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. :

2009/04136 April 21, 2010

Richard Parkin United States Environmental Protection Agency Region 10 1200 Sixth Avenue, Suite 900 Seattle, Washington 98101-3140

Re: Endangered Species Act Section 7 Biol ogical Opinion and Magnuson-Stevens Fishery Conservation and Management Act E ssential Fish Habitat Conservation
Recommendations for the Siuslaw River O cean Dredged Material Disposal Site Designation.

Dear Mr. Parkin:

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 the Environmental Protection Ag ency’s (EPA) proposal to designate two ocean dredged material disposal sites, and to adopt a Site Management and Monitoring Plan pursuant to section 102(c) of the Marine Protection, Research and Sanctuaries Act, as amended, 33 U.S.C. §§ 1401 to 1445, near the mouth of the Sius law River, Lane C ounty, Oregon. Based on conversations with EPA, this consultation contains slight refinements to a consultation issued to EPA for this action on April 16, 2010. This cons ultation replaces the April 16, 2010 consultation.

In this Opinion, NMFS concludes that the pr oposed action is not lik ely to jeopardize the continued existence of Oregon Coast (OC) coho salmon ( Oncorhynchus kisutch ) or southern green sturgeon ( Acipenser medirostris ), or to destroy or adversel y modify critical habitats designated for southern green sturgeon. Moreover, NMFS concludes that the proposed action is not likely to adversely affect s outhern green sturgeon, eulachon ( Thaleichthys pacificus ), eastern Steller sea lions ( Eumetopias jubatus ), blue whales ( Balaenoptera musculus ), fin whales ( Balaenoptera physalus ), humpback whales ( Megaptera novaeangliae ), Southern Resident killer whales ( Orcinus orca ), four marine turtle species, or cr itical habitat designated for southern green sturgeon or proposed for leatherback turtles.

As required by section 7 of the ESA, an incident al take statement prepar ed by NMFS is provided with this Opinion. However, the proposed si te designations and management plan do not describe, approve, or compel any specific dredge or dredge disposal action. Thus, all take of OC coho salmon that is likely to result from subsequent dredge actions and incl ude spoil disposal at these sites will occur at the project-specific leve l, not the site designation or management plan level. Accordingly, NMFS does not exempt incident al take in this Opinion. Take exemption for any dredge and dredge disposal action that is interrelated with the EPA’s action to designate these sites will occur in a pr oject-specific consultation.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 inconsis tent with the EFH conservati on recommendations, the EPA must explain why the recommendations will not be followed, including the scientific justification for any disagreements over the effects of the ac tion and the recommendations. In response to increased oversight of overall EFH program ef fectiveness by the Office of Management and Budget, NMFS established a quarterly repor ting requirement to determine how many conservation recommendations are provided as pa rt of each EFH consultation and how many are adopted by the action agency. Therefore, we requ est that in your stat utory reply to the EFH portion of this consultation, you clearly identify the number of conservation recommendations accepted.

If you have questions regarding this consultation, please cont act Robert Anderson, Fisheries Biologist in the Oregon St ate Habitat Office, at 503.231.2226.

Sincerely,

Barry A. Thom Acting Regional Administrator

cc: Joyce Casey, Corps

# Endangered Species Act Biological Opinion

and

Magnuson-Stevens Fishery Conservation and Management Act
Essential Fish Habitat
Conservation Recommendations

for the

Siuslaw River Ocean Dredged Materi al Disposal Site Designation

Lead Action Agency: Environmental Protection Agency

Consultation Conducted By: National Mari ne Fisheries Service Northwest Region

Date Issued: April 21, 2010

Issued by: ___________________ Barry A. Thom Acting Regional Administrator

NMFS No.: 2009/04136-iTABLE OF CONTENTS

INTRODUCTION .................................................................................................................. ........ 1 Background and Consultation History ........................................................................................ 1 Description of the Proposed Action ............................................................................................ 3 Interdependent and Interrelated Actions ..................................................................................... 5
Action Area ................................................................................................................... .............. 6 “Not Likely to Adversely Affect” Finding ................................................................................. 8

ENDANGERED SPECIES ACT BIOLOGICAL OPINION ....................................................... 11 Status of the Species and Critical Habitat ................................................................................. 12
OC Coho Salmon .............................................................................................................. 1 2 Southern Green Sturgeon Critical Habitat ........................................................................ 15
Environmental Baseline ........................................................................................................ .... 17 Species Within the Action Area ........................................................................................ 20
Critical Habitat Within the Action Area ........................................................................... 20 Effects of the Proposed Action ................................................................................................ . 20
Environment Within the Action Area ............................................................................... 20 Species Within the Action Area ........................................................................................ 22
Critical Habitat Within the Action Area ........................................................................... 22
Cumulative Effects ............................................................................................................ ........ 22 Synthesis and Integr ation of Effects ......................................................................................... 22
Conclusion .................................................................................................................... ............ 23
Incidental Take Statement...................................................................................................... ... 23
Amount or Extent of Take ................................................................................................ 24
Conservation Recommendations .............................................................................................. 24
Reinitiation of Consultation .................................................................................................. .... 24
MAGNUSON-STEVENS FISHERY CONSER VATION AND MANAGEMENT ACT .......... 25
EFH Conservation Recommendations ...................................................................................... 25 DATA QUALITY ACT DOCUMENTATION AND PRE-DISSEMINATION REVIEW ........ 26

LITERATURE CITED .............................................................................................................. ... 28-1- INTRODUCTION

This document contains a biolog ical opinion (Opinion) that wa s prepared by National Marine Fisheries Service (NMFS) in accordance with sec tion 7(b) of the Endangered Species Act of 1973, as amended (16 U.S.C. 1531, et seq .), and implementing regulations at 50 CFR 402. 1 It also contains essential fish habitat (EFH) c onservation recommendations prepared by NMFS 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 Appropriati ons Act of 2001 (Data Quality Act) (44 U.S.C. 3504 (d)(1) and 3516), and underwent pre-dissemination review. The administrative record for
this consultation is on file at the Ore gon State Habitat Office in Portland, Oregon.

Background and Consultation History

On February 23, 2009, NMFS received a request from the U.S. Environmental Protection Agency (EPA) requesting a species list for an Ocean Dredged Material Disposal Site (ODMDS) proposed offshore of the mout h of the Siuslaw River.

On March 30, 2009, NMFS provided the following list of threatened or en dangered species that may occur in the proposed project area, and s ubsequently amended the list on April 8, 2009 to include the following species:

1. Anadromous Fish

a. Salmon
i. Chinook salmon ( Oncorhynchus tshawytscha ) (1) Lower Columbia River (LCR) (2) Upper Willamette River (UWR) (3) Upper Columbia River spring-run (UCR) (4) Snake River spring/summer run (SRSS) (5) Snake River fall-run (SRF)
ii. Coho salmon ( O. kisutch ) (1) LCR (2) Southern Oregon / Northern California Coasts (SONCC) (3) Oregon Coast (OC)
b. Southern green sturgeon (Acipenser medirostris)

2. Marine Mammals

a. Whales
i. Southern resident killer whale ( Orcinus orca )
ii. Blue whale ( Balaenoptera musculus )
iii. Fin whale ( Balaenoptera physalus )
iv. Humpback whale ( Megaptera novaeangliae )
b. Pinnipeds
i. Eastern Steller sea lion ( Eumotopias jubatus )

1 With respect to designated critical habitat, the following analysis relied only on the statutory provisions of the ESA, and not on the regulatory definition of “destruction or adverse modification” at 50 CFR 402.02.-2- In that same letter, NMFS also informed the EPA that 53 species of gr oundfish, two species of Pacific salmon, and five coastal pelagic species have EFH designa ted within the proposed project

area.

