John Bruno: When summer arrives, my friends and family inevitably roll their eyes when I tell them I’m packing for my fieldwork in the Caribbean. They picture a book and a white-sand beach. I do get a tan. But it’s no vacation.
I study ocean ecosystems. The work is chronically underfunded, so food and housing is basic or worse. When we’re in Belize monitoring the health of coral reefs, about half the nights we sleep under the stars on a dock. When I can afford a roach- and gecko-infested room, it’s often so rustic that it’s preferable to sleep outside.
There are also the tropical diseases we acquire (dengue, for instance), the insects that lay eggs under our skin (bot flies), stinging jellyfish, scorpions hiding in our shoes and, of course, feisty sea turtles (on one trip an enormous loggerhead turtle bit one of my graduate students on the rear). It’s also physical work, made harder by the intense heat and humidity. One former undergrad in my lab was in the National Guard. After she was deployed to Kuwait, she emailed us to say that the assignment was easier than fieldwork with us.
Still, I love all of it. One of the big rewards is the wonders you stumble into by just spending so much time in nature, the kind of things you see in BBC documentaries narrated by David Attenborough. Last summer I woke up in the middle of the night, looked over the dock and saw a dozen spotted eagle rays slowly circling beneath me. It looked like a mobile you’d hang over a baby’s crib. We’ve also come across mating leatherback turtles (awesome, but not so sexy), orcas and manta rays in the Galápagos Islands, a huge tiger shark in Moorea and fields of tiny eels peeking out of their holes on the sandy seafloor in Palau.
Like many of my peers, I’ve walked away from the type of purely basic academic science I was trained to do to focus on trying to understand and slow the rapid changes underway in ocean ecosystems. My team has been working on determining whether protection from fishing and pollution in well-policed marine reserves can moderate or reverse the loss of Caribbean corals, the small invertebrate animals that build up reefs over thousands of years.
Since 2009 we’ve been annually surveying 16 reefs across the Belizean Barrier Reef, half of which are inside a protected reserve. We typically survey two reefs a day, filming the seafloor with video cameras and counting and identifying every fish in 100-foot-long bands.
Unfortunately, we’ve found local conservation is ineffective in stopping coral loss. Dozens of other studies around the world have reported the same finding. The most striking example is probably mass bleaching and coral mortality on Australia’s Great Barrier Reef in 2016 and again this year. This well-protected reef, relatively isolated from human activities, is nevertheless susceptible to global warming. I was a co-author of a paper last year that found (to my surprise) that the world’s most isolated reefs were no healthier than those adjacent to coastal cities. Even the most remote marine ecosystems in the Central Pacific and the North Atlantic and around Antarctica are being radically altered as oceans warm and become more acidic.
The Caribbean has warmed by about two degrees Fahrenheit during my lifetime. Carbon dioxide and other greenhouse gases act as a sort of blanket around the earth, trapping heat that would otherwise be lost to space. Incredibly, 94 percent of this extra heat is going into the oceans, and it’s not just coral reefs that are being affected. Thousands of species are rapidly migrating away from the Equator, trying to stay cool. This is creating new mixtures of plants and animals that are interacting in new and unpredictable ways.
Our goal as scientists isn’t to save only endangered invertebrates like coral but to preserve the reefs that hundreds of millions of people depend on. Food, jobs, tourism revenue, recreation and buffers from coastal storms are just some of the value coastal communities get from healthy reefs.
I grew up in South Florida in the 1970s, when the reefs of the Florida Keys were still relatively healthy. Snorkeling just a foot or two above acres of golden elkhorn corals was like flying over golden fields of wheat. That is what inspired me to spend my life learning and teaching about the oceans. I was about 10 years old then.
By the time I graduated from high school, most of that coral splendor was gone. A disease linked to ocean warming wiped out about 99 percent of elkhorn coral colonies across the entire Caribbean — literally hundreds of millions of corals disappeared in a matter of months. This species and closely related staghorn corals had dominated Caribbean coral reefs for at least 5,000 years.
Things aren’t getting any better. A few days ago, a colleague, Bill Precht, a coral reef scientist with an environmental consulting firm, sent me a note describing what he saw on a recent dive at Florida Keys National Marine Sanctuary. It’s typical of my summer correspondence from fellow scientists. Depressing.
“This reef is a coral graveyard,” he wrote. “Lots of recently dead colonies now covered with a thin veil or sediment and turf algae.”
So what can be done to protect corals and other marine animals from ocean warming? The obvious solution is to switch to solar and wind energy, now a cheaper source of electricity than coal. Although our economy is already making this shift, it’s happening too slowly to avoid catastrophic warming. A revenue-neutral carbon tax is one effective mechanism to promote renewable energy sources. This solution has been championed by a bipartisan patchwork that includes the former NASA scientist James Hansen; the Republican elders James A. Baker, George P. Shultz and Henry Paulson; and my dad.
Despite all the loss and the looming threats, there is still so much left to conserve. Like the amazingly healthy Orbicella coral reefs I saw in the crystal-clear waters of the Bay of Pigs, Cuba, a few years ago, and the staghorn coral reefs within swimming distance of the beachfront hotels of Fort Lauderdale that are now threatened by an Army Corps of Engineers dredging project. There are also a few reefs at higher latitudes or in other lucky locations that are warming much more slowly and could hold out for decades or centuries.
I really don’t know how this will all turn out. Corals and other creatures could adapt to their changing environments. People could radically reduce their carbon emissions. Yet both outcomes are unlikely, and reality is draining my ocean optimism. It isn’t too late, but we need to act very soon.
John Bruno is a marine ecologist at the University of North Carolina, Chapel Hill.
Source: NY Times