Microplastics in our water is a relatively new problem and many are rightfully concerned. Spurred by encouragement from the broader LLTK community, we reviewed the available research to determine if marine plastics pose a threat to salmon survival. The following information is based on studies assessing marine plastic effects on zooplankton and fish conducted inside and outside of the Salish Sea. We looked specifically at zooplankton and forage fish when reviewing available research because they are important food for salmon and may play a role in transferring plastics through marine food webs.
As many of us know, plastic is a pervasive human-caused pollutant in the marine environment. Plastics can enter the marine environment either from marine-based activities like fishing, aquaculture, and shipping, or land-based activities that result in wastewater effluent, runoff, or river discharge (Desforges et al. 2014). When we’re thinking about plastics affecting salmon, size matters. Smaller sized plastics less than 5 millimeters, also known as microplastics, are concerning because they are the most likely to be consumed by juvenile and adult salmon either intentionally (they can look like food) or accidentally.
Upon consumption, marine plastics can physically and chemically affect zooplankton and fish. Physical effects from eating it can obstruct their mouths and throats, block their digestive track, artificially fill their stomachs, and be absorbed into other parts of their body (Cedervall et al. 2012; Cole et al. 2013; Rochman et al. 2013; Desforges et al. 2014, 2015). Chemical effects may also occur from the toxic ingredients in the plastic (e.g., petroleum products) or from environmental chemicals that attached to the plastic from seawater (e.g., PCBs) (Cole et al. 2013; Rochman et al. 2013; Hipfner et al. 2018). It’s important to note that effects from plastics may be unique among species, types of contaminants, and types and sizes of plastics (Desforges et al. 2015; Ašmonaitė et al. 2018).
Despite marine plastic pollution being a widely known environmental issue, very little field research has been done in our region to assess how salmon are affected after consuming marine plastic either directly or via their food. Most of the research assessing effects has been laboratory-based and results are often varied. In 2019, researchers performed a thorough review of plastic effects on marine organisms and found an effect was more likely to be detected at higher concentrations of microplastics and mortality occurred at extreme concentrations that are not typically found in the environment (Bucci et al. 2019). This review indicates that field studies may provide a more realistic understanding of exposure and consumption rates for target species, such as salmon.
Along the British Columbia coastline, two different field studies assessed marine plastic consumption rates for zooplankton and forage fish, important food for salmon. In the first study, scientists determined about 3% of copepods and around 6% of euphausiids (AKA krill) were eating microplastics and that there was no correlation between the amount of microplastics eaten and the amount in the seawater (Desforges et al. 2015). In the second study, scientists determined that very few forage fish, sand lance (1.5%) and herring (2.0%), had eaten microplastics (Hipfner et al. 2018). This research also suggested that larger forage fish are less likely to consume plastic. Together, these studies indicate that zooplankton and forage fish are most likely NOT conduits for indirect plastic consumption in salmon on the outer coast of British Columbia.
As was mentioned previously, very little is known about the impacts of marine plastics on salmon either through direct consumption or via their food (pers. comm. A. Spanjer 2019). The first and only field study regarding plastic consumption rates by salmon in the Salish Sea determined juvenile Chinook consume an average of 1.15 microplastic pieces per day (Collicutt et al. 2018). At this rate of consumption, it is unlikely to lead to significant mortality events. This study also found no significant relationship between the amount of microplastics found in seawater and sediment compared to the amount consumed by the juvenile Chinook. The United States Geological Survey (USGS) is currently doing a laboratory-based study examining how long polyester fiber is retained in the gut of juvenile Chinook after consumption, but that research is currently ongoing (pers. comm. A. Spanjer 2019).
Based on the available research investigating marine plastic effects on zooplankton and fish, we can conclude that marine plastics do not currently pose a significant threat to salmon survival in the Salish Sea. However, marine plastics will continue to persist as pollution on land and in our oceans if we do not take action to reduce them. Ellen MacArthur with the World Economic Forum estimated that the world’s oceans will have more plastic than fish by 2050. Whether her estimate is accurate or not, we can all do our part to help reduce plastic pollution. Please see below for a list of five ways you can reduce marine plastic pollution:
- Join a beach cleanup – Puget Soundkeeper Alliance and The Surfrider Foundation are frequently hosting beach and lake cleanups to reduce the amount of debris in our waterways.
