(Hrm - long time, no posts... I was talking with someone about this community the other day, and they thought it was an interesting idea, if only as a forum to force yourself to read one paper per...oh, month, week, whatever personal deadline you have set for yourself, and then post a normal-person-readable assessment of it - an idea that perhaps some of y'all might be interested in, if only as a way to force you to confront the ever growing Stack that I know is sitting on your desk)
So, I was recently fascinated by Essington et al's Fishing Through Marine Food webs
. As a conservation minded food web ecologist, I open nearly every grant proposal with something like "In marine systems, we are removing species at the top of the food web first (Pauly 1998)." Which comes from Paul's Fishing down the food web
paper. Now, the data from that is actually publically available
, and I recently decided to jump in to look at patterns of biomass change by trophic level in California. And you know what, I didn't see the "fishing down the food web" thing at all. Rather, change in mean trophic level was driven soley by anchovy, sardine, and oyster harvest. Weird, I thought to myself.
And then comes Essington's piece, showing that "Fishing down the food web", the phenomena of fishing at lower and lower trophic levels at species at the top of the food chain are depleted, at least in catch data, is only true for the Gulf of Maine. Everywhere else, it's driven by ADDITIONS of lower trophic levels, while biomass at upper trophic levels stays relatively constant.
Of course, there's all of the work by Ram Myers and the like that shows that, when looking at assessment data, not catch data, we're still taking out the top of the food web first, but, this whole thing has made me look at fisheries catch data and data from harvesting (e.g. logging, hunting, etc) with a far more critical eye. How useful is this data, and what care needs to be taken with it? Quel interesant.