Small fish | Marine planning and conservation | Oceans | Science & policy | Marine planning and conservation | Issues
Photo: Small fish

Millions of herring spawn in PNCIMA every winter. (Credit: iStock)

Welcome to the small fish page of the 'I Am Fish' tour. These three guiding words, I am fish, appear simple. But they reflect an ancient and extraordinary web of biological activity that connects humans with the ocean.

I am small fish

If you were to count all the fish in the Pacific North Coast Integrated Management Area (PNCIMA), most would be small schooling fish such as herring and sardines. These small fish feed on zooplankton and are a critical connection in the food web to larger fish, seabirds and marine mammals.

Sardines are migratory visitors, whereas herring spend most of their lives either in or close to PNCIMA. In late winter, millions of herring move toward the kelp laden shores of PNCIMA to spawn. Their eggs, or roe, are energy-rich packets that are readily consumed by a wide range of species including migratory birds. Herring will utilize a variety of areas throughout their lives, from the intertidal zones to the open ocean, transferring ecosystem energy to hundreds of different species in the process.

Why are small fish important to humans?

The herring roe fishery has long been a lucrative and controversial fishery. The controversy lies in the conflicting values we place on herring. Economic value is derived from the selling of herring roe, while there are cultural values among coastal First Nations who have harvested herring roe for thousands of years. There is also the crucial ecosystem value of herring.

The traditional coastal First Nation's method of using herring, which involves collecting eggs that have been deposited on the kelp, allows all three values to be upheld. The spawning herring survive to grow and spawn again or to be later eaten by something else in the ecosystem.

The commercial herring roe fishery, however, captures large masses of both male and female herring — even though only the eggs of the female are used. Only about 12 per cent (by weight) of herring caught commercially is actually turned into an economic commodity, mostly in the form of roe exported to Japan. The other 88 per cent is turned into fertilizers and animal feeds. While the fishery may not pose an immediate population threat to herring, removing these small fish simply for their eggs is not the best use of the ecosystem service which herring provide.

What can we do to protect them?

During their spawning, herring are harvested from the waters of Pncima for their roe, which is then exported overseas. Herring are at low abundance coast-wide and the herring fishery is presently confined to two of the five major assessment regions.

Herring found along the B.C. coast are also now nearly 50 per cent smaller than they were 40 years ago. DFO has attributed this trend to changes in ocean productivity but a growing body of science worldwide suggests that fishing gears, by removing the largest individuals from the gene pool, could also be playing a role. A growing body of science worldwide suggests that fishing gears are removing the largest individuals from the gene pool, thereby decreasing the average size of individuals over time.

The importance of herring to the larger ecosystem makes proper herring fisheries management essential. This includes ensuring conservative catches and protecting their spawning habitats.

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http://www.davidsuzuki.org/issues/oceans/science/marine-planning-and-conservation/small-fish/

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