Tag Archives: marine environment

Mercury in the Global Ocean

Study shows three times more mercury in upper ocean since Industrial Revolution

Although the days of odd behavior among hat makers are a thing of the past, the dangers mercury poses to humans and the environment persist today.

Mercury is a naturally occurring element as well as a by-product of such distinctly human enterprises as burning coal and making cement. Estimates of “bioavailable” mercury—forms of the element that can be taken up by animals and humans—play an important role in everything from drafting an international treaty designed to protect humans and the environment from mercury emissions, to establishing public policies behind warnings about seafood consumption. (more…)

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Penguin chicks

UD study connects penguin chick weights to local weather conditions

Adélie penguins are an indigenous species of the West Antarctic Peninsula (WAP), one of the most rapidly warming areas on Earth. Since 1950, the average annual temperature in the Antarctic Peninsula has increased 2 degrees Celsius on average, and 6 degrees Celsius during winter.  (more…)

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Expedition finds Nemo can travel great distances to connect populations

Clownfish spend their entire lives nestling in the protective tentacles of host anemones, but new research shows that as babies they sometimes travel hundreds of kilometres across the open ocean. Although the process of long-distance dispersal by reef fish has been predicted, this is the first time that the high level exchange of offspring between distant populations has been observed.

Dr Steve Simpson, Senior Lecturer in Marine Biology and Global Change in Biosciences at the University of Exeter, and colleagues from the Australian Research Council Centre of Excellence for Coral Reef Studies (ARC COE CRS), Sultan Qaboos University (Oman) and the Centre National de la Recherche Scientifique (France) have published their findings on the dispersal of Omani clownfish larvae in the journal PLOS ONE. (more…)

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Fishing for Answers off Fukushima

Japan fisheries data provides a look at how the ocean is faring 18 months after the worst accidental release of radiation to the ocean in history

Japan’s triple disaster,” as it has become known, began on March 11, 2011, and remains unprecedented in its scope and complexity. To understand the lingering effects and potential public health implications of that chain of events, scientists are turning to a diverse and widespread sentinel in the world’s ocean: fish.

Events on March 11 began with a magnitude 9.0 earthquake, the fourth largest ever recorded. The earthquake in turn spawned a massive 40-foot tsunami that inundated the northeast Japanese coast and resulted in an estimated 20,000 missing or dead. Finally, the wave caused catastrophic damage to the Fukushima Dai-ichi nuclear power plant, resulting in the largest accidental release of radiation to the ocean in history, 80 percent of which ended up in the Northwest Pacific Ocean. (more…)

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Tracking Fish Through a Coral Reef Seascape

Ear-bone ‘tree rings’ provide evidence of connectivity

Ocean scientists have long known that juvenile coral reef fishes use coastal seagrass and mangrove habitats as nurseries, later moving as adults onto coral reefs. But the fishes’ movements, and the connections between different tropical habitats, are much more complex than previously realized, according to a study published September 3 in Proceedings of the National Academy of Sciences. The findings have important implications for management and protection of coral reefs and other marine environments.

A number of studies have demonstrated a strong relationship between the presence of coastal wetlands and offshore fish abundance and fisheries yield, but it has proved difficult to develop quantitative assessment of habitat use by fish or their movement among different habitats. “The rationale for this study,”says Simon Thorrold, a biologist at Woods Hole Oceanographic Institution (WHOI), “was to determine the relative importance of different nursery habitats to reef fishes that spend their adult lives on coral reefs but may spend at least part of their juvenile residency elsewhere.” (more…)

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Sampling the Pacific for Signs of Fukushima

An international research team is reporting the results of a research cruise they organized to study the amount, spread, and impacts of radiation released into the ocean from the tsunami-crippled reactors in Fukushima, Japan. The group of 17 researchers and technicians from eight institutions spent 15 days at sea in June 2011 studying ocean currents, and sampling water and marine organisms up to the edge of the exclusion zone around the reactors.

Led by Ken Buesseler, a senior scientist and marine chemist at the Woods Hole Oceanographic Institution (WHOI), the team found that the concentration of several key radioactive substances, or radionuclides, were elevated but varied widely across the study area, reflecting the complex nature of the marine environment. In addition, although levels of radioactivity in marine life sampled during the cruise were well below levels of concern for humans and the organisms themselves, the researchers leave open the question of whether radioactive materials are accumulating on the seafloor sediments and, if so, whether these might pose a long-term threat to the marine ecosystem. The results appear in the April 2 online edition of the journal Proceedings of the National Academy of Sciences (PNAS). (more…)

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Study of Patagonian Glacier’s Rise and Fall Adds to Understanding of Global Climate Change

Glaciers play a vital role in Earth’s climate system, and it’s critical to understand what contributes to their fluctuation.

Increased global temperatures are frequently viewed as the cause of glacial melt, but a new study of Patagonia’s Gualas Glacier highlights the role of precipitation in the glacier’s fluctuation. The study, conducted by Sébastien Bertrand of the Woods Hole Oceanographic Institution (WHOI) and his colleagues, reconstructs a 5,400 year-record of the region’s glacial environment and climate, comparing past temperature and rainfall data with sediment records of glacier fluctuations and the historical observations of early Spanish explorers. (more…)

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Sea Cucumbers: Dissolving Coral Reefs?

Washington, D.C. — Coral reefs are extremely diverse ecosystems that support enormous biodiversity. But they are at risk. Carbon dioxide emissions are acidifying the ocean, threatening reefs and other marine organisms. New research led by Carnegie’s Kenneth Schneider analyzed the role of sea cucumbers in portions of the Great Barrier Reef and determined that their  dietary process of dissolving calcium carbonate (CaCO3) from the surrounding reef accounts for about half of at the total nighttime dissolution for the reef. The work is published December 23 by the Journal of Geophysical Research.

Reefs are formed through the biological deposition of calcium carbonate (CaCO3). Many of the marine organisms living on and around a reef contribute to either its destruction or construction. Therefore it is crucial that the amount of calcium carbonate remain in balance. When this delicate balance is disrupted, the reef ceases to grow and its foundations can be weakened. (more…)

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