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.

Spring Creeks by Mike Lawson

Spring Creeks Cover

Fly fishing in Puget Sound for sea run cutthroat trout and coho salmon means the typical fly is a baitfish or crustacean pattern – think Clousers, Deceivers, and the like. And most of the casting is blind casting surface or sub surface patterns where presentation isn’t always essential.

As a saltwater fishery it doesn’t quite prepare a fly fisher for going to storied streams in the Rocky Mountains like the Madison or Henry’s Fork where the life cycle of insects dictate the type of fly to be used – and where presentation, particularly of dry flies, is essential for catching fish. Knowing terms such as Blue Winged Olives or Pale Morning Duns doesn’t help much when there’s lack of understanding of the fishery and how to fish it.

There are several steps in preparing for such a trip. First, it goes without saying practice of presentation casts with the appropriate tackle is needed. The next is to read up on the fishery and the flies and techniques needed. Finally, if schedules and finances allow, hire a guide.

In terms of the second step, one of the best books I’ve read is Spring Creeks by Mike Lawson (Stackpole Books, 2003). Mike is the founder and now general manager of Henry’s Fork Anglers and a founding member of the Henry’s Fork Foundation.

Spring Creeks begins with chapters on spring creeks and trout behavior. As an aside, for those who’ve forgotten or never knew, spring creeks form from underground sources; freestone streams arise from snowmelt or rain.

Spring creeks such as the Henry’s Fork or Silver Creek in Idaho are celebrated for their dry-fly fishing and the skills needed to catch their resident trout; it was a revelation to me that the more constant water of spring creeks results in low diversity but high density of insects – meaning the trout are finicky about what they eat. Freestone rivers on the other hand support a great diversity of insects.

The remaining chapters discuss matching/unmatching the hatch; mayflies, caddisflies; midges and craneflies; terrestrials; presentation; and strategy. But this book is neither a catalog of flies and their recipes or a book on entomology.

While not a book on entomology, there is a fascinating discussion of how mayflies emerge from nymphs to duns. After molting up to thirty times, the nymph’s internal digestive organs begin to shrink creating a cavity that fills with internally generated gases enabling the nymph to float to the surface. The same gases then splits the exoskeleton allowing the mayfly dun to emerge.

It’s a brief discussion, but one that reminds me of the complexity and wonder of all the life with which we share this planet.

Much of the rest of the chapter and those that follow are filled with recommendations for how to fish a particular insect mixed with anecdotes of past fishing successes – and failures.

The final chapters on presentation and strategy represent a lifetime of fly fishing experience and wisdom. Studying them will benefit any fly fisher on any trout stream.

Many books are read and then put on the shelf soon to be forgotten. Mike Lawson’s Spring Creeks is not one of them. I will use it before my next trip to the Henry’s Fork.

Highly Recommended.