By Bianca T. Esposito, NWNL Research Intern
(Edited by Alison Jones, NWNL Director)
NWNL research intern Bianca T. Esposito is a senior at Syracuse University studying Biology and minoring in Economics. Her research focuses primarily on how watershed degradation affects biodiversity.
Figure 1. Salmon utilizing a manmade fish ladder to bypass a dam in their quest for migration. (Creative Commons)
“Elders still tell stories about the tears tribal fishermen shed as they watched salmon throwing themselves against the newly constructed Grand Coulee Dam.”
-John Sorois, Coordinator of Upper Columbia United Tribes
What are the impacts of hatchery and why do we need them? Hatcheries were created in the late 1800’s to reduce the decline of fish populations caused by hydroelectric dam development. Hatcheries (Figure 2) are part of a fish farming system that produces artificial populations of anadromous fish for future release into the wild. Upon release, these fish enter a freshwater location, specifically a tributary, with no dam to bypass on their way to and from the ocean. Anadromous fish, such as salmon, white sturgeon and lamprey spend most of their life at sea, but return to their native tributaries in freshwater to spawn. Once anadromous fish spawn, they die off and the life cycle is continued to be carried out by the next generation of juveniles. Since returning to their native breeding grounds is a necessity for anadromous fish, hatchery-raised fish released into tributaries without dams is one way to combat this impediment of migration that dams have created.
In this blog, we will look at hatcheries as they relate to the declining salmon populations in the Columbia River Basin.
Besides hatcheries, another way for salmon to bypass the dams constructed along the Columbia River Basin is with the use of fish ladders or fish passages built on the dams (Figures 1 and 3). However, these methods can be harmful to the salmon. Fish ladders require that salmon climb up many platforms to access the reservoir on the other side of the dam. There is evidence that supports claims of an increased rate of exhaustion in salmon utilizing the ladder. Ultimately this leads to avoidance of the ladder and decreased migration rates of salmon.
Fish ladder at Rocky Reach Dam on the Columbia River
Hatcheries are an attempt to overcome this low success rate of released salmon returning to tributaries. Stock transfers are one hatchery approach whereby salmon eggs are incubated and hatched in one part of the basin and then shipped to streams all over for release. This method of stock transfer is used to re-populate areas in which salmon populations are declining, or in places they no longer inhabit. However, because of the changes in location, these farmed salmon have trouble returning to the reassigned tributary, since instinctively they would return to their birth stream.
Another major problem hatcheries face is that once artificially-grown salmon are released, they still have to face the same problems that confront wild salmon. These challenges include water pollution, degraded habitats, high water temperatures, predators and overfishing. However, the salmon who mature on the farm have no prior experience on how to handle these threats, which is one reason they face very low survival rates. Overall, these artificial salmon are not considered as “fit” for survival, nor do they have the ability to adapt to the environment in which they are released because they grew up on a farm.
Figure 2. The raceways where salmon are kept at Little White Salmon National Fish Hatchery in Washington State. (Creative Commons)
In the 1980’s fisheries moved towards a more “ecosystem-management” approach. They began conserving wild, naturally spawning stocks, as well as hatchery-bred fish. Yet, the overbearing problem with this method was that if hatchery-bred fish were to mate with wild fish, it could cause genetic and ecological damage.
A shift has been made towards utilizing “supplementation facilities”, a more natural, albeit artificial environment for raising the fish that includes shade, rocks, sand, and various debris typical of their natural habitat. This natural approach allows the salmon somewhat “ready” for the wild. The idea behind this technique is that after the salmon are released into streams and spend time in the ocean, they know to return to that tributary to spawn, instead of the hatchery. While this method has increased the number of adult salmon returning to spawn, it still bears the negative possibility of genetically compromising the remaining gene pool of the wild fish.
Besides the genetic problems faced with breeding artificial salmon alongside with wild salmon, breeding solely within hatcheries can also ultimately lead to inbreeding depression. This results in the salmon having a reduced biological fitness that limits their survival due to breeding related individuals. Additionally, artificial selection and genetic modification by fish farms can also cause reduced fitness in reproductive success, swimming endurance and predator avoidance. Another reason farmed salmon are not as “fit” as wild salmon is due to the treatment they receive in the hatchery. The food salmon are fed is not healthy for them – its main purpose is to make them grow faster. This forced rapid growth can lead to numerous health problems.
