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Ocean Research


June 2014 Issue

Climate Change Will Localize Coral Reef Growth
Researchers have found that increasing ocean temperatures due to climate change will soon see reefs retaining and nurturing more of their own coral larvae, leaving large reef systems less interconnected.

The study, which was published in Nature Climate Change, was conducted by Nova Southeastern University's Oceanographic Center, the Australian Research Council Centre of Excellence for Coral Reef Studies, the School of Marine and Tropical Biology at James Cook University in Australia, and Sesoko Station, Tropical Biosphere Research Center at the University of the Ryukyus, Japan.

These findings have both positive and negative implications.

At higher temperatures more coral larvae will tend to stay on their birth reef. This is good news in an otherwise cloudy picture for isolated reefs, because in the future they will be able to retain more of their own larvae and recover faster from severe storms or bleaching events.

While more coral larvae will stay close to their parents, fewer will disperse longer distances, leaving reefs less connected.

The loss of connectivity can make reef systems such as the Great Barrier Reef (in Australia) or the Florida Coral Reef Barrier more vulnerable, so interconnected reef systems that depend on the recruitment of coral larvae may take more time to recover after a disturbance, such as a hurricane, because fewer larvae will disperse from other reefs to the disturbed reef.

Weaker connections between reefs can mean that warm-adapted corals, such as those in the Caribbean, may take longer to expand their ranges to the north.

Similarly, for isolated reefs, while these can retain more of their own larvae, they are left with fewer possibilities to change their species composition to adjust to climate change.

The results demonstrate that global warming will change patterns of larval connectivity among reefs. On a positive note, the stronger link between adults and recruits means an even greater benefit if local threats are reduced, such as dredging and fishing methods that can damage corals.

NOAA Hydrographic Survey Season Opens
NOAA ships, small boats and hydrographic services contractors have their sailing orders to survey more than 2,000 square nautical miles in U.S. coastal waters this year, collecting data that will strengthen the foundation of U.S. environmental intelligence.

The NOAA Office of Coast Survey will manage and conduct surveys that will measure water depths and collect seafloor data to update nautical charts, identify navigational hazards, support wind farm sitings, map ocean habitats, and assist state governments with their ocean projects.

In one project, NOAA Ship Thomas Jefferson will survey in Long Island Sound, performing habitat mapping in Fishers Island Sound as well as continuing post-Sandy hydrographic surveys.

Since vibrant tourism and commercial fishing industries mean more ocean traffic, NOAA ships Rainier and Fairweather will gather hydrographic data to supplement old and sparse depth measurements on nautical charts covering Alaska's Kodiak Island.

This year's plans also include data acquisition in San Francisco Bay, San Pablo Bay, Suisun Bay, and Richmond Harbor, California, to address charting discrepancies; Carquinez Strait, California, to chart a shoal that has migrated toward the federal shipping channel; Galveston Bay, Texas, and vicinity in response to requests by pilots and port authorities; St. Andrew Bay's Grand Lagoon, Florida, to investigate shoaling and a changing channel course; West Bay and West Bay Creek, along the Intracoastal Waterway north of Panama City, Florida; and a proposed anchorage area near Jacksonville, Florida, to investigate reported hazards to navigation.

Longest Underwater Stay Planned for This Fall
This fall, Roane State Community College associate professor of biology Bruce Cantrell and adjunct instructor Jessica Fain plan to live and work under the sea for 72 days at the floor of the lagoon at the Marine Resources Development Foundation's facilities in Key Largo, Florida. The venture will be called Classroom Under the Sea.

While underwater, Cantrell and Fain will host a weekly program featuring interviews with leading scientists and explorers, covering topics such as conservation and undersea exploration.

During their stay, Cantrell and Fain will set a world record for the longest time spent living underwater. They will stay in Jules' Undersea Lodge. Located 21 feet below the surface of the sea at the Marine Resources Development Foundation, the underwater habitat features a wet room, two bedrooms and a common room. For safety, the facility is monitored at all times.

Pumice Drift Prediction to Help Protect Vessels, Shipping
A technique by researchers from the National Oceanography Centre Southampton (NOCS) and the University of Southampton will aid in predicting the dispersal and drift patterns of large floating 'islands' of pumice created by volcanic eruptions at sea. Known as pumice rafts, these large mobile accumulations of pumice fragments can spread to affect a considerable area of the ocean, damaging vessels and disrupting shipping routes for months or years.

The ability to predict where these rafts will end up could give enough advance warning for protective measures to be put in place on shipping routes or in harbors where the presence of pumice is hazardous.

This technique can also be used to predict the spread of other floating objects in surface ocean waters, such as anthropogenic waste or passively drifting organisms.

Researchers simulated the drift of a 400-square-kilometer raft of pumice from Havre, a deep submarine volcano in the southwest Pacific, using a high-resolution model of global ocean circulation.

The team, which included researchers from the University of Tasmania in Australia, the University of Otago in New Zealand and Stanford University in the U.S., tested the results against satellite imagery and direct observations from sailing crews.


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Sea Technology is read worldwide in more than 110 countries by management, engineers, scientists and technical personnel working in industry, government and educational research institutions. Readers are involved with oceanographic research, fisheries management, offshore oil and gas exploration and production, undersea defense including antisubmarine warfare, ocean mining and commercial diving.