Thompson River Steelhead: Climate Change and Gill Nets

Steelhead

The Thompson River is the largest tributary of the Fraser River, which is the tenth largest river in Canada and the largest river in British Columbia.

Though the 1990s, the Thompson was one of the premier steelhead fishing rivers in North America. In the late 1980s, the steelhead run was estimated at over 10,000 fish; these were large fish with the average male weighing over 16 pounds with some as heavy as 30 pounds. Steelhead are aggressive fish with streamlined bodies and large tails; catching a steelhead is an unforgettable event – something I hope to experience at some point; they are not called the fish of a thousand casts for nothing.

Steelhead (Oncorhynchus mykiss) are anadromous rainbow trout, spending several years in the ocean before returning to spawn in their natal rivers. Unlike salmon that die after spawning, steelhead can return to the ocean, spending a year or two before returning to spawn a final time – if they are successfully able to migrate out.

Spawned steelhead are exhausted and their outward journey is complicated by competing fish, angling pressure, reverse osmotic chemistry and biological fatigue. Any obstructions on the journey doom them. So it’s vital that the first spawn include large numbers of steelhead to continue to propagate the fish.

Unfortunately the Thompson River steelhead fishery has collapsed. In 2016, the run was estimated at 400 steelhead. The estimate for 2017 for spawning Thompson River steelhead is 175 out of 240 entering the Fraser River.

There are several causes for the collapse.

The first and most apparent cause is climate change. Numbers of returning steelhead and other salmonids are declining significantly in multiple river systems due to warming oceans. This is another example of the ongoing Anthropocene extinction – with the possibility of large numbers of animal extinctions occurring in our lifetimes and the high probability of the same in the lifetimes of our children and grandchildren.

A second cause of the collapse of the Thompson River steelhead is the use of gill nets in the Fraser River by both commercial and First Nations fishers. Steelhead have no commercial value – it is a sport fishery only.

Unfortunately for the steelhead, their journey up the river occurs at the same time as that of chum salmon – which is a commercial fish. While slightly smaller than the chum salmon, steelhead can still be caught in the nets and be fatally injured even if released after capture.

The impact of the collapsing fishery has been recognized by the small communities along the Thompson who rely on the dollars spent by visiting fishers. And the Cook Ferry First Nation did not participate in the Fraser River chum season this year out of concern for the Thompson River steelhead.

Saving the Thompson River steelhead is dependent on the actions of the British Columbia government and there is a petition campaigns underway to pressure it to act.

But this isn’t just an issue of fly fishing for Thompson River steelhead. Whether one has fished there or hopes to do (and I’m in the second category) or whether one has any interest in casting for any fish, the primary issue is one of saving the wild things on this planet. The return of the Thompson River steelhead and the emergence of mayfly nymphs on the Henry’s Fork in Idaho are connected.

They are both threads in the web of life on Earth that sustain other species. The Henry’s Fork mayfly feeds the rainbow trout; the decay of a steelhead after its death feeds microbes, stream invertebrates, mammals and birds – as do salmon.

Life propagates when all processes of natural systems work together.

The plight of the Thompson River steelhead is another example of the combined impacts of human arrogance and ignorance. But taking action to save those fish is one opportunity to commit to the natural processes that sustain life on this planet – including ours.

Here is the link to the petition.