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NFLUENCE
ENVIRONMENTAL COMPANY
146 N Canal St, Suite 111 • Seattle, WA 98103 • www.confenv.com
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BDN Inc. lit
SMERS H FARM CUMULATIVE IMPACTS-REPORT
FINAL REPORT
Prepared for:
BDN Inc.
3011 S. Chandler St.
Tacoma, WA 98409
Attn: Brad Nelson
Authored by:
Confluence Environmental Company
May 2019
146 N Canal St, Suite 111 d Seattle, WA 98103 o www.confenv.com
BDN Inc. - SMERSH FARM CUMULATIVE IMPACTS REPORT
TABLE OF CONTENTS
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1.0 INTRODUCTION...................................................................................................................................................1
2.0 PROJECT DESCRIPTION....................................................................................................................................1
3.0 EFFECTS ANALYSIS...........................................................................................................................................2
3.1 Biological Impacts.....................................................................................................................................2
3.1.1 Water Quality......................................................................................................................2
3.1.1.1 Filtration....................................................................................................................................3
3.1.1.2 Turbidity During Harvest..........................,...............................,..,.............................................3
3.1.2 Habitat Functions......................................................................................................................3
3.1.2.1 Sediment Character/Quality................................................................................................4
3.1.2.2 Sediment Supply and Delivery ................................................................... ..........................4
3.1.2.3 Submerged Aquatic Vegetation......................................................................... ..... .........4
3.2 Impacts to Navigation..............................................................................................................................6
3.3 Impacts to Aesthetics....................................................................................................................... ....7
3.4 Impacts to Public Access..........................................................................................................................7
4.0 CONCLUSION......................................................................................................................................................7
5.0 REFERENCES......................................................................................................................................................9
TABLES
Table 1. Cumulative Impact Determinations.... . ................................................................. . ................... ........8
............... .
FIGURES
Figure1. Project area and vicinity..................................................................................................................................1
Figure 2. Eelgrass delineation (2016, 2018) results........................................................................................................5
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1.0 INTRODUCTION
BDN, Inc. has leased parcel 721031007 (Smersh parcel) on Shine Road, west of the Hood Canal
Bridge, and is proposing to operate a geoduck farm at the site (Figure 1). A conditional use
permit is required by Jefferson County and, as part of the permit application, a cumulative
impacts assessment has been requested by the County pursuant to Jefferson County Code (JCC)
18.25.440 and JCC 18.25.590.
This report provides an assessment of cumulative impacts that may result from the proposed
project. Cumulative environmental effects can be defined as environmental effects caused by
the combined results of past, current, and future activities. This assessment incorporates the
following factors in an assessment and summation of potential cumulative impacts: current
ecological functions, human factors influencing shoreline processes, foreseeable future shoreline
development, beneficial effects of regulatory programs, and conservation measures.
Figure 1. Project area and vicinity.
2.0 PROJECT DESCRIPTION
BDN, Inc proposes to plant up to 5.15 acres of geoducks at the site between +2 feet and
approximately -2 feet relative to mean lower low water (MLLW). The lower boundary of
planting will be determined based on the location of the eelgrass bed below approximately -2
feet MLLW (Confluence 2016, 2018a).
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To protect juvenile geoduck until they can burrow deep enough to avoid predators, PVC tubes
4" in diameter by 10" long would be placed into the sandy substrate. Tubes would be placed at
an approximate density of 1 tube per square foot with 3" to 5" of the tube exposed above the
substrate. Area netting may be placed over the tubes to prevent them from becoming dislodged
during severe weather. Tubes would be removed after 18-24 months once the geoduck have
reached a sufficient size and depth to avoid predation.
Routine maintenance of the proposed geoduck aquaculture area ensures that gear is preserved
on-site, and would begin once gear has been installed. Maintenance would occur monthly, and
also immediately following large storm events. Maintenance activities may include monitoring
shellfish weight and health, collecting unnatural debris, ensuring that predator netting is
suitably anchored to the substrate, and confirming that PVC tubes are not becoming dislodged
from the substrate. Maintenance would typically be done by a two -person crew over a 4 -hour
period.
