InFocus Magazine

Early in March each year, malady the waters around Vancouver Island turn a milky blue-green.  It looks like the Mediterranean Sea, prosthetic but what’s actually happening is intricately dependent on local conditions.  Everything has to be just right: the water temperature and depth, the marine plant and animal life, the day length.

Then, and only then, it happens: the herring spawn.  It’s an event of great, and fascinating, significance—biological, socio-economical and cultural.

For local residents who consider the ocean a source of inspiration, the herring run is an invitation to head to the beach and watch the spectacle.  Colored waters, silver flashes of fish, eagles swooping, herons diving, enormous, raucous flocks of gulls squawking and squabbling, sea lions gorging and rolling their great bulk in the water, fishing boats charging back and forth, and all of it permeated by the pungent smell of ocean life.

For the people on the fishing boats this is a brief and often frenzied opportunity to catch their allowed quota of herring.  The herring, full of eggs that are prized in Asian markets, bring needed income to these fishers and are a significant important component of the commercial fishing economy in BC.

Biologically, the herring run is the indispensable centre of a web of interrelated life.  All those creatures you see feeding so voraciously during the run, and others not so visible, rely not just on the annual feast of highly-nutritious roe, but also on the year-round supply of herring that are being created during this massive procreative event.  The herring are a keystone species on the food chain, helping ensure the survival of salmon, cod, seals, whales, and many birds, including the threatened Harlequin Duck and the mysterious Marbled Murrelet.

For environmentalists, the herring run is both a wondrous reminder of the regenerative power of nature, and a cause for worry, due to concerns about the sustainability of the fishery and its impact on the ecosystem, as well as about the impact of global warming on this important species.

For all, the annual herring run is an early harbinger of spring, a shared ritual that speaks of fertility, interdependence and the cycle of life.

The waters of the Comox Valley—from the Comox Harbor stretching to encircle both Hornby and Denman Islands—is where the herring run is often most abundant.

Retired marine biologist John Tayless explains why this is so, and also talks about just what is happening in those startlingly-pale, opaque waters.  A Denman Island resident and former Dean of North Island College, Tayless brings more than just professional understanding to the topic.  His grandfather had a small fleet of herring boats off the East Coast of England, and Tayless says he grew up knowing the herring fishery intimately.

The herring run, says Tayless, is a marvellous phenomenon.  “It’s a cornucopia of food; it’s nature exploding!

“Now, why does this happen specifically here?” he asks.  With his British accent and air of learned enthusiasm, he sounds a bit like Richard Attenborough narrating a nature documentary.

“Well, the herring are very specific about what they need.  They need shallow water and intertidal zones with lots of algae so they have something to deposit their eggs on.”

As well, local waters provide needed sustenance for the larval herring that hatch out of the eggs about 25 days later.  When they first hatch, they live off of a yolk sac, but after that they need a large population of phytoplankton (microscopic ocean plants that are at the very bottom of the global food chain).  And the local conditions are perfect for phytoplankton.

“The great storms of winter have created lots of minerals in the surface layers of the ocean.  As the days get longer, they are bathed in light,” says Tayless.  “The photosynthesis cycle gets going and the single-celled algae (the phytoplankton) explode like mad.  A week or two later, the zooplankton (microscopic marine animals) that feed on the phytoplankton get going.  The larval herring feed on these.”

The colored water and the roe that seems to be everywhere—floating around in the waves, stuck to kelp, eelgrass, pilings, rocks and driftwood—happen because herring are part of the Clupeid family of fish, which also includes Smelt and Oolichan.  Clupeid reproduction is very inefficient, relying on quantity over quality, says Tayless.

Unlike salmon, herring don’t have to work hard at spawning.  Basically, thousands of fish of both genders school together.  When the time is right, the males release their sperm, called milt, into the water.  This is what changes the colour of the ocean.  The females then drop their eggs, ideally in shallow waters where they can stick to the seaweed.  With all that sperm floating around, fertilization is no problem.