|In just a few weeks, the annual spawning of Pacific herring will unfold along British Columbia’s coast, as it has for thousands of years.
Herring, considered the region’s most abundant forage fish, provide fundamental food to a web of marine life. Fueling humpback whales, salmon, seals, seabirds and more, it’s no surprise that herring have been called the”food basket of the sea”.
The interactions between Pacific herring and the wider marine ecosystem is somewhat documented, but little scientific knowledge has accumulated on sea-to-land relationships, despite longstanding awareness of these interactions by coastal peoples.
When Raincoast first began to study these relationships, we observed blackbears consuming large quantities of herring eggs and sand hoppers (beach invertebrates). Other species, including gray wolves and songbirds, also emerged from the forest to feast on recently spawned herring eggs.What we had stumbled upon was the ancient connection between herring, shorelines and forest dwellers that bore strong resemblance to that of salmon and coastal watersheds.
Turns out, sand hoppers that eat herring eggs show the same elevated levels of ocean-derived lipids, carbon and nitrogen as do creatures that feed on salmon. And in a similar way, they represent a link between herring and the terrestrial animals that feed upon them. Published earlier this month, this research on herring, sand hoppers and black bears is the first evidence of the marine “subsidy” from herring into shoreline and forest ecosystems.
Decades of fishing pressure however, combined with other factors, has dramatically reduced herring biomass and caused concern for their ongoing ability to support coastal foodwebs.
In spite of this, herring biomass in BC is roughly three times that of all five species of Pacific salmon combined, implying that they still provide a significant subsidy to coastal ecosystems.
As marine coastlines everywhere face increasing pressures, our increasing knowledge of just how important these little silver fish are dictates more effective conservation, not less.
For the Coast,
Caroline Fox, a Postdoctoral Fellow and biologist with Raincoast, spent four years studying these interactions in Quatsino Sound, on northern Vancouver Island.
|In December 2013, the federal fisheries minister, Gail Shea, approved the opening of several commercial herring fisheries on BC’s coast.
She did this against the explicit request of several coastal First Nations and the recommendations of her own science and fishery staff.
In response, the Nuu-chah-nulth launched a legal challenge.
This week, the judge ruled in favour of science, conservation and the First Nations.
Photo credits: Caroline Fox and Hal Schulz