Researchers Discover a Whale Shark Highway
At 60ft (18m) long, endangered whale sharks are the biggest fish in the sea but figuring out where they travel has proven a challenge. Now, scientists have discovered that the huge animals travel well-defined whale shark highways across the ocean.
Biological oceanographer John Ryan at the Monterey Bay Aquarium Research Institute (MBARI) analyzed data generated by 27 whale sharks that had been satellite tagged in the Eastern Tropical Pacific Ocean by researchers from Ecuador and England. He correlated that information with infrared and microwave radiation data from satellites that allowed him to calculate ocean temperatures as the whale sharks traversed 2,500 miles (4,000km) west across the Pacific, according to a study published in the journal PLoS One.
“The whale sharks could have ranged anywhere in the Eastern Tropical Pacific,” Ryan said in a statement, “but they were primarily following frontal boundaries between warm and cold water.” That zone is also where whale sharks may find plentiful zooplankton and other small fish that they eat.
Those insights could help conservation efforts to save the imperiled animals. The researchers noted that all but one of the tracked sharks were pregnant.
The Coral That Could Resist Ocean Acidification
Researchers at the University of Wisconsin-Madison have discovered that the way one species of coral builds its skeleton could provide shelter from acidifying oceans.
They found that the coral species, Stylophora pistillata, builds the bony structure that protects individual corals by adding large pieces of amorphous calcium carbonate (ACC) to its growing skeleton, rather than adding to it molecule by molecule from precipitating seawater as previously been thought.
That allows the coral, known as hood coral, to build its protective skeleton at a faster rate.
“Corals are affected by warming-induced bleaching and postmortem dissolution, but the finding here that ACC particles are formed inside tissue may make coral skeleton formation less susceptible to ocean acidification than previously assumed,” the researchers wrote in the study published in the Proceedings of the National Academy of Science.
The scientists used high-energy light technology from Lawrence Berkeley National Laboratory to identify minerals in the coral skeleton and create an image of the growing coral.
“If this mode of formation is verified in other species of coral, then it could be a more general mechanism, and that would enable us to predict that corals will actually form just as well in acidifying oceans,” Pupa Gilbert, a professor of physics at the University of Wisconsin-Madison, said in a statement. “Coral reefs only cover 1 percent of ocean floors, but they host 25 percent of all marine species, so they’re incredibly diverse and important from a biological point of view. But they’re also economically important for the fishing industry, tourism and because of their role in providing coastlines with protection from tropical storms.”
Counting Manatees With Sonar
Determining how many endangered manatees survive in Panama’s murky wetlands has been difficult. Now, researchers are using sonar to estimate their population.
Hector Guzman, a marine biologist at the Smithsonian Tropical Research Institute, scanned 1,200 miles (2,000km) of rivers with sonar over a year to calculate that San San Pond Sak wetlands has a seasonal population of two to 33 Antillean manatees, according to the study published in the Wildlife Society Bulletin. That data can be used to help Panama wildlife officials improve manatee conservation efforts.