On July 27, 2009, NMFS received a letter and biological assessment (BA) from the EPA the requesting formal consultation under section 7( a)(2) of the ESA, and EFH consultation under section 305(b) of the MSA regarding the likely effects of designating Siuslaw ODMDS under section 102 (c) of the Marine Protection, Re search and Sanctuaries Act (MPRSA).

In that BA, the EPA determined that its proposed action may affect, and is likely to adversely affect (LAA) OC coho salmon and southern gr een sturgeon, and may affect, but is not likely to adversely affect (NLAA) the other salmon and marine mamm al species on this list. The EPA also concluded that eulachon may occur in the pr oposed action area, alt hough NMFS did not include that species on its March 30, 2009 sp ecies list, and that the propos ed action would be NLAA for that that species. 2 Further, the EPA determined the propos ed action will have no effect on any designated critical habitat, excep t for southern green sturgeon, for which the EPA concluded the proposed action was NLAA. Finally, the EPA’s e ffects determination regarding EFH for all species with EFH within the proposed pr oject area was that the proposed action may adversely affect

.

On December 18, 2009, NMFS received a letter from the EPA that withdrew its request for formal consultation and requested informal c onsultation. That letter included a BA Addendum that changed the EPA’s previous effect calls for OC coho salmon and southern green sturgeon from LAA to NLAA. As a reason for changing its effects calls to NLAA, the EPA cited the lack of overlap between peak outmigration and dis posal times for OC coho, the small number of likely disposal events each year (20 or less), and the fact that disposal would mostly consist of sand released gradually from a hopper dredge wh ile the dredge is underway, thus reducing the potential for physiological effects to any n earby salmon or sturgeon. NMFS did not respond to this request in writing but did discuss the requ est with the EPA, and explained that NMFS had sufficient information to complete the consultati on and intended to issue a biological opinion. 3

On January 5, 2010, NMFS proposed to revise critic al habitat for leathe rback turtles by, among other things, include offshore marine areas fr om Cape Flattery, Washington, to the Umpqua River, Oregon, in the designation (75 FR 319). In light of this propos al, NMFS provides NLAA
determinations for marine turtles.

2 NMFS proposed eulachon for listing on March 13, 2009 (74 FR 10857), and listed this species as threatened on March 18, 2010 (75 FR 13012).

3 NMFS recently issued two biological opinions to the EPA for designation of ocean dredge disposal sites in Oregon: ESA Section 7 Formal Consultation and MSA EF H Consultation for the EPA Site Designation of the Rogue River Ocean Disposal Site, Pacific Ocean, Curry County, Oregon (EPA: ETPA -083) (refer to NMFS No.: 2008/05437) (March 19, 2009) and ESA Section 7 Formal Consultation and MSA EFH Consultation for the EPA Site Designation of the North and South Umpqua River Ocean Disposal Sites, Paci fic Ocean, Douglas County, Oregon (EPA: ETPA-083) (refer to NMFS No.: 2008/05438) (March 20, 2009).-3- Description of the Proposed Action

The proposed action is the EPA’s proposal to de signate the Siuslaw ODMDS pursuant to section 102(c) of the MPRSA. Included in this designa tion is the adoption of a Site Management and Monitoring Plan (SMMP). These sites are intended primarily for, but will not be limited to, use by the U.S. Army Corps of Engineers (Corps) for disposal of material removed from the Siuslaw River federal navigation project (Siuslaw River Nav Project). E ach specific proposal to dispose of dredged material at the propos ed Siuslaw sites would require a permit, or in the case of the U.S. Army Corps of Engineers (Corps), a demo nstration that substantive permit requirements have been met, before disposal could occur.

The proposed Siuslaw ODMDS consists of tw o areas, North and South, to be designated approximately 1 mile offshore of the entrance to the Siuslaw River (Figure 1). For both sites, the disposal site, placement area, and drop zone are identical.

The proposed North Site is 4,800 feet (ft) by 2,000 ft, ranges in depth from approximately 30 ft to 120 ft, and has an average depth of 90 ft. North Site coordinates, in longitude and latitude relative to North American Datum (NAD) 83, are as follows:

44 o 01’ 31. 025”N, 124 o 10’ 12. 917”W

44 o 01’ 49. 393”N, 124 o 10’ 02. 848”W

44 o 01’ 31. 965”N, 124 o 09’ 01. 857”W

44 o 01’ 13. 454”N, 124 o 09’ 11. 408”W

The proposed South Site is 3,000 ft by 2,000 ft, ranges in depth from approximately 80 ft to 125 ft, and has an average depth of 78 ft. South Site coordinates, in longitude and latitude relative to NAD 83, are:

44 o 00’ 46. 724”N, 124 o 10’ 26. 551”W

44 o 01’ 06. 405”N, 124 o 10’ 24. 448”W

44 o 01’ 04. 13”N, 124 o 09’ 43. 516”W

44 o 00’ 44. 446”N, 124 o 09’ 45. 626”W-4- Figure 1. EPA’s proposed Siuslaw ODMDS locations.-5- The EPA’s proposal to complete this designation and planning are administrative acts that do not, by themselves, describe, approve, or compel any specific dredge or dr edge disposal action.

Interdependent and Interrelated Actions

The EPA and Corps intend for the proposed designa tion to supersede all other ocean disposal
sites related to the Siuslaw Ri ver Nav Project. Moreover, sec tion 103(b) of the MPRSA requires the Corps to use designated ODMDS sites that ar e designated by the EPA to the maximum extent feasible. Because disposal at th is site depends on the EPA’s propos ed action for its justification, NMFS considers further use of the site by the Co rps to dispose of dre dged material from the Siuslaw River Nav Project to be interrelated with the pr oposed action. Conversely, NMFS does not consider the actual dredging of the Siusla w River Nav Project to be interrelated (or independent) with the proposed action because designation of the site does not justify, or legitimize, dredging, per se, and because dredging has utility that is inde pendent of the proposed
action.

Under section 7(a)(2) of the ESA, the “effects of the action” means

the direct and indirect effects of an action on the species or critical habitat, together with the effects of other activities that are interrelate d or interdependent with that action, that will be a dded to the environmental baseline

50 CFR 402.02

Accordingly, to complete the analysis of effect s in this Opinion, NMFS c onsidered the effects of dredge disposal as part of th e Siuslaw River Nav Project, an action that NMFS found to be interrelated to the proposed action, to be part of the effects of this action. In this case, the effects of the interrelated action, dredgi ng, are the only effects that the act ion will have on the species or
critical habitat.

