Climate Change Influences The Size Of Marine Organisms: Big Advantage For The Small

The ice is melting, the sea level is rising and species are conquering new habitats. The warming of the world climate has many consequences. Researchers now report that climate change influences the size of aquatic organisms.

For a long time scientists have observed the biological consequences of global climate change. One of the most famous symptoms is the shift of habitats from the equator further north or further south. More recent studies show that not only the habitats but also the size of organisms is affected.
Dr. Martin Daufresne of the HYAX Lake Ecosystem Laboratory in Aix-en-Provence, France, as well as Prof. Ulrich Sommer and Dr. Kathrin Lengfellner of the Leibniz-Institute of Marine Sciences (IFM-GEOMAR) in Kiel have shown that global warming leads to reduced body size of organisms in the ocean and in freshwater. Very different organisms showed this tendency: bacteria, plankton-algae, zooplankton and fishes in the North and Baltic Sea and in French rivers.
Three mechanisms seem to play a role in this process.
First: The proportion of smaller species grows.
Second: The proportion of smaller individuals grows within one species.
Third: The animals reach sexual maturity with smaller body size.
“This development affects the functioning of the whole eco-system: The body size is decisive for what animals can eat and by whom they are eaten. A shift to smaller species and individuals within the fish population could lead to a reduction of zooplankton because small fish will eat less fish and more zooplankton. This could pave the way fvor massive and unpleasant algal blooms. Furthermore, with smaller fish the economic value of fishery declines”, explains Prof. Sommer.
The bacteria, algae and zooplankton were examined in experiments of Baltic Sea plankton as part of the German Research Foundation-programme AQUASHIFT. The results about fish size are based on long term measurements in the North Sea, the Baltic Sea and in French Rivers.
Journal reference:
Daufresne et al. Global warming benefits the small in aquatic ecosystems. Proceedings of the National Academy of Sciences, 2009; DOI: 10.1073/pnas.0902080106
Adapted from materials provided by Leibniz Institute of Marine Sciences (IFM-GEOMAR).

Marine life at Pulau Perhentian (Malaysia) under threat from trash

Pulau Perhentian Besar and Kecil, the havens for marine life, are under threat environmentally due to poorly planned tourism development, ineffective sewage treatment and solid waste disposal.The state government is worried that this could lead to severe damage to coral reefs found in abundance surrounding both islands.State Commercial, Industry and Environment Committee chairman Toh Chin Yaw said the new chalets have compounded the problem as many of them did not have proper sewage and rubbish disposal systems."Some of these operators are taking the easy way out by diverting all types of wastes from their chalets direct into the sea," he said in an interview yesterday.Toh said during the peak season, mounds of garbage bags could also be seen around the islands, believed to have been left by these operators."They are blaming us for not centralising the sewage system and garbage collection without realising that it is too costly for the state government to do that.Just dumped: A photo showing bags of rubbish dumped onto floating rafts meant for tourists at Pulau Perhentian, Terengganu."We have commissioned a contractor to regularly collect the garbage from the islands to be disposed of on the mainland, but many of the operators are refusing to pay the maintenance fees and continued to indiscriminately throw their garbage into the sea," he added.Toh said the state government would build a sewage treatment plant on the islands if the operators were willing to pay the monthly maintenance fees.However, he doubted that they would do so as at present, they were also unwilling to share part of their revenues to be utilised for the pollution control efforts as advocated by the state government."We are intensifying our environmental awareness programme, besides encouraging operators to improve their waste facilities."We will also rope in the relevant authorities to educate these operators on the importance of protecting the eco-system at these islands," he added.Source: http://www.thestar.com.my/news/story.asp?file=/2009/6/15/nation/4120173&sec=nation

THE STAR Online: Marine life at Pulau Perhentian under threat from trash

Noisy oceans 'threaten sea life'

