dredging season will result in a mound that is 1.2 feet high. After 20 years, the mound height in one site is estimated to be 12 feet high. Since there will be a preference for disposal at the Yaquina north ODMD site, it will likely accrete se diment at a higher rate than the south ODMD site. However, the south ODMD site will be used fo r disposal when the north site is determined to have reached or is near its capacity.

Based on the dynamic, high-energy environmen t found along the Oregon coast, sediment transport, erosion, and accretion are more de pendent upon surrounding ocean forces that operate independent of the proposed action. Therefore, long-term mounding due to these actions is not likely in the future at current disposal rates. Further, annual bathymetry surveys will be conducted at disposal sites and compared to base line surveys for previous year’s survey. The annual surveys will verify placement of material w ithin the sites, monitor changes and trends in bathymetry, and ensure the site capacity is not exceeded.-36- Coarse-grained material deposition . Disposal of coarse-gra in dredged material is reasonably certain to result in the exposure of all organisms in its descent path to adverse environmental conditions. This disposal could oc cur within both the Yaquina north and south ODMD sites, approximately 1,194 acres of the oc ean in any single dredging season. Unlike the fine-grain material previously discussed, this coarse-grain material wi ll move through the water column rapidly at a descent rate of 11 feet/second to start with and 7 feet/second near the end of the load. As water is added to the dredged materi al to help wash it out of the hopper, the slurry mixture becomes more neutrally buoyant and desce nds at a slower rate. It is NMFS’ judgment that any planktonic organisms in the path of th is material will become entrained within the material and carried to the bottom. Pelagic speci es are likely to try and avoid the descending material, but some are reasonably certain to be entrained and taken to th e ocean floor with the coarse-grain dredged material. A more detailed di scussion of this interaction is provided in the “effects to the species section.” An unknown numbe r of individuals of various vertebrate and invertebrate species are reasonabl y certain to be exposed and lik ely injured and killed by this

material.

Reduction in prey availability

. These two new sites will receive the same quantity of disposal material as the previous smaller site s. Some accumulation of sediment will occur from the action. Sandy sediment will cover infaunal and epifaunal invertebrates with a layer of sandy sediment. The EA (EPA and Corps 2011d) estimates these areas will accrete 1.2 feet of dredged material after the first year a nd 12 feet after 20 years. However, because these accretion depths were calculated using an averag e of 310,000 cy, this estimate does not apply for years where dredged material from all three dredging sites in Yaquina Bay (up to 495,000 cy) are disposed of at the proposed ODMD sites. Accret ion of dredged materials during those years is likely higher; however, this will likely occur infrequen tly (3-4 times over the next 20 years).

Re-colonization is uncertain while the site is in active use for dr edged material disposal over the life of the designation, an anticip ated 20-year period. The specif ic operation of each ODMD site is somewhat open-ended based on the proposed acti on. The preferred site for disposal will be the north ODMD site, but disposal in both sites co uld occur in any year. For this analysis, NMFS will assume that disposal will occur in both si tes annually. Therefore, the interval between disposal events will be from November through May, except for six days of disposal in April or May. The length of intervals between deposit ion events, particle size, currents, and compaction/stabilization following deposition a ffects the potential for re-colonization (Newell et
al. 1998, Van der Veer et al. 1985). Rates of recovery listed in the literature range from several months for estuarine mud, and up to two to th ree years for sands and gravels (Hitchcock et al. 1999). Re-colonization may take longer in ar eas with lower current (Van der Veer et al. 1985). This action area is indicative of a dynamic near shore ecological zone th at naturally would be characterized by a disturbance-based ecosystem. Di sturbance-based ecosystems are have rapid re-colonization rates by opportunistic organisms to lerant of conditions th at are physiologically stressful (Pemberton and MacEachern 1997).

The EPA conducted the most recent efforts to desc ribe the baseline densities and diversities of benthic infauna in June and August 2008 (see Sec tion 2.3 Environmental Baseline). The data that EPA collected appeared to show that density and diversity of be nthic invertebrates was reduced in the north ODMD site drop zone (northern half of the north ODMD site ) due to disposal of-37- dredged material (EPA 2011). This reduction is r easonably certain to occur at both ODMD sites as disposal continues and will occur on a long-term basis. Because of the short interval between disposal activities, re-colonization of invertebrates will likely be slower. This effect will occur to the 1,722 acres of the Pacific Ocean that are the north and south ODMD sites.

Fish species that are forage for OC coho salm on and green sturgeon may also be impacted by

this action due to the coarse-material desce nding through the water co lumn. In addition to various invertebrates, green sturge on appear to be opportunistic fo ragers and feed on various fish species, such as lingcod (Dumauld et al. 2008), herring (Erickson a nd Hightower 2007), sand lace, and anchovies (Moyle 2002) that may also be adversely impacted by the disposal. Adult OC coho salmon may also forage on similar pelagic species. Individuals of these forage species may be physically harmed by the disposed dredge d material. Typically th ese fish are smaller species and also less likely to avoid physical harm than larger and faster swimming species. The number of individuals impacted is difficult to es timate, but it is reasonably certain the number adversely affected would not significantly depl ete the overall abundance of forage fish and invertebrates available to listed species in th e action area because fo rage fish and benthic

invertebrates are not limited in num ber, they are well distributed, a nd the impact of disposal is localized, affecting a small area re lative to the surrounding habitat.

2.4.2 Effects to ESA-listed species

Presence of ESA-listed species and their spatial and temporal overlap with dredged material disposal activities is described as follows:

 OC coho salmon smolts from the Yaquina River and other nearby populations (Beaver Creek, Alsea, Siuslaw, and Siletz rivers populations) enter the ocean in mid-February through June and reside in the action area a nd the surrounding ocean for several months before migrating north. Adult OC coho salmon return to the action area in late August and peak during September and October. Weitkamp and Neely (2002) showed that coded-wire tagged adults from each of th e independent populations of OC coho salmon were recovered in the vicinity of the action area. Disposal ty pically occurs before adults have returned to the area but the Corps repor ts dredging could occur as late as October 31; therefore NMFS cannot discount exposure of adults.

 North and south migration of green sturgeon al ong the continental shelf and their use of the Yaquina River provides th e potential spatial and tempor al overlap between dredged material disposal and green sturge on presence in the action area.

 Adult eulachon presence in the nearshore P acific Ocean depths within the depth range (112 – 152 feet) of the proposed north and s outh ODMD sites will overlap spatially and temporally with dredge d material disposal.

The Corps identified dredging and disposal may occur in Yaquina Bay from April 1 through October 31. Therefore, the NMFS is reasonably ce rtain that exposure of adult and smolt OC coho salmon, adult and subadult green sturgeon, and adult and juvenile eulachon will occur during dredged material disposal as sociated with the proposed action.-38- As described above, mounding and chemical contam ination are unlikely cause sufficient effect to be considered any further in this document . Water quality degrada tion due to fine-grain suspended solids and reductions in forage base fo r ESA-listed species may adversely affect listed species. The NMFS analyzes these effects further in this section of the opinion. Physical injury from the deposition of coarse-grain material ma y also adversely affect OC coho salmon, green sturgeon, and eulachon and is analyzed in detail.

Water quality – suspended solids from fine-grain material . Exposure to suspended sediment increases as low as 17 mg/l can lead to inflammation of the gill s and respiratory stress in juvenile OC coho salmon (Berg and Nort hcote 1985). The NMFS is reasonably certain suspended sediment concentrations caused by fine-grained dredged ma terials will exceed 17 mg/l, resulting in injury to juve nile OC coho salmon. However, NM FS is also reasonably certain yearling OC coho salmon will not remain in the sediment plume for a period (4 to 96 hours) sufficient to elicit an adverse physiological or behavioral response. Th e duration and dispersion of the suspended sediment plume are dependent on variables such as ocean currents, size composition of disposal materials, wave action, dr edge ship speed, and disposal rate. The NMFS is reasonably certain turbidity will drift approx imately 500 feet outside of the ODMD site and cover approximately 1,722 acres, which includes both the north and south ODMD sites. The EPA stated that dredged material disposal coul d occur at both disposal sites in any one year. 3

Movement by salmonids to avoid sediment plumes has been observed in lotic environments (McLeay et al . 1984, 1987, Sigler et al . 1984, Lloyd 1987, Scannell 198 8, Servizi and Martens 1991). In the ocean, localized sediment plumes from disposal will only affect the immediate ocean environment and should not inhibit year ling OC coho salmon from moving away from suspended sediment plumes. Therefore, while e ffects to some OC coho salmon may occur from exposure to project-related sediment plumes, these effects will not occur on a spatial or temporal scale that will significantly disrupt their normal behavioral patterns. The physical effects from exposure to elevated suspended sediment leve ls are insignificant to yearling OC coho salmon. The NMFS is reasonably certain the increased concentrations of suspended sediment are unlikely to physically harm or disrupt adult OC c oho salmon normal behavioral patterns and are insignificant.

Adult and subadult green sturgeon are far less sensitive to suspended sediments than salmonids and elevated suspended sediment concentrations will result in insignificant effects to green sturgeon. Subsequently, green sturgeon will not di splay a significant behavioral or physical response because of their higher tolerance to suspended solids. Green sturgeon usually inhabit environments with higher suspended sediment concentrations than do salmonids. Erickson and Hightower (2007) observed green sturgeon typica lly occupying depths from 130 to 230 feet and making occasional rapid ascents toward the surface during their migration journey. The maximum depth in the action area is 152 feet so green sturgeon are likely to occupy the lower regions of the water co lumn. If green sturgeon are occupyi ng the lower reaches of the water column they will likely be exposed to lower turbidity levels because much of the fine material will have suspended higher in the water column . Because green sturgeon have higher tolerances for suspended sediment and the suspended sedi ment is in the upper water column, green sturgeon’s normal behavioral patterns are unlik ely to be disrupted by suspended fine sediment. Therefore, any effects of the proposed action on gr een sturgeon are expected to be insignificant.-39- Research pertaining to the concentrations and dura tion of exposure resulting in adverse effects to eulachon from increased suspended sediments is lacking. The NMFS is not aware of any studies or research relating the two. However, the effect s of increased suspended sediments to eulachon are likely similar to those observed by Berg and Northcote (1985) for juvenile coho salmon. Eulachon are also likely to exhi bit similar avoidance strategies as those shown by salmonids avoiding suspended sediment plumes. In the ocean, localized sediment plumes from disposal will only effect the immediate ocean environment a nd should not inhibit eula chon from moving away from suspended sediment plumes. It is likely th at eulachon exposure to fine-grained suspended sediments will occur, but unlikely that they will experience physical harm or disruption of normal behavior patterns because exposure will not occur at a spatial or te mporal scale that is significant enough to elicit an advers e response. Therefore, the eff ects of fine-grained suspended sediments to eulachon are insignificant.