Geoduck will be harvested 5-7 years after planting. Netting may remain on the site until harvest
to protect the crop from theft and/or predation.
3.0 EFFECTS ANALYSIS
Potential effects to fish and wildlife habitat, boat navigation, aesthetics, and public access/use
are considered in this assessment. Biological impacts and visual impacts have been assessed in
detail in separate reports (Confluence 2018b, Confluence 2018c). Summaries of the findings of
those assessments are included below in addition to evaluations of effects to boat navigation
and public access.
3.1 Biological Impacts
Biological impacts are discussed below as a function of potential effects to water quality (i.e.
filtration by shellfish, turbidity during harvest) and physical habitat functions (i.e. sediment
quality, sediment supply and delivery, submerged aquatic vegetation). Additional detail on
each of these elements is provided in Confluence 2018b.
3.1.1 Water Quality
Potential effects to water quality and fish and wildlife species or their habitat are different
during the growing and harvest phases of geoduck aquaculture. During the growth phase,
geoducks filter phytoplankton and other particles from the water column. During harvest,
sediment is re -suspended into the water column. These two aspects are addressed in further
detail below.
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3.1.1.1 Filtration
The depth at which photosynthetic submerged aquatic vegetation (SAV) can grow is limited by
the depth at which light penetrates through the water column. Shellfish aquaculture can result
in a beneficial reduction in turbidity, and increase in light penetration, due to removal of
phytoplankton and particulate organic matter through filtration. Improvements to water clarity
and light penetration can improve habitat conditions through the growth of SAV.
Shellfish aquaculture or the presence of a naturally dense bivalve community may provide
some control of human nutrient loading to water bodies. Bivalves remove phytoplankton and
suspended sediment from the water column through filtration, which can have a net benefit to
water quality. When shellfish are harvested, sequestered nutrients are permanently removed
from the system which benefits areas with high nutrient loading, such as Hood Canal.
Shellfish aquaculture infrastructure also provide microhabitats for communities of nitrifying
microbes. Through filtration, sequestration, and hosting of nitrifying microbes, commercial
shellfish aquaculture can be considered a net benefit to water quality ecosystem functions.
3.1.1.2 Turbidity During Harvest
Geoducks can be harvested when the tide is out or by divers when the tide is in; both methods
use a water jet to loosen the sediment around the geoduck which causes a temporary increase in
suspended sediment and turbidity. A geoduck harvest event is limited geographically and
temporally compared to natural storm events which increase suspended sediment and turbidity
to comparable levels.
Exposure to high levels of suspended sediment can stress fish and result in reduced survival
and growth but studies have shown that fish are likely to avoid localized, elevated turbidity
events such as a geoduck harvest.
Both the timing and intensity of potential harvest impacts are below the natural disturbance
regime of typical Puget Sound storm events (VanBlaricom et al. 2015). Experimental results
show that levels of total suspended sediment associated with geoduck harvest are low, with the
majority of sediment deposited within 3 feet of the harvest hole (Short and Walton 1992).
Additionally, mobile species are able to avoid the area during harvest activity. Harvest will
happen only periodically (e.g. 5-7 years after geoducks have been planted). Because turbidity
impacts during harvest are anticipated to be similar to, or less than, natural storm events,
harvest is not anticipated to result in negative impacts to ecological functions.
3.1.2 Habitat Functions
In -water projects may have the potential to alter sediment character and quality, sediment
supply and delivery, or distribution of submerged aquatic vegetation. Changes to these
elements could result in either negative or beneficial alteration of habitat in the vicinity of the
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project. The potential effects to each of these elements from geoduck culture and harvest is
discussed further below.
3.1.2.1 Sediment Character/Quality
Sediment along the north shore of Squamish Harbor is primarily sandy in the lower elevations
with gravel and cobble on the upper intertidal beach. No sediment contaminants are known in
the proposed project area and the surrounding land use is low density residential, so industrial
sediment contaminants are not likely to be found in the area. The proposed project will not be
using any chemicals that may cause sediment contamination. The proposed project would not
change existing sediment character or quality.
3.1.2.2 Sediment Supply and Delivery
The sandy beach on the north shore of Squamish Harbor slopes gradually and is exposed to
wind -generated waves from the south, where winter storms typically come from in Puget
Sound. East of the project area there is a high, eroding bluff that supplies sediment to the beach.
