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NEXT STEPS
1. Estuaries are essential for salmon production. Work to
continue estuary rehabilitation and protection in the
Strait of Georgia is highly recommended.
2. Removal of marine debris from estuaries is required
to allow for successful restoration.
3. Signage providing information about extent of local
eelgrass and kelp habitats, as well as creation of
eco-friendly mooring buoys, could reduce damage to
these important habitats.
4. Studies are required to determine effective strategies
to mitigate high levels of contaminants, including
hydrogen sulfide, in estuarine sediments that would
otherwise be suitable for eelgrass productivity.
5. An ongoing study evaluates the effects of temperature
stress on kelp populations in the Salish Sea. There
appear to be kelp populations that are adaptable to
local temperature regimes: work is being carried out
to assess thermal tolerance with the hope that warm
water-adapted populations could be more effective for
restoration activities, particularly under climate change.
6. Research is needed to find possible genetic strains
of eelgrass resistant to wasting disease (Labyrinthula
zosterae), a mold disease related to increased sea
surface temperatures.
7. Research is needed to define areas of eelgrass and kelp
on the entire coast of BC. A mapping of the extent of
local kelp and eelgrass habitats, and protection of these
habitats is highly recommended.
Figure 4. Chinook smolts leave both the Green and Skagit Rivers early
as small fry and later as larger parr. However, returning adults to the
more developed Green River are only derived from those smolts that
left as parr. The fry component did not appear to survive. Similar
results were apparent in a number of other degraded estuaries.
Figure provided by Lance Campbell, WDFW.
Figure 5. Changes in spatial distribution of eelgrass between two
consecutive mapping years in Horton Bay along with shoreline
activities. Eelgrass is seen to progressively deteriorate as boat
traffic increases and more docks are built. Figure provided by
Natasha Nahirnick.
KELP LIMITING FACTORS
Prolonged (>35 days) temperatures >16° C.
Grazing pressure from sea urchins and kelp crabs.
Competition from other algae for substrate.
EELGRASS LIMITING FACTORS
Salinity over 42 ppt, high turbidity (lack of light),
pH outside of 7.3 to 9.0, temps outside of 5° C to 30° C.
Substrates with high levels of hydrogen sulfide (from
long term log booming).
Direct damage due to anchorages and presence
of marine debris.
