Document ID: EPA-R10-OW-2010-0086-0024
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2010-05-03T04:00Z

SIUSLAW River, Oregon, 

Ocean dredged material disposal site Designation

Biological Assessment

For listed species including coho salmon, Chinook salmon, Green
Sturgeon, pacific eulachon,

mARINE MAMMALS, marine birds, Terrestrial birds, invertebrates and
plants

Essential Fish Habitat Assessment

For groundfish, coastal pelagic, 

and salmonid species

Prepared BY

U.S. Environmental protection agency

REgion 10, seattle, washington

July 2009



Table of Contents

  TOC \o "1-2"  Biological Assessment	  PAGEREF _Toc235865756 \h  1 

Introduction	  PAGEREF _Toc235865757 \h  1 

Proposed Action	  PAGEREF _Toc235865758 \h  4 

History of Ocean Disposal Sites	  PAGEREF _Toc235865759 \h  4 

Environmental Baseline	  PAGEREF _Toc235865760 \h  7 

Physical Characteristics	  PAGEREF _Toc235865761 \h  7 

Overview of Aquatic Resources	  PAGEREF _Toc235865762 \h  11 

ESA-Listed Species Status and Occurrence in the Vicinity of the Proposed
Siuslaw Ocean Disposal Sites	  PAGEREF _Toc235865763 \h  22 

Assessment of Effects	  PAGEREF _Toc235865764 \h  27 

Coho Salmon	  PAGEREF _Toc235865765 \h  28 

Chinook Salmon	  PAGEREF _Toc235865766 \h  29 

Green Sturgeon	  PAGEREF _Toc235865767 \h  29 

Pacific Eulachon	  PAGEREF _Toc235865768 \h  30 

Marine Mammals	  PAGEREF _Toc235865769 \h  30 

Coastal Birds	  PAGEREF _Toc235865770 \h  30 

Cumulative Effects	  PAGEREF _Toc235865771 \h  31 

Determination for ESA-Listed Species and Designated Critical Habitat	 
PAGEREF _Toc235865772 \h  31 

Essential Fish Habitat Assessment	  PAGEREF _Toc235865773 \h  33 

Potential Effects of the Proposed Action on EFH	  PAGEREF _Toc235865774
\h  35 

Determination for Essential Fish Habitat	  PAGEREF _Toc235865775 \h  38 

Literature Cited	  PAGEREF _Toc235865776 \h  39 

 

LIST OF TABLES

  TOC \h \z \c "Table"    HYPERLINK \l "_Toc232920992"  Table 1. 
ESA-listed Fish, Marine Mammals, Marine Turtles, Marine Birds, and
Terrestrial Bird, Invertebrate and Plant Species that may occur in the
Action Area	  PAGEREF _Toc232920992 \h  3  

  HYPERLINK \l "_Toc232920993"  Table 2.  Siuslaw River Project Dredging
Volumes	  PAGEREF _Toc232920993 \h  6  

  HYPERLINK \l "_Toc232920994"  Table 3.  Dominant Benthic Invertebrate
Fauna by Station, August 2008	  PAGEREF _Toc232920994 \h  11  

  HYPERLINK \l "_Toc232920995"  Table 4.  Dominant Benthic Invertebrate
Fauna by Station, September 2008	  PAGEREF _Toc232920995 \h  13  

  HYPERLINK \l "_Toc232920996"  Table 5.  August 2008 Trawl Data,
Siuslaw ODMDS	  PAGEREF _Toc232920996 \h  18  

  HYPERLINK \l "_Toc232920997"  Table 6.  September 2008 Trawl Data,
Siuslaw ODMDS	  PAGEREF _Toc232920997 \h  20  

  HYPERLINK \l "_Toc232920998"  Table 7.  Species with Designated EFH
Offshore from the Siuslaw River as Provided by NMFS	  PAGEREF
_Toc232920998 \h  34  

 

LIST OF FIGURES

  TOC \h \z \c "Figure"    HYPERLINK \l "_Toc232920999"  Figure 1. 
Proposed Siuslaw River North and South Ocean Disposal Sites	  PAGEREF
_Toc232920999 \h  2  

  HYPERLINK \l "_Toc232921000"  Figure 2.  Historical Siuslaw River
Ocean Disposal Sites	  PAGEREF _Toc232921000 \h  5  

  HYPERLINK \l "_Toc232921001"  Figure 3.  Siuslaw River ODMDS Sampling
Locations, 2008	  PAGEREF _Toc232921001 \h  10  

  HYPERLINK \l "_Toc232921002"  Figure 4.  2008 Densities of Benthic
Invertebrates, Siuslaw ODMDS	  PAGEREF _Toc232921002 \h  14  

  HYPERLINK \l "_Toc232921003"  Figure 5.  2008 Diversity of Benthic
Invertebrates (H’), Siuslaw ODMDS	  PAGEREF _Toc232921003 \h  15  

  HYPERLINK \l "_Toc232921004"  Figure 6.  2008 Diversity of Benthic
Invertebrates (SDV), Siuslaw ODMDS	  PAGEREF _Toc232921004 \h  15  

  HYPERLINK \l "_Toc232921005"  Figure 7.  2008 Species Richness of
Benthic Invertebrates, Siuslaw ODMDS	  PAGEREF _Toc232921005 \h  16  

 Biological Assessment

Introduction

The U.S. Environmental Protection Agency (EPA) is proposing final
designation under the Marine Protection, Research and Sanctuaries Act of
1972, as amended, 33 U.S.C. §§ 1401 to 1445, (MPRSA), for the two
proposed ocean dredged material disposal sites (ODMDS).  These sites are
located approximately 1 mile offshore of the entrance to the Siuslaw
River on the central Oregon Coast (Figure 1).  The proposed North site
is 4,800 feet by 2,000 feet with an average depth of 90 feet, and the
South site is 3,000 feet by 2,000 feet with an average depth of 78 feet.

The primary anticipated user of the proposed Siuslaw North and South
ocean disposal sites is the U.S. Army Corps of Engineers (USACE), who
anticipates using the site for disposal of dredged material from the
federally authorized Siuslaw River navigation project.  Persons or
entities who want to use the proposed sites for disposal of suitable
dredged material must seek a permit, or in the case of the USACE, meet
the substantive requirements for a permit, including EPA concurrence,
before the proposed ocean disposal sites may be used.  The EPA’s
proposed site designation does not authorize any disposal activity.

In March 2009, the list of federally listed species that may occur in
the Siuslaw River coastal area (Lane County, Oregon) was obtained from
the National Marine Fisheries Service (NMFS) by mail and from the U.S.
Fish and Wildlife Service (USFWS) website.  This Biological Assessment
(BA) is being prepared pursuant to Section 7(c) of the Endangered
Species Act of 1973 (ESA), as amended, 16 U.S.C. §§ 1531 to 1544 to
evaluate the effects of designation of the proposed ocean disposal sites
on the federally listed fish, marine mammals, marine turtles, coastal
birds, and terrestrial bird, invertebrate and plant species that may
occur in the Siuslaw River action area (Table 1).

Under the ESA, “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).  Indirect effects are those
effects that are caused by or will result from the proposed action and
are later in time, but are still reasonably certain to occur (50 CFR
§402.02).  For this BA, the action area for the Siuslaw coastal area
includes the two ocean disposal sites, the water column within the
disposal sites, and an area 200 feet in every direction from the
boundaries of the disposal sites (see Figure 1).  Disposal of material
at the two proposed ocean disposal sites is an indirect effect of site
designation and the most likely environmental impacts of disposal
(turbidity, physical disturbance, and benthic effects) would generally
be limited to this action area.

Effects to essential fish habitat (EFH) are being assessed in that
attached Essential Fish Habitat Assessment, pursuant to the
Magnuson-Stevens Fishery Conservation and Management Act (Public Law
94-265), as amended by the Magnuson-Stevens Fishery Conservation and
Management Reauthorization Act (MSA) of 2006 (P.L. 109-479).  The
species that have designated EFH in the vicinity of the proposed Siuslaw
North and South ocean disposal sites include five coastal pelagic
species, numerous groundfish species, and coho and Chinook salmon.  The
same general concept as described for the ESA “action area” is used
for the EFH Assessment.

Table   SEQ Table \* ARABIC  1 .  ESA-listed Fish, Marine Mammals,
Marine Birds, and Terrestrial Bird, Invertebrate and Plant Species that
may occur in the Action Area

Species	Status	Federal Register (FR)

Listing	Critical Habitat

OC Coho Salmon

Oncorhynchus kisutch	Threatened	73 FR 7816; 2/11/2008	73 FR 7816;
2/11/2008

SONCC Coho Salmon

Oncorhynchus kisutch	Threatened	70 FR 37160; 6/28/2005	64 FR 24049;
5/5/1999

Lower Columbia River Coho Salmon

Oncorhynchus kisutch	Threatened	70 FR 37160; 6/28/2005	Not applicable

Lower Columbia River Chinook

Oncorhynchus tshawytscha	Threatened	70 FR 37160; 6/28/2005	70 FR 52630;
9/2/2005

Upper Willamette River spring run Chinook  Oncorhynchus tshawytscha
Threatened	70 FR 37160; 6/28/2005	70 FR 52630; 9/2/2005

Upper Columbia River spring-run Chinook  Oncorhynchus tshawytscha
Endangered	70 FR 37160; 6/28/2005	70 FR 52630; 9/2/2005

Snake River spring/summer run Chinook Oncorhynchus tshawytscha
Threatened	70 FR 37160; 6/28/2005	64 FR 57399; 10/25/1999

Snake River fall-run Chinook

Oncorhynchus tshawytscha	Threatened	70 FR 37160; 6/28/2005	58 FR 68543;
12/28/1993

Southern DPS Green Sturgeon

Acipenser medirostris	Threatened	71 FR 17757; 4/07/2006	Proposed 73 FR
52084; 9/8/2008

Southern DPS Pacific Eulachon

Thaleichthys pacificus	Proposed threatened	74 FR 10857; 3/13/2009	None
designated or proposed

Eastern DPS Steller Sea Lion

Eumetopias jubatus	Threatened	62 FR 24345; 5/05/1997	58 FR 45269;
8/27/1993

Blue Whale

Balaenoptera musculus	Endangered	35 FR 18319; 12/02/1970	None designated

Fin Whale

Balaenoptera physalus	Endangered	35 FR 18319; 12/02/1970	None designated

Humpback Whale

Megaptera novaeangliae	Endangered	35 FR 18319; 12/02/1970	None
designated

Southern Resident Killer Whale

Orcinus orca	Endangered	70 FR 69903; 11/18/2005	71 FR 69054; 11/29/2006

Marbled murrelet

Brachyramphus marmoratus	Threatened	57 FR 45328; 10/01/1992	61 FR 26255;
05/24/1996

Brown Pelican

Pelecanus occidentalis	Endangered	35 FR 8491; 06/02/1970	None designated

Short-tailed albatross

Phoebastria (=Diomedea) albatrus	Endangered	35 FR 8491; 06/02/1970	None
designated

Western snowy plover

Charadrius alexandrinus nivosus	Threatened	58 FR 12864; 03/05/1993	70 FR
56969; 09/29/2005

Northern spotted owl

Strix occidentalis caurina	Threatened	55 FR 26114; 06/26/1990	57 FR
1796; 01/15/1992

Oregon silverspot butterfly

Speyeria zerene hippolyta	Threatened	45 FR 44935; 07/02/1980	45 FR
44935; 07/02/1980

Fender’s blue butterfly

Icaricia icarioides fenderi	Endangered	65 FR 3875; 01/25/2000	71 FR
63861; 10/31/2006

Kincaid’s lupine

Lupinus sulphureus ssp. kincaidii	Threatened	65 FR 3875; 01/25/2000	71
FR 63861; 10/31/2006

Willamette daisy

Erigeron decumbens var. decumbens	Endangered	65 FR 3875; 01/25/2000	71
FR 63861; 10/31/2006

Bradshaw’s desert parsley

Lomatium bradshawii	Endangered	53 FR 38448; 09/30/1988	None designated

Proposed Action

The proposed action consists of designation of the proposed North and
South ODMDS located approximately 1 mile offshore of the entrance to the
Siuslaw River on the central Oregon Coast (see Figure 1).  For both
sites, the disposal site, placement area, and drop zone are identical. 
The proposed North ODMDS is 4,800 feet by 2,000 feet with an average
depth of 90 feet (depth ranges from approximately 30 ft to 120 ft), and
has the following coordinates (NAD 83):

44o 01’ 31.025”N, 124o 10’ 12.917”W

44o 01’ 49.393”N, 124o 10’ 02.848”W

44o 01’ 31.965”N, 124o 09’ 01.857”W

44o 01’ 13.454”N, 124o 09’ 11.408”W

The proposed South ODMDS is 3,000 feet by 2,000 feet with an average
depth of 78 feet (depth ranges from approximately 80 ft to 125 ft), and
has the following coordinates (NAD 83):

44o 00’ 46.724”N, 124o 10’ 26.551”W

44o 01’ 06.405”N, 124o 10’ 24.448”W

44o 01’ 04.123”N, 124o 09’ 43.516”W

44o 00’ 44.446”N, 124o 09’ 45.626”W

Use of the proposed Siuslaw North and South ocean disposal sites would
be for disposal of material dredged from maintenance of the federal
navigation project at the Siuslaw River, and through separate Section
103 permit evaluations pursuant to the MPRSA for the disposal of
suitable dredged material from other dredging projects.  Each specific
proposal to dispose of dredged material at the proposed Siuslaw sites
would require a permit, or in the case of the USACE, a demonstration
that substantive permit requirements have been met, before disposal
could occur.

