From Smolt to Spawn: crash course on a West Coast salmon lifecycle

By: James Crofton

Let me take you on a journey. A seemingly impossible journey that starts in a small backwater stream of the Fraser River. It is late spring and the rivers in BC all begin to swell from snow melt high in the mountains. Far up the Fraser river a small Coho salmon fry is hatching. After one or two years of feeding on small invertebrates—never straying too far from the comforts of her stream—she evolves into a smolt and is ready for the open ocean. A mass exodus ensues with the Coho and her relatives all venture out in search of the best feeding grounds. It is a journey against the odds: killer whales, sea lions, dolphins, and man all compete to catch the nutritious fish. She will be hunted for the rest of her life.

How salmon are able to locate the exact stream from which they left is still somewhat of a mystery, but it is believed they use the earth’s magnetic field as well as a keen sense of smell. Should she survive the arduous pilgrimage, what awaits back at her natal stream is equally grim. Along the riverbank, grizzlies, gray wolves, and other scavengers wait in hungry anticipation while bald eagles circle overhead. Her strong body—developed over several years at sea—is needed now more than ever to swim against the current, jump waterfalls and other obstacles, and evade predators until she is back to where it all began. It is a last-ditch effort of sheer willpower. Of the 2500 eggs laid by her mother, she is one of only a few survivors to spawn and carry on the lineage.

As salmon return to spawn, the waiting predators take their kill far into the forest where decomposing salmon carcasses enrich the soil with nutrients, enabling the growth of the towering canopy overhead. Traces of salmon DNA can even be found in the top needles of conifer trees, many miles from the closest stream and hundreds of miles inland. These animals truly are the life force of the Pacific northwest—a link between forest and sea.

Unfortunately, many salmon runs have seen sharp declines in recent years. Some see only a fraction of their historic return numbers while others no longer see any at all. A myriad of challenges now confront salmon, threatening their future survival in some places. By-catch and overfishing continue to put pressure on the species while the logging of old-growth forests is altering stream habitats and creating impassable barriers. Open-net pen aquaculture presents an additional threat. With so many fish crammed into a small space, disease and lice can spread quickly and have shown to spread to their wild counterparts. As seen at one of Cooke Aquaculture’s sites in Washington State, these pens are also prone to collapse, releasing thousands of farmed salmon into the open ocean where they can outcompete wild salmon for food and space, and even prey upon them.

Now, more than ever, new technologies are needed to provide alternative sources of salmon protein that alleviate pressure on wild stocks without polluting the marine environment. One such solution is moving salmon farms on land. Aquaculture presents us with an enormous opportunity to feed the world while taking pressure off wild populations. However, to fulfill its potential aquaculture must be acted on with sustainability as a pillar to its foundation. We are very proud to be able to offer Sustainable Blue, land-raised Atlantic salmon; a farm only an hour outside of Halifax! They are at the forefront of land-based technology and boast a 100% recirculating salt water aquaculture facility. The fish they yield are nutritious, tasty, and most importantly, do not harm our wild salmon populations. Stay tuned for our next post all about Sustainable Blue!

Halifax Oyster Festival September 2017

Hello,

Afishionado Fishmongers is looking for volunteers for the Halifax Oyster Festival to help shuck and schlep. If you are interested in participating we would love to have you. Please feel free to contact us if you have any question or just fill your information below.

Would you like to volunteer with us? E-mail hello@afishionado.ca or choose your suitable session for volunteering to help us shuck!

Friday night session volunteer: click HERE.
Saturday afternoon session volunteer: click HERE.
Saturday night session volunteer: click HERE.

For more information about Halifax Oyster Festival and to buy tickets click HERE.