By Jeff Rice

How many fish are in the Salish Sea? It’s an impossible question that drives the Puget Sound Institute’s newest senior scientist Marc Mangel. 

“In a way, yes,” says Mangel, a mathematical biologist who has spent his career working on fish and fisheries issues.

Mangel uses mathematical models to answer critical questions about species such as their population numbers and population health. He joins PSI this month as an affiliate professor at the University of Washington Tacoma where he will focus on a range of subjects related to species such as salmon and forage fish.

Mangel comes to PSI from the University of California, Santa Cruz where he is a Distinguished Research Professor of Mathematical Biology. For the past 30 years, he has been a leader in ocean conservation and his research has been cited by fisheries managers worldwide. He currently serves as chair of the board of directors at Fishwise and is a member of the review board of the Pacific Halibut Commission. In 2014, Mangel was a principle scientific expert in a successful lawsuit by the Australian government to stop Japanese whaling in the Antarctic. This spring, he was elected to the American Academy of Arts and Sciences.

One of the challenges when studying the ocean — and fish in particular, Mangel says — is getting enough good field data. “We barely know how many fish we take out,” he says of fisheries catch reports and other sources. Numbers for actual fish populations are even more complicated, requiring more opaque ecological studies and plenty of math. In Puget Sound, for example, Mangel has been working with biologists on Protection Island to enlist “seabirds as samplers” as part of a long-term study counting the numbers of forage fish consumed as prey by birds such as rhinoceros auklets. “Based on that, we can infer the abundance of prey species,” he says. Other collaborations include ongoing studies of steelhead numbers with scientists at the Manchester Environmental Laboratory in Manchester, Washington.

Mangel has been a regular contributor to PSI as a visiting scholar since 2013 when he co-chaired PSI’s Forage Fish Study Group, with PSI Lead Ecosystem Ecologist Tessa Francis. The study group produced a set of research and management recommendations for Puget Sound’s forage fish species, including Pacific herring. Last year, Mangel and Francis were co-authors on a paper, led by University of Bergen student Gabriella Ljungström, investigating the tradeoffs faced by migrating herring between feeding, survival, and reproduction, using Puget Sound as a case study (Ljungström et al. 2018).

Read a Q & A with Marc Mangel

Other related articles:

• PSI visiting scientist key advisor in halt to Japanese whaling 
• PSI visiting scientist receives honorary doctorate
• Browse some of Marc Mangel’s scientific publications