History of Ocean Disposal Sites

An Interim ocean disposal site, or areas in the same vicinity, have been
used by the USACE Portland District since 1929, when hopper dredges
began to work the bar and entrance channels.  The Interim ODMDS (Area A
on Figure 2) was designated an EPA Interim Site in 1977 (40 CFR 228.12).
 It was suspected that ocean currents were transporting dredged material
placed in the Interim Site back into the Siuslaw entrance channel.  In
1986-1987, the USACE completed dye and seabed drifter studies (USACE
1988).  Results demonstrated dredged material deposited south and/or
east of the centroid of the interim site, with prevailing north to
northwest winds, could possibly drift back across or into the Siuslaw
entrance channel.  The Interim site also experienced mounding to 14 feet
relative to the 1981 bathymetry due to its small size and the volume
dredged.  Therefore, two adjusted ocean disposal sites, ODMDS B and C,
were selected by the USACE under Section 103 of the MPRSA (Area B and C
on Figure 2).  Since 1997, material removed from the Siuslaw federal
navigation project has been deposited into ODMDS B and C (see Figure 2
and Table 2).  

Site B and C have also experienced mounding.  Disposal restrictions,
until lifted in 2008, were placed on the southeast corner of Site B
which overlapped the Interim Site A.  In addition the bulk of the
material dredged has been placed in the larger Site B.  Pending final
designation by EPA, the USACE extended the selection of ODMDS B and C
for a final 5-year period in 2004 (expires in 2009).  Following
expiration, the EPA must designate ocean disposal sites under Section
102 of the MPRSA in order for dredged material to be disposed of at this
location.  Table 2 presents the volume of material placed offshore of
the Siuslaw River.  

Figure   SEQ Figure \* ARABIC  2 .  Historical Siuslaw River Ocean
Disposal Sites

   Area A = EPA-designated Interim ODMDS used for dredged material
disposal from 1977 to 1996.

   Areas B & C = USACE-selected Section 103(b) ODMDS used for dredged
material disposal since 1996.

   Proposed North ODMDS = upper rectangle encompassing Areas A + B.

   Proposed South ODMDS = lower rectangle encompassing Area C.

Table   SEQ Table \* ARABIC  2 .  Siuslaw River Project Dredging Volumes

Fiscal Year	Dredging

Volumes (x 1,000 cy)

1929-1977	2,800.0

1977	139.3*

1978	191.4*

1979	246.6*

1980	94.2*

1981	388.4*

1982	193.4*

1983	213.3*

1984	221.1*

1985	271.2*

1986	218.8 *

1987	215.8 *

1988	114.5 *

1989	116.8 *

1990	99.0 *

1991	65.9 *

1992	194.2 *

1993	239.6 *

1994	223.3 *

1995	121.6 *

1996	84.8 *

1997	40.0 (C)

1998	69.6 (C)

1999	43.5 (B)

2000	55.1 (C)

2001	101.2 (C)

2002	117.3 (B)

2003	55.0 (B)

2004	14.1 (B) & 9.0 (C)

2005	33.4 (B)

2006	22.3 (B)

2007	76.0 (B)

2008	69.9 (B)

* Dredged material from 1977 to 1996 was placed in the EPA-designated
Interim ODMDS (Area A).

Future dredged material disposal volumes are not expected to exceed
100,000 cy/annually (based on a 10 year average of about 53,000 cy and
range of 22,300-99,975 cy) and material is expected to be disposed over
a period of 20 days of dredging and disposal (average is about 7 days;
range 3-23).  Generally, dredging and disposal are expected to occur
between June 1 and October 31 of each year.  

EPA’s primary goals in locating the proposed ODMD sites were to
maximize the capacity of the sites since a Section 102 site designation
is indefinite, minimize the potential for mounding and associated safety
concerns, and maximize the volume of material that remains in the
littoral system.  Since there has been a history of mounding at all of
the previously utilized sites, it was clear that the sites should be
expanded to increase capacity and minimize mounding.  At other ODMD
sites along the Oregon Coast, EPA and the Corps have found that the
strategy of placing a site to the north and another to the south of the
river mouth has worked well (Coos Bay, Umpqua, etc.), primarily because
it allows for adaptive management of the sites given a dynamic current
environment.  Therefore, EPA is proposing both a north and south site
for the Siuslaw River ODMD sites.  Generally, material placed deeper
than 60 feet remains where it is placed and is therefore, removed from
the active littoral system.  To keep more material in the active
littoral system and to potentially feed the beach, EPA proposes a North
Site configuration that expands the existing 103 Site B to include the
original 1977 Interim Site (Site A), and a similar area to the north of
Site A (see Figure 3).  EPA acknowledges that previous studies showed
the potential for material disposed at Site A to re-enter the channel. 
However, considering that there are now two larger sites proposed,
allowing for adaptive management, EPA and the Corps do not expect
measurable volumes of dredged material to migrate back into the channel
from the proposed North Site.  To further address potential mounding,
the proposed South Site’s southern boundary was moved to the south,
doubling the size of the Site.

EPA proposes to utilize the shallower portions of the North Site to the
maximum extent possible in order to keep material in the active littoral
zone, limit wave effects due to mounding, and keep material from
reentering the navigation channel.  Annual bathymetric surveys have
shown the potential for mounding at the two previously utilized Section
103 Sites B and C.  Continued management and monitoring of the new
Section 102 North and South sites will take place in accordance with a
Site Management and Monitoring Plan (SMMP), which is currently being
drafted and will be available for public comment before EPA finalizes
its proposed action to designate the proposed Siuslaw North and South
ocean disposal sites.

Environmental Baseline

Physical Characteristics

The Siuslaw River estuary covers about 1,780 acres and opens into the
Pacific Ocean about 160 miles south of the mouth of the Columbia River. 
It lies within the Heceta Head littoral cell, which extends for about 56
miles from Heceta Head south to Cape Arago.  The estuary is fed mainly
by Siuslaw River, which is 108 miles from its mouth to headwaters and
has a drainage basin of 773 square miles.  The watershed encompasses
part of the Coast Range, with the Siuslaw River extending inland to
Cottage Grove.  The coastal zone of the littoral cell consists of a wide
plain that is 1- to 2-miles wide, covered by active and stabilized sand
dunes backed by the mature upland topography of the Coast Range.  The
lower portion of the Siuslaw River is bordered by broad alluvial flats. 
Between the Siuslaw River and Yaquina River estuaries, the continental
shelf is at its widest along the Oregon Coast, extending over 44 miles
offshore forming the Heceta Bank.  Just south of the Siuslaw River, the
shelf begins to narrow and is only about 19 miles wide at the mouth of
the Umpqua River.  At the mouth of the Siuslaw River, the first 2 miles
or so of the shelf is covered with sand.  From there a thin layer of mud
(about 1-inch thick) mantles the surface.

The Heceta Head littoral cell is the largest on the Oregon Coast. 
Landward of the cell, the coast is primarily beach-fronting sand dunes. 
Headlands are located at the north and south landward ends of the cell. 
Three major river systems enter the cell.  From north to south, these
are the Siuslaw River, the Umpqua River (largest of the three), and the
Coos River.

Ocean water circulation near the proposed Siuslaw sites is directly
influenced by large-scale regional currents and weather patterns in the
northwestern Pacific Ocean.  During the winter, strong low-pressure
systems with winds and waves predominantly from the southwest contribute
to strong northward currents.  During the summer, high-pressure systems
dominate and waves and winds are commonly from the north.  In both
seasons there are short-term fluctuations related to local wind, tidal
and bathymetric effects.  Along the Oregon Coast, there is a southerly
wind in summer that creates a mass transport of water offshore resulting
in upwelling of bottom water nearshore.

Siuslaw River Sediments

In 1991, the Portland District collected 10 sediment samples from the
Siuslaw River federal navigation channel for physical analysis; one
sample from the turning basin at river mile (RM) 5.0 near Florence was
subjected to chemical analyses (USACE 1991).  Sediments were found to be
99.9% poorly graded sand with low volatile solids content (1.1%).  The
median grain size of 0.32 millimeters (mm) was that of medium sand.  The
results of the chemical analysis from the turning basin had metals
concentrations below established levels of concern.  No pesticides,
polychlorinated biphenyls (PCBs), polynuclear aromatic hydrocarbons
(PAHs), or phenols were detected.

In 1996, 10 surface grab samples were collected from the entrance to RM
8 (USACE 1996).  These samples were subjected to physical tests, with
grain-size ranging from 100% to 92.7% (mean 98.6%) poorly graded sand
with volatile solids content ranging from 1.4% to 0.3% (mean 0.8%).  The
mean grain-size was that of medium sand (0.294 mm).

In 2001, eight surface grab samples were collected from the entrance to
RM 6 (USACE 2001).  All samples were submitted for physical analyses,
with grain-size ranging from 100% to 97.9% (mean 99.2%) poorly graded
sand with volatile solids content ranging from 0.42% to 3.0% (mean
1.29%).  The mean grain-size was that of medium sand (0.29 mm).  Two
samples were selected for chemical analyses to include metals, total
organic carbon (TOC), PCBs, chlorinated hydrocarbons, phenols,
phthalates, miscellaneous extractables, and PAHs; one sample was
submitted for organotin (TBT - pore water method) analysis.  The samples
submitted for chemical analysis were taken from the federal channel near
the outfall to the sewage treatment plant and near the boat dock.  The
one sample analyzed for TBT was collected near the boat dock.  Sediment
represented by samples collected during this sampling event would meet
the guidelines established in the Sediment Evaluation Framework (SEF
2009) for unconfined in-water placement without further
characterization.

In August 2006 (Sherman 2007), seven samples were collected from the
Siuslaw entrance to RM 5.  All samples were submitted for physical
analyses, with grain-size ranging from 98.5% to 95.4% poorly graded sand
(mean 97.1%), with volatile solids content ranging from 0.69% to 2.24%
(mean 1.14%).  One sample was selected for chemical analyses to include
metals, TOC, PCBs, chlorinated hydrocarbons, phenols, phthalates,
miscellaneous extractables, and PAHs.  Two samples were submitted for
TBT analysis, one from the turning basin adjacent to the marina and the
second from the federal channel by the fuel dock.  Pore-water TBT was
not analyzed due to insufficient pore-water volume in the samples, a
result of the high sand content.  The chemical analyses showed only low
levels of contamination in any of the samples, with all levels well
below their respective SEF screening levels.  No pesticides, PCBs, PAHs,
chlorinated hydrocarbons, or miscellaneous extractables were detected in
any of the samples.  Several metals, phthalates, phenol, and dibutyltin
were detected, but at low levels and well below their respective
screening levels.  Detection levels were sufficiently low enough to
evaluate material proposed for dredging.  The analytical results of this
characterization are consistent with historical data.  Sediment
represented by the samples collected during this sampling event met the
guidelines established in the SEF for unconfined in-water placement
without further characterization.

ODMDS Sediments

In August 2008, 10 surface-grab sediment samples were collected at ODMDS
B and C (proposed North and South sites) with a 0.96 m2 modified
Gray-O’Hara box core sampler (Figure 3).  Three samples (01, 02 and
03) were collected from east to west on the centerline of Site B.  Three
samples (07, 08 and 09) were collected from east to west on the
centerline of Site C.  Four reference samples were collected north,
south, and between Sites B and C (04, 05, 06, and 10).  All samples were
subjected to physical and chemical analysis.

Physical Analysis and TOC.  The mean value for a grain-size of sand or
greater was 97.25% with a mean value of 3.71% fine-grained material
(less than 230 sieve); mean value for TOC was 0.107%.

Metals.  Sediments were analyzed for 10 metals.  Of these, all but
antimony (Sb), silver (Ag), and mercury (Hg) were present in all of the
samples.  Antimony was not present in any sample at 0.02 ppm.  No
detected metal values approached their respective SEF screening levels.

Pesticides/PCBs.  Chlordane was reported as technical chlordane in one
sample (01), and alpha and gamma Chlordane in three samples (01, 02,
06).  All values were below method reporting levels and well below SEF
screening levels.  No other pesticide was detected.  No PCBs were
detected.

Chlorinated Hydrocarbons, Phthalates, Phenols, and Miscellaneous
Extractables.  No chlorinated hydrocarbons were detected.  Several
phthalates, miscellaneous extractables, and phenols were detected at
very low levels; all were well below their respective SEF screening
levels.

PAHs.  Various “low molecular weight” and “high molecular
weight” PAHs were detected, but at very low levels and well below
their respective SEF screening levels.

Water Quality

Water quality throughout the action area is expected to be typical for
seawater of the Pacific Northwest.  There is no reason to expect
significant chemical contamination in either the water or sediments as
few industries are located along the estuary.  A large data set
regarding the impact of dredged material disposal on the water column
was accumulated in the early 1980s, and focus has shifted away from the
water column pathway to one having more direct contact with bulk or
suspended sediment.  Currently, water column tests are rarely performed
unless there is a “reason to believe” a water column release may
occur.