Prey availability . Yearling OC coho salmon and adult and juvenile eulachon forage on zooplankton and other planktonic species that occur in the acti on area. The interrelated actions are unlikely to reduce the overa ll abundance of these prey species. Green sturgeon forage on benthic invertebrates in the action area. Impact s of dredged material disposal on the abundance of benthic invertebrate species that are forage for green sturge on are unlikely to significantly limit the overall forage availability for green sturgeon. The action is also unlikely to limit the availability of forage fish species to a level that would limit surviv al or growth potential of green sturgeon or adult OC coho salmon. The NMFS is r easonably certain the reduc tion in prey species due to interrelated actions is insignificant becaus e: (1) Prey abundance is determined by larger scale physical and biological fact ors; (2) the abundance of prey available to green sturgeon, OC coho salmon, and eulachon throughout their range in the Pacific Ocean is great; and (3) the action area is small compared to the available surrounding habitat for thes e prey species in the

Pacific Ocean.

Physical injury . Previous sections of this opinion describe the temporal and spatial overlap of dredged material di sposal and adult and juvenile OC coho salmon, adult and subadult green sturgeon, and adult and juvenile eulac hon. The factors important to assessing the likelihood for this disposed dredged material to physically adversely a ffect the aforementioned ESA-listed species and life stages include: (1) Avoidance response to th e ship; (2) avoidance response to the disposal material; (3) discha rge field size; (4) fish swim ming speed; (5) material’s descent rate; (6 ) quantity of materia l; (7) material wei ght; and (8) physical

interaction of the fish and the material. The avoida nce response from either the ship or the falling sediment will be considered first because if the fish can avoid the exposure, then there would not be physical consequences. If th e fish cannot avoid the material , then the other factors are important for the response to this exposure. This discharge occurs with in the ODMD sites only; therefore the impact would occur within the 1,194 acres.

Ship avoidance

. For a fish to avoid the disposal materi al, it must first de tect and react to either the ship or the disposal material descending around them, and then must react quickly enough to avoid direct exposure to the material. Behavior studies related to other water vessels would suggest that unless the juvenile OC coho sa lmon are near the surface, they are unlikely to react to a ship passing above them (Satterthwaite 1995). Fernandes et al. (2000) contend fish do not avoid survey vessels in their study of vessel avoidance by herring. There is no clear-40- conclusion with this premise based on study resu lts for other species (Gerlotto and Freon 1992; Misund 1993, Misund et al. 1996, Jorgensen et al. 2004). In these other studies, vertical and horizontal avoidance responses were observed where some fish reacted to the noise of the vessel by diving, others moved horizontally from the noise , and some moved away ahead of the vessel. Based on the conflicting result s, the NMFS is reasonably cert ain not all yearling OC coho salmon, green sturgeon, or eulachon will react to the ve ssel and move away from the discharge

field.

Avoidance to disposed material

. It is unknown whether the OC coho salmon, eulachon, or green sturgeon will elicit an a voidance response to the disposed material. The Corps (2005) speculated pelagic salmon would not be adversely affected by disposal ma terial, but the NMFS is not aware of any research or observations to document yearling OC coho salmon, eulachon, or green sturgeon response to this material. The NMFS is reasonably certain the fish will detect the descending material and will attempt to evade the material, because the fish will likely perceive

the material as a threat. Based on the observed ship avoidance res ponse research, it is the NMFS’ judgment the likely initial movement by the fish will be to dive and th en initiate horizontal evasion. The determining factor then will be whet her the fish can swim fast enough to move out of the discharge field.

Discharge field size . The size of the discharge field is primarily determined by the size of the dredge material disposal vess el, the volume of disposal materi al, the depth of water, and the length of the disposal run, alt hough water depth appears to be the most significant variable in determining overall discharge field size. In-w ater disposal by hopper dredge will create a discharge field from the bottom of the vessel’s hu ll to the ocean or estuar y floor. The depths of the Yaquina ODMD sites range from 112 to 152 feet.

As a hopper dredge releases dredged material, it falls through the water column and mixes with the ambient water to create a plume. This proce ss is called convective descent. The greatest risk to pelagic fish species occurs when they inte ract with this desce nding column of dredged material. The discharge field during each disposal run will vary based on the depth of the disposal site; with the volume of water exposed increasing wi th depth. Because actual disposal locations within each ODMD site will vary based on site specific bathymetric conditions at the time of disposal, for the purposes of this consul tation, estimates of the volume of water exposed

to the convective descent column have been calculated by the Corps the Yaquina based on the typical volume of dredged material disposed in 60 feet of water. The beam of the dredge ship Yaquina , the ship primarily used for dredging Ya quina Bay, is approximately 58 feet wide. When the depth of the disposal site is -60 feet , the disposal plume will begin at approximately - 16 feet (bottom of hull) and be approximately 10 f eet in diameter. As the plume descends to the bottom, the radius of the plume will be approximately 92 feet (EPA 2011). This discharge field will extend along the travel route of the dredge sh ip. The estimated areal coverage resulting from a single load placed by the Yaquina in 100 feet of water is about 21 acres (EPA and Corps 2011d).

The amount of dredged and subsequently dispos ed material depends on many factors including the sediment characteristics and dredging condi tions. While the specific volume of sediment dredged may vary at any given time because of these variables, the goal of any dredging-41- operation is to work as efficiently as possible to complete the job. Therefore, for the purposes of this consultation, a “typical” volume of dredged ma terial disposed during a single disposal event is considered approximately 800 cy for the Yaquina . The volume of water exposed during disposal of this amount of material th en is approximately 25,000 cubic meters (m 3 ) for the Yaquina

.

Spatial overlap between ESA-lis ted fish and discharge field . The distance from the bottom of the hopper dredge to the surface of the water will vary depending on the specific dredge and how loaded the dredge is. This dist ance will change as the hopper dredge discharges material into the disposal location. Fish occurr ing near the water surface, above the discharge doors, will be safe from exposure to the material . However, the hopper dredge will start rising as it releases dredged materials thereby increa sing the area of the di scharge field. Yearling salmonids have been shown to use the upper 20 to 25 feet of the water column, although they may use water column depths rang ing from 22 to 37 feet (Carlson et al. 2001, Beeman et al. 2003). Off of the Oregon coast, surface trawls that sampled from the surface down to 54 feet in depth captured yearling OC coho salmon (Brodeur et al. 2004). Green sturgeon may use various portions of the water column, but are likely at a much deeper depth than the OC coho salmon. Erickson and Hightower (2007) obs erved green sturgeon typically occupying depths from 130 to 230 feet, making occasional rapid ascents toward the surface. Barraclough (1964) describes the depth range at which eulachon we re caught as bycatch in mid- water trawls and pink shrimp trawls from 72 to 630 feet. Hay and McCarter (2000) showed the o ffshore distribution of

eulachon in British Columbia as determined in res earch trawl surveys, which indicate that most eulachon were taken at around 328 feet, although so me were taken as deep as 1,640 and some less than 33 feet. Groundfish surveys that captured eulachon (Weinberg et al . 1994, Wilkins et
al. 1998, Shaw et al . 2000, Weinberg et al . 2002) occurred at depths of 180 to 600 feet along the

continental shelf.

Swimming speed of ESA-listed fish . Successful avoidance wi ll depend on the swimming speed of the fish, the distance it must travel to avoid the discharge field, and the descent speed of the material. Although the Corps theorizes that th e juvenile OC coho salmon would either avoid the dispersal area or the physics of the disposal plume would displa ce the fish laterally, no direct evidence supports such an asse rtion (Corps 2005). The Bell Fi sheries Handbook (1990) describes three swimming speeds including: (1) Cruising sp eed – speed that can be maintained for long periods of time (hours); (2) sustained speed – speed that can be maintained for minutes; and (3) darting speed – speed that is a non-sustainable singl e effort lasting for only five to ten seconds. Yearling OC coho salmon are approximately five inches in length when upon ocean entry from the Oregon’s coastal river basins. Their darting speed, the likely response when the disposal material is detected, is estimated at 4 to 5 feet/second (Bell Fisheries Handbook 1990). The darting speed of adult OC coho salmon may exceed 20 feet/second (Bell Fisheries Handbook 1990). The darting speed of green sturgeon is unknown. Niggemeyer and Duster (2003) estimated cruising speed, a sustained sw imming speed, for green sturgeon at 1 body length/second. Darting speed would likely be higher than this, possibly twi ce as fast. Adult green sturgeon captured in various re search studies range from 3.9 to 7.4 feet in length (Moser and Lindley 2007, Erickson and Webb 2007). Juveni le green sturgeon may enter the ocean environment when they are 2- to 3-ye ars old and possibly 2 feet long (Adams et al. 2002). Based on the body lengths, darting speed for adult green st urgeon of this reported size would be 8 to 15-42- feet/second (2 body lengths/second) and 4 feet/second for small subadults. Darting speed for eulachon has not been studied to provide an estimate; however, Swanson et al . (1998) determined that critical swimming velocity 7 for delta smelt ( Hypomesus transpacificus ) was about 6.6 body lengths/second. Eulac hon of similar size to the de lta smelt studied by Swanson et
al . (1998) likely swim at similar speeds, therefore, NMFS will use this velocity for the eulachon analysis. This comparison may not be optimal, but represents the best available scientific information at this time. Darting speed is likely higher than 6.6 body lengths/second, possibly two times as fast or 13.2 body lengths/second. Ba sed on body lengths, juvenile eulachon would have darting speeds of 1.3 to 4.4 feet/second. Adult eulachon would have dart ing speeds of 4.4 to

10.8 feet/second.

