Page 27 - 2021PSF-ResilientCoastsForSalmon-NewLogo-Primer-Web

Photo by: Tavish Campbell on Flickr

On armoured shorelines, salmon are unable to light seems to make salmon nervous, they
access their preferred prey items . Studies have cannot see predators, find ample prey, properly
found that shoreline armouring reduced the orient themselves, or school together (Munsch
number and diversity of epibenthic invertebrate et al . 2017) . They end up altering their natural
(critters that reside on or above the rock, sand and behaviours and avoid the shallow areas that
mud of the seafloor) compared to unarmoured should be their safe havens with plentiful food
shoreline (Morley et al . 2012) . As a result, when (Munsch et al . 2014) . Instead, salmon are swim-
young salmon are next to a seawall and other ming in deeper water, expending more energy,
artificial structures, they end up feeding on and exposing themselves to predators .
alternative types of prey that might be harder Coastal modification also disrupt overall land and
to catch and less nutritious .
sea connectivity (Heerhartz et al . 2014) . Coastal
Quality shallow habitat is also lost under traditional riparian vegetation is lost on modified shores
overwater structures, such as piers and docks . along with the insects that would fall into the
The areas beneath them are bleak . They cast too water – another important food source for salmon
much shade and seagrasses and algae cannot (Toft et al . 2007) . Surf smelt, a prized prey item for
thrive (Burdick and Short 1999; Nahirnick et al . salmon as they grow in coastal areas, also suffer
2020) . While you may be able to spot crabs and without overhanging coastal vegetation . The shade
some barnacles or mussels under these structures, of the vegetation regulates the temperature of the
overall, there are few fish or other animals . Salmon upper shoreline and this is important for successful
avoid these areas — it is too dark — the lack of surf smelt beach spawning (Munsch et al . 2017) .

BOTTOM LINE:

Coastal modifications disrupt natural, dynamic coastal processes, ecosystems,

as well as Pacific salmon. Change along our coastlines is inevitable because that’s
what natural coastal processes do! It is in our best interests — and salmons’ —
to work with nature, not against it!

26