- Remember your reusable containers – Actively using your reusable water bottle, coffee mug, or to-go containers will not only reduce plastic but can save you money in the long run.
- Buy microbead-free products –Microbeads are too tiny to be filtered out at the wastewater treatment facility. Buying personal products that do not contain microbeads will reduce the amount of microplastics entering our oceans.
- Reduce clothes washing – When we wash our clothes, they shed microfibers that do not get filtered out, like microbeads. By reducing how often we wash our clothes, we can lower the number of microfibers that are being released. We’re not saying wear dirty clothes, but if you can, wear items more than once and choose natural fiber clothing (these fibers will biodegrade over time).
- Make informed decisions – As consumers, we can make conscientious decisions about the products we buy and the companies we support. This can take the form of buying items in bulk rather than individually wrapped items, as well as the packaging our purchases come in. By being aware of how much plastic your household generates, you can find ways to reduce it and ultimately lower your carbon footprint.
Ašmonaitė, G., Larsson, K., Undeland, I., Sturve, J., Almroth, B.E. 2018. Size matters: Ingestion of relatively large microplastics contaminated with environmental pollutants posed little risk for fish health and fillet quality. Environ. Sci. Technol., 52: 14381 – 14391.
Bucci, K., Tulio, M., Rochman, C.M. 2019. What is known and unknown about the effects of plastic pollution: A meta-analysis and systematic review. Ecological Society of America, doi:10.1002/eap.2044.
Cole, M., Lindeque, P., Fileman, E., Halsband, C., Goodhead, R., Moger, J., Galloway, T.S. 2013. Microplastic ingestion by zooplankton. Environ. Sci. Technol.,47: 6646 – 6655.
Collicutt, B., Juanes, F., Dudas, S.E. 2019. Microplastics in juvenile Chinook salmon and their nearshore environments on the east coast of Vancouver Island. Environmental Pollution, 244: 135 – 142.
Desforges, J.W., Galbraith, M., Dangerfield, N., Ross, P.S. 2014. Widespread distribution of microplastics in subsurface seawater in the NE Pacific Ocean. Marine Pollution Bulletin, 79: 94 – 99.
Desforges, J.W., Galbraith, M., Ross, P.S. 2015. Ingestion of microplastics by zooplankton in the Northeast Pacific Ocean. Arch. Environ. Contam. Toxicol., 69: 320 – 330.
Gall, S.C. and Thompson, R.C. 2015. The impact of debris on marine life. Marine Pollution Bulletin, 92: 170 – 179.
Hipfner, J.M., Galbraith, M., Tucker, S., Studholme, K.R., Domalik, A.D., Pearson, S.F., Good, T.P., Ross, P.S., Hodum, P. 2018. Two forage fishes as potential conduits for the vertical transfer of microfibres in Northeastern Pacific Ocean food webs. Environmental Pollution, 239: 215 – 222.
Rochman, C.M., Hoh, E., Kurobe, T., Teh, S.J. 2013. Ingested plastic transfers hazardous chemicals to fish and induces hepatic stress. Scientific Reports, 3: 3263.
The salmon lost a king this week. The world lost a beacon of civility, and a guide to integrity and commitment. And Long Live the Kings lost a leader and a friend.
Bill Ruckelshaus was a member of our board of directors from 1996 to 2015. He was a pragmatic optimist, a respecter of science, and supremely skilled at pulling people with disparate points of view together to craft a new approach.
He strongly believed communities should be empowered, and if needed pushed, to work as one to solve their own problems. To save salmon and restore its populations to abundance was something no single group, government agency, or strategy could accomplish. “It’s not enough,” he used to say, “to stand on shore and throw rocks at the ship of state as it passes by.” To him, bringing the salmon home and ensuring they had a home to come to is the work of all of us, together.
We will miss his great good humor, his engagement at board meetings and events, his inspiration, and his support. With Bill aboard, anything and everything was possible.
Our sympathies and condolences go to Jill Ruckelshaus and the family.
