A white shark filmed off the Central California Coast, where they are tagged each fall and winter. Credit: Stanford University.
“We’ve studied these sharks for nearly 20 years, and they’ve told us consistently that the White Shark Café is a really important place in the ocean – but we’ve never known why
HONOLULU (PRWEB) April 17, 2018
White sharks are found all over the globe, but are most known from the coastal waters they inhabit, near seal colonies where they forage as adults. Over the past two decades it has become clear that white sharks in the Northeastern Pacific have a mysterious offshore lifestyle, too. Once thought to live exclusively near shore, white sharks carrying satellite tracking tags have demonstrated that they travel offshore for up to six months of the year, to regions far from land, where there is less food.
Dr. Barbara Block, Stanford University, and her team have been studying the population of white sharks found off the California coast for over two decades. Their research, which uses a variety of electronic tracking tags, has pinpointed a region of the Pacific Ocean about half-way between Hawaii and Mexico’s Baja Peninsula that sharks visit regularly. The Stanford team, along with marine biologists and oceanographers from the Monterey Bay Aquarium, the Monterey Bay Aquarium Research Institute (MBARI), the University of Delaware, and the NOAA Office of Exploration will embark on a month-long investigation, using sophisticated oceanographic techniques and equipment – including underwater robots – in an effort to learn what draws the sharks to these seemingly inhospitable waters.
They will document the physical and biological characteristics of the White Shark Café using SuBastian, a 4,500 m capable remotely operated vehicle; a free-swimming, torpedo-shaped robot called a Slocum Glider; and two wind-powered Saildrones. The group will also use environmental DNA technology to help identify the community of animals using these waters. “We’ve studied these sharks for nearly 20 years, and they’ve told us consistently that the White Shark Café is a really important place in the ocean – but we’ve never known why,” said Dr. Salvador Jorgensen, a senior research scientist and shark research lead at Monterey Bay Aquarium.
To find the exact location of individual sharks, researchers will rely on data provided by the satellite and acoustic tags previously placed on the white sharks during the late fall of 2017 and winter of 2018 off the California coast. The tags are programmed to release from the sharks and report their locations at the café beginning April 23rd. The Saildrones and Slocum Glider carry specially designed acoustic listening devices to hear the coded “pings” emitted by acoustic tags on white sharks. The satellite tags also provide environmental data like preferred water temperatures and swimming depths. “Using the tools of modern oceanographic science we hope to better understand what makes this high seas place so attractive to one of the most iconic shark species on our planet,” said Block. “By integrating all of the data collected we hope to generate a better understanding of the Café environment and linkages to the midwater environs teeming with life.”
Documenting biology, chemistry and physical conditions throughout the entire region – a section of the Pacific Ocean the size of Colorado – the researchers hope to better understand how and why this oceanic region serves as an annual hot spot for white sharks in oceanic habitats.