Relationship between the discharge fi eld and ESA-listed fish swimming speeds . The EPA and Corps predict the initial plume veloci ty just before impact will reach 11 feet/second. They also predict material last to leave the hopper to have a maximum velocity of 7 feet/second because the slurry mixture would have a greater proportion of neutral buoyant water. Assuming a

central location in the discha rge field (29 feet from edge of the field) and direct movement to the edge of the field, it would take a yearling OC coho salmon 5.8 seconds to reach the plume edge. The maximum time a fish can sustain a darting speed is 5 to 10 seconds. Yearling OC coho salmon may not be able to reach the edge of the plume in the allotted time, even if they choose

the correct direction and move dir ectly toward the edge. With the material descending at 7 to 11 feet/second, it will be challengi ng for yearling OC coho salmon to avoid the descending plume. In five seconds the plume will descend 35 to 55 feet. Conversely, adult OC coho salmon have a high likelihood of reaching the edge of the plum e due to their speed. Based on a central location and given a darting speed of 20 feet/second, an adult OC coho salmon would reach the edge of

the 58-foot wide field in slightly over 1 second.

Adult green sturgeon, with darting speeds of 8 to 14 feet/second, are likely to evade the descending material. Given the same conditions previously described and similar response, adult green sturgeon may reach the edge of the discharge field in 2 to 3.6 seconds. In 3.6 seconds, the plume will descend 25 to 40 feet. Younger and smaller green sturgeon may not be capable of reaching the edge. Small subadult green sturgeon may be closer to 2 feet long, therefore their speed would be possibly 4 feet/s econd, similar to that of the yearling OC coho salmon; therefore

NMFS concludes with reasona ble certainty younger green sturgeon could be exposed and physically harmed by this material.

Adult and juvenile eulachon could be exposed and injured or killed by disposed dredged

material. Adult eulachon darti ng speeds range from 4.4 to 10.8 feet/second. Assuming the same descent rate and width of the plume some adult eulachon would not make it to the edge of the plume before the dredged material engulfed them . It would take adult eulachon from 2.7 to 6.6 seconds to reach the edge of the plume. In 6.6 seconds, the plume would descend 46 to 73 feet from the hopper dredge. Juvenile eulachon dartin g speeds are estimated to range from 1.3 to 4.4 feet/second. At these speeds, it would take juve nile eulachon 6.6 to 22.3 seconds to reach the edge of the plume. The plume descent rate is such that before 22.3 seconds, the material will hit the ocean floor in the deepest parts of the ODMD s ites. Therefore, some adult and most juvenile

7 Critical swimming velocity is the maximum velocity that a fish can maintain for a period. This velocity is higher than sustained swimming velocities and eventually results in fatigue of the fish.-43- eulachon exposed to the disposal plume will not be able to evade the descending plume and will be injured or killed by descending material.

Given that the fish cannot sustain darting speeds for longer than five s econds; the fish may also have to rely on sustained speed to avoid the pl ume. The sustained speed of a five-inch yearling OC coho salmon is predicted to be 2.1 fee t/second (Bell Fisheries Handbook 1990). It would require almost 14 seconds for the fish to reach the edge of the 58-foot wide plume if they started

in the center of the plume. In 14 seconds, the pl ume would descend 98 to 154 feet. The Yaquina ODMD sites range in depth from 112 to 152 feet deep so the plume could hit the floor of the disposal area before a year ling OC coho salmon could evade. The expectation is that given these swimming speed challenges and descent rate, many yearling OC coho salmon are not going to be able to avoid the disposal plume. A confounding problem is that these yearling OC coho salmon may be exhibiting schooling behavior; therefore, numerous fish may be exposed at one time. Typical avoidance response may also include an initial dive to avoid the material and then horizontal movement, thus losing time to evade the descending material. It is likely that adult OC coho salmon can evade the sediment plume, but some of the yearling OC coho salmon will not.

Evasion by green sturgeon is likely more probable than OC c oho salmon due to their expected

location in the water co lumn. Whether relying on darting or sustained speed the green sturgeon occupying the deeper depths of the water column have more time to detect the descending

sediments and initiate an avoidance response. It is assumed that adult green sturgeon, given their larger size, faster swi mming speed, and inhabiting deeper depth will avoid the discharge plume. The youngest and smallest green sturgeon may not escape the falling sediment. These younger subadults that may only be 2 feet in length would have a sustained swimming speed of 2 feet/second and may still not be able to successfully avoid the descending plume, despite their deeper depth location. The NMFS is reasonably certain that adult and larger subadult green sturgeon are unlikely to be physically harmed because these individuals will avoid the descending sediments. Smaller indi viduals, those near to the 2-foot length, are more likely to be unsuccessful in avoiding the desce nding material and this action pos es physical risk to any of these individuals directly exposed to the disposed dredge material.

The effects to eulachon are likely similar to those that occur to juvenile OC coho salmon.

Juveniles and adults that cannot reach the edge of the plume with in five seconds using darting speeds must rely on slower swimming speeds to reach the edge of the plume. Critical swimming speed, which is faster than sustained speed, is estimated for juvenile eulachon at 0.66 to 2.2

feet/seconds and 2.2 feet/second for adult eulachon that did not reac h the edge of the plume with their darting response. If starting from the cente r of the 59-foot wide disposal plume, it would take juvenile eulachon 13.2 to 44 seconds to reach the edge of the disposal plume. It would take adults 13.2 seconds to reach the edge from the center of the plume. The disposal plume will have

descended to 92.4 feet to the ocean floor in th at time range. Given the distribution of eulachon throughout the water column, indivi duals occupying shallower dept hs have a higher likelihood of becoming entrained of physically injured or kill ed by the descending disp osed dredged material. Those individuals occupying deeper depths of th e action area are likely to have more time to detect and react to the descending discharge plume. It is reasonab ly certain that some juvenile

and smaller adult eulachon exhibitin g slower darting speeds (at or near 4.4 feet/second) relative-44- to their position near the disposal plume will not be able to avoid the descending disposed dredged material.

Dredged material disp osal quantity and weight . Disposal quantities and discharge time are important variables to consider while assess ing the likelihood for OC coho salmon juveniles, small subadult green sturgeon, and eulachon to be adversely affected th rough a physical injury from disposal material. Based on the previous discussion, NMFS concludes exposure to this disposed material is inevitable for yearling coho salmon, small subadult green sturgeon, and juvenile and adult eulachon. The Yaquina dredge capacity is 1,042 cy, however, the EPA used a value of 800 cy per load as an estimate of a volum e in a typical disposal load for the purposes of calculating the volume of water exposed to the di sposal plume. A cubic yard of wet sand may weigh as much as 4,000 pounds (lbs). At 800 cy of sand, a maximum of 3,200,000 lbs of material may be discharged during a si ngle event. If a typical load on the Yaquina is discharged over a period of five minutes, this equates to over 10,000 lbs per second of discharge. The amount and weight of this material is significant for a small fish to resist from being entrained by the descending material and dragged down to the ocean floor. The quantity of dredge material displaces a large volume of water; therefore, if some fish are pushed ahead of the discharge plume they would be entrained within the vortices of the turbulent flow. In order to assess the physical risk posed by the exposure to disposed dr edge material the physi cal interaction between

the fish and the material is of most interest.

Physical interaction between ESA-listed fish and disposed dredged material . The Corps

theorizes in their assessment entitled Parameters Describing the Convective Descent of Dredged Material Placed in Open Water by a Hopper Dredge , which was developed by the Corps in March 4, 2005, as an amendment letter to anothe r dredge disposal cons ultation (refer to NMFS No.:2004/01041, Corps 2005), that the fish that come into contact with the material and are unable to escape will either resi st the material and be exposed to a drag force caused by the

material or the fish will not resist and will be di splaced by the material plume. If the fish does not resist, the Corps theorized, a bounda ry layer at the lead ing edge of the plume would reduce the likelihood of the fish becoming entrained in th e material plume. If the fish does become entrained, then the Corps expects the fish will be carried with the plume toward the bottom. In that assessment, the Corps’ conclusion for any of th e scenarios is that it is unlikely the fish would be adversely affected because the fish would: (1) Allow the material to move around them and only be pulled down by the material but not injured; (2) be pushed ahead of the plume due to a boundary layer and then laterally as the plume reached the ocean floor; or (3) be moved aside by the material. The NMFS considers that a high degr ee of uncertainty exists regarding the response and risk of fish exposed to disposed materi als. Without substantia l supporting evidence the Corps’ assessment can be considered representa tive of possible outcomes, but not all outcomes.

The NMFS considers that enough uncertainty exists regarding the physical interaction between fish and disposal material that it is reasonably certain to conclude that listed species are subject to physical risk. Additional outcomes include a fish being carried along with the downward

movement of the sediment and buried under the de posited material and th e physical abrasion of their epidermis.-45- Several adverse physical consequences for fish may occur, even given the Corps’ possible outcomes. The Corps’ first outcome described abov e would require the fish to spend a length of time surrounded by dredge material and would result in the respiration of this material past the gills. Very high concentrations of suspended sediments will occur within the water column of the plume. Physical damage to gill membranes is the li kely result of this expos ure to the material and the subsequent increased probability of indirect effects of disease and in fection would lead to increased mortality. The Corps’ second and third outcomes described above are also likely to lead to similar adverse physical effects. The fluid dynamics and charac teristics of the plume result in significant turbulence of the water along the edge and within the plume. A fish caught in this turbulence and the collapse phase of the disc harge field will be entrained in an environment with very high suspended sediment concentratio ns for a time that would require the fish to respire this damaging sediment. In addition to the gill damage, so me fish are likely to receive abrasion from material passing around them that would remove some of the protective epidermal mucus or when they are forced down to the ocean floor, which is most likely the point where

mucus would be removed. Whether the fish is fo rced into the ocean floor or pushed along the bottom with the collapsing front of the plume, the fish will likely have physical abrasions that are susceptible to secondary infections. Another possible outcome with th ese scenarios is the disorientation of a fish caught in the turbulence of the plume. Thes e fish are likely to be more susceptible to predation due to the disorientation. The NMFS is reasonably certain exposing yearling OC coho salmon, smaller green sturgeon, a nd eulachon to disposed material could result in increased predation or physical harm to the fish from either becoming entrained and buried in

the material when it settles on the ocean floor ; respiring high concentr ations of suspended sediments; being physically abraded by the materi al; and/or harmed by collision with the bottom

substrate.

