Brian Riddell: Where have all the Fraser River sockeye salmon gone?
By Brian Riddell
Where have the fish gone?
This question was posed last week in media across Canada, following notice by the Fraser River Panel that Fraser River summer sockeye may return at less than one-tenth of their expected abundance. It’s a seemingly simple question that is without an adequate answer. But it merits a serious response.
The “fish” in question is one group of sockeye that is produced in two lake systems of the Fraser River (Quesnel and Chilko lakes) and returns in the “summer” season. In 2009, other sockeye populations in B.C. have not suffered the apparent demise of this group, but if the 2009 return of Fraser “summer” sockeye remains at its current estimate, this will be the lowest return rate measured for Fraser River sockeye salmon in over 50 years of records.
Regrettably, resource agencies will not be able to explain this loss. Explanation would require historical records for these sockeye in several stages of their life cycle—from their parents to the return of their offspring as the next generation of adults.
To appreciate these needs and information currently available, I have summarized the life cycle of Fraser sockeye. It should be recognized though that management of Fraser River sockeye salmon is widely recognized as one of the most intensively and well managed resources in the world (see www.psc.org/).
1. Parental spawning and juvenile rearing in freshwater (18 months duration): For Quesnel and Chilko lake sockeye, the numbers of spawners and juveniles produced are amongst the best estimated for salmon in B.C., and are tabulated annually.
2. Juvenile sockeye emigrating from the Fraser River (from lake to estuary, passage likely requires one to a few weeks): There is essentially no information on the survival of small migrants (called smolts) during this stage.
3. Growth and survival in the estuary and coastal seas—for example, the Strait of Georgia (involves a few to several months, assume five months overall): Limited surveys for environmental conditions and salmon abundances within the strait. No dedicated long-term monitoring, but sampling in July 2007 indicated very low numbers of sockeye salmon (2007 is the year-to-sea for the 2009 “summer” sockeye of interest).
4. Growth and survival in the open ocean (approximately 20 months in the North Pacific): Minimal information in this stage, and information is based on indices of environmental conditions (e.g., current values relative to values perceived to be good or bad for a species). In past years, this stage would have included high-seas fishing impacts. But no surveys are currently conducted, and the situation is well monitored (see www.npafc.org/).
5. Maturation and return migration to Fraser tributaries (likely about four months), including migration to coastal waters, fisheries in B.C.’s coastal waters, up-river migration, and spawning in “home” streams: This period is intensively monitored for management of fisheries and assessment of the returning abundance. Monitoring must assess the numbers of salmon by populations of origin, the timing of the migration (see figure for 2005 Fraser sockeye return timing), and environmental conditions in the Fraser River. All of this information is essential in order to provide the desired number of spawners for each population.
What does all this mean? In the circle of these salmons’ life, information is very strong at the beginning and end of life but sadly lacking during life in marine environments (estuary, coastal seas, and open ocean).
This situation evolved for two primary reasons. First, for a long period, returns from the open ocean were variable but, on average, quite productive and provided for substantial fisheries (i.e., things were generally good and production was determined by the numbers of fish allowed to spawn). Secondly, work in the open ocean was very expensive, results were limited by the research “tools” available, and these costs were deemed unnecessary given the first point. Today, ocean productivity for Fraser sockeye is generally poorer (since the mid 1990s), is more variable, and is limiting fisheries and achievement of the desired numbers of spawners.
If the 2009 Fraser “summer” sockeye return does not improve in the next few days (see figure for 2005), then there will be demands for a fuller explanation—and rightly so. The impacts on First Nations communities and commercial fishing families will certainly be substantial. Unfortunately, this song has been heard too frequently in recent years and without adequate explanation. I know because in my past career I tried to provide those answers. To provide fuller explanation in the future, the following is necessary:
a) A dedicated research effort on early marine survival of salmon. This requires dedicated funds (in B.C., we have the people expertise to do this). This effort should start from the estuary and early marine period in the Strait of Georgia before the more difficult steps into the open ocean.
b) Replacement of the one fishery research vessel in B.C. This is scheduled by the federal government but it must be considered uncertain in these economic times. This logistic support is essential.
c) A unified front of interest groups to sustain this commitment to research and provision of answers. While many Canadians will express interest and concern in this story, the people of B.C. will feel the pain of this loss, and we need to respond together.