Net shore -drift of sediment is to the west, from the eroding bluff toward the proposed project
site (Ecology 2019). Shoreline armoring is prevalent along the north shore of Squamish Harbor,
which may generally limit sediment supply in the area (ESA Adolphson et al. 2008).
The two types of potential disturbances associated with geoduck aquaculture that could affect
sediment supply and delivery include the use of tubes and netting that slow the transport of
sediments, and sediment re -suspension due to harvest activities.
A small accumulation of sediment may collect in the proposed geoduck tubes and is expected to
rapidly redistribute through wave and current action after one or two tidal cycles following the
removal of nets and tubes (Short and Walton 1992).
During a geoduck harvest, the overlying sediments are loosened around the clam by a low-
pressure water hose. Although this activity results in minor, localized changes in elevation and
sediment grain size, both quickly return to baseline conditions within one month after harvest
(Short and Walton 1992).
In summary, geoduck harvest and the presence of culture tubes and/or cover nets do not lead to
significant impacts to sediment transport or bathymetry. Minor changes in elevation may
persist for up to 1 month, but these effects are insignificant compared to the natural sediment
dynamics along the shoreline associated with the project area.
3.1.2.3 Submerged Aquatic Vegetation
A dense bed of eelgrass (Zostera marina) extends from approximately -3 ft MLLW, waterward of
the project area to an unknown depth. A narrow band of sparse, patchy eelgrass is landward of
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the dense bed between approximately -2 and -3 feet MLLW. Several sparse patches of non-
native dwarf eelgrass (Zostera japonica) were observed distributed in the proposed project area.
Throughout the Puget Sound, a 16 -foot protective buffer around native eelgrass beds is used to
minimize the impact of new shellfish aquaculture activities (Corps 2015). The width of this
buffer is based on field experiments and observations that suggest the maximum distance of
seed dispersal is 5 meters (16.4 ft) and the maximum potential annual migration zone is -5m to
+4m (DNR unpublished data, Ruckelshaus 1996). By maintaining a protective buffer around
eelgrass beds of 16 ft, it is presumed that geoduck farming activities would not intersect
eelgrass beds and would have no impact on the growth and survival of nearby native eelgrass.
At present, eelgrass occurs at least 16 ft from the proposed geoduck planting area based on
multiple bed delineation surveys (Confluence 2016, 2018a). While eelgrass beds are known to
expand, contract, and shift on an annual basis, it is not likely that eelgrass would move into the
proposed culture area. The consistent location of the eelgrass bed edge mapped in two surveys
two years apart indicates the stability of this landward bed edge, with little change to the extent
of dense eelgrass found below -2 ft MLLW (Confluence 2016, 2018a).
Figure 2. Eelgrass delineation (2016, 2018) results.
The location of the landward edge of eelgrass beds is largely determined by physical
characteristics associated with the intertidal zone; primarily desiccation stress (Koch 2001, Boese
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et al. 2005). Eelgrass higher in the intertidal zone is exposed to air more frequently and for
longer durations with each tidal cycle, resulting in increased desiccation damage (Boese et al.
2005). Zostera species are relatively tolerant of desiccation, but patches of Z. marina in the higher
intertidal zone are usually associated with drainage channels or depressions (Thom 1990).
Z. japonica is more tolerant of desiccation and therefore occurs at higher tidal elevations than the
native eelgrass (Leuschner et al. 1998).
Waves can also limit the expansion of eelgrass beds, as seedlings and new shoots are not
tolerant of high current velocities and wave action (Koch 2001). The Smersh parcel faces south
into Hood Canal and is positioned such that waves originating in the southern portions of Hood
Canal have approximately 12 miles of fetch in which to gain amplitude. Prevailing winds over
the Puget Sound are south or southwest during the winter, when the strongest storms move in
off the Pacific Ocean (Finlayson 2006). Southerly winter winds and long fetch distances create
the potential for significant wave action at the proposed farm site. During low tide events at the
project location, the beach is exposed to waves and resulting scour/erosion, as well as
desiccation; both of which increase stress on the plants and limit its landward expansion. Thus,
the edge of the native eelgrass bed is unlikely to move to areas landward of its current extent at
approximately -2 ft MLLW.