Figure   SEQ Figure \* ARABIC  3 .  Siuslaw River ODMDS Sampling
Locations, 2008

Overview of Aquatic Resources

Benthic Invertebrates

Field sampling in October 1984 and January 1985 gathered information on
benthic invertebrates at 14 stations off the mouth of the Siuslaw River
(USACE 1992).  Another benthic study was conducted at 11 offshore
stations in September 1988 (USACE 1992).  During these studies, the
Siuslaw offshore area exhibited diverse benthic invertebrate
communities.  A total of 135 taxa were collected in October 1984, 106
taxa in January 1985, and 163 taxa in 1988.  Densities were very similar
in 1984 and 1985, with approximately 2,200 individuals/m2 collected.  An
average of 4,445 individuals/m2 was collected in the 1988 survey. 
Polychaetes (annelid worms) were the numerically dominate species
collected during the 1984-1985 sampling periods.  Scoloplos armiger,
Chaetozone setosa, and Megelona sacculata were the dominant polychaete
species, reaching densities of approximately 2,500/m2, 1,500/m2, and
1,400/m2, respectively.  Other dominant species collected included the
amphipods Eohaustorius sencillus, Mandibulophoxus gelesi, and E.
sawyeri.  The area also had a large number of sand dollars, Dendraster
excentricus.  In 1988, the dominant polychaete species was Owenia
fusiformis, although the density of this polychaete was low to moderate
when compared to other coastal areas.  Another dominant polychaete
collected was Spiophanes bombyx.

Field surveys were conducted in 2008 by Marine Taxonomic Services (USACE
2009) to supplement earlier benthic invertebrate data and provide
current information on fish and epibenthic species present in the area
of ODMDS B and C (proposed North and South sites).  The benthic infaunal
study used a modified Gray-O’Hara box core to take five biological
cores at each of the ten sampling stations (Figure 3).  The demersal
fish and epibenthic study used a 12-foot semi-balloon otter trawl with a
0.25-inch mesh liner to take 20-minute (bottom time) trawls at each of
the six trawl sites.  Both studies were undertaken in August and
September 2008.

The benthic invertebrate fauna collected in 2008 were typical of the
nearshore, high-energy environment found along the Oregon Coast.  Tables
3 and 4 provide the dominant species at collected at each station in
August and September 2008, respectively.  Figure 4 shows the densities
of the animals per square meter at each station, and Figures 5, 6, and 7
show the diversity and species richness of benthic invertebrates at each
station.

Table   SEQ Table \* ARABIC  3 .  Dominant Benthic Invertebrate Fauna by
Station, August 2008

Station and Species,

August 2008	Number of Animals	Animals per

square meter

Station 1

Nemertinea	213	443.04

Diastylopsis dawsoni	578	1202.24

Siliqua sp juv.	243	505.44

Spiophanes bombyx	216	449.28

Scoloplos armiger	70	145.60

Station 2

Nemertinea	408	848.64

Diastylopsis dawsoni	162	336.96

Siliqua sp juv.	780	1622.40

Scoloplos armiger	38	79.04

Guernea reduncans	70	145.60

Station 3

Nemertinea	80	168.48

Siliqua sp juv.	97	201.76

Scoloplos armiger	78	162.24

Magelona sacculata	64	133.12

Mandibulophoxus gilesi	62	128.96

Station 4

Scoloplos armiger	77	160.16

Spiophanes bombyx	114	237.12

Siliqua sp juv.	1008	2096.64

Diastylopsis dawsoni	172	357.76

Nemertinea	514	1069.12

Station 5

Magelona sacculata	78	162.24

Scoloplos armiger	78	162.24

Siliqua sp juv.	1856	3860.48

Nemertinea	379	788.32

Dendraster excentricus juv.	59	122.72

Station 6

Nemertinea	157	326.56

Diastylopsis dawsoni	1364	2837.12

Siliqua sp juv	365	759.20

Spiophanes bombyx	110	228.80

Scoloplos armiger	75	156.00

Station 7

Nemertinea	376	782.08

Diastylopsis dawsoni	106	220.48

Siliqua sp juv	617	1283.36

Spiophanes bombyx	153	318.24

Scoloplos armiger	39	81.12

Station 8

Nemertinea	347	721.76

Diastylopsis dawsoni	678	1410.24

Siliqua sp juv	433	900.64

Spiophanes bombyx	50	104.00

Dendraster excentricus juv	56	116.48

Station 9

Nemertinea	255	530.40

Diastylopsis dawsoni	234	486.72

Siliqua sp juv	743	1545.44

Macoma sp juv	40	83.20

Spiophanes bombyx	39	81.12

Station 10

Nemertinea	284	590.72

Diastylopsis dawsoni	156	324.48

Siliqua sp juv	226	470.08

Spiophanes bombyx	115	239.20

Scoloplos armiger	80	166.40

Table   SEQ Table \* ARABIC  4 .  Dominant Benthic Invertebrate Fauna by
Station, September 2008

Station and Species,

September 2008	Number of Animals	Animals per

square meter

Station 1

Nemertinea	214	445.12

Guernea reduncans	132	274.56

Heteropodarke heteromorpha	65	135.20

Spiophanes bombyx	89	185.12

Diastylopsis dawsoni	78	162.24

Station 2

Nemertinea	761	1582.88

Guernea reduncans	304	632.32

Neomysis kadiakensis	129	268.32

Mytilis sp juv.	79	164.32

Dendraster excentricus	43	89.44

Station 3

Alienacanthomysis macropsis	148	307.84

Nemertinea	82	170.56

Scoloplos armiger	137	284.96

Mandibulophoxus gilesi	70	145.60

Chaetozone nr. setosa	34	70.72

Station 4

Nemertinea	541	1125.28

Siliqua sp juv.	340	707.20

Macoma sp juv.	290	603.20

Diastylopsis dawsoni	78	162.24

Tellina sp juv.	88	183.04

Station 5

Nemertinea	445	925.60

Cirripedia	191	397.28

Siliqua sp juv.	269	559.52

Macoma sp juv.	92	191.36

Tellina sp juv.	72	149.76

Station 6

Diastylopsis dawsoni	183	380.64

Tellina sp juv.	232	482.56

Siliqua sp juv.	336	698.88

Macoma sp juv.	462	960.96

Glycinde armigera	215	447.20

Station 7

Nemertinea	264	549.12

Siliqua sp juv.	113	235.04

Macoma sp juv.	136	282.88

Spiophanes bombyx	83	172.64

Scoloplos armiger	62	128.96

Station 8

Nemertinea	314	653.12

Mytilis sp juv.	273	567.84

Guernea reduncans	106	220.48

Siliqua sp juv..	66	137.28

Scoloplos armiger	49	101.92

Station 9

Nemertinea	355	738.40

Scoloplos armiger	66	137.28

Mandibulophoxus gilesi	63	131.04

Siliqua sp juv.	36	74.88

Spiophanes bombyx	30	62.40

Station 10

Nemertinea	256	532.48

Siliqua sp juv.	355	738.40

Macoma sp juv.	205	426.40

Mytilis sp juv.	145	301.60

Tellina sp juv.	142	295.36

Figure   SEQ Figure \* ARABIC  4 .  2008 Densities of Benthic
Invertebrates, Siuslaw ODMDS

Figure   SEQ Figure \* ARABIC  5 .  2008 Diversity of Benthic
Invertebrates (H’), Siuslaw ODMDS

Figure   SEQ Figure \* ARABIC  6 .  2008 Diversity of Benthic
Invertebrates (SDV), Siuslaw ODMDS

Figure   SEQ Figure \* ARABIC  7 .  2008 Species Richness of Benthic
Invertebrates, Siuslaw ODMDS

The density distribution data indicates large juvenile recruitment of
most species from spring spawning.  This recruitment includes both
opportunistic short-lived species (Spiophanes bombyx) and longer-lived
species (razor clams, Siliqua sp. juv. and Dendraster excentricus).  The
large recruitment of these longer-lived species and the recruitment of
some shorter-lived species, mostly polychaeta and crustacea, indicate
good ocean conditions in spring and summer months in this area.

The crustaceans showed some population spikes throughout the data;
however, the same species were not always the driving factors.  Gammarid
amphipods were often present but also present were Diastylopsis dawsoni
(Cumacea) and barnacles (Cirripedia), which showed up on hard features
such as snail shells and the occasional rock.  The echinoderms were
driven by Dendraster sp. juv/Dendraster excentricus and the other
miscellaneous groups were largely populated by Nemertinea and juvenile
holothuroids.

The benthos in the area of the ocean disposal sites is typical of sandy
bottom communities found near other disposal sites along the Oregon
Coast, such as Coos Bay sites E and F, Rogue River, Siuslaw River and
Chetco River (Hancock et. al., 1981; USACE 1985, 1988a, 1988b, 1990). 
This benthic community, largely dominated by very mobile organisms,
provides an important link in the marine 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 the tube building species help to stabilize the bottom
sediments.

Many of the benthic species in this study are able to survive in this
dynamic environment being either very mobile or being able to react both
to natural or man-made perturbations.  They readily recolonize in
disturbed areas such as dredging scars or disposal site events.

Fish and Epibenthic Species

The commercially and recreationally important epibenthic species in
inshore coastal areas of Oregon include shellfish and Dungeness crab
(Cancer magister).  Clam beds are located on the north side of the
Siuslaw estuary at RM 1.  Gaper clams (Tresus capex) are the dominant
bivalves harvested.  Dungeness crab adults occur on sandflat habitat
along the entire Oregon Coast.  They spawn in offshore areas and occur
in the estuary when conditions are favorable in late summer and fall.

The nearshore area has been known to be a squid spawning area with the
location and size varying annually (USACE 1992).  Although there have
been incidental catches of squid within 1.5 nautical miles of the mouth
of the Siuslaw, there has been no directed squid harvest within this
area.  There have been reports of egg capsules and adults caught in
trawls, as well as the presence of egg capsules on crab gear.  Outside
of the 1.5 nautical mile radius from the mouth, there have been directed
squid harvests south of Heceta Head to Cape Perpetua.  Squid spawn
between at water depths of 5 to 40 meters, with maximum spawning
occurring at 15 meters.  After hatching, they school in the middle of
the water column, moving toward the surface as they mature.  Mature
squid feed mostly at water depths of 20 to 50 meters (USACE 1992).

The nearshore area off the Siuslaw River supports anadromous salmonids
including coho salmon (Oncorhynchus kisutch), winter steelhead
(Oncorhynchus mykiss), and spring and fall Chinook salmon (Oncorhynchus
tshawytscha), as well as a variety of other pelagic and demersal fish
species.  Other pelagic species include the Pacific herring (Clupea
harengus pallasi), northern anchovy (Engraulis mordax), and surf smelt
(Hypomesus pretiosus).

Demersal species present in the inshore area are mostly residents and
include a number of sculpins, sea perch, and rockfish species associated
rocky habitats, as well as flatfish species occurring predominantly over
open sandflats.  Flatfish include English sole (Parophrys vetulus),
sanddab (Citharichthys sp.), and starry flounder (Platichthys
stellatus).  English sole and starry flounder, along with the sand sole
(Psettichthys melanostictus), spawn in the inshore area in the summer
and juveniles of these, as well as other marine species, may rear in the
Siuslaw estuary.

Field surveys were conducted in August and September 2008 by Marine
Taxonomic Services (USACE 2009) to provide current information about the
fish and epibenthic species present in the area of ODMDS B and C
(proposed North and South sites).  Tables 5 and 6 show the trawl results
with numbers of individuals, average size, and size range for the fish
and crabs captured.

