The diversity of marine life and the structure of the ocean food web were at the heart of some of the top discoveries of 2010.
2010 was a big year for ocean science. Here are my (and your) picks for the most important advances of the year. There’s one for each of the greatest threats facing the ocean (pollution, overfishing, and the two arms of climate change – warming and acidification), plus an overall winner. Enjoy!
1. First Census of Marine Life completed
October 2010 marked the end of a decade-long, international effort to catalogue the diversity of life in the ocean. The work of some 2,700 scientists from 80 nations resulted in thousands of new species being described, upping the total number of known marine species to almost 250,000. Scientists estimate that there may be over a million kinds of marine life that earn the rank of species, plus tens or even hundreds of millions of microbes. A number of scientists involved in the Census told me that one of the most shocking discoveries was the frequency and rate at which species are being driven into decline, even extinction. Ensuring that we have the information necessary to know when species disappear was a major motivation for the gargantuan effort.
2. Dramatic phytoplankton decline linked to warming seas
Pioneering work combining over a century of low-tech observations with modern modeling and mapping resulted in a dramatic (if somewhat controversial) finding – evidence of a 40% decline in phytoplankton (the microscopic marine plants that generate half of the oxygen on Earth) since 1950, strongly linked to rising ocean temperatures. Phytoplankton are the foundation of the marine food web, draw down atmospheric carbon dioxide, and produce half the oxygen on Earth. Their decline has ramifications for all life on Earth. That’s why ClimateCentral, Wonk Room’s Brad Johnson, and several Climatide commenters voted this the hands-down discovery of the year.
3. Ocean acidification is happening NOW
Over the course of the past 200 years, the ocean has absorbed nearly a third of carbon dioxide emissions, resulting in a 30% increase in ocean acidity – a phenomenon known as ocean acidification. Acidic water conditions impair the ability of animals like oysters and corals to extract the calcium carbonate they need to build their skeletons or shells. Scientists have generally considered such impacts of ocean acidification to be a problem of the (near) future. But in September 2010, two marine scientists from Stony Brook University published a study that forced a revision of that thinking by demonstrating that modern carbon dioxide levels produce shellfish with thinner shells, slower growth, and death rates almost double those of shellfish grown in pre-industrial water conditions.
4. We are NOT fishing down the food chain (or Why we need a new indicator of fisheries sustainability)
For years, prevailing wisdom has held that we are “fishing down the food chain” – over-harvesting the top-level predators, then moving on to fish lower and lower on the chain. But a new research showing that catches of fish (and other marine life) at all levels of the food chain have generally increased since the 1970s has upended this theory, leaving scientists and managers fishing for a new measure of ecosystem health (sorry, subscriptions needed for both articles). When this story hit, I overheard people talking about it in the local coffee shop. Granted, that’s in Woods Hole, where the vast majority of people in the coffee shop are likely to be ocean scientists. Still, this was big news.
5. There’s plastic in the Atlantic, too
Scientists have long known that plastic debris accumulates in parts of the northern Pacific Ocean bounded by circular ocean currents, or gyres; these regions have been called The Great Pacific Garbage Patches. This year, scientists from Sea Education Association and Woods Hole Oceanographic Institution confirmed what many have suspected for years: that there is a similar accumulation of plastic debris in the Atlantic Ocean. One of the most interesting findings in the landmark study was the fact that, while plastic use and disposal has skyrocketed in recent years, the amount of floating plastic debris hasn’t changed much. That begs the question – where is all the extra plastic going? Answering that question should keep scientists busy for years to come.