The Siuslaw River Nav Project was authorized by the Rivers and Harbor Acts of September 19, 1890; June 25, 1910; March 3, 1925; and July 3, 1 958; and a 1960 section 107 project and Public Law 96-367 dated October 1, 1980. The authorized project includes these nine components:

 North jetty, 8,390 ft long

 North spur jetty, 400 ft long

 South jetty, 4,200 ft long

 South spur jetty, 400 ft long

 Entrance channel, ocean to river mile (RM) zero, 300 ft wide, 16 ft deep

 Navigation channel, 5 mi l ong, 200 ft wide, 16 ft deep

 Turning basin at the City of Floren ce, 600 ft long, 400 ft wide, 16 ft long

 Navigation channel from Florence to RM 16. 5, 11. 5 miles long, 150 ft wide, 12 ft deep

 Turning basin at RM 15. 5, 500 ft long, 300 ft wide and 12 ft deep

Dredging for the Siuslaw River Nav Project occurs between the months of June and October. The Corps targets a volume of 100,000 CY (CY) per year, although from 1997 through 2007 was-6- only 53,136 CY. The dredging occurs over a maximu m of 20 days each year, but averages 7.9 days. Based on the maximum capacity of the dredge Yaquina, the Corps can haul an average of 800 CY per load, a volume of 100,000 CY would requi re 125 hauls to remove, or 1 haul every 3. 84 hours averaged over the 20-day period.

Action Area

The action area includes the geographic area contai ned within each rectangular area in Figure 1 as described by the boundary points plus an area outside of each re ctangle measuring 200 ft in all
directions from the boundaries of th e disposal sites to account fo r suspended sediment occurring outside the ODMDS, based on inform ation provided to NMFS by EPA.

Based on information provided by the EPA and developed during consultation, NMFS determined the proposed action is LAA Ore gon coast (OC) coho salmon and, for reasons explained below, NLAA for all ot her species that may occur with in the action area (Table 1).
NMFS also determined that the action is NLAA for critical habitat designated for southern green sturgeon, and NLAA critical habitat proposed for leat herback turtle. Critical habitat has not been designated or proposed for any other species within the action area.-7- 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 listed 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 6/28/05; 70 FR 37160 9/02/05; 70 FR 52630 6/28/05; 70 FR 37160
Upper Willamette River T 6/28/05; 70 FR 37160 9/02/05; 70 FR 52630 6/28/05; 70 FR 37160
Upper Columbia River spring-run E 6/28/05; 70 FR 37160 9/02/05; 70 FR 52630 ESA section 9 applies
Snake River spring/summer run T 6/28/05; 70 FR 37160 10/25/99; 64 FR 57399 6/28/05; 70 FR 37160
Snake River fall-run T 6/28/05; 70 FR 37160 12/28/93; 58 FR 68543 6/28/05; 70 FR 37160
Coho salmon ( O. kisutch ) Lower Columbia River T 6/28/05; 70 FR 37160 Not applicable 6/28/05; 70 FR 37160
Oregon Coast T 2/11/08; 73 FR 7816 2/11/08; 73 FR 7816 2/11/08; 73 FR 7816
Southern Oregon / Northern California

Coasts T 6/28/05; 70 FR 37160 5/5/99; 64 FR 24049 6/28/05; 70 FR 37160

Green sturgeon ( Acipenser medirosris
Southern T 4/07/06; 71 FR 17757 10/09/09; 74 FR 52300 P 5/21/09; 74 FR 23822

Eulachon ( Thaleichthys pacificus )
Eulachon T 3/18/10; 75 FR 13012 Not applicable Not applicable

Marine Mammals
Steller sea lion ( Eumetopias jubatus )

Eastern T 5/5/1997; 63 FR 24345 8/ 27/93; 58 FR 45269 11/26/90; 55 FR 49204

Blue whale ( Balaenoptera musculus )
E 12/02/70; 35 FR 18319 Not a pplicable ESA s ection 9 applies

Fin whale ( Balaenoptera physalus )
E 12/02/70; 35 FR 18319 Not a pplicable ESA s ection 9 applies
Humpback whale ( Megaptera novaeangliae )
E 12/02/70; 35 FR 18319 Not a pplicable ESA s ection 9 applies

Killer whale ( Orcinus orca )
Southern Resident E 11/18/05; 70 FR 69903 11/26/06; 71 FR 69054 ESA section 9 applies

Sei whale ( Balaenoptera borealis )
E 12/02/70; 35 FR 18319 Not a pplicable ESA s ection 9 applies
Sperm whale ( Physeter macrocephalus )
E 12/02/70; 35 FR 18319 Not a pplicable ESA s ection 9 applies

Marine Turtles

Green turtle ( Chelonia mydas )

Excludes Pacific Coast of Mexico and
Florida ET 7/28/78; 43 FR 32800 9/02/98; 63 FR 46693 ESA section 9 applies

Leatherback turtle ( Dermochelys coriacea )

E 6/02/70 ; 39 FR 19320 3/23/79; 44 FR 17710

P 1/5/201075 FR 319 ESA section 9 applies

Loggerhead turtle ( Caretta caretta ) T 7/28/78; 43 FR 32800 Not applicable 7/28/78; 43 FR 32800
Olive ridley turtle ( Lepidochelys olivacea ) ET 7/28/78; 43 FR 32800 Not appl icable ESA section 9 applies-8- “Not Likely to Adversely Affect” Finding

No further consultation is necessa ry if NMFS concur with an acti on agency’s determination that a proposed action is NLAA for a sp ecies or critical habitat. Th is NMFS concurrence must be based on NMFS finding that the effects are all exp ected to be discountabl e, insignificant, or completely beneficial (USFWS and NMFS 1998) . Beneficial effects are contemporaneous positive effects without any adverse effects to the species. Insignificant effects relate to the size of the impact and should never reach the scale wh ere take occurs. Discountable effects are those extremely unlikely to occur. Based on best judgment, a person would not (1) be able to meaningfully measure, detect, or evaluate insignificant effects; or (2) expect discountable effects

to occur.

Salmon

After most salmon enter coasta l waters, their swimming movement s are oriented and directed, usually to the northwest toward the migration co rridor of the Alaska Cu rrent although the speed of this migration is affected by the size of the salmon and the direction and intensity coastal currents (Pearcy 1992). Given this strong natura l swimming ability and determined northward orientation, it is extremely unlikely that young salmon would find themselves in a nearshore 4
area away from their natal stream, where any cu rrent or eddy would de lay them. Coho salmon are an exception to this pattern. They can delay leaving the area near th e mouth of their natal stream, sometimes for months, before migr ating northward (Shapalov and Taft 1954, and literature cited therein). OC coho salmon is the only species in Table 1 that spawns in the Siuslaw River, and thus is the on ly species likely to occur within the nearshore action area. Thus, NMFS finds that effects of the action are expe cted to be insignificant or discountable ( i.e., NLAA) for all ESA-listed salmon in Table 1, ex cept for OC coho salmon. Further, because the effects of operations associated with the Corps’ use of the action area are likely to alter migratory conditions, water quality and foraging condition s for OC coho salmon, NMFS finds that the effects of the proposed action are not all expected to be insignif icant or discountable for OC coho
salmon.

