We met in 1974 on the north coast of Jamaica, in Discovery Bay, then one of the great pioneer centers of coral reef science. At the time, many of us blithely took the reefs for granted. They were already largely fishless, which we noted, but luxuriant living corals carpeted the reefs built up by their ancestors over thousands of years. We had no inkling of a time when the corals themselves might be on the brink of disappearing. But that time was soon to come. First Hurricane Allen in 1980 pulverized the once-dominant acroporid corals, the iconic elkhorn and staghorn corals of the Caribbean; we dutifully tagged the survivors, but they failed to recover. Then, starting in 1983, much more widespread catastrophes affected the entire sea basin: the loss of the herbivorous sea urchin Diadema and the consequent rise of coral-smothering algae; coral bleaching; then coral disease. For a while, we assumed that this was, globally speaking, a local catastrophe, but marine scientists came to realize that not only were reefs being lost around the world, but so were many other marine organisms and ecosystems—mangroves, seagrasses, estuaries, all the large herbivores and predators. An entire generation of scientists has now been trained to describe, in ever greater and more dismal detail, the death of the ocean.
Fortunately, many students today take a different attitude. Like medical doctors, they want to save their patients, not write their obituaries. Even the media dictum of “if it bleeds, it leads” seems to be losing its grip as the public tires of reading stories of doom and gloom. But is there any good news to report? When we started organizing our “Beyond the Obituaries” symposium at the Smithsonian Institute in 2009, several of our colleagues wondered if we could even fill a program. Yet there is good news—reasons for hope and evidence of positive change—to be found if you hunt for it.
First, all is not lost. Relatively few extinctions have occurred in the sea, so most pieces of marine ecosystems remain. Yes, we have lost the giant auk, the sea mink, and the Caribbean monk seal, but bluefin tunas are still with us, at least for now. Moreover, in some remote places too far from human settlements to be worth exploiting, quasi-pristine marine ecosystems remain. The remarkable trophic structures of the Northern Line Islands and northwestern Hawaiian Islands, dominated by top predators in a way once thought to be energetically impossible, show us what ecosystems look like when people don’t eat everything big. Second, many once-dire situations have substantially improved. Sea otters and some seabirds, whales, turtles, and fishes like the striped bass have increased in numbers, in some cases markedly so. Shellfish beds, also, are coming back in many places, and even a few coral populations are showing signs of rebounding.
What lessons can we learn from our successes? Biologically, perhaps the most important lesson concerns scale. Widespread destruction is difficult to reverse with tiny, scattered steps. Restoration of oyster beds has depended on creating large, three-dimensional mounds of shells. Recovery of coral reefs has only occurred where marine protected areas are large, genuinely well-protected, and long term. Likewise, recovery of whales required a near total moratorium on whaling.
Politically, the implications are clear: success stories rarely just happen–unless a convenient political accident intervenes, such as the fall of the Soviet Union and the consequent reduction of pollution in the Black Sea. Large-scale solutions may be obvious in principle but they don’t get enacted if people don’t care about solving the problem. In some cases, single individuals work tirelessly for a cause and eventually succeed in inspiring others to take action. In other cases, the environments or organisms—for example, the Great Barrier Reef in Australia or whales—are so culturally important that nascent political consensus already exists. For these exceptions to become the norm, global adoption of policies that provide large-scale protection of coastal waters and the open ocean is needed. Only then will overharvested species be able to rebound and coastal ecosystems suffocating in polluted and anoxic waters be able to breathe deeply again.
But even when the desire for change is broadly shared, short-term economic interests can make change difficult, no matter the long-term economic benefits. The broader the economic impacts, the greater the conservation challenge. Today, global climate change and ocean acidification gravely threaten our growing roster of success stories. This should not discourage us from local conservation actions—healthy ecosystems are more resilient in the face of stresses posed by rising temperatures. Acting locally buys us time globally. Indeed, restoration of mangroves and seagrasses can contribute not only to the health of the local ecosystems they support, but also to that of the entire planet, by serving as blue carbon sinks. Stabilizing carbon dioxide concentrations in the atmosphere in the near future, if we manage it, will be our most important ocean success story.