Numbers exposed

. The NMFS is required to evaluate th e magnitude of the adverse effect to determine the potential leve l of mortality and to assess the potential for jeopardy. The magnitude of the adverse effects from dredged ma terial disposal will be evaluated separately. The following approaches are intended to asse ss the upper limits of the magnitude for the purposes of determining the poten tial that the proposed impacts are significant to result in jeopardy to ESA-listed fish species. However, it is important to note that due to the uncertainty associated with these methods, these values should be considered estimates and are not precise. There is a range of adverse effects based on day-to-day abundance of yearling coho salmon in the action area at the time of disposal. This an alysis builds upon conser vative assumptions for understanding the potential magnitude of the adverse effects due to dredged material disposal resulting from the proposed action.

During disposal, the primary exposure pathway for pelagic fish occurs during an encounter with the sediment plume associated with the convect ive descent phase of di sposal. The volume of sediment disposed per event is variable, however work is t ypically conducted in the most effective manner possible and therefore, we estimated that a typical disposal load consists of 800 cy for the Yaquina . Using these volumes, we then calcula ted the number of disposal loads that would be necessary to complete dredging work at Yaquina Bay based on the maximum anticipated disposal volume provided by the EPA. The EPA proposed a maximum amount of dredged material disposed at the Yaquina ODM D sites of 495,000 cy that includes disposal activities occurring from the Corps and all othe r entities of Yaquina Bay that may need to-46- dispose of dredged material. Using the typical load amount of 800 cy for the Yaquina dredge, dividing this into the maximum amount of dr edged material disposed at the Yaquina ODMD sites yields approximately 619 di sposal loads per dredging season.

To estimate likely numbers of yearling OC coho salmon adversely affected by dredged material disposal, NMFS used information obtained from Global Ocean Ecosystem Dynamics (GLOBEC) and the Northwest Fisheries Scien ce Center (NWFSC) crui ses off of northern California and Oregon coasts (NWFSC 2000 and 2002). Estimates for small subadult green sturgeon and eulachon will rely on best judgment based on the use of this area by these species. The NMFS recognizes that these estimates are not exact; however, they provide a relative estimate of the potential impact from ocean di sposal, allowing NMFS to better evaluate these impacts and inform the final jeopardy analysis.

The NMFS assumes some of the individuals in the disposal area will avoid direct exposure to the discharge plume by: (1) Avoiding the ship; (2 ) randomly being positioned in the action area away from the direct path of th e ship; (3) exhibiting some avoidan ce to the discharge field due to their position in relation to the discharge plume; and (4) being randomly near the edge of the discharge field thereby facilitati ng avoidance. However, at least some of these fish directly exposed to the convective descent phase of in-wat er disposal will be adversely affected, likely leading to mortality for those individuals ca ught directly in the plume because they will experience injury and death due to this expos ure to the discharged dredged sediments.

In 2000, more OC coho salmon yearlings were capt ured in the trawls in August than June (Brodeur et al. 2004). In the combined data reviewed for the two years of trawl data, the abundance of OC coho salmon yearlings varied and for most stations the average abundance was highest during June (NWFSC 2000 and 2002). For th is analysis, we considered June densities represented the highest abundance based on the outmigration of OC coho salmon smolts from the rivers and the combined two years of ocean tr awl data. Based on NWFSC (2000) and (2002) data

an estimated 45 OC coho salmon smolts/1,000,000 m 3 may be present in the nearshore Pacific Ocean near Yaquina Bay. The total maximum number of fish that may be injured or killed by a disposal event in the action area is a function of water volume aff ected by disposal and density of OC coho salmon smolts in the ocean. The disposal plume from the dredge Yaquina will affect approximately 25,000 m 3 of water. Therefore, on average a single disposal event from the Yaquina will adversely affect 1.1 OC coho salmon year lings. No evidence exists to provide an assessment as to whether individuals from adjace nt ocean areas may move into or out of the ODMD sites between disposal loads, whether within the same day or different days. If fish leave the area due to an avoidance of the discharge fiel d, some of these individuals, or others nearby, are likely to reoccupy the disposal site after some short, but uncer tain period of time; it is likely that the longer the time between disposal load s the higher the probability that the ODMD sites will be reoccupied to the base abundance. When disposal is occurring during the months when OC coho salmon smolts are entering the ocean, th ere are a higher likelihood these individuals may enter the ODMD sites immediately upon oc ean entry. Assuming the disposal areas repopulate between loads the total maximum year ling OC coho salmon exposed to the disposal activities is the number of individuals affected by a single disposal event multiplied by the number of disposal events. For this consultation the number of disposal loads (619) was based on the maximum proposed amount of material disp osal (495,000 cy) divided by the typical load-47- amount disposed by the Yaquina dredge (800 cy). The number of yearling OC coho salmon exposed to dredged material disposal per dred ging season is 697. Because of year-to-year variability in the amount of mate rial and the number of loads needed to dispose of dredged material, the number of yearling OC coho salmon e xposed to dredged material disposal will also vary annually. This estimate builds upon cons ervative assumptions for the purpose of understanding the potential magnit ude of the adverse effects and constitutes the maximum number of individuals likely exposed. Exposur e of 697 yearling OC coho salmon in a single dredging season is likely every fi ve to eight years. In other y ears, when the maximum amount of material is not disposed of at the proposed sites, the number of yearling OC coho salmon exposed is approximately 522 (based on 370,000 cy of material). The NMFS assumes 100% mortality for the number of individuals exposed to dredged material disposal.

Yearling OC coho salmon individuals from the Yaquina and Alsea rive rs and Beaver Creek populations will make up the total number of those injured or killed by the disposal of dredged material. As previously presented in the sec tion 2.2.1 (status of the species) of this opinion, NMFS calculated estimates of yearling OC c oho salmon for each population. The yearling OC coho salmon present in the action area represent mostly a composite of the three populations. Assuming equal impact across all three populations, the average numbe r of yearlings that may be entering the ocean per year is 247,796 (average fo r combined Yaquina, Alsea, and Beaver Creek populations 1995 to 2010). The lowest and highest number of yearlings during this time frame was 17,284 and 545,381 individuals, respectively. The total maximum mortality from disposal of dredged material (697) represen ts 0.28% (range 0.13% to 4%) of the combined Yaquina, Alsea, and Beaver Creek populations for th ose given years. The NMFS is r easonably certain that 4% is an overestimate because yearling coho salm on abundance in the action area would be proportionately lower when there are only 17,28 4 yearling coho salmon produced from the three populations, the density of yearling OC coho salm on in the action area could be significantly lower than the densities reporte d by NWFSC (2000) and (2002).

The total abundance of green sturgeon is unknown (Adams et al. 2007), therefore the abundance of the green sturgeon within each of the ODMD sites is unknown but likely to be very low. Lindley et al. (2008) tracked the migrating tagged green sturgeon along the west coast (Figure 4). It is apparent green st urgeon are migrating along the Oregon coast, but whether they actually

enter the action area is unknown. It is also unknown whether the younger smaller individuals of green sturgeon migrate to the Ya quina River area. In addition to their exact location, these migrating fish are likely moving through the area at a high rate of speed (Lindley et al. 2008) and

therefore not likely to stay within an i ndividual action area very l ong. The most likely migration

scenario where green sturgeon might enter the action ar ea would be for green sturgeon that are

headed into Yaquina River estuary. The NMFS is unable to estimate the number of green sturgeon adversely affected by this action, but expects this number to be low because: (1)

Limited information exists on the number of green sturgeon using the Yaquina River; (2) migrating green sturgeon spend limit ed time in one area as they move from estuary to estuary and are possibly further offshore; (3) the green sturgeon do not spawn in any of Oregon coastal river basins, and therefore, sma ll juvenile green sturgeon will not be present; and (4) the relative size of the action area compared to the range of gr een sturgeon is extremely small. Nonetheless, the NMFS is reasonably certain adverse effects will occur to some smaller subadult green sturgeon at the time of the material disposal.-48- Eulachon abundance across the range of the entire DPS is not well known. Presence and abundance in the action area is dependent on marine distribution patterns of eulachon that are not well known, but a previous study (Beacham et al . 2005) has shown that eulachon likely travel large distances from their natal stream during the ocean part of their life cycle. Marine

distribution of eulachon is partly dependent on the loca tion and abundance of spawning populations of eulachon. We previously determined that eulachon are reas onably certain to occur in the action area, but because of the lack of information on eulachon abundance, we cannot accurately quantify the number of individuals that could potentially be present in the action area. The most likely scenario for eulachon presence in the action area is a school foraging within or migrating through the action area. Eulachon are a pelagic species and lik ely exhibit schooling behavior when in the ocean. When they are pr esent in the action area, it is likely that many

individuals will be concentrated in a small area. Based on the above analysis, exposure of eulachon to disposed dredged mate rial will occur; however, the fr equency of exposure is likely low. Known spawning populations of eulachon on the Oregon Coast are the Columbia River, Tenmile Creek (near Yachats, Oregon), and th e Umpqua River. Presumably, eulachon off the Oregon Coast are mostly from the Columbia River because populations south of there are thought to have severely declined (Gustafson et al . 2010). The NMFS cannot predict the number of eulachon injured or killed by disposed dredged material, but expects this number to be small because: (1) There is littl e information explaining the distribution and abundance of eulachon in the action area; (2) known spawni ng populations are north (Columbia River – greater than 110 miles) and south (Tenmile Creek and Umpqua River – greater than 24 miles) of the action area, limiting the number of eulachon potentially pres ent in the action area; (3) schooling eulachon will be actively foraging and/or migrating and wi ll not be present in the action area for long periods of time; and (4) the relative size of the action area compared to the range of eulachon is extremely small.

Summary of effects to OC coho salmon . Exposure of adult and yearling OC coho salmon to disposed dredged material will occur because of the proposed action. The risk to adult OC

coho salmon individuals is low based on their fast er swimming speed and ability to avoid the descending sediment plume. Some yearling OC coho salmon will, however, be exposed to the descending dredged material plume. Yearlings w ill exhibit minimal avoidance behavior from the ship and, depending on their location in the plume, may not be able to swim fast enough to avoid dredged material. The NMFS is reasonably certain dr edged material disposal will result in injury or death to up to approximately 697 yearli ng OC coho salmon per year from: (1) Becoming

entrained and buried in the material when it settles on the ocean fl oor; (2) respiring high concentrations of suspended sediments; (3) be ing physically abraded by the material; and (4) collision with the bottom substrate. The dispos al of dredged material will injure or kill individuals from the three populations of the mid-coast stratum of OC coho salmon.

