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Ocean Research


February 2013 Issue

NOAA Maps Shallow-Water Reefs But Many Yet to be Examined
NOAA’s National Centers for Coastal Ocean Science (NCCOS) published in December a summary of more than 12,100 square kilometers of coral-reef ecosystems in U.S. states and territories in the Pacific Ocean, Atlantic Ocean and Caribbean Sea, mapped by the National Ocean Service since 2000.

This includes approximately 5,000 square kilometers of hard-bottom habitats, such as coral reef, rubble and rock, and another 7,100 square kilometers of soft-bottom habitats, such as sand and mud.

The report, “National Summary of NOAA’s Shallow-water Benthic Habitat Mapping of U.S. Coral Reef Ecosystems,” details mapping methodologies and technologies developed, regional and local applications of the maps and products, and existing data gaps. NCCOS and NOAA’s Coral Reef Conservation Program, Office of National Marine Sanctuaries and Coastal Services Center partnered on this effort.

The region with the largest mapped area is the Florida Reef Tract, with more than 6,000 square kilometers of mapped habitats. The next closest region is the Northwestern Hawaiian Islands, with 2,000 square kilometers mapped, followed by Puerto Rico and the main Hawaiian Islands.

The mapping technology used includes lidar, acoustic sensors, multibeam sensors, optical imagery sensors and other remote-sensing tools. NOAA also created biogeography software: the BIOMapper, an interactive, online feature, and the Benthic Habitat Digitizer Extension, a GIS tool.

The report, available at http://1.usa.gov/10EnVYS, encompasses 10 coral-reef regions, but the total area mapped represents less than half of the total potential area of coral-reef ecosystems defined by the shallow-water 30-meter depth contour. There are also vast areas of unmapped deeper reef habitats at 30 to 150 meters depth.

China, Japan Advance Manned Sub Operations as US Makes Cuts
Some marine biologists, such as Robert Ballard, discoverer of the Titanic wreck, advocate the use of telepresence to conduct ocean exploration, but James Cameron pointed out in Newsweek that funding cuts for manned submersibles are not necessarily translating into more funds for ROV and AUV exploration.

“No money is being freed up by these draconian cuts,” he wrote. “Funding is being cut across the board, in the U.S., including for ROV and AUV operations, and deep-ocean science in general.”

The Chinese, meanwhile, have launched what Cameron calls “the most advanced piloted research submersible in the world,” the 7,000-meter-rated Jialong, which is rumored to have cost hundreds of millions. Also, Japan is developing a $150 million program to dive the Shinkai sub to 6,500 meters to explore trenches and hydrothermal vent sites worldwide.

“I believe the correct approach is combining the strengths of fully autonomous vehicles, remotely operated vehicles, and human-piloted vehicles, into a suite of tools to explore this vast dark territory at the bottom of the world’s oceans,” Cameron wrote. “Each type of vehicle provides important and necessary capability.”

Sea Anemones Could Thrive As Ocean Acidifies
Research has shown that corals and other calcifying organisms, which produce outer shells or skeletons of soluble calcium carbonate, will be corroded by ocean acidification. However, new research by the Universities of Essex and Plymouth has shown that noncalcifying relatives of corals can thrive under ocean acidification.

David Suggett and Jason Hall-Spencer examined what happened to sea anemones with increasing proximity to a natural CO2 vent site on the seabed near the Italian island of Vulcano, where CO2 and pH conditions are similar to those predicted for much of the world’s oceans in 50 to 100 years.

The study, published in Global Change Biology, showed that while calcified organisms dissolve away, sea anemones grow larger and much more abundant with more CO2, partly because CO2 appears to increase the productivity of the symbiotic algae that live with the anemones. In effect, the CO2 provides the anemones with more energy to grow.

Pacific Gooseneck Barnacle Gets Pregnant With Floating Sperm
The Pacific gooseneck barnacle is the first spermcasting species of ocean-dwelling arthropods found, according to a study in Proceedings of the Royal Society B. Male barnacles cast sperm into the water, which females use to fertilize their eggs. 

Barnacles in general can self-fertilize. But the Pacific gooseneck barnacle has not been observed as self-fertilizing, yet it can reproduce outside the penis range of other nearby barnacles.

Pacific gooseneck barnacles were collected from Barkley Sound, Canada, and the DNA of embryo-carrying barnacles was analyzed. Pregnant barnacles outside the range of another barnacle’s penis had one genetic marker from a barnacle other than itself, which suggested the sperm came from the ocean. It is unknown exactly how the barnacles catch sperm.

Self-fertilization cannot be ruled out, though. Videotaping barnacles in the wild is the next step in the research.

Oahu Losing Land Mass, Will Eventually Diminish Into Ocean
Oahu will flatten into a low-lying seamount in 75,000 to 1.75 million years, a study in Geochimica et Cosmochimica Acta found. It will keep growing via plate tectonics in the meantime.

The researchers measured solids dissolved in surface and groundwater from 45 streams, and 30 springs and wells on Oahu for a total of 170 water samples, including previously reported data. They calculated the mass Oahu loses each year and found that underground freshwater springs removed more mineral material than erosion. Groundwater had three to 12 times more dissolved solids than surface water.

While the younger Hawaiian Islands push the Pacific tectonic plate downward, Oahu is pushed upward. The uplift happens at a rate of 0.2 feet per 1,000 years, which presently counteracts the losses caused by groundwater removing land mass.


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