Tuesday, May 12, 2009

So, Vern, Whatever Happened to those Rivers Inlet Sockeye

I moved from Rivers Inlet to Sointula in 1993 and even today I’m often stopped on the dock or at the Co-op store where someone invariably asks me, “So what happened to the Rivers Inlet (or Smith Inlet) sockeye, Vern?” This always leads to an interesting discussion as to the cause of the collapse of one of the largest sockeye runs on the B.C. coast. The fishing heritage of Sointula has been involved with the salmon runs in Rivers Inlet for generations, just as the Wuikinuxv people have relied on the sockeye arriving literally at the door step of their longhouses for some nine thousand years.

Since 1996 there have been only thousands of sockeye returning instead of hundreds of thousands.


The link above will get you to a Google image of Rivers Inlet and the foot of Owikeno Lake.

A number of causes for the decline of sockeye salmon in this seemingly pristine fjord have been put forward. Overfishing, logging around the larger spawning streams in Owikeno Lake and varying ocean conditions due to changes in climate might have all played a role in causing the stock to collapse. What is even more alarming is that after the complete closure of the sockeye commercial fishery in 1995 the stock failed to rebuild.

Most of the commercial salmon fishermen that I’ve spoken with have not been up to Rivers Inlet for over a decade now and have often asked if anything is being done to determine the cause of the collapse of a once very productive fishery.

There are people working diligently in Rivers and Smiths to try and figure out why the sockeye returns have declined so precipitously.

The Rivers and Smith Salmon Ecosystems Planning Society was formed to bring together different parties and interests to pursue the common goal of stewardship for salmon and their ecosystems. www.rsseps.ca

Recent studies by Rick Routledge and his team of graduate students from SFU along with members of the Wuikinuxv and Gwa’sala-‘Nakwaxda’xw Nations are trying to figure out through a combination of traditional knowledge and science why the salmon have all-but-disappeared from this region. Their studies have focused on early marine survival of sockeye. Evidence so far seems to indicate increased mortality in the early marine phase of the sockeye life cycle as one of the reasons for the decline of the Rivers Inlet sockeye population.


It’s all a matter of timing.

When Owikeno Lake sockeye smolts, which are usually about half the size/weight of other nursery lake smolts, emigrate downstream to the inlet it is critical for them to grow quickly before heading out to the open ocean. If they are lucky, when they emerge from the Wannock River they will encounter a bloom of zooplankton (in turn fed by a phytoplankton bloom) comprised of mussel and barnacle larvae and other tiny crustaceans. However, if there has been heavy fresh water discharge from the Wannock resulting in an extensive layer of nutrient-poor, sometimes glacially turbid lake water covering much of the inlet, then the smolts will be under fed and under size by the time they migrate to the open ocean.

To substantiate and extend these preliminary findings, the current ecosystem will have a focus on understanding the driving forces of spring-summer plankton productivity.

Further studies on the whole Owikeno Lake/Rivers Inlet ecosystem are planned and valuable financial assistance has been provided by the Tula Foundation.


For most people, the enduring mystery of salmon is their epic struggle upriver as they fight to spawn and continue the life cycle. But for those who study salmon in the ocean, who harvest salmon and whose ancient cultures still rely on salmon to this day the ocean biology of Pacific salmon is equally grand and considerably more mysterious. Answering some of the questions about what salmon do in the ocean and why they are motivated to do so may also be of considerable importance to maintaining the health of our fisheries, particularly given recent sharp downturns in ocean survival for most salmon stocks in southern BC.

No comments:

Post a Comment