Yearling OC coho salmon individuals injured or killed by the disposal plume are from the Yaquina and Alsea rivers and Beaver Creek populations of OC coho salmon. The numbers of yearling OC coho salmon injured or killed from dre dged material disposal (697 or 522) is related to the numbers of yearling OC coho salmon out migrating from each population and the location of the population in relation to the action area. No population should be impacted inequitably, such that the total impact will be spread betw een the three populations. Mortality that could occur from dredged material disposal represen ts 0.28% of the average number of yearling OC-49- coho salmon produced in the Yaquina, Alsea, and Beaver Creek populations. The effects on abundance and productivity at the population scal e will be insignificant because such a small portion of each population will be affected. Therefore, effects on population abundance and productivity will not be measurable or meaningfully.

Summary of effects to green sturgeon . Some individual green sturgeon will experience effects from the discharge of these dredged sediments from the hopper dredge. Adult and subadult green sturgeon may inhabit the action area during their migration fr om their natal rivers in California to northern waters in Oregon, Washington, and Canada. Green sturgeon use the Yaquina River estuary and due to the close proximity of the acti on area to the Yaquina River, a possible overlap in time and space with the disp osal activity has some likelihood of occurring. The potential use, behavior and abundance of green sturgeon are not known for the action area. Based on general abundance, capture information, and migration routes green sturgeon may use

the action area. For those that do occur within th e action area, the exposur e of green sturgeon to the disposal material was determined to be inevitable based on the expectation that the fish will not exhibit avoidance behavior from the ship. Larger adult and subadult green sturgeon will successfully evade the sediment pl ume without significant physical injury that would result in death because their faster swimming speed and occ upation of deeper water depths will facilitate evasion. Younger, smaller subadults that are approxi mately 2 feet or less in length have a higher risk than the larger fish due to their slower swimming speed. The NMFS is reasonably certain smaller green sturgeon exposed to the disposed dredged material will have a high likelihood of experiencing physical injury and death. Although the NMFS is unable to estimate the number per year killed, NMFS is reasonably certain this number is low.

The effects on abundance and productivity at the population scale will be insignificant because

such a small number of individuals could be exposed to the activity. The NMFS is reasonably certain the proportion of the population that will be affected is small based on the research results that have demonstrated large numbers of green sturgeon are present in Canadian waters, the Washington estuaries and the Columbia Ri ver during the summer months (Lindley et al . 2008, Moser and Lindley 2007, Adams et al . 2007, Grimes 2006). Therefore, effects on abundance, productivity or genetic diversity will not be m easurable or meaningfully expressed at the population scale.

Summary of effects to eulachon . Adult and juvenile eulachon exposure to dredged material disposal will occur. Adult eul achon that cannot swim fast enough to avoid the descending dredged material plume and juvenile eulachon will experience adverse effects and injury and/or death from disposed material. Eulachon will likely exhib it avoidance behavior when the ship is detected and move away fr om the dredge ship, but some individuals will

remain. The NMFS determined that some eulach on would experience exposure to disposed dredged material. The risk to eulachon includes physical injury from either becoming entrained

in the material when it settles on the ocean floor; being physic ally abraded by the material; and/or injured by collision with the ocean substr ate when the individual is advected with the descending material.

The effects on abundance and productivity at the population scale will be insignificant because the number of individual eulachon that will be injure d or killed from disposal activities is small.-50- While commercial fishery data can not provide a reliable estimate of abundance of a species it can provide perspective on the relative impact the effects of an action can have at the population and species scales. Commercial data for the eu lachon fishery on the Columbia River shows an average of 122,157 (range 2,160 to 190,555) eu lachon caught from 2005 – 2009. Since most eulachon in the action area are most likely from th e Columbia River, if individuals from a school of eulachon were injured or kill ed by disposed dredged material it would still make up only a small portion (likely less than 1%) of the Co lumbia River population. Therefore, effects on population abundance, productivity, di stribution, and genetic diversity will not be measurable or meaningfully at the population scale.

2.4.3 Effects to Critical Habitat

Green sturgeon . The specific critical habitat that will be affected by the interrelated actions to the proposed action is the designate d critical habitat for green sturgeon in the

nearshore area of the Pacific Ocea n. Designated critical habitat for green sturgeon is identified as the Coastal Marine Waters (withi n 110 meters depth) (Table 1). The habitat features required to support successful subadult and adul t migration include water qual ity, food resources, and safe passage. This area may also support the maturation of subadults to the adult life stage. Of these, water quality, food resources, and safe passage are likely to be affected by the proposed action. The impacts are described below.

1. Water Quality . Suspended sediment levels will be increased over background due to fine sediment mobilized by disposal from a hopper dredge transport ship. Suspended sediment levels are likely to increase for a short time w ith the highest concentrations occurring at the ship’s disposal point and dispersing fr om that point depending on ocean currents, disposal material size composition, wave acti on, dredge ship spee d, and disposal rate. The NMFS predicts suspended sediment will dr ift approximately 500 feet outside of the ODMD sites. It is likely that suspended se diment concentrations generated by dredge material disposal will exceed the 17 mg/l effects threshold for injury as described above for salmonids, but adult and subadult green sturgeon are less sensitive to suspended sediments than salmonids. Green sturgeon inha bit much more turbid environments than do salmonids and are more benthic oriented; therefore the NMFS is reasonably certain these elevated suspended sediments concen trations will occur primarily in the upper water column and the duration of exposure will result in insignificant change to this PCE.

The EPA’s proposed action includes the adoptio n and implementation of the SMMP that requires any proposed sediments for disposal to adhere to the procedures approved by the Regional Sediment Evaluation Team (RSET) . Only “clean” dredged material can be placed into the ocean under current statutes a nd regulations. Sediment suitability must be documented prior to disposal at the site. Al though trace levels of various heavy metals, PAHs and other compounds will occur with th e sediments, these levels will not exceed concentrations harmful to the organisms occ upying the action area; therefore disposal of this dredge material will not alter th e quality and function of this PCE.

2. Food Resources . Disposal of dredge materials co ntributes a layer of unconsolidated sediment on the ocean floor. In doing this, in faunal and epifaunal invertebrates will be-51- covered with a layer of sandy sediment. Before the winter storms disperse the material some reduction of invertebrates on the ocean floor may occur. The result would be a

reduction in the food source and habitat availabl e to marine organisms in the area for up to 6 or 7 months between the disposal and wh en the winter storms disperse the material. The likely change in prey species is dependent then on the reco lonization rate of this area.

Recolonization is uncertain while the site is in active use for dredged material disposal over the 20-year life of the designation. The maximum interval between disposal events is approximately one year. Reco lonization potential is affected by the interval duration between deposition events, par ticle size, currents, and compaction/stabilization following deposition (Newell et al. 1998, Van der Veer et al. 1985). Rates of recovery listed in the literature range from several months for estu arine muds, and up to two to three years for sands and gravels (Hitchcock et al. 1999). Recolonization may take longer in areas with lower current (Van der Veer et al. 1985). This site is indicative of a dynamic nearshore ecological zone that naturally would be ch aracterized by a disturbance based ecosystem. Disturbance-based ecosystems are indi cative of rapid reco lonization rates by opportunistic organisms tolerant of cond itions that are physiologically stressful (Pemberton and MacEachern 1997).

Although conducting feeding studies on green sturgeon have proven difficult, some

information is available. In addition to various invertebrates, green sturgeon appear to be opportunistic foragers and feed on various fish species, such as lingcod (Dumauld et al. 2008), herring (Erickson and Hightower 2007) , sand lace and anchovies (Moyle 2002) that may also be adversely impacted by the disposal. Similar exposure, avoidance response, and risks are likely with forage fi sh species as were described for the coho salmon, green sturgeon, and eulachon. Typically these fish are smaller species and less likely to avoid physical harm. The number of individuals prey items impacted is difficult to estimate, but NMFS is reasonably certain the number adversely affected would not significantly deplete the overall abundance of forage available to green sturgeon. Because these impacts to forage base is highly local ized, the likely decrease in forage abundance is considered insignificant to the total food resources av ailable to green sturgeon. The food resources PCE will not be functionally changed.

3. Safe Passage . Safe passage for green sturgeon is ch allenged by the physical threat of the disposal material. The NMFS concludes some risk to the safe passage of a few younger, smaller (2 feet) subadults exists due to this action, but the action: (1) Is limited to 1,722 acres of the Pacific Ocean; (2 ) is only temporary; (3) will on ly affect a few individuals; and (4) the amount of migration habitat adjacen t to the action area is considerably greater than within the action area. Therefore the qua lity and function of the safe passage PCE will not be changed by designating these ODMD sites and the subsequent dredge material disposal.

Information presented in the status and baseline sections of this opini on show that the ocean habitat conditions are driven by factors working at a much larger scale than this action area. Three PCEs will be affected, but will not be f unctionally changed because effects will be small scale, short term, or unlikely. Since the effects w ill not adversely change the habitat functions at-52- the site scale, the effects from the proposed project will not impair the ability of critical habitat to play its intended conservation role.

2.5 Cumulative Effects

“Cumulative effects” are those effects of future State or private activit ies, not involving Federal activities, that are reasonably ce rtain to occur within the action area of the Federal action subject to consultation (50 CFR 402.02). Future Federal actio ns that are unrelated to the proposed action are not considered in this section because they require separate consulta tion pursuant to section 7 of the ESA. The NMFS looked in the BA provide d by the EPA and did not identify any future

non-Federal actions that would affect ES A-listed species or critical habitats.

2.6 Integration and Synthesis

The Integration and Synthesis section is the final step of NMFS’ assessment of the risk posed to species and critical habitat because of implemen ting the proposed action. In this section, we add the effects of the action (Sec tion 2.4) to the environmental baseline (Section 2.3) and the cumulative effects (Section 2.5) to formulate the agency’s biological opinion as to whether the proposed action is likely to: (1) Result in ap preciable reductions inthe likelihood of both survival and recovery of the species in the wild by reducing its numbers, reproduction, or distribution; or (2) reduce th e value of designated or propos ed critical habitat for the conservation of the species. These assessments are ma de in full consideration of the status of the species and critical habitat (Section 2.2).