Some whales show damage suggesting they surfaced too quickly, experts say Increasing noise pollution in the world's oceans is threatening the survival of whales and dolphins, a UN-backed conference has heard. Experts say the noises sea creatures use to communicate are being drowned out by noises from commercial shipping, new military sonar and climate change. They become disoriented, cannot find mates or food and behave differently, scientists say. Suggestions to cut noise include installing quieter engines. The Convention on the Conservation of Migratory Species of Wild Animals, which representatives from 100 countries are attending, is considering issuing a resolution that would oblige countries to reduce sound pollution. 'Cocktail party' Other suggested measures include re-routing shipping, cutting speed and banning tests and sonar use in the habitats of endangered animals. Describing the increasing noise in oceans, Mark Simmonds from the Whale and Dolphin Conservation Society said: "Call it a cocktail-party effect: you have to speak louder and louder until no-one can hear each other anymore." He said there were a growing number of cases where the stranding of whales and dolphin could be linked to sound pollution. In some cases, the mammals had tissue damage similar to divers who surface too quickly, leading scientists to suggest that they were scared by military sonar or seismic testing, and surfaced beyond their physical limits, he added. Other research suggests that rising levels of carbon dioxide are increasing the acidity of the Earth's oceans, making sound travel further through sea water. According to a report by the International Fund for Animal Welfare, the distance over which blue whales can communicate has been cut by 90% as a result of higher noise levels over the last 40 years. A spokesman for the UN Environment Programme said governments seem ready to take action to alleviate the problems caused by noisy oceans. BBC News

Acid Oceans Threatening Marine Food Chain

The world's oceans are turning acidic due to the buildup of carbon dioxide (CO2) in the atmosphere, and scientists say the effects on marine life will be catastrophic. In the next 50 to 100 years corrosive seawater will dissolve the shells of tiny marine snails and reduce coral reefs to rubble, the researchers say (coral photos, facts, more). Four leading marine experts delivered this grim prognosis yesterday at the annual meeting of the American Association for the Advancement of Science in San Francisco, California. The scientists stressed that increased ocean acidity is one of the gravest dangers posed by the buildup of atmospheric CO2. "Ocean chemistry is changing to a state that has not occurred for hundreds of thousands of years," said Richard Feely of Seattle's Pacific Marine Environmental Laboratory. "Shell-building by marine organisms will slow down or stop. Reef-building will decrease or reverse." Already, Feely said, ocean acidity has increased about 30 percent since industrialization began spurring harmful carbon emissions centuries ago. Unless emissions are reduced from current levels, an increase of 150 percent is predicted by 2100. Such an increase would make the oceans more acidic than they've been at any time in the last 20 million years, he added. Sea Creatures' Uncertain Fate The organisms most directly affected are those that build hard shells or other mineral structures of calcium carbonate. These include numerous species of corals, marine snails, and crust-building algae. As oceans absorb CO2 from the air, the gas reacts with water to produce carbonic acid. The acid in turn consumes the carbonate that sea creatures need to build their shells. "This is a problem that no living corals have encountered in their past evolutionary history," said Charlie Veron, of the Australian Institute of Marine Science.Over time, coral reefs have been able to adjust to changes in ocean temperature and sea level, Veron said. But acidification appears to be a problem that the ancestors of today's corals were unable to solve. Mass extinctions of marine life in the distant past, he said, were probably caused by chemical changes similar to those happening today. "It took coral reefs about four to ten million years to recover each time," he added. In shallow waters where most corals presently grow, carbonate is not in short supply. But at greater depths carbonate concentration decreases until it reaches a point beyond which shell- and reef-production is no longer possible. That critical threshold is rising closer to the surface as oceans grow increasingly acidic, limiting the depths at which corals and other organisms can live. Feely said that this limit has already risen several hundred meters, particularly in the Indian and Pacific oceans. Recent measurements in the Gulf of Alaska found that carbonate was in short supply less than 325 feet (100 meters) below the surface. James Orr, of the International Atomic Energy Agency's Marine Environmental Laboratory in Monaco, said that by the end of this century, shell- and reef-building sea creatures will be unable to live at any depth across a huge area of the world's oceans. "Two-thirds of cold-water corals will be exposed to corrosive waters by 2100," Orr said. Far-Reaching Effects Initial concerns about ocean acidification have focused on corals, which are already experiencing die-offs and "bleaching" due to warmer water temperatures. (Read related story: "Global Warming Has Devastating Effect on Coral Reefs, Study Shows".) Unfortunately, Veron said, "the very corals that will escape mass bleaching are those most prone to the effects of ocean acidification." Scientists now recognize that the danger extends to other organisms as well. Robert Buddemeier, of the Kansas Geological Survey, said mineral-producing "coralline" algae are especially vulnerable. The algaes' cementlike secretions are the "glue" that helps hold coral reefs together, Buddemeier said, and also help stabilize coastlines in nonreef areas. Perhaps even more alarming is the threat to marine snails called pteropods. Populations of these tiny creatures can reach up to ten thousand individuals per cubic meter (35 cubic feet) in the Southern Ocean. Their loss, Orr said, would have far-reaching effects. "They're an integral component of marine food webs, a huge food source for many marine predators," he said. The snails' calcium carbonate shells are so thin they are virtually transparent, Orr added, which makes them particularly vulnerable. "Pteropod shells can start to dissolve in 24 hours," he said, "under [the seawater] conditions we expect for 2100."