Green Sturgeon

Southern green sturgeon migrate along the Pacific coast at dept hs less than 328 feet and are typically found at depths ranging between 131 feet and 230 feet over the Continental shelf (Erickson and Hightower 2007). At the ODMDS water depths range from minus 30 feet North American Datum 1983 (NAD) 83 to minus 120 feet NAD 83, and water depths at the Siuslaw River south ODMDS range from minus 80 f eet NAD 83 to minus 125 feet NAD 83. Research conducted by Moser and Lindley in 2006 on Southe rn green sturgeon dist ribution and migration patterns reported that Southern green sturgeon are only present in the estuaries of Willipa Bay, Washington, Grays Harbor, Washington, and the Columbia River during the months of June through October. In addition to the aforemen tioned estuaries, Southern green sturgeon infrequently may occur in Coos Bay, Winchest er Bay, and Yaquina Bay, although field surveys carried out by the Oregon Department of Fish and Wildlife over a 4-year period (2000-2004)

4 Nearshore means the zone from coastal high tide line offs hore to the 30-fathom (180 feet or 55 meter) depth contour (ODFW 2006).-9- captured no green sturgeon in the Coos, Coquille, Yaquina, or Siuslaw rivers, and 33 green sturgeon were captured in the Umpqua River (F arr and Kern 2005). Coos Bay and Winchester Bay lie approximately 30 to 50 miles south of the ODMDS, and Yaquina Bay lies approximately
50 miles to the north of the ODMDS. Based on the water depth preference for oceanic migration of Southern green sturgeon, and the field-based evidence on Southern green sturgeon distribution and occurrence, or lack thereof, especially in the Siuslaw River, in the aforementioned estuaries, NMFS is reasonably certain that Southern green sturgeon are unlikely to occur in the ODMDS as the overwhelming majority of Southern green st urgeon are resident in the estuaries of Willipa Bay, Washington, Grays Harbor, Washington, the Columbia River, and the Umpqua River during the June through October dredge and disposal activities carried out by the Corps. Therefore, NMFS finds that effect s of the action are expected to be insignificant or discountable ( i.e., NLAA) for southern green sturgeon.

Eulachon

Eulachon have occurred in Siuslaw River, alt hough apparently none have been observed there since the 1970s (Drake et al . 2010), such that NMFS considers that an occurrence now would be extremely unlikely. Therefore, NMFS finds that a ll effects of the action are expected to be discountable or insignificant ( i.e. , NLAA) for eulachon.

Marine Mammals

Steller sea lions, blue whales, fin whales, humpback whales, and Southern Resident killer whales may occur in the action area but, based on previous analyses (NMFS 2009a, 2009b), their presence, at most, would be in frequent and transitory. The mo st proximate Steller sea lion haulout (Sea Lion Caves) is suffi ciently distant from the propos ed action area (at least eight miles away from the proposed disposal sites) that NMFS does not anticipate any effects to haulout behavior. If marine mammals are present during disposal activities , vessel operations and dredge discharge procedures associated w ith the proposed action may cause temporary
disturbance. Minimal vessel transits will be a ssociated with the proposed action (hopper dredge, estimated 20 days of activity annually). Barge-si zed vessels, such as a hopper dredge, associated with the proposed action would require short tr ansits to the nearshore or ODMDS, where the vessel would remain relatively immobile until work is complete, with minimal sound or potential for disturbance. Any temporary disturbance would be short-term and localized, with no lasting effects, and therefore insignificant. Vessel stri kes are extremely unlikely because the barge-sized vessels are slow moving, follow a predictable course, do not target marine mammals, and should be easily detected and avoided by marine mammal s. Potential effects from vessel strikes are
therefore discountable.-10- The proposed action is not likely to adversely affect the quality of marine mammal prey; however, it may affect the quantity of prey availa ble, by take of juvenile salmon. Any take of juvenile salmon associated with disposal activities would result in an insignificant reduction in adult equivalent prey resources for marine mammals that may intercept OC coho salmon and other prey species within their range ( i.e ., Southern Resident killer wh ales or Steller sea lions). Therefore, NMFS finds that all effects of th e action are expected to be discountable or insignificant ( i.e. , NLAA) for ESA-listed marine mammals in Table 1.

Marine Turtles

Marine turtles are highl y migratory, and the life historie s of all species exhibit complex movements and migrations through geographica lly disparate habitats, so defining their geographic range is difficult. Gr een, leatherback, loggerhead and o live ridley turtles all nest on beaches within the U.S. and all depend on U.S. coastal waters for foraging and migratory habitat during certain stages of their lif e history. However, marine turt les have no breeding areas in Oregon and, except for leatherback turtles, are ex tremely rare in Oregon’s nearshore habitats, although this may change if ocean currents become warmer. Most leatherback sightings occur in marine waters within the coastal zone. Although sightings of marine turtles occur in Oregon, they are nonetheless exceptionally rare, therefore NMFS finds that all effects of the proposed action are expected to be discountab le, insignificant or beneficial ( i.e. , NLAA) for ESA-listed
marine turtles in Table 1.

Leatherback Turtle Proposed Critical Habitat

The PCEs that NMFS identified as essential for the conservation of leatherback turtles when it proposed to revise critical habit to include marine waters off th e U.S. West Coast, including the action area, are: (1) A sufficient quantity and qual ity of their jellyfish prey; and (2) migratory pathway conditions that allow for safe and timel y passage to, from, and within high use foraging areas, including areas within the action area. Dredge disposal activities may result in the loss of polyp life-stage jellyfish and adult medusa jellyfis h, 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 (ODMDS site) when dredge spoils would be released would result in an insignificant reduction in adult-e quivalent prey available to l eatherbacks in their proposed critical 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 occurrence in the action area. Therefore, NMFS finds that all effects of the action are expected to
be discountable or insi gnificant for proposed critical ha bitat of leathe rback turtles.

Southern Green Sturgeon Critical Habitat

The primary constituent elements (PCEs) NMFS id entified as essential for the conservation of the southern green sturgeon in coastal marine ar eas, including the action ar ea, are (1) a migratory pathway necessary for safe and timely passage wi thin marine and between estuarine and marine-11- habitats; (2) water qualit y with adequate dissolved oxygen leve ls and acceptably low levels of contaminants, and (3) abundant prey items for s ubadults and adults, which may include benthic invertebrates and fishes. Because operations associ ated with the Corps’ use of the action area are not likely to significantly alter PC Es for southern green sturgeon critical habitat, NMFS finds that the effects of the propos ed action are expected to be insignificant or discountable.

ENDANGERED SPECIES ACT BIOLOGICAL OPINION

Section 7(a)(2) of the ESA requires Federal agenci es to consult with NMFS to ensure that their actions are not likely to jeopardize the continued existence of endangered or threatened species, or adversely modify or destroy th eir designated critical habitat. The Opinion that follows records the results of the interagency consultation for this proposed action. The ITS provided after the Opinion specifies (1) the impact of any taking of threatened or endangered species that will be incidental to the proposed action; (2) reasona ble and prudent measures that NMFS considers necessary and appropriate to minimize such impact, and (3) nondisc retionary terms and conditions (including, but not limited to, reporting requirements) that must be complied with by the Federal agency, applicant (if any), or both, to carry out the reasonable a nd prudent measures.