Table   SEQ Table \* ARABIC  5 .  August 2008 Trawl Data, Siuslaw ODMDS

August 2008 Trawl#	1	2	3	4	5	6

Cancer 

magister	Dungeness Crab - Female	 	 	 	 	 	 

	number of individuals	14	3	3	6	60	7

	size range (mm)	40-140	120-150	110-140	125-140	30-162	55-175

	average size (mm)	114.1	140	126.6	131.6	50	133.6

Cancer 

magister	Dungeness Crab - Male	 	 	 	 	 	 

	number of individuals	5	 	2	2	188	5

	size range (mm)	120-155	 	75-165	135-145	32-150	130-140

	average size (mm)	138	 	120	140	47.7	136

Bothidae

juv.	Juvenile Flat  Fishes	 	 	 	 	 	 

	number of individuals	 	1	 	2	1	 

	size range (mm)	 	41	 	20-42	38	 

	average size (mm)	 	41	 	31	38	 

Citharichthys

sp.	Sanddab	 	 	 	 	 	 

	number of individuals	 	4	 	1	2	1

	size range (mm)	 	70-170	 	110	110	55

	average size (mm)	 	113	 	110	110	55

Engraulis

mordax	Northern Anchovy	 	 	 	 	 	 

	number of individuals	 	 	 	1	 	 

	size range (mm)	 	 	 	90	 	 

	average size (mm)	 	 	 	90	 	 

Enophrys

bison	Buffalo Sculpin	 	 	 	 	 	 

	number of individuals	 	 	 	1	4	1

	size range (mm)	 	 	 	118	90-135	100

	average size (mm)	 	 	 	118	115	100

Gadidae	Pacific Tom Cod	 	 	 	 	 	 

	number of individuals	47	94	13	116	129	39

	size range (mm)	50-175	52-185	60-190	56-188	48-185	55-170

	average size (mm)	78.6	79	102.7	87.1	85.9	96.7

Isopsetta 

isolepis	Butter Sole	 	 	 	 	 	 

	number of individuals	150	144	80	131	2	54

	size range (mm)	40-200	45-172	40-210	50-220	140-143	45-235

	average size (mm)	117	118	120	125.2	141.5	149

Leptocottus armatus	Staghorn Sculpin	 	 	 	 	 	 

	number of individuals	30	17	 	14	9	12

	size range (mm)	128-190	139-189	 	145-205	115-192	110-170

	average size (mm)	162.6	162.4	 	163.7	143	140.6

Liparis

pulchellus, Liporidae	Showy Snailfish	 	 	 	 	 	 

	number of individuals	27	24	15	4	1	3

	size range (mm)	16-120	18-150	20-112	14-34	53	120-150

	average size (mm)	34.5	37.2	40.6	22	53	133.3

Liparididae

juv.	Snail Fish	 	 	 	 	 	 

	number of individuals	 	 	 	 	2	1

	size range (mm)	 	 	 	 	16-18	20

	average size (mm)	 	 	 	 	17	20

Ophiodon elongatus	Ling Cod	 	 	 	 	 	 

	number of individuals	 	2	 	1	1	2

	size range (mm)	 	112-150	 	120	135	100-100

	average size (mm)	 	136	 	120	135	100

Osmeridae	Smelt	 	 	 	 	 	 

	number of individuals	31	7	27	26	2	 

	size range (mm)	32-112	35-102	28-110	30-90	95-97	 

	average size (mm)	65.3	71.7	59.4	50.5	96	 

Parophrys

vetulus	English Sole	 	 	 	 	 	 

	number of individuals	45	38	11	147	15	43

	size range (mm)	82-330	35-265	67-285	45-275	87-120	38-240

	average size (mm)	152	157.5	146.1	140.5	105.4	129

Pholis 

ornata	Saddle Back gunnel	 	 	 	 	 	 

	number of individuals	 	 	20	 	 	4

	size range (mm)	 	 	130-190	 	 	85-145

	average size (mm)	 	 	166	 	 	120

Pleurenectidae

juv.	Flat Fishes	 	 	 	 	 	 

	number of individuals	71	26	30	16	5	1

	size range (mm)	28-53	30-45	27-88	30-45	35-46	50

	average size (mm)	37.7	37.1	39	36.4	39.8	50

Psettichthys 

melanostictus	Sand Sole	 	 	 	 	 	 

	number of individuals	1	3	1	3	4	10

	size range (mm)	48	143-195	175	165-250	152-192	115-200

	average size (mm)	48	171	175	195	171.5	147.8

Raja

binoculata	Big Skate	 	 	 	 	 	 

	number of individuals	 	 	 	 	 	1

	size range (mm)	 	 	 	 	 	365

	average size (mm)	 	 	 	 	 	365

Scorpaenidae	Juvenile Rock Fish	 	 	 	 	 	 

	number of individuals	 	2	2	1	 	 

	size range (mm)	 	45-52	50-53	60	 	 

	average size (mm)	 	48.5	51.5	60	 	 

Stellerina

xyosterna	Prickle Breasted Poacher	 	 	 	 	 	 

	number of individuals	140	149	87	139	30	8

	size range (mm)	15-63	116-131	17-65	18-72	18-60	25-56

	average size (mm)	38.1	40.6	37.6	40.3	36.2	40.75

Pallasina

barbata	Tube Nose Poacher	 	 	 	 	 	 

	number of individuals	 	6	4	 	3	 

	size range (mm)	 	73-149	47-77	 	68-170	 

	average size (mm)	 	96.2	62.75	 	105.3	 

Pisaster

brevispinus	Pink Short Spined Starfish	 	 	 	 	 	 

	number of individuals

 	 	1	 	 

	(not measured)

 	 	 	 	 

Crangon spp, Cancer larval forms, isopods, amphipods, mysids, drift
algae (present but not counted)	X	X	X	X	X	X



Table   SEQ Table \* ARABIC  6 .  September 2008 Trawl Data, Siuslaw
ODMDS

September 2008 Trawl#	1	2	3	4	5	6

Cancer

magister	Dungeness Crab - Female	 	 	 	 	 	 

	number of individuals	2	1	 	 	1	 

	size range (mm)	50-55	45	 	 	135	 

	average size (mm)	52.5	45	 	 	135	 

Cancer 

magister	Dungeness Crab - Male	 	 	 	 	 	 

	number of individuals	6	8	 	2	18	4

	size range (mm)	108-165	45-170	 	110-140	110-180	8-138

	average size (mm)	138.6	110	 	125	136.9	70.5

Citharichthys

sp.	Sanddab	 	 	 	 	 	 

	number of individuals	1	13	2	8	4	16

	size range (mm)	105	90-125	120-150	90-150	50-188	90-174

	average size (mm)	105	109.2	135	109.4	114.5	114.6

Gadidae	Pacific Tom Cod	 	 	 	 	 	 

	number of individuals	49	5	1	1	13	 

	size range (mm)	50-130	80-130	102	120	88-178	 

	average size (mm)	99.8	95	102	120	130.2	 

Hexagrammos decagrammus	Kelp Greenling	 	 	 	 	 	 

	number of individuals	 	 	 	 	1	 

	size range (mm)	 	 	 	 	108	 

	average size (mm)	 	 	 	 	108	 

Isopsetta

isolepis	Butter Sole	 	 	 	 	 	 

	number of individuals	37	7	9	15	48	22

	size range (mm)	38-210	55-190	125-200	55-170	110-220	84-170

	average size (mm)	120.6	129.3	158.3	117.9	141.8	133.1

Leptocottus armatus	Staghorn Sculpin	 	 	 	 	 	 

	number of individuals	16	2	1	9	23	1

	size range (mm)	105-200	140-160	130	120-160	95-140	115

	average size (mm)	135.75	150	130	138.8	115.1	115

Liparis 

pulchellus	Showy Snailfish	 	 	 	 	 	 

	number of individuals	 	1	6	1	4	2

	size range (mm)	 	59	55-145	135	65-180	80-130

	average size (mm)	 	59	77.5	135	100	105

Osmeridae	Smelt	 	 	 	 	 	 

	number of individuals	57

 	 	 	 

	size range (mm)	30-110

 	 	 	 

	average size (mm)	49.5	 	 	 	 	 

Parophrys 

vetulus	English Sole	 	 	 	 	 	 

	number of individuals	23	11	9	13	10	33

	size range (mm)	45-170	49-180	45-140	42-125	40-125	44-150

	average size (mm)	88.6	96.8	65.1	69.3	56.9	73.5

Pleurenectidae

juv.	 	 	 	 	 	 	 

	number of individuals	 	2	4	9	 	1

	size range (mm)	 	50-50	45-50	40-50	 	45

	average size (mm)	 	50	47.5	47.4	 	45

Psettichthys melanostictus	Sand Sole	 

 	 	 	 

	number of individuals	1	3	2	3	5	3

	size range (mm)	215	110-180	180-250	145-150	140-190	130-180

	average size (mm)	215	150	215	148.3	167	154

Raja 

binoculata	Big Skate	 	 	 	 	 	 

	number of individuals	1	 	1	 	 	 

	size range (mm)	235	 	280	 	 	 

	average size (mm)	235	 	280	 	 	 

Stellerina

xyosterna	Prickle Breasted Poacher	 	 	 	 	 	 

	number of individuals	38	5	38	8	30	 

	size range (mm)	40-100	50-70	20-85	55-140	45-120	 

	average size (mm)	55.1	60.6	49.2	74.1	63.3	 

Pallasina

barbata	Tube Nose Poacher	 	 	 	 	 	 

	number of individuals	4	3	 	1	7	4

	size range (mm)	55-100	95-100	 	100	75-100	90-110

	average size (mm)	78.75	96.6	 	100	89	98.3

Pisaster

brevispinus	Pink Short Spined Starfish	 	 	 	 	 	 

	number of individuals	 	1	1	4	 	 

	(not measured)	 	 	 	 	 	 

Crangon spp, Cancer larval forms, isopods, amphipods, mysids, drift
algae (present but not counted)	X	X	X	X	X	X

The trawl data shows that non-commercial species are present in the
ODMDS area.  These included quantities of krill (Mysidacea) and various
species of sand shrimp, mostly of the genus Crangon along with several
species of fish.  These data also showed several commercially and
recreationally important species in the study area.  Most of the
specimens are juvenile or sub-legal individuals.  Commercially and
recreationally important species included the following:

Cancer magister (Dungeness crab)

Citharichthys sp.  (sand dab)

Isopsetta isolepis (butter sole)

Psettichthys melanostictus (sand sole)

Ophiodon elongates (ling cod)

Parophrys vetulus (English sole)

The trawl samples denote this near shore area as a nursery ground with
an abundant food source.  Most of the species encountered in the trawl
samples were benthic feeders that tend to utilize the shallower areas
both because of the abundant food and because of fewer predators.  The
majority of the fish and crabs captured in the trawls were juveniles and
young of the year.  However, larger crabs and fish have the ability to
avoid the trawl net.

ESA-Listed Species Status and Occurrence in the Vicinity of the
Proposed Siuslaw Ocean Disposal Sites

The federally listed species that may occur in the Siuslaw River coastal
area (Lane County, Oregon) was obtained from the NMFS and USFWS
websites.  Table 1 details the listed species and designated critical
habitat that may occur in the action area.  Those species and critical
habitat are addressed further below.

Coho Salmon

Coho salmon are distributed throughout the Pacific Ocean north of
central California.  This anadromous salmonid exhibits a relatively
short 3-year life cycle.  Adults typically reenter freshwater in late
summer through fall, spawn by mid-winter, and die thereafter.  Variation
is exhibited between and within populations of coho salmon.  Depending
upon water temperature, incubation in river gravels requires 1.5 to 4
months.  Juvenile coho salmon rear in freshwater up to 15 months after
emerging from the gravel.  They undergo considerable instream migration
during this period in the upper tributaries to find suitable winter and
summer rearing habitat (Miller and Sadro 2003).  After rearing, smolts
outmigrate to the ocean in the spring as age 1+ juveniles.

Juveniles tagged by Miller and Sadro (2003) in Coos Bay, an estuary to
the south of the Siuslaw River, showed that residence time in the lower
reach of South Slough in Coos Bay was brief, averaging 5.8 days with a
range of 4.2 to 6.2 days (based on a sample size of four fish). 
Residence time in the upper portion of Isthmus Slough of Coos Bay was
considerably longer.  Fish occurred in the upper area for up to 8 months
before becoming smolts and moving down into the lower portion of the
slough.  Although the fish appeared to have the capability of moving
through the lower portion of the slough and into the ocean in 24 hours
or less, their combined behavior of holding and occasionally moving
upstream with flood tides prolonged their residence.  This behavior may
be necessary for their final adaptation to salt water before entering
the ocean and is presumed to be representative of behavior along the
Oregon Coast.

For several months before they disperse into the open ocean, coho
typically stay in nearshore areas close to their natal streams (Groot
and Margolis 1991).  Juvenile coho from California to British Columbia
typically migrate northward along the coast, generally remaining over
the continental shelf within sight of land and at depths less than 90 to
150 meters (Groot and Margolis 1991).

Juvenile coho salmon feed primarily on aquatic invertebrates while in
freshwater, but fish become an important prey as they grow larger (Groot
and Margolis 1991).  In estuarine and marine environments, chum and pink
salmon fry, as well as larvae of pacific crab are important prey. 
Typically, coho salmon spend two growing seasons (approximately 18
months) in the ocean before returning to their natal streams to spawn. 
However, precocious male ‘jacks’ return after 6 months.

NMFS announced listing of Oregon Coast (OC) coho salmon as a threatened
species on February 4, 2008 (73 FR 7816).  The listing includes all
naturally spawned populations of coho salmon in Oregon coastal streams
south of the Columbia River and north of Cape Blanco, including the Cow
Creek (ODFW stock # 37) coho hatchery program.  Critical habitat also
was designated.  The Siuslaw River and estuary were designated as
critical habitat but the ocean waters off the Siuslaw River were not. 
Therefore, there is no designated critical habitat for OC coho in the
action area.

Since 1950, fish spawning surveys conducted by the Oregon Department of
Fish and Wildlife (ODFW) in standard index areas along the Oregon Coast
have been used to assess the status and trends of coastal coho salmon
populations.  Annual estimates (1990-2006) of the total spawning
escapement of naturally produced adult coho for the Siuslaw River are
shown below (Jacobs et al., 2002 and   HYPERLINK
"http://oregonstate.edu/Dept/ODFW/spawn/index.htm" 
http://oregonstate.edu/Dept/ODFW/spawn/index.htm ).

