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Keeping Coral Clean Seaweed overgrowth is a major problem for coral reefs and also seems to be a consequence of excessive harvesting of herbivorous fish. Dixson and Hay (p. 804) examined this effect on Fijian reefs. Species of small herbivorous gobies and coral-associated damselfish were compared for their effect on the toxic Chlorodesmis seaweed in experiments that required caging colonies of the branching coral Acropora nasuta and the associated fish species. Only the gobies actively removed algal fronds attached to the cages and only one species (itself toxic to predators) ate them; the damselfish simply defected from the arena when toxic algae were present. The hydrophobic toxins exuded in the algal mucus lysed coral polyps releasing cell constituents that, together with the algal toxin, attract the gobies, which then eat the algal fronds. Interestingly, the toxic goby became more toxic to predators after consumption of the seaweed, which may help to drive symbiosis with a coral colony.

"In some cases, cheaper types of fish were substituted for expensive species. In others, fish that consumers have been urged to avoid because stocks are depleted, putting the species or a fishery at risk, was identified as a type of fish that is not threatened. Although such mislabeling violates laws protecting consumers, it is hard to detect. Some of the findings present public health concerns. Thirteen types of fish, including tilapia and tilefish, were falsely identified as red snapper. Tilefish contains such high mercury levels that the federal Food and Drug Administration advises women who are pregnant or nursing and young children not to eat it."

December 18, 2012 The Ten Best Ocean Stories of 2012 | | | Share on redditReddit | Share on diggDigg | Share on stumbleuponStumble | Share on emailEmail | More Sharing ServicesMore Two market squids mating 2012 was a big year for squid science. Photo Credit: © Brian Skerry, www.brianskerry.com 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. Schooling sardines form a "bait ball." Small fish, such as these schooling sardines, received well-deserved attention for being an important part of the food chain in 2012. Photo Credit: © Erwin Poliakoff, Flickr 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, marin

"USC researcher experiments with changing ocean chemistry Jan. 19, 2011 | Molly Peterson | KPCC In his lab, USC's Dave Hutchins is simulating possible future atmospheres and temperatures for the Earth. He says he's trying to figure out how tiny organisms that form the base of the food web will react to a more carbon-intense ocean. Burning fossil fuels doesn't just put more carbon into the atmosphere and help warm the climate. It's also changing the chemistry of sea water. KPCC's Molly Peterson visits a University of Southern California researcher who studies the consequences of a more corrosive ocean. Tailpipes and refineries and smokestacks as far as the eye can see in Los Angeles symbolize the way people change the planet's climate. They remind Dave Hutchins that the ocean's changing too. Hutchins teaches marine biology at USC. He says about a third of all the carbon, or CO2, that people have pushed into earth's atmosphere ends up in sea water - "which is a good thing for us because if the ocean hadn't taken up that CO2 the greenhouse effect would be far more advanced than it is." He smiles. Hutchins says that carbon is probably not so good for the ocean. "The more carbon dioxide that enters the ocean the more acidic the ocean gets." On the pH scale, smaller numbers represent more acidity. The Monterey Bay Aquarium Research Institute estimates we've pumped 500 million tons of carbon into the world's oceans. Dave Hutchins at USC says that carbon has already lowered the pH value for sea water. "By the end of this century we are going to have increased the amount of acid in the ocean by maybe 200 percent over natural pre-industrial levels," he says. "So we are driving the chemistry of the ocean into new territory - into areas that it has never seen." Hutchins is one of dozens of scientists who study the ripples of that new chemistry into the marine ecosystem. Now for an aside. I make bubbly water at home with a soda machine, and to do that, I pump ca