June 7, 2013
Ocean plants produce some 50% of the planet’s oxygen. Seawater absorbs a quarter of the carbon dioxide we pump into the atmosphere. Ocean currents distribute heat around the globe, regulating weather patterns and climate. And, for those who take pleasure in life’s simple rewards, a seaweed extract keeps your peanut butter and ice cream at the right consistency!
Nonetheless, those of us who can’t see the ocean from our window still feel a disconnect—because the ocean feels far away, it’s easy to forget the critical role the ocean plays in human life and to think that problems concerning the ocean will only harm those people that fish or make their living directly from the sea. But this isn’t true: the sea is far more important than that.
Every year, scientists learn more about the top threats to the ocean and what we can do to counter them. So for tomorrow’s World Oceans Day, here’s a run-down of what we’ve learned just in the past 12 months.
This year, we got the news that the apparent “slow down” in global warming may just be the ocean shouldering the load by absorbing more heat than usual. But this is no cause to celebrate: the extra heat may be out of sight, but it shouldn’t be out of mind. Ocean surface temperatures have been rising incrementally since the early 20th century, and the past three decades have been warmer than we’ve ever observed before. In fact, waters off the U.S. East Coast were hotter in 2012 than the past 150 years. This increase is already affecting wildlife. For example, fish are shifting their ranges globally to stay in the cooler water they prefer, altering ecosystems and fisheries’ harvests.
Coral reefs are highly susceptible to warming: warm water (and other environmental changes) drives away the symbiotic algae that live inside coral animals and provide them food. This process, called bleaching, can kill corals outright by causing them to starve to death, or make it more likely that they will succumb to disease. A study out this year found that even if we reduce our emissions and stop warming the planet beyond 2°C, the number considered to be safe for most ecosystems, around 70% of corals will degrade and die by 2030.
Although coral reefs can be quite resilient and can survive unimaginable disturbances, we need to get moving on reducing carbon dioxide emissions and creating protected areas where other stressors such as environmental pollutants are reduced.
More than a hit of acid
The ocean doesn’t just absorb heat from the atmosphere: it also absorbs carbon dioxide directly, which breaks down into carbonic acid and makes seawater more acidic. Since preindustrial times, the ocean has become 30% more acidic and scientists are just starting to unravel the diverse responses ecosystems and organisms have to acidification.
And it really is a variety: some organisms (the “winners”) may not be harmed by acidification at all. Sea urchin larvae, for instance, develop just fine, despite having calcium carbonate skeletons that are susceptible to dissolving. Sponges that drill into shells and corals show an ability to drill faster in acidic seawater, but to the detriment of the organisms they’re boring into.
Nonetheless, there will be plenty of losers. This year saw the first physical evidence of acidification in the wild: the shells of swimming snails called pteropods showed signs of dissolution in Antarctica. Researchers previously found that oyster larvae fail under acidic conditions, potentially explaining recent oyster hatchery collapses and smaller oysters. Acidification may also harm other fisheries.
Plastic, plastic, everywhere
Americans produced 31 million tons of plastic trash in 2010, and only eight percent of that was recycled. Where does the remaining plastic go? A lot of it ends up in the ocean.
Since last World Oceans Day, trash has reached the deep-sea and the remote Southern Ocean, two of the most pristine areas on Earth. Most of the plastic trash in the ocean is small—a few centimeters or less—and can easily be consumed by animals, with damaging consequences. Some animals get hit on two fronts: when already dangerous plastic degrades in their stomachs it leaches toxic chemicals into their systems. Laysan albatross chicks are fed the bits of plastic by their parents in lieu of their typical diet and one-third of fish in the English Channel have nibbled on plastic.
Where have all the fish gone?
A perennial problem for the ocean, overfishing has only gotten worse with the advent of highly advanced gear. Despite fishing fleets going farther and deeper, the fishing gains are not keeping up with the increased effort.
Our brains can’t keep up either: even as we catch fewer fish, we acclimate to the new normal, adjust to the shifting baseline, and forget the boon that used to be, despite the fact that our memories are long enough to realize that most of the world’s fisheries (especially the small ones that aren’t regulated) are in decline.
Thankfully, those responsible for managing our fisheries are aware of what’s at stake. New knowledge about fish populations and their role in ecosystems can lead to recovery. A report from March 2013 shows that two-thirds of U.S. fish species that are closely managed due to their earlier declines are now considered rebuilt, or on their way.
Learn more about the ocean from the Smithsonian’s Ocean Portal. This post was co-authored by Emily Frost and Hannah Waters.
December 18, 2012
Despite covering 70 percent of the earth’s surface, the ocean doesn’t often make it into the news. But when it does, it makes quite a splash (so to speak). Here are the top ten ocean stories we couldn’t stop talking about this year, in no particular order. Add your own in the comments!
