Reviewed by Philip W. Conkling
This is a tour de force of almost numbing thoroughness, cataloging the indignities that we have heaped upon the world’s terrestrial and marine ecosystems. It will be hard to dispute David Pimm’s figures Ñ one can only hope that his careful accounting for all the tons of biomass and lost acres of productivity don’t prove to be easy for policy makers to ignore. Pimm deserves major credit for getting all this information out of the academic journals and into the light of day.
The section on the Oceans is particularly good. Pimm is adept at presenting the Big Picture Ñ distinguishing the Blue Sea (deserts of low productivity) from the Green Sea (coastal oceans and upwellings where the water turns green, as in the Gulf of Maine, from plant production).
His chapter on the Marine Fisheries collapses of the last decade were a little disappointing, but that’s probably because this reviewer is too close to the subject. His generalizations here are pretty broad-brush, ascribing much of the problem to the oft-cited “Tragedy of the Commons.” That’s probably inevitable, given his Big Picture orientation. Still, he could have done some positive good by also pointing out that flawed marine science is part of the problem: we keep over-harvesting individual species in part because we do not know enough of the basic annual life cycle of species we catch and how their numbers are influenced by natural oceanographic fluctuations of temperatures, currents and global circulation.
Pimm could have also said that the population biology models based on single species assessments that simultaneouly try to maximize sustainable yield of prey and predator alike are biologically impossible to acheive and guaranteed to fail.
It was good to see the section on Daniel Pauly’s Science article about fishing down lower and lower on the food chain. Pauly’s hypothesis and observations were widely reported in the academic world and to a lesser extent in newspapers (eg “Science Tuesday” of the New York Times), but it is hopefully now going to find a wider audience. Pimm and Pauly are clearly concerned that as we fish down the food chain of major predators like swordfish and tuna, it’s proper to wonder where the expanding world’s population will derive additional protein. “The prospects for increases in catches are dim,” Pauly writes. To which Pimm adds, “The only consistently increasing fisheries are for carp, tilapia, and farmed salmon. Their catches more than doubled in the decade from 1984 to 1993. They now represent nearly a fifth of the world’s fish consumption.”