To complete the jeopardy analysis presented in this Opinion, NMFS reviewed the status of each listed species 5 considered in this consu ltation, the environmental base line in the action area, the effects of the action, and cumulative effects (50 CFR 402.14(g)). From this analysis, NMFS
determined whether effects of the action were like ly, in view of existing risks, to appreciably
reduce the likelihood of both the survival and re covery of the affect ed listed species.

For the critical habitat adverse modification anal ysis, NMFS considered the status of the entire designated area of the critical ha bitat considered in this consul tation, the environmental baseline in the action area, the likely effects of the ac tion on the function and c onservation role of the affected critical habitat, and cumulative eff ects. NMFS used this assessment to determine whether, with implementation of the proposed acti on, critical habitat would remain functional, or retain the current ability for th e PCEs to become functionally es tablished, to serve the intended conservation role for the species. 6

If the action under consultation is likely to jeopardize the conti nued existence of an ESA-listed species, or destroy or adversely modify critical habitat, NMFS mu st identify any reasonable and prudent alternatives for the action that avoid je opardy or destruction or adverse modification of
critical habitat and meet other re gulatory requirements (50 CFR 402.02).

5 An “evolutionarily significant unit” (ESU) of Pacific salmon (Waples 1991 ) and a “distinct population segment” (DPS) (Policy Regarding the Recognition of District Vert ebrate Population; 61 FR 4721, Feb 7, 1996) are both “species” as defined in section 3 of the ESA.

6 Memorandum from William T. Hogarth to Regional Administrators, Office of Protected Resources, NMFS (November 7, 2005) (Application of the “Destruction or Adverse Modification” Standard Under Section 7(a)(2) of the Endangered Species Act).-12- Status of the Species and Critical Habitat

The summaries that follow describe the status of the ESA-listed species, and their proposed or designated critical habitats, that occur within the geographic area of this proposed action and are considered in this Opinion. More detailed info rmation on the status and trends of these listed resources, and their biology and ecology, can be found in the listing re gulations and critical habitat designations published in the Federal Register (T able 1, above).

It is likely that climate change will play an increasingly important role in determining the abundance of ESA-listed species, and the conservati on value of designated cr itical habitats, in the Pacific Northwest. During the last century, average regional air temperatures increased by 1.5°F, and increased up to 4°F in some areas (USGCRP 2009). Warming is likely to continue during the next century as average temperatur es increase another 3 to 10°F (USGCRP 2009). Overall, about one-third of the current cold-water fish habitat in the Pacific Northwest is likely to exceed key water temperature thresholds by the end of this ce ntury (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 a nd less during summer, and more of the winter precipitatio n is likely to fall as rain rather than snow (ISAB 2007, USGCRP 2009). Where snow occurs, a warmer climate will cause earlier runoff so stream flows in late spring, summer, and fall will be lower and water temp eratures 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, and in creased competition and predation 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).

OC Coho Salmon

This species includes all natu rally-spawned populations of coho salmon in Oregon coastal
streams south of the Columbia River and north of Cape Blanco, and progeny of five artificial propagation programs. The Oregon Coast Techni cal Recovery Team (OC-TRT) identified 56 historical populations, grouped into five major “b iogeographic strata,” ba sed on consideration of-13- historical distribution, geographic isolation, dispersal rate s, genetic data, life history information, population dynamics, and environmental and ecological diversity (Table 2) (Lawson et al. 2007).

Of the 56 historical populations identified by the OC-TRT, 13 populations were identified as functionally independent, eight as potentially independent, and 35 historical populations were identified as dependent popul ations. Functionally independent populations are identified as highpersistence populations whose population dynamics or extinction risk ove r a 100-year time frame is not substantially alte red by exchanges of individuals with other populations. These populations are net “donor” populations that may provide migran ts for other types of populations. Potentially independent populations are id entified as high-persistence populations whose population dynamics may be substantially influenced by peri odic immigration from ot her populations. In the
event of the decline or disa ppearance of migrants from other populations, a potentially independent population could become a func tionally independent population. Dependent populations are considered low-persistence populations that rely upon immigration from other populations. Without these inputs, dependent populations woul d have a lower likelihood of persisting over 100 years. Dependant populations are “receiving” populations that are dependent on sufficient immigration from su rrounding populations to persist.

The OC-TRT concluded that, if r ecent past conditions continue into the future, OC coho salmon are “moderately likely” to persist over a 100-year period without artificia l support, and have a
“low to moderate likelihood” of being able to sustain their gene tic legacy and long-term adaptive potential for the foreseeable futu re (Wainwright et al . 2008). The major f actors limiting recovery
of OC coho salmon include altered stream mo rphology, reduced habitat complexity, loss of overwintering habitat, excessive sediment, hi gh water temperature, and variation in ocean
conditions.-14- Table 2. OC coho salmon populations in Oregon. P opulation type “D” means dependent; “FI” means functionally independent; and “PI” means potentially independent.

Stratum Population Type Stratum Population Type

North

Coast Necanicum PI
MidCoast (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

MidCoast Salmon PI
Lakes Siuslaw FI

Devils D 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
MidSouth

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

NMFS does not expect coho salmon from any populat ion other than the Siuslaw to be affected by the proposed action, so the remaining analysis will focus only on that population.

Siuslaw River Population

. All coho salmon outmigrating or returning to the Siuslaw River move through both the navigation channel a nd the nearshore ocean portions of the action area. Estimates of returning Sius law Basin adult coho spawners show considerable variability in the annual abundance from year to year (Table 5) . Adult OC coho salmon return to the Siuslaw River in the fall/winter, migrating upstream to sp awn, with a peak in October. Out-migration of juveniles to the ocean occurs from February th rough July, with a peak from April to mid-May.
The estimated number of wild a dults returning to the Yaquina Bay basin since 1990 has averaged 9,702, with a range of 668 to 57,129 (Table 3). Du ring the period from 2002 to present, these data on the number of returning adult OC coho salmon were collected using a different protocol then the previous years, and therefore, not enti rely comparable. However, during the overlapping years of 2002 – 2004, the results were not extremely different, and are the best available for the purposes of this evaluation.-15- Table 3 . Estimated wild OC coho salmon spawne r abundance in the Siuslaw River basin (http://oregonstate. edu/de pt/ODFW/spawn/cohoabund. htm)

Estimated Wild Coho Po p ulation

Siuslaw Sub-Basin OC ESU

Year Number of fish Est. % of ESU Number of fish

1990 2,685 16% 16,510

1991 3,740 13% 29,078

1992 3,440 9% 38,604

1993 4,428 10% 44,266

1994 3,205 9% 37,477

1995 6,089 15% 41,303

1996 7,625 13% 59,453

1997 668 5% 14,068

1998 1,089 5% 19,918

1999 2,724 8% 34,696

2000 6,767 13% 54,085

2001 11,024 7% 147,981

2002 57,129 25% 231,411

2003 29,257 14% 206,286

2004 8,443 5% 176,576

2005 16,907 12% 140,053

2006 5,869 6% 103,551

2007 3,552 7% 53,653
Average 9,702 12% 80,498
1998-2007 Avg. 14,276 12% 116,821

The number of OC coho salmon juvenile outmigrant s from the Siuslaw River basin has not been studied enough to provide a reliable estimate by direct sampling. However, it can be estimated by back-calculation dividing the number of returning adults by marine survival. Marine survival predictions averaged 4%, with a range of 0. 5% and 11. 7%, between 1970 and 1999 (PMFC 2000). The average number of outmigrants estimate d by this back calcula tion is 242,550 with a range of 16,700 to 5,737,375.