We’ll treasure Bill’s friendship. For the long run.
Prepared by Barbara Cairns, LLTK Executive Director 1997-2010, and Jacques White, current LLTK Executive Director.
As we have heard time and again over the last year, our southern resident orcas are in trouble. There simply isn’t enough salmon to support them, and other factors make this deficit more consequential. They consume fat reserves filled with accumulated toxics while they desperately forage for salmon, a task made more difficult by our noisy waters. It’s a troubling combination of challenges, but salmon recovery is likely to have the largest impact.
Long Live the Kings (LLTK) has worked for decades on efforts to the increase survival and population size of salmon and steelhead that provide the prime sustenance for our orcas. Last year, in response to worrying population declines, Governor Inslee convened the Southern Resident Orca Task Force to address the crisis. LLTK has participated from the start of this effort as the only salmon recovery nonprofit at the table. Since then, orca recovery has occupied much of the region’s attention, and LLTK is using our salmon expertise to bring our resident orcas more food.
In November, the task force delivered 36 first-year recommendations, which the Governor and state agencies advanced to the state legislature for approval and funding. Notably, over 20% of these recommendations were influenced by LLTK’s work, mostly driven by ongoing findings from the Salish Sea Marine Survival Project.
In what is being acknowledged as the best session for environmental legislation in four decades, this spring the legislature passed key orca policy protections related to noise, vessel traffic, toxics, oil spills and shoreline habitat. Both the Governor and the legislature deserve praise for these very positive outcomes.
But not all of the needed actions have been implemented, and there is still much work to do. Shovel-ready Chinook recovery projects have only received about a quarter of what is necessary over the past decade. So clearly, much more effort is needed to fully fund salmon recovery, LLTK is working with our partners to secure funds to support this work.
To this end, LLTK again travelled to Washington, DC this past May as a part of ‘Puget Sound Day on the Hill’ and ‘Salmon Day on the Hill’, along with over 80 stakeholders from the west to meet with members of Congress and present the importance of a healthy Puget Sound and Pacific salmon recovery. During the DC visit, LLTK was invited to give a presentation on the Salish Sea Marine Survival Project and facilitate a panel of NW restoration experts for the Congressional Estuarine Caucus, a group of elected officials invested in protecting important water bodies around the country. The trip resulted in increases in federal funding and renewed focus, as Congressman Derek Kilmer has requested to visit the LLTK Lilliwaup Field Station this summer.
Back in the Northwest, we are happy to announce that you helped us raise over $12M for the Salish Sea Marine Survival Project, smashing our $10M goal for this ground-breaking international project. Results from the project have already been incorporated into National Oceanic and Atmospheric Administration’s Recovery Plan for federally listed Puget Sound steelhead, which will be released at the end of this year.
Our work with members of the Washington State Legislature is also proving to be successful. In the most recent legislative session, we helped secured $1.5M for the Salish Sea Marine Survival Project and $10M for the Middle Fork Dam removal. This dam removal project is supported by American Rivers, the Paul G. Allen Family Foundation and the City of Bellingham and will provide access to 16 miles of previously blocked river habitat for federally listed Chinook and steelhead.
The Hood Canal Bridge Ecosystem Assessment is nearing completion for Phase 1 research. LLTK and project partners are working to synthesize and report on our findings, and are now beginning to plan for Phase 2, solutions testing. Preliminary Phase 1 results suggest that many steelhead experience the bridge as a physical barrier, delaying migration, and indicate predation by a deep-diving, warm-blooded animal. Predation may be associated with patterns of fish biomass, predator location, and localized water flow in surface waters near the bridge.
Survive the Sound, our education and outreach campaign that invites the public to track their favorite fish through an epic migration, completed its third year. The campaign has assisted LLTK in graphically and interactively communicating the impacts of the bridge on juvenile steelhead to the public. This year we quadrupled participation, and nearly 2,000 of the participants were educators who reported serving over 200,000 students! And over half of the educators surveyed reported that they were not covering salmon issues prior to participating in Survive the Sound. If you raced with us, did your fish survive? What did you learn? If you missed the campaign this year, you can still visit SurvivetheSound.org to pick your favorite fish and watch its migration.
