Photo by Katie Davis
This is obvious, but still important: humans are not a marine species. Even as we have colonized most of our planet’s terrestrial landscapes, we have not yet colonized the oceans. And for most of our history, we have impacted them only on the periphery. A new review in Science finds that this has saved marine species and ecosystems from large-scale damage and degradation—that is, until the last couple centuries. (…)
But looming in the background of all of this—and rising to the foreground—are climate change and ocean acidification. Researchers have warned repeatedly that these twin carbon impacts could lead to mass extinction across marine environments, if we fail to reign in fossil fuels quickly.
In other words, according to McCauley and his colleagues, the oceans have not yet suffered the same human impacts as terrestrial ecosystems, but they could soon without better care and management. (…)
“According to the U.N. Food and Agriculture Organization (FAO), 40 times more wild animal biomass is harvested from the oceans than from land,” the researchers write. “Declines in this source of free-range marine food represent a major source of concern.”
To better safeguard the ocean, the authors suggest more Marine Protected Area, which to date only cover around 3 percent of marine waters. But they also note that this oft-repeated solution can’t be the only approach given how far many ocean species roam and disperse. Instead, other solutions must include improved management, much stricter zoning, and innovative programs. (…)
Yet, the biggest challenge—the most global challenge—remains the evil twins of climate change and ocean acidification.
“This may be the hardest and yet most important part of slowing marine defaunation,” said McCauley. “Big marine protected areas and smart harvest policy isn’t going to do us any good if we cook and acidify ocean habitats. By some measures climate change is going to be harder on marine animals than it is on terrestrial fauna.”
Scientists especially fear for coral reefs as the world’s oceans both heat up and acidify. Research has shown also that a number of shell-dependent invertebrates could be hugely impacted by ocean acidification, which is happening at a faster rate than anytime in the last 300 million years. Ocean acidification may also screw with the behaviors of many marine species, including fish.
“Yet, marine animals are already exhibiting some impressive potential to adapt to this change,” noted McCauley. “If we can slow rates of ocean warming and acidification, even a bit, we buy these animals more time to adapt and can do a lot to help protect the intrinsic resiliency of the oceans.”
This means rapidly curtailing global greenhouse gas emissions, which continue to rise despite decades of research and warnings. (…)
Jeremy Hance, Mongabay, 15 January 2015. Article.