1990	1991	1992	1993	1994	1995	1996	1997	1998

2,685	3,740	3,440	4,428	3,205	6,089	7,625	668	1,089

1999	2000	2001	2002	2003	2004	2005	2006

2,724	6,767	11,024	57,129	29,257	8,443	16,907	5,869

Coho spawning primarily occurs during November and December in coastal
Oregon streams.  However in the Mid-coast Monitoring Area (includes
Siuslaw River), coho stocks generally exhibit the most protracted
spawning timing on the coast, with significant portions of the spawning
run occurring throughout November and into mid-January (Jacobs et al.,
2002).  Peak juvenile outmigration is typically observed from early
March through early April (with the range extending from early February
through early July).

The Southern Oregon/Northern California Coast (SONCC) coho ESU was
listed as threatened on May 6, 1997 and includes all naturally spawned
populations of coho salmon in coastal streams between Cape Blanco,
Oregon, and Punta Gorda, California (62 FR 24588).  A NOAA technical
memorandum (Good et al., 2005) found that recent data do not suggest any
marked change in the abundance or distribution of SONCC coho.  Critical
habitat was identified on May 5, 1999 (64 FR 24049).  In that final
rule, designated critical habitat, “consists of the water, substrate,
and adjacent riparian zone of estuarine and riverine reaches” in
specified hydrologic units of river reaches accessible to coho salmon
within the listed ESU (64 FR 24049).  The proposed Siuslaw ocean
disposal sites are not located within designated critical habitat for
the SONCC coho ESU.  This coho ESU, like other west coast coho ESUs,
typically migrate north along the coast.  Therefore, SONCC coho may
utilize the action area for migratory purposes, however, migrating
individuals are likely to be further offshore than the action area.

In 2005, SONCC coho ESA status was reaffirmed as threatened and three
artificial propagation programs were added as part of this ESU:  (1)
Cole Rivers Hatchery (ODFW stock #52), Rogue River, Oregon; (2) Trinity
River Hatchery, Trinity River, California; and (3) Iron Gate Hatchery,
Klamath River, California (70 FR 37160).  The NMFS determined that these
artificially propagated stocks are no more divergent relative to the
local natural population(s) than what would be expected between closely
related natural populations within the ESU (70 FR 37160).

Also in 2005, the Lower Columbia River Coho Salmon ESU was listed as
threatened and includes all naturally spawned populations of coho salmon
in the Columbia River and its tributaries in Washington and Oregon, from
the mouth of the Columbia up to and including the Big White Salmon and
Hood Rivers, and includes the Willamette River to Willamette Falls,
Oregon, as well as twenty-five artificial propagation programs (70 FR
37160).  

Chinook Salmon

Several ESUs of Chinook salmon listed in 2005 (70 FR 37160) could
potentially be in the action area during disposal activities.  Those
include the Lower Columbia River Chinook (threatened), Upper Willamette
River spring-run Chinook (threatened), Upper Columbia River spring-run
Chinook (endangered), Snake River spring/summer run Chinook
(threatened), and Snake River fall-run Chinook (threatened).  All of
these ESUs have designated critical habitat, but only the Upper
Willamette River Chinook has designated critical habitat within the
action area (from the line of extreme high tide to a depth of 100 ft and
inclusive of Lane County).  None of these ESUs spawn in the Siuslaw
River, but they are ocean-type Chinook and adults may be transiting the
action area during disposal activities.   

Green Sturgeon

The threatened Southern distinct population segment (DPS) of the green
sturgeon includes all green sturgeon that spawn within the
Sacramento-San Joaquin rivers.  Critical habitat was proposed for the
Southern DPS in September 2008 (73 FR 52084).  The proposed ODMD sites
are within the proposed critical habitat.  However, neither dredging nor
disposal of dredged material are proposed as activities that may affect
the proposed primary constituent elements proposed within that
geographic area.  Green sturgeon that spawn to the north, primarily in
the Klamath and Rogue rivers, constitute the Northern DPS, which is not
federally listed.  The Northern DPS and the Southern DPS were found to
be genetically distinct.  Israel and others (2004) showed genetic
differences between one group of San Pablo Bay and Columbia River fish
and a second group of Klamath River and Rogue River fish.

Green sturgeon spend more time in the marine environment than other
sturgeon species (Adams et al., 2002).  Green sturgeon spawn in their
natal rivers and migrate downriver to the ocean after 3 to 5 years and
disperse along the coastline.  Green sturgeon have delayed sexual
maturity, somewhere from 13 to 20 years, and they apparently only spawn
every 2 to 5 years (Moyle 2002).  Green sturgeon in the ocean can be
assumed to remain largely inside the 100-meter depth contour and
typically occupy depths of 40-70 meters (Erickson and Hightower 2007). 
In the Rogue River, green sturgeon spend approximately 6 months in fresh
water annually and have been captured as far upriver as RM 65 (105 km)
and emigrate to the ocean between October and January (Erickson et al.,
2002; Erikson and Webb 2007).  Southern DPS green sturgeon, radio-tagged
in the Sacramento River, have recently been shown to occur seasonally in
Willapa Bay, as well as other northern estuaries including the Columbia
River estuary during the summer and early fall (Moser and Lindley 2007).
 Although there appears to be substantial spatial overlap in the two
DPSs, the Northern DPS appears to utilize smaller river estuaries, such
as the Siuslaw River estuary, to a greater extent than the Southern DPS
(NMFS 2007).

The NMFS identified one of the major threats to the Southern DPS green
sturgeon as harvest in the spawning and natal areas of the
Sacramento-San Joaquin rivers and in more northern ocean, coastal, and
estuarine waters.  In the northern fisheries, it is during their
aggregation in estuaries that the greatest catch of Southern DPS green
sturgeon occurs.  In northern waters, green sturgeon are captured either
in directed sturgeon fisheries in estuarine waters, as by-catch in
salmon gillnet fisheries in estuaries and rivers, or in coastal trawl
fisheries along the West Coast (NMFS 2007).  Historically, harvest came
predominately from the Columbia River (51%), coastal trawl fisheries
(28%), the Oregon fishery (8%), and the California tribal fishery (8%;
Adams et al., 2002).

Moser and Lindley (2007) propose that green sturgeon utilize northern
estuaries to optimize their growth potential in summer by foraging in
warm, saline estuaries and caution that altering the quality of
estuarine habitats could negatively affect this species throughout its
range.

Habitat use and food habits of green sturgeon in northern estuaries have
not been investigated in detail.  Digestive tract contents from 46
commercially caught Columbia River green sturgeon were found to contain
only algae (species unknown) and pebbles.  A digestive tract sample from
one Rogue River green sturgeon contained an exoskeleton of one crayfish
(Pacifasticus spp.) and algae (ODFW 2005).  The Rogue River fish was
likely from the Northern DPS.  Collection of green sturgeon from Willapa
Bay showed that they fed on burrowing thalassinidean shrimp that are
abundant in the bay (Moser and Lindley 2007).  Adults captured in the
Sacramento-San Joaquin delta were benthic feeders on invertebrates
including shrimp, mollusks, amphipods, and small fish (Houston 1988;
Moyle et al., 1992).  Juveniles in the Sacramento River delta fed on
opossum shrimp, Neomysis mercedis and Corophium amphipods (Radtke 1966).

From 2000 to 2004, ODFW conducted a study of coastal streams to examine
characteristics of green sturgeon populations in Oregon.  The Siuslaw
River was sampled during 3 weeks in May and June 2003 with gill nets,
seines, and underwater cameras.  This location was chosen based on areas
previously noted by anglers as supporting sturgeon, however, no green
sturgeon were captured during this time period (Farr and Rien 2003). 
According to NMFS (see 73 FR 52084), Southern DPS green sturgeon
presence is likely, but not confirmed in the Siuslaw River estuary.  The
Siuslaw River estuary is not identified as proposed critical habitat for
Southern DPS green sturgeon (see 73 FR 52084).  Southern DPS green
sturgeon may occur at or near the proposed North and South Siuslaw ocean
disposal sites as they migrate to northern estuaries during summer and
early fall.

Pacific Eulachon

The Southern Distinct Population Segment (DPS) of Pacific Eulachon was
proposed threatened in March 2009 (74 FR 10857).  Eulachon (commonly
called smelt, candlefish, or hooligan) are a small, anadromous fish from
the eastern Pacific Ocean.  Eulachon typically spend 3 to 5 years in
saltwater before returning to freshwater to spawn from late winter
through mid spring.  Eulachon occur in nearshore ocean waters and to
1000 feet (300 m) in depth, except for the brief spawning runs into
their natal (birth) streams.  In the continental United States, most
eulachon originate in the Columbia River Basin. Other areas in the
United States where eulachon have been documented include the Sacramento
River, Russian River, Humboldt Bay and several nearby smaller coastal
rivers (e.g., Mad River), and the Klamath River in California; the Rogue
River and Umpqua Rivers in Oregon; and infrequently in coastal rivers
and tributaries to Puget Sound, Washington.  The NMFS Status Review for
Eulachon concluded that eulachon were thought to occur in “rare”
relative abundance in the Siuslaw River (NMFS 2008).  Although eulachon
migrate along the coast, little is known about eulachon use of the
nearshore and marine habitat.

Marine Mammals

The Steller sea lion, listed as threatened in 1990 and reconfirmed as
threatened for the Eastern DPS in 1997 (58 FR 45269), breeds along the
West Coast of North America from California’s Channel Islands to the
Kurile Islands and the Okshotsk Sea in the western north Pacific Ocean. 
They are year-long residents along the Oregon Coast, and are expected to
occur as migrants in the vicinity of the proposed North and South
Siuslaw ocean disposal sites.  Steller sea lions are known to haul out
at 10 sites along the Oregon Coast:  Columbia River South Jetty (Clatsop
County), Ecola State Park (Clatsop County), Three Arch Rocks (Tillamook
County), Cascade Head (Tillamook County), Seal Rock (Lincoln County),
Sea Lion Caves (Lane County), Cape Arago (Coos County), Blanco Reef
(Curry County), Orford Reef (Curry County) and Rogue Reef (Curry
County).  Of these sites, Orford Reef and Rogue Reef are rookeries and
are designated critical habitat for Steller sea lion.  Designated
critical habitat at both the Rogue and Orford Reefs includes an air zone
that extends 3,000 feet above the site measured vertically from sea
level and an aquatic zone that extends 3,000 feet seaward in state and
federally managed waters [50 C.F.R. § 226.202(b)].  Orford Reef and
Rogue Reef are located over 80 miles south of the action area. 
Therefore, the proposed North and South Siuslaw ocean disposal sites are
not located in or near designated critical habitat for Steller sea lion.

Steller sea lion population counts for Oregon have increased since 1977,
when the statewide non-pup population totaled 1,431, to 4,169 in 2002,
an annual rate of increase of about 3.7% (Brown et al. 2002).  Brown and
others (2002) also found that the pup counts for the Rogue Reef have
increased over time, from 492 in 1990 to 746 in 2002, and at Orford Reef
from 298 in 1990 to 382 in 2002, although the pup counts have not been
completed annually.  Steller sea lion numbers appear to be lower off
Oregon in the winter than summer.  However, exchange between rookeries
by breeding adult females and males (other than between adjoining
rookeries) appears low (Angliss and Outlaw 2005).  Steller sea lions
forage at river mouths and nearshore areas along the coast.  Roffe and
Mate (1984) determined that proximity to the mouth of a river was the
most important factor in determination of forage areas.

The blue whale, fin whale, humpback whale, and southern resident killer
whale are all listed as endangered and occur as migrants in waters off
the Oregon Coast.  The population status of most of these species is
described in the 2007 U.S. Pacific Marine Mammal Stock Assessments
(Carretta et al., 2007).  According to Maser and others (1981), blue
whales occur off the Oregon Coast in May and June, as well as August
through October.  Blue whales typically occur offshore as individuals or
in small groups and winter well south of Oregon.  Fin whales also winter
far south of Oregon and range off the coast during summer.  Whaling
records indicated that fin whales are harvested off the Oregon Coast
from May to September.  Humpback whales primarily occur off the Oregon
Coast from April to October with peak numbers from June through August. 
Green and others (1992) observed 35 humpback whales near Heceta Bank
(approximately 15-30 miles off the Oregon Coast in Lincoln and Lane
counties) in June 1990.  They noted that humpback whales were
particularly concentrated in Oregon along the southern edge of Heceta
Bank and found this species primarily on the continental shelf and
slope.

The southern resident killer whale population contains three pods (or
stable family-related groups)—J pod, K pod, and L pod—and is
considered a stock under the Marine Mammal Protection Act.  Their range
during the spring, summer, and fall includes the inland waterways of
Puget Sound, Strait of Juan de Fuca, and Southern Georgia Strait.  Their
occurrence in the coastal waters off Oregon has been documented.  Little
is known about the winter movements and range of the southern resident
stock.  The southern resident population is currently estimated at about
88 whales, a decline from its estimated historical level of about 200
during the mid- to late-1800s.  Critical habitat was designated for this
whale in 2006 (see 71 FR 69054), but is restricted to Washington State.

Coastal Birds

The species list from the USFWS website identified the federally listed
species that may occur in Lane County, Oregon.  From this list, EPA
ascertained that the proposed Siuslaw ocean disposal sites are within
the range of three listed coastal avian species for which USFWS has
primary responsibility.  These include marbled murrelet, short-tailed
albatross, and the brown pelican (see Table 1).  Critical habitat has
been designated for the marbled murrelet, but it is restricted to upland
areas and does not include any marine areas, such as the proposed ocean
disposal sites.  The brown pelican was proposed for delisting in
February 2008 (73 FR 9407) and does not have any designated critical
habitat.  Likewise, no critical habitat has been designated for the
short-tailed albatross.