2.6.1 ESA-listed Species

After careful review of the effects of the proposed action, species’ status, environmental baseline, and cumulative effects (none identified) it is reasonably certain th at the proposed action will not result in appreciable reductions in su rvival and recovery of OC coho salmon, green sturgeon, and eulachon in the wild by reducing their numbers, reproduction, or distribution. The status of OC coho salmon, green sturgeon, and eul achon are such that removal of a small number of individuals will not affect the species’ ab ility to replace or sustain themselves. The

environmental baseline in the acti on area is likely currently provi ding the basic biological needs of OC coho salmon, green sturgeon, and eulacho n. Disposal activitie s will occur in a highenergy and dynamic ocean environment where larg er scale physical and biological processes than the action area control productivity and environmental and base line conditions. The proposed action will not occur on a large enough spatia l or temporal scale to significantly change productivity and environmental and baseline conditi ons such that normal behavioral patterns of OC coho salmon, green sturgeon, or eulachon woul d change when in the ocean environment.

The physical threat to OC coho salmon, green sturgeon, and eulachon from the proposed action comes from exposure of these fish to disposed dredged material. The consequences of fish exposure to disposed dredged material include injury and death of up to 697 yearling OC coho salmon individuals per year. This number will be spread over the Yaquina River, Beaver Creek, and Alsea River populations of OC coho salmon a nd will occur every five to eight years with lower numbers of individuals injured or killed in other years. The NMFS is reasonably certain-53- that the effects to abundance and productivity are insignificant at the population scale because such a small portion of each population will be affected (approximately 0.28%). The NMFS is also reasonably certain that the number of green sturgeon and eulachon injure d or killed will be

low and effects to abundance a nd productivity at the population scale will be insignificant because such a small proportion of the green st urgeon and eulachon populations will be exposed to disposed dredged material.

2.6.2 Critical Habitat

After review of the effects of the proposed action, environmental baseline, and cumulative effects (none identified) NMFS is reasonably cert ain that the proposed action will not reduce the value of designated critical habitat for the cons ervation of green sturge on. The action area is not designated critical habitat for OC coho salmon or eulachon. The proposed action will affect three PCEs of green sturgeon designa ted critical habitat including water quality, food resources, and safe passage. The quality and function of these PCEs in the action area will not significantly change as a result of the proposed action because the effects will be lo calized, short-term, or unlikely. Therefore, critical habitat for green stur geon will retain its ability to play its intended conservation role for this species.

2.7 Conclusion

After reviewing the current status of the listed species, the environmental baseline within the action area, the effects of the proposed action, and cumulative e ffects, it is NMFS’ biological opinion that the proposed action is not likely to jeopardize the c ontinued existence of OC coho salmon, green sturgeon, or eulachon or to destroy or adversely modify cr itical habitat designated for green sturgeon.

2.8. Incidental Take Statement

Section 9 of the ESA and Federal regulations pur suant to section 4(d) of the ESA prohibit the take of endangered and threaten ed species, respectively, without a special exemption. Take is defined as to harass, harm, pursue, hunt, shoot, w ound, kill, trap, capture or collect, or to attempt to engage in any such conduct. Harm is furt her defined by regulation to include significant habitat modification or degradation that results in death or injury to listed species by significantly impairing essential behavioral patterns, includin g breeding, feeding, or she ltering. Incidental take is defined as take that is incidental to, and not the purpose of, the carry ing out of an otherwise lawful activity. For this consulta tion, we interpret “harass” to me an an intentional or negligent action that has the potential to injure an animal or disrupt its normal be haviors to a point where

such behaviors are abandoned or significantly altered. 8 Section 7(b)(4) an d section 7(o)(2)

8 The NMFS has not adopted a regulatory definition of harassment under the ESA. The World English Dictionary defines harass as “to trouble, torment, or confuse by continual persistent attacks, questions, etc.” The U.S. Fish and Wildlife Service defines “harass” in its regulations as “an intentional or negligent act or omission which creates the likelihood of injury to wildlife by annoying it to such an extent as to significantly disrupt normal behavioral patterns which include, but are not limited to, breeding, feeding, or sheltering (50 CFR 17.3). The interpretation we adopt in this consultation is consistent with our understanding of the dictionary definition of harass and is consistent with the Service’s interpretation of the term.-54- provide that taking that is incident al to an otherwise lawful agency action is not considered to be prohibited taking under the ESA if that action is performed in compliance with the terms and

conditions of this incide ntal take statement.

2.8.1 Amount or Extent of Take

The EPA’s proposed action is designating the two Yaquina River ODMD sites pursuant to section 102(c) of the MPRSA as amended, 33 U.S.C §§ 1401 to 1445, near the mouth of the Yaquina River, Lincoln County, Oregon. The adverse effects id entified in this opinion that NMFS is reasonably certain will occur are the resu lt of indirect effects of subsequent Federal actions carried out by the Corps and other entities ca rrying out the dredging and disposal of dredged material. The EPA expects the two ODMD site s will be used in the future for disposal of material dredged by other publ ic or private entities ( e.g. the U.S. Coast Guard, Port of Newport, Port of Toledo) in accordance with section 201 of the MPRSA. These individual actions are likely to cause take of ESA-lis ted species during dre dging and disposal. Therefore, it is more appropriate to consider exempting this take on a case-by-case basis as su ch actions are proposed in the future. These disposals would require se ction 103 permits (which could be multiple-year authorizations up to 7 years) from the Regulat ory Branch of the Corps and EPA concurrence. Individual permits are publicly noticed and require other federal consultation ( e.g. ESA, EFH) and authorizations ( e.g. water quality certification), and EP A’s action here does not authorize and will not itself result in disposal of a ny dredged materials. Therefore, although NMFS anticipates indirect effects from EPA’s action, it does not anticipate any take will result from the site designation and adoption of the SMMP. Any furt her analysis of the effects of disposal of dredged material at the disposal site and issuance of an incidental take statement with reasonable and prudent measures and non-discretionary te rms and conditions to minimize take will be prepared when an ESA consultation on a dr edging and disposal action is requested.

2.9. Conservation Recommendations

Section 7(a)(1) of the ESA directs Federal agen cies to use their authorities to further the purposes of the ESA by carrying out conservation pr ograms for the benefit of the threatened and endangered species. Specifically, conservation recommendations are suggestions regarding discretionary measures to minimize or avoid adverse effects of a proposed action on listed species or critical habitat or regarding the development of information (50 CFR 402.02). The following conservation recommendation is a di scretionary measure that NMFS believes is consistent with this obligation and therefore should be carried out by the Federal action agency:

1. The EPA should work with the Corps and NMFS to finalize the interagency methodology to evaluate the effects of dredging and disposal on ESA-listed species.

2. The EPA should work with the Corps and NMFS to develop a study to determine the seasonal distribution, abundance, and habitat use of salmonids, green sturgeon, eulachon,

and marine turtles that occur in the nears hore region within and near the contour of ODMDS designations.-55- Please notify NMFS if the EPA carries out any of these recommendations so that we will be kept informed of actions that are intended to improve the conservation of listed species or their designated critical habitats.

2.10 Reinitiation of Consultation

As provided in 50 CFR 402.16, reinitiation of formal consultation is required where discretionary Federal action agency involvement or control over th e action has been retained, or is authorized by law, and if: (1) New informati on reveals effects of th e agency action on listed species or designated critical habi tat in a manner or to an extent not considered in this opinion; (2) the agency action is subsequently modified in a manner that causes an effect on the listed species or critical habitat not consid ered in this opinion; or (3) a new species is listed or critical habitat designated that may be affected by the action.

2.11 “Not Likely to Adversely Affect” Determinations

In this biological opinion, NMFS concludes that the proposed action is not likely to adversely affect the following species and critical habitats:

1. LCR Chinook salmon

2. UCR Chinook salmon

3. UWR Chinook salmon

4. SR fall Chinook salmon

5. SR spring/summer Chinook salmon

6. LCR coho salmon

7. SONCC coho salmon

8. Eastern DPS Steller sea lions

9. Blue whales

10. Fin whales

11. Humpback whales

12. Southern Resident killer whales

13. Sei whales

14. Sperm whales

15. Green turtles

16. Leatherback turtles

17. Loggerhead turtles

18. Olive ridley sea turtles

19. Leatherback turtle critical habitat

2.11.1 ESA-listed Fish Species

Chinook salmon

. LCR, UCR, UWR, SR fall and SR spring/summer run Chinook salmon all potentially occur in the act ion area. Weitkamp and Neely ( 2002) showed that coded-wire tagged adult Chinook salmon from each ESU were recovered in the northern Oregon Coast recovery area, which is where the action area is located. Although they potentially occur in the-56- action area, Chinook salmon will likely be presen t in low numbers because they are highly dispersive once they leave the Columbia Rive r. Adult Chinook salmon potentially would be present during disposal activities. It is unlikely that a young Chinook salmon would find itself in the nearshore environment away from their na tal stream. After most young salmon enter coastal waters, their swimming movements are oriented and directed, usua lly to the northwest toward the migration corridor of the Alas ka Current although the speed of this migration is affected by

size of the salmon and the direction and intens ity of coastal currents (Pearcy 1992). The NMFS concludes the proposed designati on of two ODMD sites near Yaqui na Bay in the Pacific Ocean is NLAA LCR, UCR, UWR, SR fall and SR spring/summer run Chinook salmon for the following reasons: (1) Implementation of the SMMP ensures no contaminated sediment will be disposed in the ODMD sites; (2) adult and j uvenile Chinook salmon presence is discountable because they are likely to be using areas furthe r offshore for migration; and (3) adverse impacts to the forage base for Chinook salmon are insignificant because the suspended sediment plumes

are localized and are not expected to reduce the primary or se condary production of the affected area. Critical habitat designate d for LCR, UCR, UWR, SR fall and SR spring/summer run

Chinook salmon does not occur in the action area.

Coho salmon. LCR and SONCC coho salmon potentia lly occur in the action area and may be affected by the proposed designation of ODMD sites near Yaquina Bay in the Pacific Ocean. According to Shapalov and Taft (1954), y earling coho salmon enter the ocean and spend

a few months outside their nata l streams before migrating north to far northern waters. During this northern migration, yearling coho salmon di stribute throughout the continental shelf and

move further offshore than the nearshore envi ronment of the action area. The NMFS concludes that the proposed designati on of two ODMD sites near Yaqui na Bay is NLAA LCR and SONCC because: (1) Presence of adu lt and juvenile LCR and SONCC coho salmon is discountable because they are likely using areas further o ffshore than the action area for migration; (2) implementation of the SMMP ensures no contaminated sediments are disposed of in the ODMD sites; and (3) adverse impacts to the forage base for coho sa lmon are insignificant because the suspended sediment plumes are localized and are not expected to reduce the primary or secondary production of the affected area. The acti on area is not designated critical habitat for

LCR or SONCC coho salmon.