Southern Green Sturgeon Critical Habitat

The final designation of critical habitat for s outhern green sturgeon includes approximately:

 487 mi of habitat in the S acramento-San Joaquin Delta,

 135 mi 2 of habitat within the Yolo and Sutter bypasses of the Sacramento River,

 320 miles (mi) of riverine habitat,

 897 mi 2 of estuarine habitat,

 11,421 mi 2 of coastal marine habitat.-16- To assist in the designation of critical habitat for southern green sturgeon, NMFS convened a Critical Habitat Review Team, or “CHRT,” comprise d of 9 federal biologists with demonstrated expertise regarding sturgeon habita t and related protective efforts.

The CHRT assessed biological information pe rtaining to areas under consideration for designation as critical habitat to identify the areas occupied by southern green sturgeon,
determine whether those areas contained PCEs e ssential for the conservation of those species, and whether unoccupied areas existed within the hi storical range of the southern green sturgeon may also be essential for conservation. The CHRT then scored each habi tat area based on the quantity and quality of the physical and biological feat ures; rated each hab itat area as having a ‘‘high,’’ ‘‘medium,’’ or ‘‘low’’ conservation valu e; and identified management actions that
could affect habitat for southern green sturgeon.

The ESA gives the Secretary of Commerce discre tion to exclude areas from designation if he
determines that the benefits of exclusion out weigh the benefits of designation. Considering economic factors and information from CHRT, NMFS partially or completely excluded the following types of areas from the southern green sturgeon critical habitat designation:

1. Military areas . Some military areas were excluded b ecause of the current national priority on military readiness, and in recognition of conservation activities covered by military integrated natural res ource management plans.

2. Tribal lands . Some Native American lands were ex cluded because of the unique trust relationship between tribes a nd the federal government, th e federal emphasis on respect for tribal sovereignty and self governance, a nd the importance of tribal participation in
numerous activities aimed at conserving listed species.

In designating critical habitat for southern gr een sturgeon, NMFS organized information at the watershed scale then identified and designated critical habitat as “s pecific areas” within freshwater rivers, the bypasses, the Sacramento-S an Joaquin Delta, coastal bays and estuaries, and coastal marine areas (within 60 fathoms depth).

NMFS reviews the status of designated critical habitat affected by the proposed action by examining the condition and trends of PCEs th roughout the designated area. For southern green sturgeon, these PCEs consist of site types and site attributes associated with life history events (Table 4).-17- Table 4. PCEs of critical habitat designated for southern green sturgeon and corresponding species life history events.

Primary Constituent Elements 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 (within 60 fathoms) 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

Environmental Baseline

The Siuslaw River ODMDS are within the nearshore area of the Pacific Ocean off the mouth of the Siuslaw River. Sediments at these sites are pr imarily medium- to fine-grain marine sands and shell debris. These sandy sediments are common on the Oregon coast with natural variations in percent fines due to variations in currents and riverine inputs. The bent hic community is typical of nearshore, high-energy environment found alo ng the Oregon coast, largely dominated by very mobile organisms. These mobile organisms provi de an important link in the marine food web.

The nearshore ocean environment outside the mo uth of the Siuslaw River supports anadromous salmonids as well as a variety of other pelagi c and demersal fish sp ecies. Summer upwelling provides the nutrients to fuel pr imary and secondary production that in turn determines habitat quality in the form of availabl e yearling coho salmon forage (Bi et al. 2008, Chase et al. 2007). Based on available information regarding gene ral water quality conditions, water depths, and primary and secondary production, the baseline conditions of the acti on area provide, at a minimum, sufficient conditions to support coho sa lmon and southern green sturgeon. The habitat quality of these conditions varies from year to year depending on the la rge scale ocean dynamics that determine nutrient upwelling and water quality conditions.

The Corps has used this general area to dispose of material removed from the Siuslaw River Nav Project since 1929, and part of the proposed site (Area A) on an interim basis since 1977 (Table-18- 5; Figure 2). Because of mounding of dredged mate rial at the interim site A, the Corps began disposing of dredged material from the Siuslaw River Nav Project at sites B and C in 1997. Sites B and C also show mounding. Until lifted in 2008, disposal restrictions were placed on the
southeast corner of Site B whic h overlapped the interim Site A. The bulk of the material dredged has been placed in the larger Site B. In 2004, the Corps extended the use of sites B and C for another 5-year period in 2004. However, secti on 102 of the MPRSA now requires the EPA to designate this site as an ODM DS for dredged material to c ontinue to be disposed here.

Table 5. Siuslaw River Nav Pr oject dredging volumes.

Fiscal

Year Dredging Volumes (x 1,000 CY) Fiscal

Year Dredging Volumes (x 1,000 CY) Fiscal

Year Dredging Volumes (x 1,000 CY)
1929/1977 2,800. 0 1987 215. 8 * 1998 69. 6 (C)
1977 139. 3* 1988 114. 5 * 1999 43. 5 (B)
1978 191. 4* 1989 116. 8 * 2000 55. 1 (C)
1979 246. 6* 1990 99. 0 * 2001 101. 2 (C)
1980 94. 2* 1991 65. 9 * 2002 117. 3 (B)
1981 388. 4* 1992 194. 2 * 2003 55. 0 (B)
1982 193. 4* 1993 239. 6 * 2004 23. 1 (B+C)
1983 213. 3* 1994 223. 3 * 2005 33. 4 (B)
1984 221. 1* 1995 121. 6 * 2006 22. 3 (B)
1985 271. 2* 1996 84. 8 * 2007 76. 0 (B)
1986 218. 8 * 1997 40. 0 (C) 2008 69. 9 (B)

* Dredged material from 1977 to 1996 was placed in the EPA-designated Interim ODMDS (Area A).-19- Figure 2. Historical Siuslaw River Nav Pr oject ocean disposal sites.-20- Species Within the Action Area

OC Coho Salmon

. Juvenile OC coho salmon begin to enter the action area at the ocean in April and out-migration is near ly complete by May 15. Once there, these fish either transit the action area toward their open ocean migration, or they may delay, sometimes for months, rearing
near the mouth of their natal st ream (Shapalov and Taft 1954, and li terature cited therein). Fish that stay nearshore generally continue to schoo l in groups of 10 to 50 or more similar sized individuals as they become acclimat ed to salt water and grow rapidl y. It is unlikely that juvenile
OC coho salmon occur within the action area between late September and early April.

Critical Habitat Within the Action Area

Southern Green Sturgeon Critical Habitat

. Although southern gr een sturgeon are not
confirmed to occur in the Siuslaw River or its es tuary, the action area is within a coastal marine area that was designated as “high conservation value” critical habitat for this species because it is part of the primary migratory/c onnectivity corridor used by for subadult and a dult southern green sturgeon as they migrate to and from summer habita ts in coastal bays and estuaries, and winter
habitats within coastal waters between Vancouver Island, BC, a nd southeast Alaska (Moser and Lindley 2007).