Finally, LLTK is working with our state, tribal, federal, and nonprofit partners in the US and in Canada to perform limited experiments at hatcheries to see if we can improve the survival and size of returning Chinook. This could eventually benefit southern resident killer whales and fishers, and teach us lessons we can translate to wild fish recovery.
At our Glenwood Springs Hatchery, LLTK will be rearing experimental groups, in addition to our standard May release, that will be reared slowly and released later. Slow rearing is done in attempt to delay maturity down the road and return bigger, older fish. There is strong alignment between this effort and the findings of the Salish Sea Marine Survival Project, the distribution and timing of releases could address potential issues of competition, predation or changes in food availability.
Clearly, LLTK is moving forward on many fronts to increase the abundance and resilience of salmon in our region, and by extension, hoping that our efforts are successful in providing more food for our southern resident orcas. Your significant support of our work has allowed LLTK to push the boundaries of what’s possible, moving ahead faster, taking bigger risks in more places, and having a bigger positive impact on our region and our future. Thank you for being a partner in our mission to save a Pacific Northwest icon.
Just a few weeks ago, we received word that there is new J-pod calf spotted in NW waters. This is reminder that we should have hope, that nature is resilient if we give it a chance. Thank you for being part of that hope, you give our salmon, steelhead and whales a chance to survive and thrive.
Harbor seals are protected by the Marine Mammal Protection Act (MMPA). At the same time, they are believed to be a significant predator of threatened Chinook salmon and could be competing with endangered southern resident killer whales. This poses a challenging management trade-off and data describing harbor seal’s historic impact on our food web, which would help guide this trade-off, is limited. By using old bone specimens stored at local museums and the scientific methods, researchers at University of Washington are uncovering more information.
Harbor seals experienced exponential growth in Puget Sound following the implementation of the MMPA, from historic lows of approximately 2,100 in 1972 before leveling off at the current population size of 18,000 (Jeffries et al. 2003). This change in predator abundance has been correlated to declines in forage fish and salmonid survival across the WA coast, which suggests harbor seals pose a threat to the recovery of endangered and vulnerable species in the region, including Chinook salmon and southern resident killer whales (Thomas et al. 2017).
However, this change in predator abundance also coincided with a broad-scale environmental regime shift known as the Pacific Decadal Oscillation in 1977/78, a phenomenon that has also been linked to productivity of fish species in WA, including salmon. Teasing apart these ecological drivers is challenging yet important for management of the Sound as an integrated system.
At the University of Washington, members of the Holtgrieve Ecosystem Ecology Lab, led by gradate student Megan Feddern, are trying to better understand the interactions between harbor seals, their prey and environmental changes to better inform management decisions from an ecosystem-based approach. They aim to do this by:
- Creating a dataset of where harbor seals have been feeding in the coastal WA food web over the past 100 years from museum skull specimens.
- Combine this dataset with other historic datasets of environmental drivers (Pacific Decadal Oscillation, El Niño Southern Oscillation, sea surface temperature) and important harbor seal prey species (herring biomass, salmon populations, Pacific Hake biomass) to identify what ecological components drive harbor seal food web position.
The research is made possible using a recent methodological advancement called compound specific stable isotope analysis of amino acids. Scientists are able to measure the nitrogen isotope ratio (15N/14N) of eleven different amino acids preserved in bone collagen. A small piece of bone (50 mg) is decalcified to access preserved collagen and measure the 15N/14N of the amino acids contained within that collagen and calculate the food web position of the harbor seal that collagen came from. Certain amino acids, called trophic amino acids, show an increase in 15N relative to 14N as an animal feeds higher in the food web. In other words, they’re able to get a better idea whether seals are eating, for instance, more herring or salmon.
During the study, 150 museum harbor seal skull specimens from seals from 1920-2017 have been obtained and the 15N/14N of their collagen has been measured. Scientists now have estimates of harbor seal food web position from the Hood Canal and Puget Sound during that time period, which they are currently comparing to data sets describing different environmental drivers.
Stay tuned for the full results!
This article was created using a flyer from the University of Washington. View it here.
