'Unnatural History of Sea' informs, alarms

THE UNNATURAL HISTORY OF THE SEA. By Callum Roberts. IslandPress/Shearwater Books. 435 pages. $28.

Not even the oldest person alive remembers the natural state of our oceans before the dawn of commercial fishing, when the bounty seemed almost inexhaustible.

Imperceptibly, the impaired recollections of succeeding generations have masked the decline of fish populations and the true extent of the sea's dramatic transformation. Callum Roberts argues that we are dangerously close to settling for this false "baseline," attempting unwisely to maintain marine ecosystems in their present degraded state.

Relying on fascinating accounts of explorers, pirates and fishermen stretching back to the 11th century, Roberts presents an almost unimaginable picture of once great abundance in places such as the Chesapeake Bay, North Sea, Cape Cod, and the Caribbean and Bering seas. Then revisiting these and other spots, employing his own and other scientists' research, he surveys how various species — cod, whales, sea otters, abalone, striped bass, tuna, seals — have since fared.

He demonstrates convincingly how the techniques of industrial fishing have depleted their ranks, forcing many to the brink of extinction. He offers a platform of common-sense reforms, centering on large-scale networks of marine reserves, complemented by other measures of fish and habitat protection, to insure the productivity of our fisheries.

Part exercise in recovered memory, part science, part plea, Roberts' powerful, almost poetic account of the history of fishing and its deleterious effects on the sea at once alarms and informs.