Diseases experienced in fish farms are also experienced in the wild. They occur naturally and are caused by pathogens such as bacteria, viruses and parasites. What exacerbates disease in a fish farm is overcrowding, which makes it fairly easy for the disease to spread throughout the hatchery. Specifically with viral infections, those who may not show symptoms of disease can be carriers of the virus and transmit further, whether in the farm or after their release into the wild. Consequently, once they are transported and deposited across river basins to be released, these diseases then go on to affect wild salmon with no immunity to the disease they have acquired. This decline in wild salmon has also caused declining effects in their predator populations, such as bears, orcas and eagles.
Figure 3. The fish ladder at John Day Dam in Washington State. (Creative Commons)
Along with all the negatives that come with farm fish, the high production from hatcheries eliminates the need to regulate commercial and recreational harvest. So, because of the production from hatcheries, overfishing continues. Hatcheries have become a main source of economic wealth because they provide for the commercial harvests, as well as local harvests. A permanent and sustainable solution to combat the decline of wild salmon populations remains to be found. This problem continues to revolve around the construction and use of hydroelectric dams which provide the main source for electricity in the region; greatly reduce flood risks; and store water for drinking and irrigation.
The concept that hatcheries are compensating for the loss of fish populations caused by human activity is said by some to be like a way to “cover tracks” for past wrongdoings because it does nothing to help the naturally wild salmon at all. Hatcheries are only a temporary solution to combat the decline of the salmon population.
Fish and river steward on the Salmo River
What we really need is an increase of spawning in wild salmon and to ensure that they have a way to survive the dams as they make their way to sea. Reforestation and protection of small spawning streams is one part of the solution. A more permanent, albeit partial, solution would be to find a way to advance the electricity industry reducing the need for hydropower. Until we find a way to make this happen, hatcheries seem to be a helpful way to continue to support the salmon-based livelihoods, as well as human food needs and preferences. Unfortunately, hatcheries do nothing to help the current situation of wild anadromous salmon in the Columbia River Basin.
In April of this year, the Lake Roosevelt Forum in Spokane WA outlined a 3-phase investigation into reintroducing salmon and steelhead to the Upper Columbia River Basin in both the US and Canada. In March 2016, Phase 1 began, dealing with the planning and feasibility of possible reintroduction. The study, expected to be released in 2018, concerns habitat and possible donor stock for reestablishing runs. All work on the studies are mostly complete and are predicted to be suitable for hundreds to thousands, or even millions of salmon. Forty subpopulations of salmon species have been identified and ranked for feasibility, including the Sockeye, Summer/Fall Chinook, Spring Chinook, Coho and Steelhead. The Confederated Tribe of the Colville Reservation stated they are waiting for one last permit from the National Oceanic and Atmospheric Administration (NOAA). Then they can begin the second phase of the decades-long research process using pilot fish release this fall.
Chinook hatchery salmon underwater
Phase Two will be the first time salmon have returned to the upper Columbia River Basin in almost 80 years. This blockage came from the completion of the Grand Coulee Dam in the late 1930’s and Chief Joseph Dam in 1955. The Confederation Tribes of the Colville Reservation fish managers plan to truck these salmon around the dam, since constructing a fish ladder would be too costly. Funding currently comes from tribes and federal agencies. Possible additional funding may come from the Environment and Climate Change Canada and the renegotiation of Columbia River Transboundary Treaty.
Renegotiations of the 1964 Columbia River Transboundary Treaty between the United States and Canada is currently underway. The first meeting took place in Washington D.C. on May 29 and 30, 2018. Just weeks ago the U.S. emphasized their stance on continuing careful management of flood risks and providing a reliable and economical power source while recognizing ecosystem concerns. The next meeting will take place in British Columbia on August 15 and 16, 2018. However, tribes are not pleased with their exclusion from negotiating teams. Tribes excluded consist of the Columbia Basin’s Native American tribes, primarily in Washington, Oregon and Idaho, and First Nation tribes in British Columbia, Canada.
Mural of human usage of salmon in British Columbia
NWNL Director’s Addendum re: a just-released study: Aquaculture production of farmed fish is bigger than yields of wild-caught seafood and is growing by about 6% per year, yielding 75 million tons of seafood. While it is a very resource-efficient way to produce protein and improve global nutrition and food security, concerns are growing about the sustainability of feeding wild “forage fish,” (eg: anchovies, herring and sardines) to farmed fish so they will grow better and faster. These small fish are needed prey for seabirds, marine mammals and larger fish like salmon. A June 14 study suggests soy might be a more sustainable alternative to grinding fishmeal for farmed seafood and livestock.
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Unless otherwise noted, all photos © Alison M. Jones.