Anthony’s and Long Live the Kings began building a partnership in 2014. The restaurant’s founder, Budd Gould and his son Herb (CEO of Anthony’s), found that their vision to preserve the health and well-being of the seafood industry aligned perfectly with Long Live the Kings’ mission to recover wild salmon and steelhead. Budd’s other son, JJ, who is a retired Chief of Wildlife for the Idaho Fish and Game and a certified Wildlife Biologist, was nominated to join the Long Live the Kings’ Board of Directors in 2016. Our partnership has grown ever since.
When we introduced Survive the Sound to the team at Anthony’s, they wanted to help make this innovative campaign a reality. They were excited for opportunity to bring information about salmon recovery to students and the public. We’ve both known that passionate salmon conservationists are often born after enjoying and learning about this precious resource. Anthony’s saw the opportunity to help create this experience for their guest.
“Providing our guests and the rest of the public with accurate information on salmon and our environment is an important step to making better decisions that benefit future generations,” says Budd. “It is an honor and a privilege to be able to partner with an organization like Long Live the Kings that are so dedicated to this very mission.”
Long Live the Kings is thrilled to have a partner like Anthony’s to help bring our mission to a broader audience. The generosity and dedication from companies like Anthony’s allows us to push the boundaries of salmon recovery; to explore new ideas and take on new challenges. Anthony’s is a leader among the growing number of local companies who are setting a high bar for investments in their local environment, empowering us to protect and restore the Pacific Northwest we want to leave for our children.
Salmon are an important part of our life and diet, but we share this resource with many other species. Birds, seals, sea lions, bears, porpoise, whales, and other fish all depend on salmon for a portion of their diet. With salmon and steelhead populations at risk, many people are asking if too many mouths are at the salmon buffet.
In Puget Sound and the Strait of Georgia, Long Live the Kings and our partners are looking at the whole ecosystem to figure out what’s killing young salmon and steelhead on their migration through Puget Sound. In some cases, as few as 10% of the fish survive to reach the Pacific Ocean. Scientists refer to this problem as high juvenile marine mortality.
One aspect of our research considers whether salmon predators are contributing to high rates of juvenile marine mortality, but we’re finding that the story is much more complicated. Interestingly, human harvest of salmon isn’t a significant factor in the case of high juvenile marine mortality because humans aren’t allowed to harvest juvenile salmon and steelhead. That’s not to say that humans aren’t a major factor contributing to these salmon deaths. There is evidence to suggest that human activity and decisions are driving a number of problems: limited prey for young salmon, a lack of estuary habitat, contaminants, and disease.
Humans have even facilitated the increase in marine mammals through the passage of the Marine Mammal Protection Act. This important law has worked well to protect many marine mammals from harassment and death, but people are wondering if it’s worked too well for some species.
Current research suggests harbor seals are eating many salmon. In Puget Sound alone, the harbor seal population has increased three-fold since the 1980s, a time when our salmon survived at much higher rates (Jeffries et al. 2003). While we are still working to better understand their impact on salmon recovery, initial studies suggest seals and sea lions may be consuming two times as many Puget Sound salmon as are caught by humans, with seals being the primary consumer (Chasco et al. 2017).
If a seal boom is contributing to the further decline of already-threatened salmon and steelhead populations in Puget Sound, we need to answer more questions to address the problem. How many seals should there be? What should they be eating? Who’s eating them, or isn’t eating them? Are there factors that make it easier for these predators to hunt salmon? While we don’t have complete answers to these questions, and continued research is absolutely critical to making thoughtful decisions, our work has uncovered some new ideas which give us options to start investing in solutions.
Seals are opportunistic predators, but by analyzing their scat, we know their diets rely heavily on forage fish. Young salmon, steelhead, and forage fish often swim amongst each other in the areas where seals hunt. With declining forage fish populations, some scientists hypothesize that seals may end up eating more salmon and steelhead to compensate. This indicates that rebuilding forage fish populations could help rebalance the food web and take some pressure off of salmon and steelhead.