Marbled murrelets are observed in small flocks or as individuals in the
ocean and near coastal embayments throughout the year.  Brown pelicans
are seasonally abundant (June to September) along the Oregon coast and
in the lower reaches of various estuaries.  Most brown pelicans on the
Oregon coast are immature birds but the population includes some
post-breeding adults that have dispersed northward from breeding
locations in California and Mexico.  Neither species is known to utilize
the sea floor at the proposed sites for foraging and feeding although
prey organisms might be present in the vicinity.  Marbled murrelets and
brown pelicans seem to prefer shallower waters (depth no greater than 40
feet) to forage.  Because they have a preference for shallower waters,
they are unlikely to be affected by the accumulation of disposed
material on the ocean floor in the deeper portions of the proposed
sites.  The shoreward portions of the disposal sites would be located
within approximately 30 feet of water and the physical disturbance
associated with disposal could result in temporary decreases or
displacement of foraging activity.  Brown pelicans are commonly observed
in and around human activities and appear to be habituated to human
activity.

The short-tailed albatross was historically hunted for feathers, but
currently, the primary threat to the continued existence to the species
is posed by a catastrophic volcanic or weather event at one of the small
handful of breeding locations in Japan.  The short-tailed albatross may
occur in the vicinity of the proposed Siuslaw ocean disposal sites
during the summer months and may utilize the waters for foraging and
feeding.

Terrestrial Birds, Invertebrates and Plants

The USFWS identified two listed terrestrial bird species, two listed
invertebrate species, and three listed plant species for Lane County,
Oregon (see Table 1).  Critical habitat has been designated for the
western snowy plover (70 FR 56969) and the northern spotted owl (57 FR
1796), but no designated critical habitat for either species is located
within the action area.  The western snowy plover may breed along the
near the Siuslaw River.  However, western snowy plover breeding and
feeding occur on beaches rather than in open water.  Therefore, the
western snowy plover would not be expected to be present within the
action area.

The Oregon silverspot butterfly occupies coastal headlands or Coast
Range peaks that provide specific habitat features, primarily because of
the presence of its host plant, the early blue violet (Viola adunca). 
This butterfly species would not occur in the Siuslaw action area
because there is no suitable habitat present.  The northern spotted owl,
Fender’s blue butterfly, Kincaid’s lupine, Willamette daisy, and
Bradshaw’s desert parsley are not aquatic, would not be at the
proposed sites, and therefore, would not be affected by EPA’s action.

Assessment of Effects

In reviewing the potential effects of EPA’s action (final designation
of ocean dredged material disposal sites) on the species identified by
NMFS and USFWS, EPA finds that site designation itself has no direct
impact on any of the identified ESA-listed species or designated
critical habitat.  This finding is supported by EPA’s analysis that
site designation does not create or confer rights on any person to use a
designated site upon the effective date of site designation.  Persons or
entities who seek to use a site must first obtain a federal permit, or
in the case of the USACE, meet the substantive permit requirements, in
order to actually use a designated ocean dredged material disposal site.
 This process would include meeting the requirements of applicable
statutes and regulations.  The use of a site is managed through
adherence to the Site Management and Monitoring Plan (SMMP) which must
be finalized prior to site designation.  The SMMP outlines site use
requirements, monitoring protocols, and incorporates adaptive management
principles for ongoing use of the site. EPA recognizes, however, that
site designation is intended to have a practical result.  When sites are
designated, it is expected that such sites will be used by persons or
entities meeting the statutory and regulatory criteria for ocean
disposal of dredged material.  Consequently, and consistent with the
Biological Opinions prepared by NMFS at other projects where ocean
disposal of dredged material occurs, EPA has considered that certain
ESA-listed species may potentially be affected by an actual disposal of
dredged materials at designated sites.  Actual disposal is an indirect
but reasonably certain outcome of site designation.

Dredging itself is not dependent on the site designation because other
disposal alternatives are available.  Other in-water sites could be
proposed by the USACE and/or material could be disposed of at upland
locations.  Therefore, the dredging is not caused by and will not result
from the proposed action (indirect effect), the dredging has independent
utility (interdependent effect), and the dredging does not depend on
site designation for its justification (interrelated effect). 
Therefore, EPA has not included the effects of dredging in the
assessment of effects of the proposed site designations.

Coho Salmon

EPA’s proposed site designation would not have a direct physical
effect on the proposed disposal site.  Disposal of dredged material at
the proposed Siuslaw ocean disposal sites will have an effect on the
water column and the bottom habitat.  The disposal plume will pass
through the water column and create a turbid environment that may cause
fish to move out of or avoid the area.  The bottom habitat would be
impacted in the portion of the disposal area where the material hits
bottom and buries the existing benthic community at the site.  Loss of
benthic invertebrate populations on the bottom in portions of the
disposal site is not likely to have an effect on food resources for
either adult or juvenile coho salmon.  Indirect impacts could occur if
disposal operations changed the value of the habitat by burying the
existing benthic community in portions of the disposal sites where
dredged material is deposited.  The benthic community would be expected
to re-colonize within a period of a few weeks to months after disposal,
limiting any effects to forage fish (USACE 1993).  Both adults and
juveniles feed principally on pelagic species which are not associated
with bottom habitat.  The only exception is sand lance, which could be
impacted in the disposal site area if individuals are buried in the sand
during disposal operations.  Though normally pelagic, sand lance bury
themselves in the sand as a defense mechanism.  However, sand lance are
very abundant in the coastal inshore area and it is unlikely that the
number of sand lance impacted during disposal events would have a
significant impact on the size of sand lance populations.  Since the
adjacent area consists of very similar habitat to that of the proposed
Siuslaw sites, the avoidance of the disposal area would not result in
increased predation or decreased food availability for coho.

Adult and juvenile coho could potentially be migrating through the
action area during use of the proposed ocean disposal sites.  Oregon
Coast coho would be migrating through the site as they transit between
the Siuslaw River and the ocean and vice versa.  SONCC and Columbia
River coho could be migrating along the coast and through the sites
during disposal activities, but would typically be expected to be
further offshore than the action area.  The proposed ocean disposal
sites do not provide any unique or relatively higher value habitat for
coho salmon migration, rearing, resting, or foraging.  It is unlikely
that adult coho would experience physiological effects as a consequence
of disposal because they are capable of faster swimming speeds and can
avoid the resulting turbidity plume and physical disturbance to the
water column.  Modeling recently completed by the USACE for the Umpqua
River ODMD sites showed that water column turbidity would be expected to
dissipate within a few minutes for 97% of the dredged material disposed
(sandier material), and within a half hour for finer grained sediments,
which at the Umpqua comprise about 3% of dredged material (USACE 2008). 
Sediment grain sizes in the Siuslaw channel are similar, but with a
slightly lower percentage of fine grained sediment.  Therefore, it is
reasonable to expect that the modeling results from the Umpqua would be
a conservative estimate of water quality turbidity persistence after
disposal.  Any adult coho avoidance behavior would be limited to the
duration of this physical disturbance.  

Outmigrating juvenile OC coho could experience physiological effects as
a result of the disposal of dredged material by the Corps or other
entity as described in the 2009 NMFS biological opinions (BOs) for the
Rogue and Umpqua ODMD site designations.  In those BOs, NMFS concluded
“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 issuance of an incidental
take statement with reasonable and prudent measures and
non-discretionary terms and conditions to minimize take will be prepared
when the disposal permit is requested by the action agency.” 
Therefore, any physiological effects to OC coho resulting from the
disposal of dredged materials at the proposed sites would be considered
indirect effects of EPA’s site designation action.

Oregon Coast coho experienced a recruitment failure (recruits failed to
replace the parental spawners) in the late 1990s.  However, Good and
others (2005) found that the 3-year period from 2000 to 2002 produced a
nearly fourfold increase in spawners for the entire ESU.  Good and
others (2005) also found that recent data do not suggest any marked
change in the abundance or distribution of SONCC coho.  Given that
disposal in the vicinity of the currently proposed Siuslaw North and
South ocean disposal sites has occurred since 1977, is unlikely that
temporary disposal related impacts described above are resulting in any
long-term negative effects to Oregon Coast, SONCC coho, or Columbia
River coho ESUs.  It is more likely that changes in the ESU populations
are related to much broader regional fluctuations.

Chinook Salmon

Like SONCC and Lower Columbia River coho, Chinook typically migrate
along the coast.  Therefore, chinook may utilize the action area for
migratory purposes.  Those migrating individuals may experience similar
effects to foraging and passage as discussed above for coho. Chinook
would also be expected to avoid the area during the brief period of
turbidity.  Since these migrating fish would be larger than outmigrating
juvenile OC coho and more capable of avoiding the dredge material plume,
they would not be expected to experience any direct physical impacts
from dredged material falling through the water column.

Green Sturgeon

According to NMFS analysis supporting the listing of the Southern DPS of
green sturgeon, “the principal factor for decline of the Southern DPS
is the reduction of the spawning area to a limited area of the
Sacramento River” (see 71 FR 17762).  No spawning habitat for the
Southern DPS is located in the vicinity of the proposed Siuslaw ocean
disposal sites.  Southern DPS green sturgeon may occur at or near the
proposed ocean disposal sites as they migrate to estuaries further
north, including the Columbia River estuary during the summer and early
fall.  Use of the proposed sites would result in physical disturbance to
the water column and turbidity, which may cause adult green sturgeon to
temporarily avoid the disposal area during disposal events.  Since the
adjacent area consists of very similar habitat to that of the proposed
Siuslaw sites, the avoidance of the disposal area would not result in
increased predation or decreased food availability for green sturgeon.
In the 2009 BOs for EPA’s designation of the Rogue and Umpqua ODMD
sites, NMFS determined that younger, subadult green sturgeon that may be
in the action area during disposal would be at risk for physical impacts
associated with the discharged dredged material due to their slower
swimming speed and that these fish would have a high likelihood of
experiencing physical injury or death. 

Critical habitat was proposed for the Southern DPS green sturgeon in
September 2008 (73 FR 52084), but that critical habitat has not been
designated.  Critical habitat was proposed in the action area, but only
for the primary constituent elements (PCE) of food, passage, and water
quality.  The activities listed in the proposal which may affect those
PCEs include bottom trawl fishing, tidal/wave energy, and point and
non-point source pollution.  Dredging and deposition of dredged material
were not listed in the activities that may affect the relevant PCEs in
coastal marine waters between Winchester Bay, OR and the Columbia River
estuary.  Therefore, no long-term effects to Southern DPS green sturgeon
proposed critical habitat are expected.

Pacific Eulachon

According to the NMFS analysis supporting the proposed listing of the
Southern DPS of Pacific Eulachon, the most significant threat to
eulachon and their habitats are changes in ocean conditions due to
climate change (see 74 FR 10870).  Dredging is identified as a low to
moderate threat to eulachon primarily due to spawning related impacts. 
However, impacts associated with disposal of dredged material were not
identified as a threat to eulachon.  Due to the relative rare abundance
of eulachon in the Siuslaw River, the potential for eulachon to be in
the action area during disposal activities is low.  In addition, little
is known about eulachon use of the nearshore and marine areas, such as
the proposed ODMD sites.  The indirect effects of EPA’s site
designation, disposal of dredged material at the proposed sites, would
result in physical disturbance to the water column and turbidity, which
may have unknown impacts to any eulachon in the vicinity.  

Marine Mammals

For the Steller sea lion, the proposed Siuslaw North and South ocean
disposal sites are not located near identified haul out and rookery
sites.  Disposal in the vicinity of the proposed sites has occurred
regularly since 1977 and since that time, the Oregon population of
Steller sea lions has increased steadily.  Therefore, it is unlikely
that disposal activities at the site are negatively impacting the
species.  It is expected that sea lions would avoid the sites
temporarily during disposal of dredged material.

The blue whale, fin whale, humpback whale, and southern resident killer
whale occur as migrants in waters off the Oregon Coast typically farther
from shore than the action area.  Whale species would likely avoid the
ocean disposal areas during disposal operations.  As described above,
any impacts to salmonid prey species for killer whale would be expected
to be temporary.  Current vessel traffic already includes transit to
similarly located disposal sites since a site has been in use in the
vicinity of the currently proposed locations since 1977.  The proposed
disposal site designations are not expected to result in any increase in
vessel traffic and therefore, no effects to marine mammals associated
with vessel transit (vessel strikes, oil spills, etc.) are expected to
result from the project.

Coastal Birds

The marbled murrelet, short-tailed albatross, and brown pelican are
known to occur in the vicinity of Oregon coastal estuaries and adjacent
ocean.  However, no critical habitat for these species has been
designated in the ocean.  Disposal activities are expected to create a
limited and temporary turbid environment which could cause prey fish to
move out of or avoid the immediate area during a disposal event.  It is
also possible that minor behavioral changes by individual birds may
occur (e.g., individuals could be displaced a few dozen to several
hundred feet by the presence of the dredge/barge) to avoid the immediate
area during and immediately following any individual disposal event.