Macroalgae beds are not found in or near the project area. Green algae (Ulva spp) were present
at a very low density, attached to a small number of hard objects such as derelict clam shells in
the proposed aquaculture area.
Macroalgae density is anticipated to increase in the project area due to geoduck farming as the
PVC tubes and cover netting provide solid substrate required by macroalgae for attachment
and growth.
Because the project will be located outside of a 16 -foot protective buffer from native eelgrass, no
negative effects are anticipated to occur to eelgrass due to the proposed project and there may
be an ecological lift from the potential increase in other macroalgal species on the tubes and
netting.
3.2 Impacts to Navigation
The project parcel is located adjacent to the W.R. Hicks County Park, which includes a small
boat ramp. Thus, there is potential for boat traffic and recreational use of the surrounding
waters by small boats and kayaks. Because geoducks are grown in the sediment and associated
infrastructure (netting and tubes) has very low relief (less than 5 inches), boating and kayaking
is unlikely to be significantly affected. Additionally, the intertidal area where the farm is
proposed is shallow and not generally suitable for boating making impacts to boat navigation
unlikely. Usual aquaculture activities (i.e. weekly farm maintenance) will require up to four
workers accessing the intertidal beach during low tide. Because this routine activity does not
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occur in the water, no impacts to kayaking are anticipated. Also, while up to two boats may be
required to support harvest events, this level of boat traffic is not expected to significantly affect
kayaking or other recreational boating activity.
3.3 Impacts to Aesthetics
A visual impacts assessment was completed as part of this project and indicates that visual
impacts due to the project would be very low (Confluence 2018b). The proposed geoduck
planting area covers less than 5 percent of the cone of vision when viewed from nearby
residences. The project is 500 feet wide along the nearly 2 -mile -long northern shoreline of
Squamish Harbor.
The Smersh site is located on a heavily altered shoreline in a medium -density, residential
neighborhood. The shoreline has been altered by rip rap hardening, there is a concrete boat
ramp and gravel parking lot on the adjacent public property, riparian trees have been removed
from a number of the adjacent properties to increase private views, and the paved roadway is
adjacent to the shoreline for approximately 1 mile next to the Smersh parcel.
Tides low enough to expose the planting area follow a seasonal pattern in the Puget Sound
region. Larger -magnitude summer low tides occur during daylight hours, while winter low
tides occur at night. Therefore, geoduck tubes and netting are more visible in summer, and
minimal in winter. Also, geoduck tubes and nets have very low relief and natural macroalgae
colonizes equipment rapidly, quickly resulting in natural color and texture.
Given the site is visible only a small portion of the time, the site is not visible from heavily
traveled routes, the surroundings are heavily altered by local residential development, and the
geoduck tubes and netting will quickly take on a natural color due to colonization by aquatic
flora and fauna, there would be only very low impacts to aesthetics.
3.4 Impacts to Public Access
Beach walking, clam digging, crabbing, fishing, boating, and kayaking are common recreational
activities near the proposed farm site. The project parcel is located next to a public county park
but is itself located on private tidelands. Thus, there will be no impacts to beach access as part of
this project as the tidelands are not currently accessible by the public. Due to the only slight
emergence of the tubes above the substrate (5 inches), water dependent uses (e.g. boat access,
kayak access) will not be significantly affected.
4.0 CONCLUSION
Based on communication with Jefferson County, no other like actions are present or proposed in
the area that will cumulatively increase impacts to the area (Bausher 2018). As presented above,
the proposed project would have minimal negative impact on the local shoreline and some
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beneficial impacts. Past and current use of the area is residential and any impacts to the
shoreline are incorporated into existing background conditions. Thus, the cumulative impact of
the project on the local ecosystem would range from none to minor as summarized in Table 1.
Table 1. Cumulative Impact Determinations.
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Impact..Impact
Determination
Biological (Water Quality and
None
0 Filtration by geoducks may improve water quality in the
Habitat Functions)
vicinity of the proposed project area.
■ Turbidity will be temporarily increased during harvest,
but this will not negatively impact habitat because
effects are less than natural disturbance levels.