Transient killer whales are the primary predators for seals and they have been spending more time in the Salish Sea (Puget Sound, Strait or Georgia, and Strait of Juan de Fuca). Estimates suggest that transients eat about 1,090 seals from the Salish Sea each year. Their presence is helping to naturally control seal populations. Reducing noise pollution, contaminants, vessel collisions and preventing oil spills will help ensure that our waters are safer for these whales.
A number of factors may also make salmon and steelhead predators more successful.
- Barriers like the Hood Canal Bridge, Ballard Locks, and dams can slow the progress of migrating fish. Smart predators learn to take advantage of these situations.
- Consolidated releases from hatcheries may be acting like a dinner bell for predators. Studies have shown predators can change their behavior in response to large hatchery releases. Most Puget Sound hatchery Chinook are released during the same two-week window.
- Salmon and steelhead that are affected by contaminants or contract diseases may be slower and easier targets for predators. Just like humans, unhealthy fish have trouble operating at their best, which is very important during their arduous migration.
Long Live the Kings and our partners are working to address these factors, which could give salmon and steelhead a better chance of avoiding predators and making it to the Pacific Ocean.
Our research and approach to recovery looks at the big picture to implement lasting solutions that restore our ecosystem – an ecosystem that will thrive if given the chance. This approach requires thorough planning, considerable funding, and cooperation from others. But, if we’re going to save salmon and steelhead, we’re going to need to restore our ecosystem, and that starts by understanding it better.
Chasco et al. (2017) Estimates of Chinook salmon consumption in Washington State inland waters by four marine mammal predators from 1970 – 2015. DOI: 10.1139/cjfas-2016-0203
Jeffries et al. (2013) Trends and Status of Harbor Seals in Washington State: 1978-1999, Journal or Wildlife Management 67(1):208–219
Image Credit: Vancouver Aquarium. LLTK use “seal-packs” that help us research predator-prey interactions.
Salmon and steelhead face many obstacles on the road to recovery – sometimes quite literally. In order to better understand how physical obstacles impact the survival of salmonids, it’s important to remember that salmonids depend on intact habitat spanning thousands of miles. When human-made structures block, delay, or reduce even a relatively small part of their habitat, it can significantly impact their whole migration.
Two of the most well-known obstacles are dams and road culverts, which can both restrict access to habitat. Other human-made obstacles can also have big impacts on fish. The Hood Canal Bridge is one local example of an obstacle to salmonid migration.
Steelhead traveling through Hood Canal towards the Pacific Ocean encounter the Hood Canal Bridge which carries State Route 104 across the Canal’s northern outlet, connecting the Olympic and Kitsap Peninsulas. The bridge floats on pontoons that span 83% of the width of Hood Canal and extend 15 feet underwater. The same fish tracking data used to create Survive the Sound show that over half the juvenile steelhead that reach the bridge do not survive to reach the Pacific Ocean. The bridge is acting as a migration barrier, delaying fish as the try to find a way around it. Up to half of the juvenile steelhead that make it to the bridge won’t survive past it. This level of mortality is alarming, and observations indicate that other salmonids, including Chinook and chum salmon, are also affected by the bridge.
Compared to dams and culverts, it’s less obvious how a floating bridge could affect the survival of migrating fish. Most ask: why don’t they just swim under it? To answer this question, LLTK and our partners are conducting an assessment to pinpoint how steelhead are dying at the bridge and implement solutions to address the problem. By gathering data on noise and light levels, predator densities, and water currents and comparing those data with the tracking data seen in Survive the Sound, we are able to isolate variables contributing to mortality. Findings indicate that the bridge creates conditions and habitat that gives a substantial advantage to predators – steelhead that reach the bridge are at high risk of being eaten before they can navigate around or underneath the physical structure. Phase 1 of the assessment is complete and you can read the full report here or the illustrated summary here.
We have long understood that human-made structures can have unintended consequences on the environment. The trouble is, we keep discovering new ways this is happening. Realizing that this cycle will continue, it’s important for us to constantly research and test innovative solutions.
