May 9 2013

On “Forage Fish”, Pew’s Peter Baker Misses the Mark

Saving Seafood

“Forage fish” management in the California Current Ecosystem is the most precautionary in the world. Current ecosystem modeling efforts find that purse seine fisheries for coastal pelagic species harvest less than four percent (or two percent, depending on source) of the planktivorous forage pool.

“According to a paper by Kaplin et al 2012 in Fish and Fisheries. Cumulative impacts of fisheries in the California Current. This paper uses the Atlantis model to look at the effects of the major fisheries (by gear type) on other fisheries and species. The purse-seine fishery has the largest effect on other ecosystem components; almost all of the effects were positive! The purse-seine fishery (for coastal pelagic species) resulted in large increases in the Large planktivores, very little change in the small planktivores (they note that the fishery takes <4% of the small planktovore biomass), increases in salmon, deep-vertical migrators, misc pelagic sharks, large zooplankton, microzooplankton, and nearshore fish.” – Dr. Richard Parrish, retired NMFS fishery biologist in Monterey who has more than 50 years’ knowledge of CPS and the California Current.

The paper A Case for Precautionary Management of Forage Fish, presented by Pew’s Peter Baker at the Managing Our Nation’s Fisheries Conference on May 8, is based on several assumptions about “forage fish” and predator species that are unproven. These unproven assumptions, as well as a lack of peer-review of the Lenfest Forage Fish Task Force that the paper extensively cites, should raise significant questions and engender in-depth review before its recommendations become standard practice in fisheries management.

The paper’s recommendations are based around the assumption that “forage fish” is a legitimate and useful categorization of species to be used in fisheries management, and that the various “forage species” can be managed under the same broad guidelines. Specifically, the paper recommends implementing restrictions intended to leave forage species biomass at 75 percent of unfished levels. The paper argues that adopting this conservative management strategy will lead to an increase in the amount of forage available and will benefit predator species.

However, these species have a variety of biological differences, and don’t have much in common outside of their common role in the marine food web. These significant differences–including fecundity, spawning periods, migration, predator-prey relationships, and habitat–are much more relevant variables for fisheries management than a shared trophic role.

Read the full story here.

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