Using boat, tags, nets, and submarines, marine biologists from 82 nations have been canvassing the oceans for the first Census of Marine Life, an ambitious effort to get a rough tally of all the creatures in the world’s oceans. The 10-year project is expected to conclude in 2010, and researchers say the broad survey will help them observe changes to marine ecosystems. Says co-senior scientist Ron O’Dor: “We are moving into this period of global warming, which is resulting in the acidification of the oceans, melting of the polar ice cap. We can use the first census as a benchmark to see what happens in the oceans over the next decade or more” [BBC News].
Although the project still has two years to go, researchers have already made a host of startling discoveries, many of which will be discussed this week at the World Conference on Marine Biodiversity in Valencia, Spain. In one study, researchers conducted a genetic analysis of deep sea octopuses from around the world, and determined that most descended from a common ancestor species that still lives near Antarctica. Researchers believe that octopuses started migrating to new ocean basins more than 30 million years ago when, as Antarctica cooled and a large icesheet grew, nature created a “thermohaline expressway,” a northbound flow of tasty frigid water with high salt and oxygen content. Isolated in new habitat conditions, many different species evolved; some octopuses, for example, losing their defensive ink sacs — pointless at perpetually dark depths [LiveScience].
Posts Tagged ‘biodiversity’
Curiosities of the Deep Revealed in First Census of Sea Life
Norway’s Lemming Populations Plunge Off the Statistical Cliff
Warmer winters in Norway seem to be causing a decline in lemming populations, according to a new study, and researchers say the decline of the rodent is having a cascading effect. Lemming predators, like foxes and owls, have been forced to hunt different prey in what researchers call a clear-cut example of how global warming can have a disruptive impact on entire ecosystems.
Lemming populations throughout Scandinavia tend to explode naturally every three to five years, causing huge numbers to go in search of food. Occasionally this leads the rodents to jump into water and swim to new pastures new—the origin of the myth that lemmings commit mass suicide. When lemmings boom, they’re hard to miss. Norwegians have had to use snowplows to clear the squashed rodents off the roads [National Geographic News]. But the study of lemming populations during the last four decades found no population explosions since 1994.
From Yellowstone’s Hills to Walden Pond’s Woods, Evidence of Global Warming
Two different studies separated by more than 1,700 miles hammer home the same point: evidence of global warming is everywhere. In Yellowstone National Park, researchers found that amphibian populations have declined dramatically over the past 15 years as some of their pond habitats have dried up and disappeared. Meanwhile, in Massachusetts’ Walden Pond, botanists discovered that more than a quarter of the plant species observed by Henry David Thoreau have disappeared since the author went to the woods to “live deliberately” in the 1850s.
The two studies, which both appear in the Proceedings of the National Academy of Sciences [subscription required], show that changes to the planet’s flora and fauna are already well underway. The Yellowstone study compared data from an amphibian survey done in 1992 and 1993 to data from a new survey conducted over the last three summers; researchers looked at the park’s “kettle” ponds, which are re-filled in spring by groundwater and snow melt running down from the hills [BBC News]. The researchers found that the number of permanently dry ponds had quadrupled, and even in the ponds that remained, amphibian populations had plummeted.
Global Warming Threatens Tropical Species, Too
Global warming isn’t just a threat to polar bears in the rapidly warming Arctic, a new study says: Species in the tropics are beginning to feel the effects as well, and it will only get worse. Researchers surveyed more than 1,900 species of plants, insects, and fungi in a Costa Rica rainforest and came to the troubling conclusion that if world temperatures continue to rise as predicted over the next 50 years, half of those species will have to move to completely new territory to find an appropriate habitat.
The situation is complicated for tropical species, says lead researcher Robert Colwell; shifting north or south doesn’t bring significantly lower temperatures, so species will have to take up residence at higher altitudes to survive. In the absence of mountainsides to serve as a cool refuge, those plants and insects that cannot face higher temperatures may disappear as it would require migrations of hundreds or even thousands of miles to find a suitable cooler climate—crossing habitats utterly changed by human impacts. “For lowland tropical species whose geographical range lies far from mountains, for example in the middle of the Amazon,” Colwell says, “the prospect for extinction cannot be dismissed” [Scientific American].