2.11.2 ESA-listed Marine Mammals

Steller sea lions, blue whales, fin whales, hum pback whales, Sei whales, sperm whales and

southern resident killer whales may occur in the action area. Blue whales, fin whales, Sei whales, and sperm whales are not generally distributed ne arshore, and their presence in the action area is unlikely. Humpback whales and Southern Resident killer whales may occur nearer to the shore, but their presence in the action ar ea is likely infrequent and trans itory. Steller s ea lion rookeries and haul-outs are sufficiently distant from the act ion area (the nearest Stel ler sea lion haulout is at Seal Rock, at least five mile s away from the disposal sites) that any effects to breeding or haul-out behavior are unlikely. The proposed ac tion may indirectly a ffect the quantity and quality of prey available to marine mammals ( i.e. , salmonid prey of sout hern resident killer whales and Steller sea lions) by ch anges to water quality and physic al injury, discussed in detail

above for OC coho salmon.-57- In the event that marine mammals are present during disposal act ivities, the proposed action may cause temporary disturbance. Vessel transits a ssociated with dredged material disposal ( i.e.

, hopper dredge) consist of up to 619 round trips to and from the Yaquina ODMD sites annually. Barge-sized vessels, such as a hopper dredge, us ed for the proposed action would require short

transits to the nearshore or ODMD sites where the vessel would remain relatively immobile until work is complete, with minimal sound or potenti al for disturbance. Any temporary disturbance would be short-term and localized, with no last ing effects, and therefore insignificant. Vessel strikes are extremely unlikely because the ba rge-sized vessels are slow moving, follow a predictable course, do not target marine mammals , and should be easily detected and avoided by

marine mammals. Potential effects from ve ssel strikes are therefore discountable.

As described in detail above, EPA adheres to sediment quality st andards for open ocean disposal. The EPA’s proposed action includes the implem entation of the SMMP that requires any proposed sediments for disposal to adhere to the procedures approved by the RSET. Only “clean” dredged material can be placed into th e ocean under current statutes and regulations. Sediment suitability must be documen ted prior to dispos al at the site.

Some marine mammals forage on adult salmon and other prey species ( i.e. , Southern Resident killer whales or Steller sea lions). Up to 697 yearling OC coho salmon may be injured or killed annually by disposal activities. Antic ipated injury or death of year ling salmonids may result in a

reduction of adult salmonids available to marine mammals as prey resour ces, but that reduction is insignificant compared to the amount of remaining prey re sources available.

The NMFS is reasonably certain that all potential adverse effects to ESA-listed marine mammals are discountable or insignifican t and concurs with the EPA’s de termination of NLAA for Steller sea lions, blue whales, fin whales, humpback wh ales, sei whales, sperm whales, and southern

resident killer whales.

2.11.3 ESA-listed Marine Turtles

Leatherback sea turtles, loggerhead sea turtles, green sea turtles, and olive ridley sea turtles may

occur in the action area. These s ea turtles are highly migratory, and the life histories of all species exhibit complex movements and migrations through geographically disparate habitats, so defining their geographic range is difficult. Leatherback, loggerh ead, green, and olive ridley sea

turtles all nest on beaches in the U.S. and a ll depend on U.S. coastal waters for foraging and migratory habitat during certain stages of thei r life history. However, sea turtles have no breeding areas in Oregon and, excep t for leatherback sea turtles, are extremel y rare in Oregon’s nearshore habitats. Most leatherback sightings oc cur in marine waters within the coastal zone. Although sightings of sea turtles oc cur in Oregon, they are, none theless, exceptionally rare. The probability of their presence in the action area when a disposal event occurs is extremely small. Therefore, NMFS finds that a ll effects of proposed action are reasonably certain to be discountable and are NLAA leatherback sea turtles, loggerhead sea turtles, green sea turtles, and olive ridley sea turtles.-58- 2.11.4 Leatherback Sea Turtle Designated Critical Habitat

The PCEs that NMFS identified as essential for the conservation of leatherback turtles when it designated critical habitat to incl ude marine waters off the U.S. West Coast, including the action area, are: (1) A sufficient quantit y and quality of their jellyfish prey; and (2) migratory pathway conditions that allow for safe and timely passage to, from, and within high use foraging areas, including areas within the action area. Dredge disposal activitie s may result in the loss of polyp life-stage jellyfish and adult medusa jellyfish, on the ocean floor and in the water column, respectively, in the immediate area where dredge spoils desce nd through the water column and settle on the ocean floor. However, the small amo unt of prey losses that may occur intermittently and in the small area (ODMD site) when dredge spo ils are released will result in an insignificant reduction in prey available to l eatherbacks in their proposed critic al habitat. No effects on prey quality are anticipated. Similarly, intermittent vessel traffic associated with dredge disposal

activities would have a discountab le effect on leatherback turtle passage through the action area, given the extremely unlikely nature of leatherback turtle occurrenc e in the action area. Therefore,

NMFS finds that all effects of the action are reasonably certain to be discountable or insignificant for designated critical habitat of leatherback turtles.

3. MAGNUSON-STEVENS FISHERY CONS ERVATION AND MANAGEMENT ACT

The consultation requirement of section 305(b) of the MSA direct s Federal agencies to consult with NMFS on all actions or proposed actions that may adversely affect EFH. The MSA (section 3) defines EFH as “those waters and substrate necessary to fi sh for spawning, breeding, feeding, or growth to maturity. Adverse effects include the direct or indirect physical, chemical, or biological alterations of the waters or substrate an d loss of, or injury to, benthic organisms, prey species and their habitat, and other ecosystem components, if such modifications reduce the quality or quantity of EFH. Adverse effects on EFH may result from actions occurring within EFH or outside EFH, and may incl ude site-specific or EFH-wide impacts, including individual, cumulative, or synergistic consequences of actions (50 CFR 600.810). Section 305(b) also requires NMFS to recommend measures that can be taken by the action agen cy to conserve EFH.

This analysis is based, in part, on the EFH a ssessment provided by the Federal action agency and descriptions of EFH contained in the fishery management plans developed by the Pacific Fishery Management Council (PFMC) and approved by th e Secretary of Commerce for Pacific Coast groundfish (PFMC 2005), coastal pelagic spec ies (PFMC 1998), and Pacific Salmon (PFMC 1999).

3.1 Essential Fish Habitat Affected by the Project

The PFMC described and identified EFH for gr oundfish (PFMC 2005), coastal pelagic species (PFMC 1998), and Pacific Salmon (PFMC 1999). Th e proposed action and action area for this

consultation are described in the Introduction to this document (section 1). The action area includes areas designated as EFH for various life-history stages of groundfish, coastal pelagics, and Pacific salmon (Table 7). There are no habita t areas of particular concern (HAPCs) present

in the action area.-59- Table 7. Species with designated EFH in the action area.

Groundfish Species

Leopard shark ( Triakis semifasciata ) Chilipepper ( S. goodei )

Soupfin shark ( Galeorhinus zyopterus ) China rockfish ( S. nebulosus )

Spiny dogfish ( Squalus acanthias ) Copper rockfish ( S. caurinus )

Big skate ( Raja binoculata ) Darkblotched rockfish ( S. crameri )

California skate ( R. inornata ) Grass rockfish ( S. rastrelliger )

Longnose skate ( R. rhina ) Rougheye rockfish ( S. aleutianus )

Ratfish ( Hydrolagus colliei ) Sharpchin rockfish ( S. zacentrus )

Pacific rattail ( Coryphaenoides acrolepsis ) Shortbelly rockfish ( S. jordani )

Lingcod ( Ophiodon elongatus ) Shortraker rockfish ( S. borealis )

Cabezon ( Scorpaenichthys marmoratus ) Silvergray rockfish ( S. brevispinus )

Kelp greenling ( Hexagrammos decagrammus ) Speckled rockfish ( S. ovalis )

Pacific cod ( Gadus macrocephalus ) Splitnose rockfish ( S. diploproa )

Pacific whiting (Hake) ( Merluccius productus ) Stripetail rockfish ( S. saxicola )

Sablefish ( Anoplopoma fimbria ) Tiger rockfish ( S. nigrocinctus )

Aurora rockfish ( Sebastes aurora ) Vermillion rockfish ( S. miniatus )

Bank Rockfish ( S. rufus ) Widow Rockfish ( S. entomelas )

Black rockfish ( S. melanops ) Yelloweye rockfish ( S. ruberrimus )

Blackgill rockfish ( S. melanostomus ) Yellowmouth rockfish ( S. reedi )

Greenspotted rockfish ( S. chlorostictus ) Yellowtail rockfish ( S. flavidus )

Greenstriped rockfish ( S. elongatus ) Arrowtooth flounder ( Atheresthes stomias )

Longspine thornyhead ( Sebastolobus altivelis ) Butter sole ( Isopsetta isolepsis )

Shortspine thornyhead ( Sebastolobus alascanus ) Curlfin sole ( Pleuronichthys decurrens )

Pacific Ocean perch ( S. alutus ) Dover sole ( Microstomus pacificus )

Quillback rockfish ( S. maliger ) English sole ( Parophrys vetulus )

Redbanded rockfish ( S. babcocki ) Flathead sole ( Hippoglossoides elassodon )

Redstripe rockfish ( S. proriger ) Pacific sanddab ( Citharichthys sordidus )

Rosethorn rockfish ( S . helvomaculatus ) Petrale sole ( Eopsetta jordani )

Rosy rockfish ( S. rosaceus ) Rex sole ( Glyptocephalus zachirus )

Blue rockfish ( S. mystinus ) Rock sole ( Lepidopsetta bilineata )

Bocaccio ( S. paucispinis ) Sand sole ( Psettichthys melanostictus )

Brown rockfish ( S. auriculatus ) Starry flounder ( Platyichthys stellatus )

Canary rockfish ( S. pinniger )

Coastal Pelagic Species

Northern anchovy ( Engraulis mordax ) Jack mackerel ( Trachurus symmetricus )

Pacific sardine ( Sardinops sagax ) Market squid ( Loligo opalescens )

Pacific mackerel ( Scomber japonicus )

Pacific Salmon

Coho salmon ( O. kisutch ) Chinook salmon ( O. tshawytscha )-60- 3.2 Adverse Effects on Essential Fish Habitat

Based on information provided by the EPA and the analysis of effects presented in the ESA portion of this document, NMFS concludes that the proposed action will have the following adverse effects on EFH designated for Pacific Coast groundfish, coastal pelagic species, and Pacific salmon: (1) Water quality degradation due to increased suspended fine sediments for younger life stages of EFH species; (2) entrainm ent and covering of EFH species prey from descending sediment plume resulting in short-te rm reduction of prey; and (3) impacts to safe passage through th e action area.