Cumulative Effects

Cumulative effects are defined as, “those effects of future State or
private activities, not involving Federal activities, that are
reasonably certain to occur within the action area of the Federal action
subject to consultation” (50 CFR §402.02).  The shoreline areas
adjacent to the proposed Siuslaw ocean disposal sites are undeveloped as
the Oregon Dunes National Recreation Area is located south of the mouth
of the Siuslaw River and the Harbor Vista County Park is located to the
north of the River mouth.  Existing development in the area occurs
primarily in Florence, located approximately 2.5 miles southeast from
the river’s mouth.  However, the action area encompasses a radius of
200 feet from the two proposed sites and does not include any shoreline.
 Currently the only anticipated user of the disposal sites is the USACE.
 Neither EPA nor the USACE has identified any future non-federal actions
that would affect ESA-listed species or their habitat.

Determination for ESA-Listed Species and Designated Critical Habitat

Coho Salmon

Based on the above assessment of the effects, it is concluded that the
proposed action may affect, and is likely to adversely affect OC coho
salmon and may affect, but is not likely to adversely affect SONCC coho
salmon and Lower Columbia River coho salmon.  Critical habitat for OC
coho salmon has been designated and the primary constituent elements
(PCEs) include “offshore marine areas with water quality conditions
and forage, including aquatic invertebrates and fishes, supporting
growth and maturation.”  However, NMFS did not designate any specific
areas based on these PCEs.  Therefore, the proposed action would result
in no effect to designated critical habitat for OC coho salmon. 
Critical habitat has been designated for SONCC coho and “consists of
the water, substrate, and adjacent riparian zone of estuarine and
riverine reaches” in specified hydrologic units of river reaches
accessible to coho salmon within the listed ESU (64 FR 24049). 
Designated critical habitat for SONCC does not include ocean waters and
therefore, the proposed action would result in no effect to SONCC
critical habitat.  No critical habitat for Lower Columbia River coho has
been designated.

Chinook Salmon

Based on the above assessment of effects, it is concluded that the
proposed action may affect, but is not likely to adversely affect Lower
Columbia River Chinook, Upper Willamette River spring-run Chinook, Upper
Columbia River spring-run Chinook, Snake River spring/summer run
Chinook, or Snake River fall-run Chinook.  Since none of these species
spawn in the Siuslaw River and only the Upper Willamette River Chinook
has designated critical habitat within the action area, the proposed
action will have no effect on designated critical habitat for any of
these ESUs.

Green Sturgeon

Based on the above assessment of the effects, it is concluded that the
proposed action may affect, and is likely to adversely affect Southern
DPS green sturgeon.  Use of the Siuslaw North and South ocean disposal
sites for disposal could result in temporary avoidance behavior in adult
green sturgeon, but smaller subadult fish would be less able to avoid
the area due to slower swimming speeds.  According to the NMFS analysis
supporting the listing of the Southern DPS of green sturgeon, “the
principal factor for decline of the Southern DPS is the reduction of the
spawning area to a limited area of the Sacramento River” (71 FR
17762).  The proposed Siuslaw ocean disposal site designations would
have no effect on the spawning area for the Southern DPS and is only
expected to result in temporary and minor modifications to migratory
pathways.  Also based on the above assessment, the proposed action to
designate two ODMD sites at the mouth of the Siuslaw River will not
destroy or adversely modify proposed critical habitat for Southern DPS
green sturgeon.

Pacific Eulachon

Based on the above assessment of the effects, it is concluded that the
proposed action is not likely to jeopardize the continued existence of
Southern DPS pacific eulachon.  Use of the Siuslaw North and South ocean
disposal sites for disposal could result in temporary avoidance behavior
in any nearby eulachon.  According to the NMFS analysis supporting the
proposed listing of the Southern DPS of pacific eulachon, the most
significant threat to eulachon and their habitats are changes in ocean
conditions due to climate change (see 74 FR 10870). The proposed Siuslaw
ocean disposal site designations would have no effect on climate related
impacts or spawning areas for the Southern DPS and is only expected to
result in temporary and minor modifications to migratory pathways.  No
long-term effects are expected to occur to pacific eulachon.

Marine Mammals 

Based upon the above assessment of the effects, it is concluded that the
proposed action may affect, but is not likely to adversely affect
Steller sea lion, blue whale, fin whale, humpback whale, southern
resident killer whale.  There is no designated critical habitat for the
above listed species in the action area and therefore, the proposed
action will have no effect on designated critical habitat for Steller
sea lion or southern resident killer whale.  Steller sea lions are
expected to avoid the sites during disposal activities.  The whale
species generally occur as migrants much farther from shore than the
action area, and it is likely that they would avoid the ocean disposal
areas during intermittent disposal activities.  

Coastal Birds

Based on the above assessment, marbled murrelets, short-tailed
albatross, and brown pelicans may temporarily avoid the disposal areas
during active disposal activities.  Therefore, the proposed action may
affect, but is not likely to adversely affect marbled murrelet,
short-tailed albatross, and brown pelican.  Since no marbled murrelet
critical habitat is located within the action area, the proposed action
will have no effect on designated critical habitat for marbled murrelet.

Terrestrial Birds, Invertebrates, and Plants

None of the other listed bird, invertebrate, or plant species is likely
to be present in the action area.  Therefore, the proposed action would
have no effect on western snowy plover, northern spotted owl, Oregon
silverspot butterfly, Fender’s blue butterfly, Kincaid’s lupine,
Willamette daisy, and Bradshaw’s desert parsley.  The proposed action
will also have no effect on any designated critical habitat for these
species.

Essential Fish Habitat Assessment

Pursuant to the Magnuson-Stevens Fishery Conservation and Management Act
(Public Law 94-265), as amended by the Magnuson-Stevens Fishery
Conservation and Management Reauthorization Act (MSA) of 2006 (P.L.
109-479) and its implementing regulations at 50 C.F.R. Part 600 Subpart
K, federal agencies are required to consult with NMFS with respect to
any action authorized, funded, or undertaken, or proposed to be
authorized, funded or undertaken, that may adversely affect  essential
fish habitat (EFH).  An “adverse effect” is defined as “any impact
that reduces quality and/or quantity of EFH.”  Adverse effects may
include “direct or indirect physical, chemical, or biological
alterations of the waters or substrate and loss of, or injury to,
benthic organisms, prey species and their habitat, and other ecosystem
components, if such modifications reduce the quality and/or quantity of
EFH.”  50 C.F.R. § 600.910(a).  The objective of federal agency
consultation is to determine whether or not the federal agency’s
proposed action “may adversely effect” designated EFH, i.e. those
waters and substrate necessary to fish for spawning, breeding, feeding,
or growth to maturity, for fish species regulated under a Federal
fisheries management plan (FMP).  If, as a result of the consultation,
NMFS determines an action would adversely affect EFH, NMFS then
determines whether or not Conservation Recommendations are needed. 
Conservation Recommendations are non-binding measures designed to
“avoid, minimize, mitigate, or otherwise offset adverse effects on EFH
resulting from actions or proposed actions authorized, funded, or
undertaken by [a federal] agency.”  50 C.F.R. § 600.905(b).  If NMFS
determines Conservation Recommendations are needed, NMFS notifies the
Federal agency of the determination and of the recommendations.  Federal
agencies are required to provide a written response to NMFS after
receiving Conservation Recommendations.  MSA § 305(b)(4)(B).  The
Federal agency response must describe the measures the agency proposes
for avoiding, mitigating, or offsetting the impact of the activity on
EFH or must explain its reasons for not following the recommendations
provided by NMFS.  50 C.F.R. § 600.920(k)(1). 

By letter dated March 30, 2009, NMFS provided EPA with a list of
species, with designated EFH in the vicinity of the proposed Siuslaw
sites.  The list was based on NMFS’ general knowledge of the presence
of EFH as determined by studies conducted by NMFS for groundfish,
coastal pelagic species, and Pacific Coast salmon.  The NMFS conducted
groundfish stock assessment studies in the areas offshore of California,
Oregon, Washington, and southern British Columbia triennially from 1977
to 2001 (Weinberg et al., 2002).  The 2001 assessment collected data
from depths ranging from 55 to 500 meters and provides useful
information on the distribution of groundfish species.  A detailed
discussion of EFH for groundfish is provided in Appendix B of Pacific
Coast Groundfish Fishery Management Plan as amended through Amendment 19
(PFMC 2006).  The report includes life history descriptions (Part 2),
EFH text descriptions (Part 3), and habitat suitability maps for
groundfish species of the Pacific Coast with associated life history
stages.  The most recent groundfish Stock Assessment and Fishery
Evaluation document was published in 2006.  A detailed discussion of EFH
for coastal pelagic species is provided in Amendment 8 to the Coastal
Pelagic Species Fishery Management Plan (PFMC 1998) and a recent Stock
Assessment and Fishery Evaluation Document, June 2007.  The salmon EFH
is discussed in the Pacific Coast Salmon Fishery Management Plan as
revised through Amendment 14 (PFMC 2003).  All of this information was
reviewed to assess the possible impacts to these species’ EFH from the
proposed action.  EPA reviewed the list of species provided by NMFS
against the areas EPA proposes to designate as the Siuslaw sites and
assessed whether or not the proposed action to designate the sites may
adversely affect EFH for any of the species with designated EFH in the
action area.  

Table   SEQ Table \* ARABIC  7 .  Species with Designated EFH Offshore
from the Siuslaw River as Provided by NMFS

Groundfish Species	Common Name	Life Stage

Larvae	Juveniles	Adults

Rockfish Species

Sebastes melanops	Black Rockfish

X	X

Sebastes goodie	Chilipepper

X	X

Sebastes rastrelliger	Grass Rockfish

	X

Sebastes mystinus	Blue Rockfish	X	X	X

Sebastes caurinus	Copper Rockfish

	X

Sebastes paucispinis	Bocaccio

X

	Sebastes nigrocinctus	Tiger Rockfish

	X

Sebastes maliger	Quillback Rockfish

	X

Sebastes entomelas	Widow Rockfish

X	X

Sebastes saxicola	Stripetail Rockfish

X	X

Sebastes proriger	Redstripe Rockfish

	X

Sebastes miniatus	Vermillion Rockfish

	X

Sebastes rufus	Bank Rockfish

	X

Sebastes rosaceus	Rosy Rockfish

	X

Sebastes pinniger	Canary Rockfish

X	X

Sebastes crameri	Darkblotched Rockfish

	X

Sebastes zacentrus	Sharpchin Rockfish

X	X

Sebastes diploproa	Splitnose Rockfish	X	X

	Sebastes levis	Cowcod

	X

Sebastes helvomaculatus	Rosethorn Rockfish

	X

Sebastes borealis	Shortraker Rockfish

	X

Sebastes flavidus	Yellowtail Rockfish

	X

Sebastes ruberrimus	Yelloweye Rockfish

	X

Sebastolobus alacanus	Short-spine Thornyhead

	X

Sebastes alutus	Pacific Ocean Perch

X	X

Sebastes auriculatus	Brown Rockfish

	X

Sebastes nebulosus	China Rockfish

	X

Sebastes variabilis	Dusky Rockfish

	X

Sebastes aleutianus	Rougheye Rockfish

X	X

Sebastes brevispinis	Silvergray Rockfish

	X

Flatfish Species

Atheresthes stomias	Arrowtooth Flounder

	X

Platyichthys stellatus	Starry Flounder

X	X

Parophrys vetulus	English Sole

X	X

Psettichthys melanostictus	Sand Sole

X	X

Isopsetta isolepis	Butter Sole

	X

Citharichthys sordidus	Pacific Sanddab

	X

Eopsetta jordani	Petrale Sole

	X

Lepidopsetta bilineata	Rock Sole

	X

Glyptocephalus zachirus	Rex Sole

	X

Pleuronichthys decurrens	Curlfin Sole

	X

Hippoglassoides elassodon	Flathead Sole

	X

Other Species

Scorpaenichthys marmoratus	Cabezon

	X

Hexagrammos decangrammus	Kelp Greenling	X

X

Raja binoculata	Big Skate

	X

Raja inornata	California Skate	X

Raja rhina	Longnose Skate

	X

Ophiodon elongatus	Lingcod	X

X

Gadus macrocephalus	Pacific Cod	X	X	X

Hydrolagus colliei	Spotted Ratfish

X	X

Squalus acanthias	Spiny Dogfish

	X

Anoplopoma fimbria	Sablefish	X	X	X

Triakis semifasciata	Leopard Shark

	X

Galeorhinus galeus	Soupfin Shark

X	X

Merluccius productus	Pacific Hake

X	X

Salmon Species	Common Name

	Oncorhynchus kisutch	Coho Salmon

	Oncorhynchus tshawytscha	Chinook Salmon

	Coastal Pelagic Species	Common Name

	Sardinops sagax	Pacific Sardine

	Scomber japonicus	Pacific (Chub) Mackerel

	Engraulis mordax	Northern Anchovy

	Trachurus symmetricus	Jack Mackerel

	Loligo opalescens	California Market Squid

	Potential Effects of the Proposed Action on EFH

The proposed sites have been selected to minimize impacts to ocean
resources by avoiding unique areas and areas of greater biological
productivity.  The proposed sites have been sized large enough to handle
disposal material for at least a 20-year period and will be managed to
minimize impacts within the sites.  In addition, both historical and
recent studies have been conducted to further characterize the sites and
help in their management and use.

