Walking home from an early appointment this morning, I considered what to write about for today’s blog post. An article about marine ecosystems and fisheries caught my eye yesterday. While intrigued, I was also reluctant – fisheries management is one subject that both interests and frustrates the hell out of me. I took one class on fisheries biology in graduate school. After seeing how politically charged fisheries management can be, and how often decisions are made with little regard for science, I swore I would never work in that field. (My vow backfired, of course and I spent 2.5 years working on fisheries-related issues for the Environmental Defense Fund* – in New England of all places, the most politically charged fishery of them all!) When I spotted a second fisheries article this morning – this one in the Washington Post about seafood choices that are “good for the oceans, good for you,” I knew I had to make my peace with the issue.
The first article reports on a comparative study of North Atlantic and North Pacific ecosystems conducted by team of American scientists from the National Oceanic and Atmospheric Administration (NOAA – I’ve worked for them, too, but not on fisheries, thank God) and Norwegian scientists. The study, Marine Ecosystems of Norway and the US (MENU) is “the first attempt to provide a comprehensive, coordinated and integrated view of a wide range marine ecosystems.”
MENU results revealed that deeper ocean boundary systems, like those off Alaska or in the eastern North Atlantic, off Europe, are more strongly influenced by bottom-up mechanisms, known as forcing. The shallower western boundary systems found on continental shelves, like Georges Bank off New England are more strongly influenced by top-down processes, like fishing.
Could this difference make these latter ecosystems less resilient, more susceptible to collapse from overfishing? Perhaps this would explain why eastern fisheries, like Atlantic cod and other “groundfish”**, are doing so poorly compared to western fisheries, like salmon and halibut. Perhaps as a result of overfishing, fisheries landings in both types of ecosystems have shifted from fish to invertebrates, and bottom-dwellers to pelagic species.
Human activity, especially fishing, pollution, and climate change are having dramatic, even catastrophic impacts on marine ecosystems. One response might be to stop eating fish altogether. On the other hand, hardly a day goes by without a new study trumpeting the heart-healthy benefits of adding fish to our diets. So what can we do?
Well, my old friends at EDF have teamed up with the Monterey Bay Aquarium to develop the ‘super green’ list of fish that are good for the oceans AND good for you. The “Best of the Best” are those fish that high in omega-3′s, low in contaminants, and caught in a sustainable manner. “Other Healthy Best Choices,” while strangely titled, are those that are lower in omega-3 but still good choices.
Lest you underestimate the importance of omega-3′s in your diet Dariush Mozaffarian, of Harvard Medical School who helped with the rankings, noted that eating an average of one serving of salmon a week provides enough omega-3 to reduce heart disease risk by 36%. (Question: If the subjects he studied had typical American diets that salmon meal probably replaced a high-fat meat dish – did that also help to lower their rate heart disease?)
The Super Green list is not yet available in a handy wallet-sized pocket guide like previous efforts but will likely be so soon. To read more , click here.
More info about the MENU study is available through NOAA Northeast Fisheries Science Center, here.
For more great science news, check out my favorite source: ScienceDaily. (I get the Earth & Climate updates delivered to my inbox daily).
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* I worked for EDF during the brief period when they dropped the “f” and became Environmental Defense. There’s a ridiculous rumor about why they changed it back, but I won’t go into it here…
** Groundfish is a bizarre term that is used in fisheries management, in spite of the fact that it has no ecological relevance. It refers to all fish that live somewhat near near the seafloor and can be caught using huge bottom-dragging nets. It is as if we referred to deer, racoon, fox, etc. as “landanimals” and hunted them together using bulldozers…