Population Correction on the Horizon: Sardines, Salmon and Sea Lions
We’ve all been privy to the recent conversations about “Market correction,” or “Housing correction.” Well, it appears it’s even a more global conversation. The question one might ask is, how high up the food chain will the correction go?
Some of my greatest education takes place outside of the Association of Northwest Steelheaders office, in this case, at the Hook, Line and Sinker tavern, following a successful steelhead tournament hosted by our local chapter in Tillamook, Oregon. There were several biologists there, all anxious to see how many quality brute broodstock steelhead the tournament would produce. Many of us have been quite surprised by the impressive number of returning broodstock steelhead this year, especially given the depressed number of coho that came back last fall.
You see, the adult returns of the two species often go hand-in-hand as both species, as juveniles, migrate out at nearly identical times; mid to late April. It’s said that the greatest amount of mortality for juvenile salmonids takes place in the first 30 days of their entry into the great salt chuck. It goes to reason, if the fall coho returns are poor, than the following winter, we’re likely to see poor returns of winter steelhead from that same out-migrating brood year. Oddly, that did not follow suit.
We therefore surmised that mortalities for coho must have happened during the adult phase of their lifecycle, just prior to entering fresh water again, on their spawning run upstream. Somehow, most of the population were either picked off by predators or starved to death before they could make it back for their spawning run. I started looking for more answers and where better than the biologists themselves who had a captivated audience.
Hatchery managers such as my friend Jim Skarr (Trask River Hatchery) are very keen individuals. They have to keep their eye on their stock. They are in the fish husbandry line of work and taking the temperature of their crop will tell them how best to produce a fine product, and the Trask River does produce a fine product. I asked Jim about the condition of returning adult coho to his facility last fall. He indeed confirmed the appearance of coho with emaciated features, particularly small bodies and large heads. This is a characteristic often found in under-nourished trout in mountain lakes. I’ve seen a few skinny salmon in my lifetime but they often have some sort of injury that prevents them from effectively harvesting prey.
In the last two years, we’ve seen some pretty remarkable events that clearly indicate we’re on a downward trend in ocean fishery resources. This is the very base of the food chain that fuels the entire success of the ocean ecosystem. Here are just a few examples:
Sardine Population Collapses, Prompts Ban on Commercial Fishing talks about how the collapse is once again effecting the California economy, not to mention marine mammals. Environmentalists blame fishery managers and fishery managers blame environmental conditions.
Ocean Salmon Estimates Plunge; Restricted Fishing Likely talks about mostly California based Chinook salmon stocks (from the Sacramento and Klamath Basins) that largely fuel the Oregon and California troll fleets, not to mention a robust river fishery. And finally,
Thousands of Sea Lion Pups are Washing Ashore and Dying Along the California Coast talks about the obvious, and has some impressive film footage of the rescue effort for these mammals.
The first article touts the success of the 1976 adopted Magnuson Stevens Act, which effectively ended overfishing in US waters. It remains the basis for fishery management today and celebrates its 40th anniversary next month. Although the Magnuson Stevens Act wasn’t so much visionary as it was reactionary to the consistent declines in ocean species, the current reauthorization may need to be more visionary than any other document produced on fisheries law in recent history. Given the dramatic swings in our recent boom and bust returns of salmon, sardines and sea lions, there are clearly some factors going on in the ocean ecosystem that we never initially took into consideration. Ocean acidification, climate change and the new big mystery, the warm water blob.
It’s another year however and no one knows what this year’s ocean will bring. No one has spent much time on the ocean this year, it’s been angry for most of the winter with only commercial crabbers willing to occasionally venture out. We’ll continue to collect our data, manage our fisheries and prosecute them too, but it’s becoming more and more evident that we continue to see signs from nature that tell us there are new challenges ahead. You likely won’t find too many upset anglers that read the sea lion population is trending downward, but as an indicator species, there will be other consequences too; we’re likely to see that in the very near future as more headlines of fishery restrictions are coming, and that’s when the sardine starts to hit the fan.