Luckily, many people are stepping up to the challenge of balancing human and fish habitat. The new Seattle seawall aims to improve salmon survival by mimicking the shallow mudflats that used to exist in that area. By creating an artificial sea floor, glass sidewalk panels, and habitat for plankton (salmon food), the new construction may improve juvenile salmon survival. Projects like these may help decrease the number of obstacles salmon face during their lives while still allowing humans to enjoy the same area.
Photo: Hood Canal Bridge, Hans Daubenberger – Port Gamble S’Klallam Tribe
Sand lance, herring, and surf smelt are called ‘forage fish’ because many larger animals forage (feed) on them, including marine mammals, birds, salmon, and humans. Forage fish are generally small, silvery fish and can be found in large schools throughout Puget Sound. Research monitoring the health of forage fish populations is limited, but the information that is available shows a tragic downward trend for some important populations.
For instance, Cherry Point, an area north of Bellingham, once hosted the largest number of spawning herring in Puget Sound. Cherry Point herring abundance has plummeted 93% since 1973; there are very few Cherry Point herring left. This is bad news for the health of Puget Sound and the prospect of salmon recovery because these small fish hold an important place in our ecosystem.
Recent research from the Salish Sea Marine Survival Project indicates that forage fish are especially important to the success of Chinook salmon in Puget Sound. Not only are they a source of food for Chinook, but they also provide food for birds and marine mammals that might otherwise feed on juvenile salmon. This information suggests that to recover salmon, we have to look at problems more broadly across our ecosystem, especially forage fish health.
Herring need kelp, eelgrass, and other substrates lower in the tidal zone to lay their eggs on and cumulative human development activity is decreasing the prevalence of this habitat. Overwater structures, such as docks, prevent aquatic vegetation from growing by not allowing in enough sunlight. Some structures are also coated in toxic chemicals that kill herring eggs. Pollutants that aren’t associated with docks can also affect forage fish. For instance, PAHs (polycyclic aromatic hydrocarbons) generated primarily during the incomplete combustion of organic materials (e.g. coal, oil, petrol, and wood) can enter marine water directly or through stormwater inputs. Research shows that these pollutants can lead to reduced growth and cardiac defects in larval herring.
Sand lance and surf smelt depend on healthy, natural beaches to provide a place to spawn and protect their eggs until they hatch, but residential and commercial shoreline development has reduced the availability of spawning grounds. For instance, shoreline armoring or bulkheads, designed to protect property from erosion and flooding, can eliminate habitat by restricting access to spawning areas on the beach. They can also prevent natural sediment processes from occurring where erosion from the land replenishes the beach gravel needed for spawning habitat. Despite efforts by many organizations and landowners, we are still struggling to remove or replace bulkheads with engineered ‘natural shorelines.’
Sea level rise and ocean acidification are likely to reduce spawning habitat even further. As sea levels rise around our developed community, tidal habitat and marine vegetation available for spawning will decrease.
Forage fish spawning habitat is currently protected through regulatory documents, which take a “no net loss” approach. This means that shoreline development should not change the ecological function of the shoreline. It’s unclear whether this standard will be enough to protect forage fish habitat given the pressures of rapid development and our changing climate. This standard must be strictly enforced and complemented by restoration activities to be effective.
To improve the health of Puget Sound and salmon runs, an abundance of forage fish is critical and there are a number of complicated issues that threaten the health of these populations. Addressing these problems requires intensive monitoring efforts, stewardship from shoreline owners, strict regulations, and a willingness to try creative ideas. In December 2020, Long Live the Kings and the Nisqually Indian Tribe started a project testing how christmas trees could be used as herring spawning substrate in the estuary. If successful, the technique could be used more widely across Puget Sound to increase the amount of spawning herring.
Photo: Pacific Herring, Steve – Flickr
Zooplankton are tiny animals that float freely in the water column. They can move very short distances on their own, but are so small that they are mostly carried around by ocean currents. There are many types of zooplankton in Puget Sound, including copepods, amphipods, crab larvae, and euphausiids (krill) (Zooplankton in Puget Sound ID sheet). These animals are important food for juvenile salmon and forage fish like herring and anchovies.
