What are Forage Fish and Why are they important?

Forage fish are small schooling fish, including species such as herring, pacific sand lance, surf smelt, capelon, eulachon, and anchovies. These little fish are a crucial component of marine ecosystems, playing multiple essential roles by supporting predator populations, and facilitating energy transfer through food webs. Their conservation and sustainable management are important for maintaining the balance and health of marine ecosystems worldwide.

In the food web, forage fish are critical prey species in the marine ecosystems, integral in facilitating the transfer of energy and nutrients from primary producers to higher trophic levels (more apex predators) in marine, estuarine, and aquatic food webs;they integrate energy across trophic levels through functioning as a link between plankton and upper-level consumers.

The conservation and sustainable management of forage fish is crucial due to their ecological and economic importance. Heavy exploitation and concerns about their conservation status underscores the need for effective management strategies to ensure the continued health of marine ecosystems.

Forage Fish Sampling

Forage fish sampling involves a range of techniques aimed at studying distribution, abundance, behaviour, and ecological roles of forage fish species in marine ecosystems. Sampling provides valuable data to help understand the dynamics of forage fish populations and their interactions within the broader marine environment.

Various methods are employed in forage fish sampling,with the vortexing method of sampling the spawning zones on the shorelines used on the Sunshine Coast. Samples of sand are scooped from the area between the high-high tide and the low-high tide and the sand sample is then strained through three different screen sizes from coarse to fine, and the fine sample is then taken and vortexed - using a centrifuge type of equipment that separates the lighter material (such as shell hash, wood bits, and other floating materials) which are the same buoyancy as the Pacific Sand Lance and Surf Smelt eggs.

Additionally, the use of telemetry and prey sampling techniques has been instrumental in revealing contaminant sources to fish species, emphasising the role of forage fish in transferring contaminants through the food web.

Sampling forage fish may also involve assessing their dietary habits, foraging behaviour, and habitat preferences to understand their role in marine ecosystems. By studying the diet and foraging patterns of forage fish, researchers can gain valuable information on their interactions with other species, including predators and prey.

The sampling of forage fish is essential for monitoring changes in their populations due to environmental factors, such as ocean climate variability, which can impact the length, condition, and distribution of forage fish species. By conducting regular sampling and monitoring, researchers can track fluctuations in forage fish populations and assess the effects of environmental changes on these vital species.

 

Forage Fish Sampling on the Sunshine Coast

Forage fish, including Pacific Sand Lance and Surf Smelt, are integral food sources for salmon, humans, and many other ocean species. They comprise over 70% of the diet of Chinook salmon and over 50% for Coho salmon. These fish spawn directly in fine and coarse sands on beaches, making their embryonic life history stage very vulnerable to stressors as spawning beaches become increasingly vulnerable to climate change (e.g. sea level rise) and shoreline development (e.g. seawalls). Without successful spawning, these forage fish will disappear. Without data, it is difficult to identify which beaches to prioritize for habitat protection.

DFO is now recognizing the presence of forage fish other than herring. Some more recognised forage fish species include Surf Smelt and Pacific Sand Lance (which spawn in the high intertidal area between the high high and low high tides); these fish are now taken under important consideration when making shoreline decisions in regard to development and other actions that will impact spawning beach habitat.

Sampling for forage fish has been carried out on the Lower Sunshine Coast for over a decade. In 2024, we plan to collect beach and embryo data for Pacific sand lance and Surf Smelt on the lower Sunshine Coast over the spring, summer, fall and winter spawning seasons at three beaches. Data will be submitted and shared with the Strait of Georgia Data Center and the Sunshine Coast regional District (SCRD) for its Habitat Atlas, thus making the information easily accessible to those who have need of it.