Disposal of dredged material will increase su spended sediment concentrations over background due to fine sediment mobilized by a hopper dredge . This will adversely affect water quality in the action area. Suspended fine sediment concentr ations are likely to increase for a short time with the highest concentrations occurring at the ship’s disposal point a nd dissipating from that point depending on current velocities and vectors. Concentrations of suspended fine sediments are likely to exceed the 17 mg/l threshold for injury of salmonid s in the action area. Although the ESA portion of this document determined that e ffects to primary production in the action area from suspended fine sediments were minor, the ac tion area likely contains younger life stages of fish ( e.g. larvae) with designated EFH that are less tolerant to increases in suspended fine sediments that will be exposed to degraded water quality.

Coarse-grained materials will also be present in disposed dredged material that will fall through the water column rather quickly, potentially entraining prey specie s or covering benthic invertebrates that are prey species of fish with designated EFH. Prey for EFH species will likely

be reduced for a short time within the ODMD s ites due to these effects. Disposed dredged materials contribute a layer of unconsolidated sediment on the ocean floor that will cover infaunal and epifaunal invertebrates. This reduc tion in food source will likely occur only until subsequent winter storms disp erse the unconsolidated material . The likely changes in prey species are dependent on the recol onization rate of this area.

Recolonization is uncertain while the site is in active use for dr edged material disposal over the life of the designation, an indefinite period. The maximum interval betwee n disposal events is approximately one year. The length of interval s between deposition ev ents, particle size, currents, and compaction/stabilization followi ng deposition affects recolonization potential (Newell et al. 1998, Van der Veer et al. 1985). Rates of recovery list ed in the literature range from several months for estuarine muds, and up to two to three years for sands and gravels (Hitchcock et al. 1999). Recolonization may ta ke longer in areas with lower current (Van der

Veer et al. 1985). This site is indicative of a dynami c nearshore ecological zone that naturally would be characterized by a di sturbance-based ecosystem. Dist urbance-based ecosystems are indicative of rapid recolonization rates by opportunistic organisms to lerant of conditions that are physiologically stressful (Pem berton and MacEachern 1997).

Similar exposure, avoidance response, and risks ar e likely with forage fish species as were described for the coho salmon and green sturgeon. Typically, these fish are smaller species and less likely to avoid physical injur y. Juveniles of larger species are also less likely to be able to avoid physical injury. The number of individuals impacted is di fficult to estimate, but it is-61- reasonable to conclude the numbe r adversely affected would not significantly deplete the overall abundance of forage available to EFH species in the surrounding ocean. Because these impacts to the forage base are highly localized, the decrease in forage abundance is considered insignificant to the total food resources availabl e to EFH management species. Because impacts to prey species, both invertebra te and vertebrate are localize d, the food resources in the ODMD sites and the EFH will not be functionally changed.

Safe passage for EFH managed species is chal lenged by the physical threat of the disposal material. Some individuals of the various species will experience effects from the discharge of these dredged sediments from the hopper dredge. The exposure of EFH management species to the disposal material was determined to be inevitable based on the expectation that the fish will not exhibit avoidance behavior from the ship. Larger animals are more likely to successfully evade the sediment plume without significant physical injury that would result in death because their faster swimming speed allows evasion. The NMFS is reasonably certain some risk to the safe passage of younger, smaller specimens exists due to this action, bu t the action : (1) Is limited to 1,722 acres of the Pacific Ocean; (2 ) is only temporary; and (3) the amount of migration habitat adjacent to the action area is co nsiderably greater than within the action area. Therefore the safe passage of the EFH managed species will not be functionally changed by designating this ODMD sites and the subs equent dredge ma terial disposal.

3.3 Essential Fish Habitat Conservation Recommendations

The NMFS expects that full implementation of these EFH conservation recommendations would protect, by avoiding or minimizing the adve rse effects described in Section 3.2 above, approximately 1,722 acres of designated EFH for Pacific Coast groundfish, coastal pelagic species, and Pacific salmon.

1. The NMFS recommends that the EPA work with the Corps and NMFS to develop a plan for monitoring fish interactions with the disposed dredged materials.

2. The NMFS recommends that the EPA work with the Corps and NMFS to develop a study

to determine the seasonal di stribution, abundance, and habi tat use of EFH species and their forage occurring in the nearshore regi on within and near the contour of ODMD site designations.

3.4 Statutory Response Requirement

As required by section 305(b)(4 )(B) of the MSA, the Federal action agency must provide a detailed response in writing to NMFS within 30 days after receiving an EFH Conservation

Recommendation from NMFS. Such a response must be provided at least 10 days prior to final approval of the action if the response is inc onsistent with any of NMFS’ EFH Conservation Recommendations, unless NMFS and the Federal ac tion agency have agreed to use alternative time frames for the Federal action agency respon se. The response must in clude a description of measures proposed by the agency for avoiding, mitigating, or offsetting the impact of the activity on EFH. In the case of a response that is inconsistent with NMFS Conservation Recommendations, the Federal action agency must explain its reasons for not following the recommendations, including the scientific jus tification for any disagreements with NMFS over-62- the anticipated effects of the action and the meas ures needed to avoid, minimize, mitigate, or offset such effects, 50 CFR 600.920(k)(1).

In response to increased oversight of overall EFH program effectiveness by the Office of Management and Budget, NMFS established a quar terly reporting requirement to determine how many conservation recommendations are provided as part of each EFH consultation and how many are adopted by the action agency. Therefore, we ask that in your statutory reply to the EFH portion of this consultation, you clearly identify the number of conservation recommendations accepted.

3.5 Supplemental Consultation

The EPA must reinitiate EFH c onsultation with NMFS if the pr oposed action is substantially revised in a way that may advers ely affect EFH, or if new info rmation becomes available that

affects the basis for NMFS’ EFH cons ervation recommendations, 50 CFR 600.920(l).

4. DATA QUALITY ACT DOCUMENTATION AND PRE-DISSEMINATION REVIEW

Section 515 of the Treasury and General Government Appropria tions Act of 2001 (Public Law 106-554) (Data Quality Act) specifies three co mponents contributing to the quality of a document. They are utility, integr ity, and objectivity. This section of the opinion addresses these Data Quality Act (DQA) components, documents compliance with the DQA, and certifies that this opinion has undergone pre-dissemination review.

4.1 Utility: Utility principally refers to ensuring that the information contained in this consultation is helpful, serviceable , and beneficial to the intended users. The intended user is the

EPA.

An individual copy was provided to the EPA. This consultation will be posted on the NMFS Northwest Region website ( http://www.nwr.noaa.gov). The format and naming adheres to conventional standards for style.

4.2 Integrity: This consultation was completed on a computer system managed by NMFS in accordance with relevant information technology security policies and standards set out in Appendix III, ‘Security of Automated Informa tion Resources,’ Office of Management and Budget Circular A-130; the Computer Security Act; and the Government Information Security

Reform Act.

4.3 Objectivity:

Information Product Category : Natural Resource Plan.

Standards : This consultation and su pporting documents are clear, concise, complete, and unbiased; and were developed using commonly accepted scientific research methods. They adhere to published standards includ ing the NMFS ESA Consultation Handbook, ESA-63- Regulations, 50 CFR 402.01, et seq ., and the MSA implementing regulations regarding EFH, 50 CFR 600.920(j).

Best Available Information : This consultation and supporting documents use the best available information, as referenced in the Li terature Cited section. The analyses in this Opinion/EFH consultation contain more bac kground on information sources and quality.

Referencing : All supporting materials, informati on, data and analyses are properly referenced, consistent with standard scientific referencing style.

Review Process : This consultation was drafted by NMFS staff with training in ESA and MSA implementation, and reviewed in accordance with Northwest Region ESA quality control and assurance processes.-64- 5. LITERATURE CITED

Adams, P.B., C.B. Grimes, S.T. Lindley, and M.L. Moser. 2002. Status review for North American green sturgeon, Acipenser medirostris . NOAA, National Ma rine Fisheries Service, Soutwest Fisheries Science Center, Santa Cruz, California. 50 p.

Adams, P.B., C.B. Grimes, J.E. Hightower, S.T. Lindley, and M.L. Moser. 2007. Population status of North American green sturgeon, Acipenser medirostris . Environmental Biology

of Fishes 79:339-356.

Beacham, T.D., D.E. Hay, and K.D. Le. 2005. Popul ation structure and stock identification of eulachon ( Thaleichthys pacificus ), an anadromous smelt, in the Pacific Northwest. Mar.

Biotechnol. 7:363–372.

Barraclough, W.E. 1964. Contribution to th e marine life history of the eulachon Thaleichthys pacificus . Bull. Fish. Res. Board Can. 21:1333–1337.

Beeman, J.W., S.P. VanderKooi, P.V. Hane r, and A. Maule. 2003. Gas bubble disease monitoring and research of juvenile salmonids. 1999. Annual report of U.S. Geological Survey to Bonneville Power Ad ministration, Portland, Oregon.

Bell, M.C. 1990. Fisheries handbook of engineeri ng requirements and biol ogical criteria. U.S. Army Corps of Engineers. North Pacific Division. Fish Development and Evaluation Program, Portland, Oregon. 322 p.

Berg, L. and T.G. Northcote. 1985. Changes in te rritorial, gill-flaring, a nd feeding behavior in juvenile coho salmon ( Oncorhynchus kisutch ) following short-term pulses of suspended

sediment. Canadian Journal of Fish eries and Aquatic Sciences 42:1410-1417.

Bi, H., R.E. Ruppel, and W.T. Peterson. 2007 Modeling the salmon pelagic habitat off the Pacific Northwest coast using logistic re gression. Marine Ecology Progress Series

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