■ Sediment character and quality will not change as part
of the proposed project.
• Sediment supply and delivery may be temporarily
impacted by accumulating sediment during the
proposed project and releasing sediment during
harvest.
Protective buffers will be maintained around native
eelgrass and macroalgae may be beneficially impacted
during the proposed project by increasing the substrate
where it can establish.
Navigation
None
H The proposed project has very low relief (e.g., 0.25 feet)
and is located in an area generally unsuitable for
boating (shallow).
Aesthetics
Minor
The proposed project will be visible for only short
duration during very low tides.
Maintenance will occur monthly to ensure farm is tidy
and tubes have not become dislodged.
While not in use, equipment will be stored off-site.
v Proposed project is located on private tidelands with no
Public Access
None
public access.
Water dependent uses (e.g. boat access, kayak access)
will not be affected because geoduck equipment
extends only 5 inches above substrate.
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5.0 REFERENCES
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Bausher, A. 2018. Personal communication between Anna Bausher, Jefferson County -
Development Review Division, and Grant Novak, Confluence Environmental. June, 14, 2018
Boese, B. L., Robbins, B. D., & Thursby, G. (2005). Desiccation is a limiting factor for eelgrass
(Zostera marina L.) distribution in the intertidal zone of a northeastern Pacific (USA)
estuary. Botanica Marina, 48(4), 274-283.
Confluence (Confluence Environmental Company). 2016. BDN Eelgrass Delineation -
Final Report. October 31, 2016.
Confluence. 2018a. 2018 Zostera marina bed edge re -verification. July, 2018.
Confluence. 2018b. Smersh Farm Habitat Management Plan and No Net Loss Report. June,
2018.
Confluence. 2018c. Smersh Farm Visual Assessment. June, 2018.
Ecology (Washington Department of Ecology). 2019. Washington State Coastal Atlas Map.
httns://Fortress.wa.govlecy/coastalatlas/tools/Map.aspx. Accessed on May 9, 2019.
ESA Adolphson, Searun Consulting, LaRoche+Associates, and Coastal Geologic Services. 2008.
Jefferson County Shoreline Master Program Update Project - Final Shoreline Restoration
Plan. Prepare for Jefferson County Department of Community Development. Ecology
Grant#G0600343. October 2008.
Finlayson, David P. 2006. The Geomorphology of Puget Sound Beaches. Doctoral dissertation.
University of Washington, Seattle.
Koch, E. W. (2001). Beyond light: physical, geological, and geochemical parameters as possible
submersed aquatic vegetation habitat requirements. Estuaries, 24(1), 1-17.
Leuschner, C., Landwehr, S., & Mehlig, U. (1998). Limitation of carbon assimilation of intertidal
Zostera noltii and Z. marina by desiccation at low tide. Aquatic Botany, 62(3), 171-176.
Ruckelshaus, M.H. (1996). Estimation of genetic neighborhood parameters from pollen and
seed dispersal in the marine angiosperm Zostera marina. Evolution 50(2):865-864
Short, K.S., and R. Walton. 1992. The transport and fate of suspended sediment plumes
associated with commercial geoduck harvesting, Final Report. Prepared for the State of
Washington Department of Natural Resources. Prepared by Ebasco Environmental,
Bellevue, Washington.
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Thom, R. M. (1990). Spatial and temporal patterns in plant standing stock and primary
production in a temperate seagrass system. Botanica marina, 33(6), 497-510.
U.S. Army Corps of Engineers, Seattle District (Corps). 2015. Shellfish Activities in Washington
State Inland Marine Waters. U.S. Army Corps of Engineers Regulatory Program. Available
at:
htt s: www.nws,usace.arm .mil Portals 27 docs re ulator NewsU dates Shellfish PBA
30 Oct 2015. df?ver-2016-09-07-185805-287
Vanblaricom, G. R., Eccles, J. L., Olden, J. D., & Mcdonald, P. S. (2015). Ecological effects of the
harvest phase of geoduck (Panopea generosa Gould, 1850) aquaculture on infaunal
communities in southern Puget Sound, Washington. Journal of Shellfish Research, 34(1),
171-188.
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