He cites numerous disturbing examples. "The shallow waters off Nova Scotia used to be full of swordfish and bluefin tuna, as well as untold numbers of hake, halibut, and haddock. Cod in particular were the apex predators in these parts," Grescoe writes.

He also goes on to quote early observers describing "cod mountains" off a once-rich Newfoundland coast where the fifteenth-century navigator John Cabot reported cod populations so thick that they actually blocked his ships' passage.

But what’s happening now there? Massive overfishing has all but decimated the cod, and stocks of lobsters and other low-in-the-food-chain species have exploded. By wiping out predator species, the fishing industry screws up ecosystems. As sea creatures high on the food chain disappear, their populations more than decimated in the last half-century, a lobster boom "may just be a tiny blip on a slippery slope to oceans filled with jellyfish, bacteria, and slime," Grescoe notes ominously.

So also consequent on relentless shark-hunting, skate and ray populations have exploded, and they are eating scallops and clams into extinction.

Over-fishing has created some 150 "dead zones" -- oxygen-free patches of ocean that can sustain no life -- around the world: Some of these patches "are now as large as Ireland."

Besides a large percentage of coral reefs worldwide are dying or already dead. They have a high biodiversity that serves as a storage bank of rich genetic resources. They are a source of food and medicine, and they protect the coast from wave erosion.