Seals and sea lions in the Salish Sea are all part of a healthy food web
We should be very cautious about predicting that a seal cull would benefit Chinook salmon. Food webs are not so simple.
Since the killing of seals and sea lions ended in the 1970s, pinnipeds in the Salish Sea have been recovering. The recovery of seals slowed by 2000 and for the last fifteen years or so the number of seals in the Salish Sea has been relatively stable. This population of fish eaters has recovered to what was likely historic levels.
Pinnipeds, such as seals and sea lions, are not affected by the low Chinook salmon numbers the way that the Southern Resident killer whales are because Chinook are only a small proportion of their diet.
Pinnipeds also predate on other predators of Chinook, like hake and pollock. So killing seals and sea lions to reduce Chinook predation could actually destabilize the food web and result in an increase of other Chinook predators.
Killing seals could also impact the Salish Sea’s most effective pinniped eater, transient killer whales. There are often more transient killer whales (marine mammal eaters) in the Salish Sea at any one time than there are Southern Residents (salmon eaters). Transient (Biggs) killer whales are very efficient predators, especially on seals. These whales can travel great distances to “munch on pinnipeds” in the Salish Sea.
Listen to Misty MacDuffee and Adam Stirling discuss the downsides of removing pinnipeds from the foodweb, the distinction between culls and harvests, and the measures that should be addressed before considering killing seals as a solution to rebuilding Chinook.
Related posts
- L124 is the newest member of the Southern Resident killer whales
- Chinook salmon, 74 killer whales, and the future of the Salish Sea
- Cabinet rejects request for an emergency order for endangered killer whales
- Fisheries closures needed for killer whales
- Backgrounder: Emergency order under the Species at Risk Act
- Take action: Emergency closures needed now
- Feds’ fisheries announcement a welcome first step: groups renew call for killer whale emergency order
- A killer whale emergency
- Groups urge federal government to protect Southern Resident killer whales with emergency order
You can help
Raincoast’s in-house scientists, collaborating graduate students, postdoctoral fellows, and professors make us unique among conservation groups. We work with First Nations, academic institutions, government, and other NGOs to build support and inform decisions that protect aquatic and terrestrial ecosystems, and the wildlife that depend on them. We conduct ethically applied, process-oriented, and hypothesis-driven research that has immediate and relevant utility for conservation deliberations and the collective body of scientific knowledge.
We investigate to understand coastal species and processes. We inform by bringing science to decision-makers and communities. We inspire action to protect wildlife and wildlife habitats.