Table 7 shows the fish species with designated EFH in the Pacific Ocean
offshore from the Siuslaw River.  Disposal of dredged material at ocean
disposal sites will have a temporary effect on the water column and
benthic habitat at the disposal sites.  Turbidity resulting from
disposal may persist within the water column for a period of a few
minutes to a half hour (USACE 2008) and the benthic community may take a
few weeks to months to re-colonize.  However, the proposed sites
generally represent only a small portion of the overall EFH for any of
the species listed below.

Groundfish Species EFH

Rockfish Species.  Fourteen of the rockfish species shown in Table 7
(stripetail, redstripe, vermillion, bank, speckled, canary,
darkblotched, sharpchin, splitnose, rosethorn, shortraker, yelloweye,
Pacific ocean perch, and short-spine thornyhead) are expected to occur
at water depths deeper than those occurring at the proposed ocean
disposal sites.  Because the proposed sites do not provide suitable
aquatic habitat, no effects to EFH for these rockfish species are
anticipated.

The remaining rockfish species shown in Table 7 rely on nearshore
habitats such as shallow bays and nearshore rocky areas, and many are
closely associated with kelp and eelgrass beds.  All life stages are
associated with some type of structure such as areas with vertical
relief, mixtures of rocks and boulders, rock ridges, crevices of rock
outcrops, pinnacles, and artificial reefs.  Because the proposed sites
do not provide the preferred aquatic habitat or habitat complexity, no
adverse impacts to EFH for these rockfish species are anticipated.

Flatfish Species.  Two of the flatfish species shown in Table 7 (rex and
flathead) are expected to occur at water depths deeper than those
occurring at the proposed Siuslaw sites.  Because these sites do not
provide suitable aquatic habitat, no effects to EFH for these flatfish
species are anticipated.

The life stages of the remaining flatfish species (arrowtooth and starry
flounder; English, sand, butter, petrale, rock, and curlfin sole; and
Pacific sanddab) would likely be present in the water column over the
proposed sites and could potentially be impacted by disposal operations.
 The proposed Siuslaw sites do provide suitable EFH for these flatfish
species.  Trawl data from August and September 2008 found sanddab and
English, sand, and butter sole at the proposed sites.

Cabezon and Kelp Greenling.  Both of these species are abundant all year
in estuarine and subtidal areas.  Larvae and young juveniles are pelagic
and have been found offshore in waters over 300 meters in depth. 
Juveniles settle to the bottom and are found primarily in shallow-water
bays and estuaries.  Kelp greenling lay eggs on or between rocks or in
algae beds.  Rocky bottoms and cobble substrata are the most frequently
used habitats by cabezon.  Because the proposed Siuslaw sites do not
provide the preferred aquatic habitat or habitat complexity for cabezon
and kelp greenling, no adverse impacts to EFH for these species are
anticipated.

Big Skate.  Big skates are relatively abundant in northern and central
California, but are not common south of Point Conception.  Records show
big skates inhabiting water as shallow as 3 meters, but in survey
catches in the North Pacific they are found most frequently on the outer
shelf in waters 50 to 200 meters deep.  Over their range, big skates
have been taken from waters up to 800 meters deep; however, few occur
deeper than 350 meters.  Juveniles are associated with soft bottom
sediments.  In an assessment of habitat types and associated fish
assemblages at Heceta Bank off the southern Oregon Coast, adult skate
were most commonly found in habitat consisting of mud substrate and
populated by sea urchins.  They were evenly and sparsely distributed
over mud bottoms, and usually lay on the bottom.  The proposed Siuslaw
sites provide suitable EFH for this species.  Trawl data from August and
September 2008 found a few big skates at the proposed sites.

Lingcod.  Lingcod are an estuarine mesobenthal species that occurs in
depths from 0 to 475 meters.  Spawning occurs from 3 to 10 meters below
mean lower low water over rocky reefs in areas of swift currents. 
Larvae occur in near shore areas from winter to late spring.  Larger
larvae are epipelagic, primarily found in the upper 3 meters of the
water column.  Juveniles settle in estuaries and shallow waters along
the coast while older juveniles move offshore as they grow but are most
common in waters greater than 150 meters.  Adults prefer slopes of
submerged banks 10 to 70 meters below the surface with sea weeds, kelp
and eelgrass beds that form feeding grounds for small prey fish.  They
also prefer channels in rocky intertidal areas with swift currents that
concentrate plankton and plankton feeding fish.  Based on these habitat
requirements, the proposed Siuslaw sites would not provide suitable EFH
for lingcod.  

Pacific Cod.  Pacific cod are a member of the inner shelf-mesobenthal
community.  The majority of Pacific cod are found at depths from 50 to
300 meters with spawning occurring at depths from 40 to 265 meters.  The
eggs are demersal, adhesive, and are found sublittorally.  Larvae and
small juveniles are pelagic, with the highest abundance in the upper 15
to 30 meters of the water column.  Larvae are found over the continental
shelf from winter through summer.  Small juveniles occur in depths from
60 to 150 meters gradually moving to deeper water with increased age. 
Larger juveniles and adults are parademersal occurring over mud, sand
and clay, and occasionally coarse sand and gravel bottoms.  Based on
these habitat requirements, the proposed Siuslaw sites would not provide
suitable EFH for Pacific cod.

Spotted Ratfish.  Ratfish are a middle shelf mesobenthal species that
occur in depths from 0 to 913 meters.  They are most abundant in depths
from 100 to 150 meters.  They also occur in estuaries during the winter
and early spring to feed and mate.  Ratfish are generally a deep water
species that prefer low relief, rocky bottoms or exposed gravel or
cobble.  They are not commonly found over sand or boulders.  Based on
these habitat requirements, the proposed Siuslaw sites would not provide
suitable EFH for ratfish. 

Spiny Dogfish.  The spiny dogfish is an inner shelf-mesobenthal species
with a depth range of 0 to 1,236 meters.  From survey data, most dogfish
inhabit waters less than 350 meters deep.  They occur from the surface
and intertidal areas to greater depths, and are common in inland seas
such as San Francisco Bay and Puget Sound and in shallow bays from
Alaska to central California.  Adult females move inshore to shallow
waters during the spring to release their young.  Small juveniles (<10
years old) are pelagic while subadults and adults are mostly
sublittoral-bathyal.  Subadults are found on muddy bottoms when not
found in the water column.  The proposed Siuslaw sites may provide
suitable EFH for spiny dogfish. 

Sablefish.  Sablefish are an inner shelf-bathybenthal species that
occurs in deep water.  Sablefish are most abundant in depths from 200 to
1,000 meters but have been reported to depths of 1,900 meters.  Spawning
occurs at depths greater than 300 meters.  Larvae and young juveniles
are pelagic and may move inshore and remain there for up to 4 years to
rear.  Older juveniles and adults inhabit progressively deeper water and
are benthopelagic on soft bottoms.  Based on these habitat requirements,
the proposed Siuslaw sites would not provide suitable EFH for sablefish.

Leopard Shark.  Leopard sharks are found from southern Oregon to Baja
California.  This species is most abundant in northern California bays
and estuaries and along southern California beaches.  They are common in
waters less than 20 meters deep and use estuaries and shallow waters for
pupping and feeding/rearing grounds.  Leopard sharks are associated with
artificial structures such as piers and jetties and a variety of bottom
habitats such as hard, mixed, unconsolidated, and vegetated bottoms. 
Based on these habitat requirements, the proposed Siuslaw sites would
not provide suitable EFH for leopard shark. 

Soupfin Shark.  Soupfin shark are an abundant coastal pelagic species
that ranges from Canada to Mexico.  They inhabit bays and muddy shallow
water areas where they are associated with the bottom.  They occur in
depths from 2 to 471 meters.  Adult males occur in deeper water in
northern California, while females occur closer to shore in southern
California.  Juveniles are also more abundant in the southern portion of
the range associated with the females.  Juveniles also occur in bays
such as San Francisco Bay to rear.  Soupfin shark exhibit large coastal
migrations; the population moves north in the summer and south in the
winter.  The proposed Siuslaw sites may provide suitable EFH for soupfin
shark.

Pacific Hake.  Pacific hake is a migratory species that inhabits the
continental slope and shelf from Baja California to British Columbia. 
Juvenile hake usually reside in shallow coastal waters, bays, and
estuaries with adults occurring further offshore, usually at depths from
50 to 500 meters.  Along the Pacific Coast from British Columbia to
California, adults use a narrow band of feeding habitat near the shelf
break for 6-8 months per year.  Based on these habitat requirements, the
proposed Siuslaw sites would not provide suitable EFH for Pacific hake.

Coastal Pelagic Species EFH

The nearshore area off the Siuslaw River has the potential to provide
EFH for northern anchovy (Engraulis mordax), Pacific sardine (Sardinops
sagax), Pacific (chub) mackerel (Scomber japonicus), jack mackerel
(Trachurus symmetricus), and California market squid (Loligo
opalescens).  The EFH for the four coastal pelagic fish species is the
water column except for the market squid, which spawns in specific
spawning grounds on the bottom.  The proposed Siuslaw sites may provide
suitable EFH for these four pelagic fish species.

Market squid range from Mexico to Alaska, although they are most
abundant from Monterey Bay to Mexico.  Although they are considered
pelagic they actually occur from the surface to depths of 800 meters. 
They prefer ocean salinities and are rarely found in bays, estuaries, or
near river mouths.  Squid spawn in dense schools on the bottom in
spawning areas that range in depth from near shore shallow areas to
depths of 800 meters.  Known spawning areas are inshore protected areas
with sand or mud bottoms at depths from 5 to 55 meters.  Squid spawning
off Oregon has been observed from May to July.  No squid spawning areas
have been identified in the vicinity of the proposed Siuslaw sites. 
Consequently, the proposed Siuslaw sites do not provide suitable EFH for
market squid.

Salmon Species EFH

The nearshore area offshore from the Siuslaw River has the potential to
provide EFH for Chinook salmon (Oncorhynchus tshawytscha) and coho
salmon (Oncorhynchus kisutch).  The proposed Siuslaw sites may provide
EFH for Chinook and coho salmon as a migratory area for adults and
juveniles.  

Determination for Essential Fish Habitat

There is a potential to impact EFH for some flatfish species (arrowtooth
and starry flounder; English, sand, butter, petrale, rock, and curlfin
sole; and Pacific sanddab), big skate, spiny dogfish, Soupfin shark,
four coastal pelagic fish species (northern anchovy, pacific sardine,
pacific mackerel, and jack mackerel), and Chinook/coho salmon by use of
the proposed North and South ocean disposal sites near the Siuslaw
River.  The amount of habitat potentially impacted by site use, however,
is expected to be very small compared to the total EFH habitat
identified for each of the species evaluated.  In no case does the
habitat provided by the proposed Siuslaw sites represent any unique
habitat that is limited in distribution.  Therefore, although the
designation of the Siuslaw sites may adversely affect EFH for the above
listed species, those effects are expected to be minor and temporary and
are not expected to reduce the quality and/or quantity in any
significant way for any EFH for any of the species listed above.  

The following measures have been considered by EPA as a way to mitigate
any adverse impacts to designated EFH at the proposed Siuslaw sites. 
EPA expects to incorporate these measures into the site management and
monitoring plans for each of the proposed Siuslaw sites.  

Dredged material to be disposed at the Siuslaw North and South ocean
disposal sites must determined to be suitable for unconfined, aquatic
disposal.  In the event that any dredged material is not suitable for
unconfined, aquatic disposal, the dredged material found unsuitable will
not be disposed at the Siuslaw ocean disposal sites, but will be placed
at acceptable upland disposal sites.

Bathymetry at the Siuslaw North and South ocean disposal sites will be
monitored on a regular basis to ensure that mounding is not occurring.  

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Carretta, J. V., K.A. Forney, M.S. Lowry, J. Barlow, J. Baker, B.
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Erickson, D. L. and J.E. Hightower.  2007.  Oceanic distribution and
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Erikson, D. L. and M.A.H. Webb.  2007.  Spawning periodicity, spawning
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Farr, R.A. and T.A. Rien.  2003.  Green Sturgeon Population
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 EPA’s interim designations were superseded by later statutory and
regulatory changes.

  Pursuant to the Ocean Dumping Regulations at 40 C.F.R. § 227.13(b),
dredged material which meets the following criteria is environmentally
acceptable for ocean dumping without further testing:  (1) dredged
material composed primarily of sand, gravel, rock, or any other
naturally occurring bottom material with particle sizes larges than
silt, and the material is found in areas of high current or wave energy
such as streams with large bed loads, or coastal areas with shifting
bars and channels; or (2) dredged material for beach nourishment or
restoration and is composed primarily of sand, gravel, or shell with
particle sizes compatible with material on the receiving beaches; or (3)
when the material is substantially the same as the substrate at the
proposed disposal site and the site from which the material is taken is
far removed from known existing and historical sources of pollution such
that there is a reasonable assurance that the material has not been
contaminated by such pollution.   The use of the SEF screening levels
provide additional safeguards for material that would otherwise meet the
regulatory criteria for environmentally acceptable material for ocean
dumping without further testing.

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Biological Assessment & Essential Fish Habitat Assessment, Proposed
Siuslaw River ODMDS Designation

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