Activities that NMFS identified as threats during the designation process that may require special management consideration to protect the conser vation value of this critical habitat include bottom trawl fishing, dredging and deposition of dredged material , alternative energy hydrokinetic projects, liquid natural gas proj ects, and point and nonpoi nt pollution generating
actions.

Effects of the Proposed Action

All effects of the proposed action identified in this Opinion are the direct effects of the interrelated action of dredge disposal at the ODMDS that will be carried out by the Corps as part of the Siuslaw Nav Project. These effects will occur as the result of vessel traffic to and from the ODMDS, and the release dredge material into the water column within the ODMDS such that it falls through the open water a nd settles on the ocean floor.

Environment Within the Action Area

Vessel Traffic

. Approximately 65 vessel trips per year by a dredge or barge will occur each year, between June and October, to tran sport the Corps’ average annual volume of 53,000 CY of dredged material between the Sius law River Nav Project and the ODMDS, and approximately 125 trips will be re quired to transport the full target volume of 100,000 CY. Each trip will average 3 nautical miles (NM) or less. T hus, the average annual vessel traffic in terms of
NM travelled is likel y to be 195 NM, and the maximum is likely to be 375 NM.

Dredge Material Disposal

. Between 65 and 125 loads of dre dged material, consisting of approximately 800 CY per load, for a total of 53,000 to 100,000 CY will be disposed of at the OMDMS each year.-21- Based on EPA’s review of modeli ng, monitoring data, analysis of sediment quality, and history of use (75 FR 5708; 2/4/2010), no detectable contamin ant concentrations or water quality effects,

e.g ., suspended solids, would be expected to reach any beach or shoreline fr om disposal activities at the sites. The primary impact of disposal activities on water quality is expected to be temporary turbidity caused by the physical moveme nt of sediment through the water column. All dredged material proposed for disposal will be evaluated according to the ocean dumping regulations and guidance devel oped by EPA and the Corps.

Under the proposed action, disposal of suitable ma terial meeting the regulatory criteria and deemed environmentally acceptable for ocean dump ing will be allowed at the proposed sites. Most of the dredged material (appro ximately 97%) to be disposed of at the sites is expected to be sandy material, while a small amount of material ( up to 3% of the material) would be classified as fine-grained. Occasionally, naturally occurring debris may be present in the dredged material. Hopper dredges, which are used for the Corps' annual navigational dredgi ng, are not capable of removing debris from the dredge site. However, specific projects may utilize a clamshell dredge, in which case there is the potential for the occasio nal placement of naturally occurring debris at the disposal sites.

Initially, coarser dredged material will descend at a rate of 11 f t/second (sec), slowing to 7 ft/sec
near the end of the load. As water is added to the dredged material to help wash it out of the hopper, the slurry mixture becomes more neutra lly buoyant and descends at a slower rate.

Although large pelagic organisms will likely be able to avoid the column of dredged material as it makes its 3 to 20 sec descent though the wate r column, smaller organisms, including plankton and small nekton are more likely to be entrained w ith the material, and to suffer injury or death due to impact and abrasion, unless they are pus hed aside by a boundary laye r of water created by
the material’s descent.

Sediment movement in the littoral zone consis ts of two mechanisms depending upon the size of
the sediment. Material that is finer than sand size is carried in suspensi on in the water and moves offshore relatively quickly. Sediments sand size or coarser may be occasionally suspended by wave action near the bottom, a nd are moved by bottom currents or directly as bedload. Tidal, wind and wave forces contribute to generating bottom currents, which act in relation to the sediment grain size and water depth to transport sediment.

Based on EPA’s review of dispersa l, horizontal transport and vert ical mixing characteristics of the area at and in the vicinity of the sites, the marine sands and fluvial gravels from the Siuslaw River distribute away from the river mouth rapidly. The b eaches do not show significant
accretion or loss. The bottom current records suggest a bias in tran sport to the north. Fine grained material tends to remain in suspension and to experience rapid offshore transport compared to other sediment sizes. Sediment transport of sand-si zed or coarser material tends to move directly as bedload, but is occasionally suspended by wave action near th e seafloor. The proposed sites are not expected to change th ese characteristics. Sediment m ounding will be closely monitored under terms of the proposed SMMP and the EP A and Corps will use adaptive management measures to address any mounding issues that may arise.-22- Species Within the Action Area

OC Coho Salmon

. In recent biological opinions on the effects of similar disposal site designations for the Rogue and Umpqua rivers on OC coho salmon, NMFS developed a method
to estimate the number of OC coho salmon that are likely to be adve rsely affected through dredging operations for each year that dred ging at Oregon Coastal (NMFS 2009a, 2009b, and in preparation). That analysis was based on consider ation of ship avoidance behavior, avoidance of disposed material, discharge field size, spatia l overlap, swimming speed, avoidance possibilities due to material descent rate and swimming spee d, disposal quantity and weight, the physical interaction between fish and disposed material , and the number of fish likely to be exposed. Application of that method to the Siuslaw River results in an estimate of 19 juvenile OC coho salmon per year that are likely to be injured or killed due to the effects of the Corps use of the action area to dispose of dredged material from the Siulsaw Nav Project (NMFS in preparation).

Critical Habitat Within the Action Area

Southern Green Sturgeon. Since NMFS does not expect southe rn green sturgeon to occur in the ODMDS during the June through October dre dge and disposal period, we do not expect disposal of dredged materials to have an eff ect on the primary constituent element migration corridor, especially when compared to the overa ll scale of the migrati on corridor. Therefore, NMFS finds that all potential adverse effects to are discountable or in significant and concurs with EPA’s determination of NLAA for designated critical habitat for so uthern green sturgeon.

Cumulative Effects

‘Cumulative effects’ are those effects of future state or private activitie s, 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). Current non-Federal activities in the acti on areas are limited to transit of recreational and commercial fishing vesse ls entering or leaving the Port of Siuslaw. Those activities are likely to c ontinue at the current levels. The NMFS is not aware of any specific future non-Federal activit ies within the action area that would cause gr eater adverse effects to listed species than presently occur in the area.

Synthesis and Integration of Effects

Species

. The direct and indirect e ffects of the EPA’s proposed designation of the Siuslaw OMDMS, including the effects of th e Corps’ interrelated action of disposing of dredge material from the Siuslaw Nav Project, are likely to inju re or kill approximat ely 19 juvenile OC coho salmon per year. Those individual s are part of the Siuslaw Rive r Population that consists of approximately 9,700 adults, or 12% of the numbe r of OC coho salmon overall (Table 2). Assuming a 0.25 smolt-to-adult surviv al ratio, 19 smolts are equiva lent to approximately five adults, or less than 0.5 x 10 -3 % of the average population size. Environmental baseline conditions within the action area appear stable, at least since completion of the Siuslaw Nav Project, are sufficient to meet the needs of the species, and are unlikely to be unchanged by the proposed action. Any environmental changes which do occur (including frequent but brief reduction in nearshore rearing and migration) have not been identified by NMFS as factors limiting the-23- recovery of this species. Similarly, cumulative ef fects do not appear likely to add any significant additional risk to this species.

Critical habitats. The direct and indirect effects of the EPA’s proposed designation of the Siuslaw OMDMS, including the effects of the Corp s’ interrelated action of disposing of dredge material from the Siuslaw Nav Project, are not lik ely to adversely affect critical habitat for southern green sturgeon.