WTO plans threaten sea life: Greenpeace

NAIROBI (Reuters) - Pirates and licensed trawlers are pillaging the world's oceans, while proposals on the table for trade ministers meeting in Switzerland next week could prove the final blow to sea life, Greenpeace said on Friday. Three-quarters of global fish stocks are now classed by the United Nations as fully or over-exploited, and the conservation group said World Trade Organization plans to slash or cancel fish and fish product tariffs would be a disaster."Under trade liberalization, only a few countries will benefit, and then only in the short term," Daniel Mittler, a political adviser on trade for Greenpeace, told reporters."The reality is, all other countries will lose. There must be regulated trade and proper management...The last thing the world needs is a relaunch of the Doha global trade round."The world's seas are already ravaged, with waters off developing nations most at risk from pirate trawlers flying cheaply purchased flags of convenience, Greenpeace said.At any one time, some 600 foreign vessels are fishing off the Kenyan coast, said Athman Seif of the Kenya Marine Forum, particularly targeting lucrative hauls of yellow fin tuna. Some of the boats are licensed, many are not, he said."They are sophisticated and unscrupulous, and something must be done," he said at the launch of the report in Nairobi.Greenpeace says illegal fishing will boom if tariffs are cut or dropped, as trawler crews hunt lucrative export stocks while dumping tons of unwanted "bycatch" caught in their huge nets.The tariff plans are included in the suspended Doha round of trade talks begun in 2001. But discussions have continued behind closed doors, Mittler said, and next week in Davos, Switzerland, ministers will try to rescue the round.Greenpeace said studies in Mauritania, Senegal and Argentina showed that trade liberalization in fisheries was a disaster for the marine environment as well as for local food security."Not even the economic case for liberalization is convincing," it said in its report. "Argentina, for example, is estimated to have lost at least $3.5 million in future earnings by over-exploiting its fish resources after liberalization."The group called for an end to double standards that saw countries like Spain declaring protected marine reserves in their own waters to guard tourism incomes, while sending deep sea trawlers to harvest distant seas off developing nations.Less than 1 percent of the world's oceans is protected under marine reserves, and Greenpeace said that figure urgently needed to be boosted to 40 percent -- alongside robust monitoring and prosecution of illegal fishing practices."It's the 'Wild West' out there," said Sari Tolvanen, a marine biologist with the group. "We need to protect large areas, logically and biologically connected, the world over."