Given the impact of this in B.C., surely the only responsible action is for all of us to seek better answers. Certainly the causes can no longer be ignored.
Brian Riddell is the president and CEO of the Pacific Salmon Foundation.
Aug 21, 2009 at 8:19pm
I believe that finally the Fraser system has been degraded to such a degree that smolts can no longer survive in adequate numbers to provide necessary returning brood stock. DFO is able to determine the approximate survival rates of fry on the spawning rivers such as the Adams but cannot determine the actual survival rates of smolts migrating down the Fraser and entering salt water. It appears DFO basis there return estimates on the number smolts migrating down the spawning rivers but cannot determine how many actually reach salt water. The usual explanation for poor returns is poor ocean survival.
I believe that polution from industries such as pulp mills and from increasing and inadequately treated sewage from cities and towns located on the Fraser and its tributaries may be contributing to the loss of salmon smolts reaching salt water. Also anadromous fish such as salmon must slowly adapt to salt water as the migrate to the ocean. Many of the estuaries and flood plains along the lower Fraser that allowed the smolts areas to safely adapt to salt water have been significantly reduced by diking and other means to provide flood control and areas for industrial and residential growth.
This year the Fraser river returns have been very much less then the amounts forecasted yet the returns to other river systems such as those along the west coast of Vancouver Island and other river systems have been very good.
Yet those very salmon were likely subject to the same ocean survival factors as Fraser River salmon. How could poor ocean survival be a reasonable explanation for the poor returns to the Fraser?
Paul in regina
Sep 5, 2009 at 6:16am
Human expansion, overpopulation and corporate greed result in destruction of habitat for almost every species. Some human populations can be compared to locusts consuming everything and leaving a barren wasteland in their wake. It's only a matter of time before humans have the same fate as the Fraser River salmon.
Sep 24, 2009 at 7:06pm
I totaly agree.
Meg In Vancouver
Nov 3, 2009 at 1:46am
While I think Dr. Riddle posted a nice article that was both politically and scientifically neutral, which is good. He also didn't ask for any real response or change from the government. The research he is asking for will take years to complete, we won't have an answer be the time next year's salmon run occurs. This is really just delaying action by calling for the need for more research. When I look at the board of governor of the PSF (Pacific Salmon Foundation (Riddle is CEO)) I am not surprised that Dr. Riddle simply suggests we just need more research rather than action now. I have to say that PSF has done excellent community work concerning salmon but suggesting that we wait for more concrete knowledge about the life stage of salmon in the ocean is only a tactic to delay any sort of action. This is exactly what Bush did in not signing the Kyoto protocol- he took the stance that we didn't know enough about climate change to take action against it. Conducting open marine water research on salmon is extremely difficult and it could take years before we understand this part of the life stage of salmon. What if the Fraser River Sockeye don’t last that long before we decide we have enough information to do something? There is enough scientific research out there to give us a good enough clue as to how we can change the way we manage the freshwater cycle of salmon for the better. If the Fraser River Sockeye run hadn’t collapsed the way it did this year, then I would agree with Dr. Riddle that we need to continue more research- unfortunately this is not the case and the collapse merits more than simply more research as usual.
Jul 6, 2010 at 10:42am
I've been on the Fraser Panel of the Pacific Salmon Commission going on 8 years now.I have been heavily involved in fisheries with the Sto:lo Nation,Sto:lo Tribal Council,Interior Indian Fisheries Commission,B.C. Aboriginal Fisheries Commission since 1985.I am now on the First Nations Fisheries Council and the Assembly of First Nations Task Force on fisheries.Riddells piece was ok but there are other factors to consider.The stocks he spoke of are referred to as 4(2)s because they spend up to 2 years rearing where they were spawned before heading out to sea.These fish have not been doing well recently.Others,4(1)s are doing well.They head out to sea soon after hatching.The Harrison and Chilliwack Lake runs are doing well;they are4(1)s.They tend to migrate out through Juan De Fuca by-pssing all the fish farms in the Strait.4(2)s migrate out through the Strait near the fish farms.There is no smoking gun.All things need to be considered.Justice Cohen certainly has his work cut out for him.He even needs to look at the massive deforestation caused by the mountain pine beetle.