For southern green sturgeon designa ted critical habitat, those a dverse effects include degraded PCEs for marine coastal food resources, migr atory corridor and water quality. Environmental baseline conditions within the action area appear stable, at least since completion of the Siuslaw Nav Project, and are unlikely to be uncha nged by the proposed action. Any environmental changes which do occur (including frequent but brief reduction in nearshore food resources, passage, and water quality) have not been identif ied by NMFS as factors limiting the recovery of this species. However, dredging and deposition of dredge material is among the activities identified by NMFS when it designated this cri tical habitat. These effects are insignificant within the action area, and the area is still functi onal as a feeding area and migratory corridor. Of the total of 11,423 mi 2 of marine coastal hab itat has been designated for southern green sturgeon,
less than 2 mi 2 will be insignificantly affected by the proposed action, or less than 0.2 x 10 -3 % of the total coastal marine area designated. Cumula tive effects do not appear likely to add any significant additional risk to these PCEs.

Conclusion

After reviewing the current status of OC coho salmon, the environmental baseline for the action area, the effects of the proposed designation of the Siuslaw ODMDS, and the cumulative effects, it is NMFS’ biological opinion th at activities associated with the proposed action are likely to adversely affect, but are not likel y to jeopardize, the continued existence of OC coho salmon.

It is also NMFS’ biological op inion that activities associated with this proposed action are not likely to adversely affect critical habitat that ha s been designated for southern green sturgeon in the action area, and therefore are not likely to resu lt in the destruction or adverse modification of
that critical habitat.

Incidental Take Statement

Section 9 of the ESA and Federal regulation pursuant to section 4(d) of the ESA prohibit the take of endangered and threatened species, respectivel y, without a special exem ption. Take is defined as to harass, harm, pursue, hunt, shoot, wound, kill , trap, capture or colle ct, or to attempt to engage in any such conduct. Harm is fu rther defined by NMFS as 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. Under the terms of section 7(b)(4) and section 7(o)(2), taking that is incidental to and not intended as part of the agency action is not prohibited unde r the ESA, provided that such taking is in compliance with the terms and c onditions of an incident al take statement.-24- Amount or Extent of Take

The EPA’s designation and development of an S MMP for the Siuslaw OMDMS, together with the Corps’ interrelated actions that use the site to dispose of dredged material from the Siuslaw River Nav Project, are likely to result in so me level of incidental take of OC coho salmon. However, because the proposed designation and S MMP do not describe, a pprove, or compel any project-specific use by the Corps, all incidental take will occur at the project-specific level, NMFS does not authorize any take in this Op inion. All take author ization will occur in subsequent site-specific consultations.

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. The following recommendati ons are discretionary measures that are consistent with this obliga tion and therefore should be carried out by the EPA.

1. Collaborate with NMFS and the Corps to finalize the interagency methodology to evaluate the effects of dredging a nd disposal on ESA-listed species.

2. Undertake a study to determine the seasonal distribution, abun dance, and habitat use of salmon, sturgeon, and marine turtles that occur nearshore within and near the contour of ODMDS designations.

Please notify NMFS if the EPA carries out this reco mmendation so that we will be kept informed of actions that are intended to improve the cons ervation of listed species or their designated
critical habitats.

Reinitiation of Consultation

Reinitiation of formal consultati on is required and shall be reques ted by the Federal agency or by NMFS where discretionary Federal involvement or c ontrol over the action has been retained or is authorized by law and: (a) If the amount or exte nt of taking specified in the incidental take statement is exceeded; (b) if new information reveal s effects of the action that may affect listed species or designated critical habi tat in a manner or to an extent not previously c onsidered; (c) if the identified action is subsequently modified in a manner that has an effect to the listed species or designated critical habitat thatwas not considered in the biol ogical opinion; or (d) if a new species is listed or critical habitat is designated that may be affected by the identified action (50 CFR 402.16).

To reinitiate consultation, cont act the Oregon State Habitat Offi ce of NMFS, and refer to NMFS Number 2009/04136).-25- MAGNUSON-STEVENS FISHERY CONSER VATION 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. Adverse effects
include the direct or indirect physical, chemical, or biological alterations of the waters or substrate and loss of, or injury to, benthic organisms, prey speci es and their hab itats, and other ecosystem components, if such modifications re duce the quality or quan tity of EFH. Adverse effects on EFH may result from actions occurring within EFH or outside EFH, and may include site-specific or EFH-wide impact s, including individual, cumulative , or synergistic consequences of actions (50 CFR 600.810). Section 305(b) also requires NMFS to recommend measures that may be taken by the action agency to conserve EFH.

The Pacific Fishery Management Council (PFMC) described and identified EFH for groundfish (PFMC 2005), coastal pelagic species (PFM C 1998), and Chinook salmon, coho salmon, and Puget Sound pink salmon (PFMC 1999). The proposed action and action area for this
consultation are described in the Introduction to this document. The action area includes areas designated as EFH for various lif e-history stages of groundfish, coastal pelagic species, and
Pacific salmon.

Based on information provided by the action agency and the analysis of effects presented in the ESA portion of this document, NMFS concludes that proposed action will have the following adverse effects on EFH designa ted for those species:

1. Increased turbidity and sedimentation within the action area over the annual dredge disposal period.

2. Loss of pelagic and macroinvertebrate prey resources and nurser y grounds within the action area due to the passage of dredge ma terials through the wate r column and their settling on the ocean floor.

EFH Conservation Recommendations

The following two conservation recommendations are necessary to avoid, mitigate, or offset the impact of the proposed action on EFH. These cons ervation recommendations are not a subset of
the ESA terms and conditions.

1. Collaborate with NMFS and the Corps to finalize the interagency methodology to evaluate the effects of dredging a nd disposal on ESA-listed species.

2. Undertake a study to determine the seasonal distribution, abun dance, and habitat use of salmon, sturgeon, and marine turtles that occur nearshore within and near the contour of ODMDS designations.

The EPA is required to complete a supplemental EFH consultation with NMFS if it substantially revises its plans for this action in a manner that may adversely affect EFH or if new information-26- becomes available that affects the basis fo r NMFS’ EFH conservati on recommendations (50 CFR 600. 920(k)).

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.

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

This document records the result s of one interagency consultation, completed under two separate legal authorities. The information presented in th is document is useful to three agencies of the Federal government (NMFS, the EPA and the Corp s), and the residents of Lane County, Oregon, and the general public. These consultations help fulfill multiple legal obligations of the named agencies. The information is also useful and of interest to the other identified people and organizations because it describes the manner in which public trust resources are being managed and conserved. The information presented in this document and used in the underlying consultation represents the best available scie ntific and commercial information and has been improved through interaction wi th the consulting agency.

Individual copies were provided to the above-lis ted entities. 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.

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.

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 Regulations, 50 CFR 402.01, et seq. , and the MSA implementing regulations regarding EFH, 50 CFR 600. 920(j).-27- Best Available Information: This consultation and suppor ting 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 NM FS staff with training in ESA and MSA implementation, and reviewed in accordance with Northwest Region ESA quality control and assurance processes.-28- LITERATURE CITED

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