One Quarter of World’s Mammals Are Threatened With Extinction
An international group of researchers has issued a dire warning about the state of the world’s wild animals. A new report from the International Union for the Conservation of Nature (IUCN) lists one in four land mammals as endangered, as well as one in three marine mammals. Life on Earth is disappearing fast with man inflicting most of the damage…. On land more species face oblivion because of loss of habitat, hunting and climate change while in the oceans pollution and the side effects of fishing are taking a huge toll [Telegraph].
The new assessment — which took 1,700 experts in 130 countries a total of five years to complete — paints “a bleak picture,” leaders of the project wrote in a paper being published in the journal Science. The overview … covers all 5,487 wild species identified since 1500. It is the most thorough tally of land and marine mammals since 1996 [Washington Post].
President Bush Could Earn a “Blue Legacy” With Marine Conservation Plan
President Bush has proposed protecting vast swaths of marine territory in the South Pacific from commercial fishing and offshore drilling, in a move that some environmentalists have said could earn him a legacy as the “Teddy Roosevelt of the seas.” This week, Bush is expected to ask his Cabinet for comments on conservation proposals for marine ecosystems around the Northern Mariana islands, the Line Islands, and American Samoa.
While the Bush administration’s environmental record has generally received harsh criticism from environmentalists, these proposals are being seen as a cause for celebration. “We have every expectation that the president will move forward on protecting these places sometime in the fall,” said Diane Regas, ocean program director at Environmental Defense Fund. “Today, we put the champagne on ice, and we will pop it open.” Two years ago, the president made a huge swath of the Northwestern Hawaiian Islands a national monument, barring fishing, oil and gas extraction and tourism from its waters and coral reefs. The area is the single largest conservation area on the planet [AP].
Evolutionary Boom in the Cretaceous Period Left out the Dinosaurs
The Cretaceous period was such a good time for evolution that researchers talk about the “Cretaceous Terrestrial Revolution,” when as an explosion of new plant and animal species appeared. But researchers say that a detailed analysis of dinosaur diversity during this period debunks the prevailing theory that dinosaurs took part in this evolutionary spree; instead, their rapid evolution had taken place millions of years before.
The Cretaceous period, which lasted from 145 million years ago to 65 million years ago… saw the diversification of pollinating insects such as bees, butterflies, and moths. New forms of lizards, crocodiles, and snakes appeared, as did many of the ancestors of modern groups of birds and mammals. The Cretaceous also saw the explosion of angiosperms, or flowering plants [ScienceNOW Daily News]. Some researchers have previously suggested that the wide availability of those flowering plants sparked an evolutionary surge in dinosaurs who fed on the plants, and others who fed on the plant-eaters.
A Glimpse Into a Future With Acidic Oceans
Of all the potential effects of global warming on the natural world, one of the most alarming (and how hard it is to choose!) is the expected acidification of the planet’s oceans. Because much of the carbon dioxide that humans pump into the atmosphere ends up in the oceans, and because dissolved carbon dioxide makes water more acidic, researchers expect the pH balance of the oceans to shift further towards the acidic side of the scale before the end of the century.
Environmental scientists had a pretty good idea of what that would mean for the marine ecosystem, but a new study published in the journal Nature [subscription required] gives researchers a small-scale glimpse at that future. An international team of marine biologists studied natural carbon dioxide vents on the sea floor, and examined the consequences on biodiversity and individual species.
Papua New Guinea’s Forests Falling Fast
You may not spend much time contemplating the benefits bestowed on the planet by Papua New Guinea’s vast tropical rain forest — in fact, you may be only vaguely aware of the island nation’s existence. But it’s down there in the Pacific Ocean, just above Australia, quietly hosting an estimated 6 percent of the world’s species in an area that accounts for less than .5 percent of the Earth’s land.
Now, a thoroughly alarming study shows that 15 percent of the rain forest had been cleared by 2002. Researchers say that if deforestation continues at the present rate, half of the forest could vanish by 2021. And if the trees go, so will many of the unique species found in this biodiversity hotspot.