2012: The Year of the Squid From the giant squid’s giant eyes (the better to see predatory sperm whales, my dear), to the vampire squid’s eerie diet of remains and feces, the strange adaptations and behavior of these cephalopods amazed us all year. Scientists found a deep-sea squid that dismembers its own glowing arm to distract predators and make a daring escape. But fascinating findings weren’t relegated to the deep: at the surface, some squids will rocket themselves above the waves to fly long distances at top speeds.
James Cameron Explores the Deep Sea Filmmaker James Cameron has never shied away from marine movie plots (See: Titanic, The Abyss), but this year he showed he was truly fearless, becoming the first person to hit the deepest point on the seafloor (35,804 feet) in a solo submarine. While he only managed to bring up a single mud sample from the deepest region, he found thriving biodiversity in the other deep-sea areas his expedition explored, including giant versions of organisms found in shallow water.
Small Fish Make a Big Impact Forage fish—small, schooling fish that are gulped down by predators—should be left in the ocean for larger fish, marine mammals and birds to eat, according to an April report from the Lenfest Forage Fish Task Force. These tiny fish, including anchovies, menhaden, herring and sardines, make up 37% of the world’s catch, but only 10% are consumed by people, with the rest processed into food for farmed fish and livestock. With the evidence mounting that forage fish are worth more as wild fish food, state governments and regional fishery management councils are making moves to protect them from overfishing.
Marine Debris and Plastic Get Around In June, a dock encrusted with barnacles, sea stars, crabs and other sea life washed ashore on the coast of Oregon. It had floated across the Pacific from a Japanese port more than 5,000 miles away—a small piece of the estimated 1.5 million tons of marine debris set afloat by the 2011 Tohoku tsunami. But that’s not the only trash in the sea. Researchers found ten times as much plastic in the “pristine” Antarctic oceans than they expected. Some species are even learning to adapt to the ubiquitous ocean plastic.
Taking Measure of Coral Reef Health Australia’s iconic Great Barrier Reef, so large it can be seen from space, is not doing well. An October study found that since 1986, half of the living coral has died because of warming water, predation and storm damage. And it’s not just Australia: the December Healthy Reefs report gave most Mesoamerican reefs a “poor” rating. It’s hard to escape that gloom, but there were glimmers of hope. Some coral species proved able to adapt to warmer water, and changing circulation caused by the warming ocean may create refuges for coral reef habitat.
Shark Finning Slowing Down? The fishing practice of shark finning—slicing off a shark’s fins before tossing it back in the ocean to slowly sink and suffocate—began its own slow death in 2012. A steady stream of U.S. states have banned the sale of shark fins
ning; the European Union will now require fisherman to land sharks with their fins on; four shark sanctuaries were created in American Samoa, the Cook Islands, Kosrae and French Polynesia; and, in July, China announced that official banquets would be prohibited from serving shark fin soup (although the ban may take up to three years to go into effect).
Arctic Sea Ice Hits All-Time Low On September 16, sea ice extent reached a record low in the Arctic, stretching 3.41 million square kilometers—that’s 49% lower than the 1979-2000 average minimum of 6.7 million square kilometers. What’s more, its melt rate is increasing: 2012 had the largest summer ice loss by more than one million square kilometers. This change is expected to affect ecosystems—from polar bears to phytoplankton—and accelerate warming in the area, eventually melting Greenland’s ice sheet and raising sea level dramatically.
Hurricane Sandy Elevates Awareness of Sea-Level Rise This year certainly opened our eyes to the severity of climate change and sea-level rise. The east coast of the U.S., where scientists project sea-level will rise three to four times faster than the global average, got a glimpse of its effects when Hurricane Sandy caused $65 billion in damage, took at least 253 lives, and flooded Manhattan’s subways in October. The disaster inspired The Economist, Bloomberg Businessweek and other major news sources to take a closer look at climate change and what it means for us all.
Counting Ocean Animals from Space Scientists took advantage of satellite technology this year to learn more about ocean wildlife. The first satellite-driven census of an animal population discovered that there are twice as many emperor penguins in Antarctica as previously thought, including seven new colonies of the large flightless birds. A second study tracked the travels of sea turtles by satellite, which could help researchers get a better idea of where they might interact with fisheries and accidentally end up caught in a net.
The Ocean Gets a Grade The first tool to comprehensively assess ocean health was announced in August 2012—and the ocean as a whole received a score of 60 out of a possible 100. This tool, the Ocean Health Index, is novel in that it considered ten ways the ocean supports people, including economies, biodiversity, and recreation. The U.S. scored a 63, ranking 26th globally, while the uninhabited Jarvis Island took home an 86, the top grade of the 171 rated countries.
–Hannah Waters, Emily Frost and Amanda Feuerstein co-wrote this post