Geoscience Reference
In-Depth Information
Despite this long litany of depredations, the Quoddy region remains relatively productive, though much less
so than it was historically. Some severely depleted species have been able to make a slow comeback with the
implementation of protection for seabird colonies, the cessation of whaling, and the removal of bounties on
seals, for example. But other severely depleted species' recovery may have to be measured in decades and per-
haps centuries, as seems to be the case for the critically endangered North Atlantic right whale, which has
found a last refuge in the North Atlantic in the outer Bay of Fundy.
Top to Bottom: Cascading Ecological Effects
The picture globally, especially for large marine species, is far from encouraging. A survey carried out by Bor-
is Worm and the late Ransom Myers—like Lotze, both members of Dalhousie's Biology Depart-
ment—revealed that large predatory fish communities had been depleted by at least 90 percent in the last fifty
to one hundred years. This disturbing revelation applied to marine predators such as sharks, tuna, billfish, and
large ground-fish like cod, as well as marine turtles and cetaceans. Until 2003, when Myers and Worm pub-
lished their landmark paper in Nature—“Rapid worldwide depletion of predatory fish communities”—the
19th-century notion that marine life was inexhaustible had pretty much held sway, at least in the public mind.
It had been assumed that marine habitats were too remote and fish populations too fecund ever to be ex-
hausted, but the statistics told a different story. The United Nations Food and Agriculture Organization con-
cluded that two-thirds of the global fisheries were fully exploited, overexploited, or depleted by the turn of the
millennium—a number that has since increased to 80 percent.
Recent studies have shown that large predatory fish like bluefin tuna have been depleted by 90 percent in the last fifty
to one hundred years.
