The ocean looks like it did when we were kids, with waters that seem endless, as they must have appeared to the first explorers of North America. But with an average depth of two miles, the ocean hides its secrets.
Changes become obvious when you shop for seafood. Species once popular are now absent. That’s because populations of swordfish, red snapper, and other large predatory fish have declined by 90% since the mid-1960s.
Overfished for consumption, these species felt a double-whammy when fisheries also stripped their prey out of the ocean. The removal of smaller fish, such as herring and sardines, often used for animal feed and fertilizer, impacts all the species that feed on them.
As fisheries shrink, fishermen have looked to a variety of nontraditional harvests. Along the coast of Maine attention has turned to rockweed, a form of kelp, where many fish reproduce. We are, as fisheries expert Dan Pauly puts it, “fishing down marine food webs.”
Marine biologists suggest fisheries can recover, but time is short to get started. For many species, the biggest individuals are the most effective reproducers. We must enforce laws that require that these animals are returned to the sea.
And more marine protected areas should be created. These are essentially national parks in the ocean with no-fishing zones. Finally, we need to work harder to establish and enforce sustainable yields across all harvests.
This means looking to science, not local politics, to guide fisheries, document food web impacts, and safeguard breeding habitat. If we fail to do so, more commercially-harvested ocean life will be regulated to a memory, with costs to the economy and biodiversity.
Photo, taken on January 8, 2010, courtesy of Kenneth J. Gill via Flickr.