One year ago, in May 2009, the Nature Conservancy released a startling report on the status of the worlds’ oyster reefs. Based on data compiled from several scientific studies and surveys, and analyzed by a group of scientists from several countries, the report found that 85 percent of oyster reefs worldwide had been destroyed.
Low in saturated fat, but high in protein, iron, Vitamin D, and healthful omega-3 fatty acids, oysters have long been considered a healthy delicacy by seafood connoisseurs. (In fact, as a vegetarian myself, I’ll readily admit that oysters are one of the few things I really miss.)
But oysters are so much more than a tasty, nutritious meal. As a vital part of the Earth’s ocean ecosystem, oysters serve as efficient water filters, removing excess nutrients and sediment from their surroundings, which helps prevent dangerous algal blooms. And oyster reefs, just like their better-publicized neighbors, coral reefs, create safe habitats and breeding grounds for many species of small fish by providing shelter from rough seas and places to hide from predators. Many other types of seafood depend on the oysters to maintain a healthy population.
Water pollution, unsustainable fishing practices like deep-sea bottom trawling, and ocean acidification due to global climate change has taken an enormous toll on oyster reefs, threatening to unbalance the delicate ocean ecosystems that depend on them — which, in turn, threatens the world’s supply of food from the sea.
Until recently, scientists had hoped that they might be able to rescue some of the damaged and dying oyster reefs around the world by reseeding them with oyster larvae from a healthy source. And one of the last remaining places in the world with more than half its oyster reefs still intact — the Gulf of Mexico.
But those oyster reefs are currently in the path of vast plumes of potentially toxic oil from the April explosion of a British Petroleum offshore oil drilling rig and the resultant massive oil spill.
No one knows yet exactly how the spill will affect the Gulf’s oysters. Adult oysters’ ability to filter toxins may well protect them to a degree from the petrochemicals and potentially toxic minerals that the oil spill contains. But oyster larvae may well be killed in large numbers by the spill. And the chemical dispersants currently being used to break up the oil in the spill have not been thoroughly evaluated for their long-term effects on sea life. And no one really knows whether oysters that have survived filtering large amounts of oil and oil dispersants will be safe to eat.
Several oyster fisheries have filed a class action lawsuit against BP to try to recover what they anticipate could be millions of dollars worth of lost revenue. But as a nation, as a planet, we may lose much more in this spill than fishing jobs and easy access to all-you-can-eat oyster platters.
If the oyster reefs in the Gulf are severely damaged by this oil spill, we may well lose one of our last best chances to preserve the Earth’s oceans as we currently know them. And that is the sort of loss that I do not believe can be valued in dollars and cents.
Image - detail of Oysters by Eduard Manet, public domain