Because zooplankton comprise the base of the marine food web and support healthy juvenile salmon populations, scientists need to understand what kinds of zooplankton and how many zooplankton are in Puget Sound. To meet this need, Long Live the Kings created a Puget Sound-wide zooplankton monitoring program through the collaboration of local governments, state agencies, and tribes. Researchers sample the zooplankton community twice a month during the juvenile salmon outmigration period (March through October).
Zooplankton are very sensitive to environmental change, so they are excellent indicators of ecosystem health. The metrics developed from data collected by the monitoring program are used to understand changes in the Puget Sound food web that might impact juvenile salmon and to provide guidance towards improved salmon harvest management and Puget Sound stewardship.
The zooplankton monitoring program has been extremely successful, collecting crucial data on environmental health and salmon survival indicators. For example, an environmental index developed from copepod abundance data has been closely linked to salmon survival. This new index is being used to improve forecasting models, which predict how many adult salmon will return to Puget Sound each year.
We need to continue collecting information on the Puget Sound zooplankton community over the long-term. Datasets that span many years allow researchers to understand environmental patterns and track ecosystem responses to changes in many factors like temperature, water chemistry, and pollution. Zooplankton data also show us how much food is available for juvenile salmon and whether that food is healthy for the fish. Continuing to collect Puget Sound zooplankton data is one crucial piece of successful salmon recovery. Learn more about findings on the marine food web and its effect on salmon from the Salish Sea Marine Survival Project.
Photo: Zooplankton, NOAA
It’s no secret that healthy habitat is critical to healthy salmon and steelhead runs, but restoring habitat is a daunting challenge and expense, often conflicting with human development ambitions. Despite the incredible resilience of salmon, habitat destruction is one of the most significant causes of their population decline. Humans have negatively impacted virtually every part of their vast habitat and we’ve been trying to correct past wrongs for decades.
Since 2005, there have been almost 6,000 salmon and steelhead restoration projects in Washington State. Those projects have worked on over 4,000 acres of estuary habitat, corrected 3,100 passage barriers, and improved over 10,000 acres of riparian land.
We’ve invested almost $982 million in habitat restoration projects since 1999. These efforts have created thousands of construction jobs, poured millions into local economies, and improved the safety and health of many communities. Yet, fewer than half of Washington’s 15 populations of salmon and steelhead listed under the Endangered Species Act are showing signs of improvement. That may not come as a surprise considering that our population has grown 30 percent since 1998 and salmon restoration efforts have only received 16 percent of the estimated funds needed to restore their habitat.
Acknowledging the large task of habitat restoration and restricted funding availability, Long Live the Kings (LLTK) conducts research to understand where best to focus our efforts to maximize effectiveness. The Salish Sea Marine Survival Project, an international research effort led by Long Live the Kings (U.S.) and the Pacific Salmon Foundation (Canada) to investigate poor survival of juvenile salmon and steelhead in the marine environment, has shed light on the importance of estuaries and nearshore habitat for juvenile Chinook salmon.
Estuaries, including the wetlands that surround them, are areas where freshwater meets saltwater. These areas are considered one of the most productive types of ecosystems in the world, providing critical habitat for many species. Nearshore habitat in the saltwater environment refers to the shallow waters near the shoreline, including the beach, intertidal, and subtidal zones. Estuaries and nearshore areas are important for juvenile salmon to rear, feed, migrate, and find shelter from predators.
Salish Sea Marine Survival Project researchers studied Chinook salmon populations in several Puget Sound watersheds. They looked at the scales of juvenile and adult fish to measure their growth and survival in Puget Sound and the Pacific Ocean. These data showed that in watersheds without intact estuaries, smaller fish disappeared from the population. This suggests that healthy estuaries protect small fish and allow them to survive better, which may improve overall adult returns to a watershed.
Estuary and nearshore habitats often fall victim to human development activities such as shoreline armoring, overwater structures (dock, piers, etc.), diking, dredging, and other activities which significantly reduce ecosystem functionality. Human infrastructure is necessary and valuable but we have prioritized easy development over environmental preservation for too long. It is important to remember that humans can improve the efficiency of our infrastructure, while the needs of our ecosystem are relatively unwavering. Adapting to our environment is a challenge that will pay off for generations.
Photo: Nisqually Estuary and Olympics, Eric Hall