Fish tale:
Scientists explain what racing boats and some fish share — speed.
The bullet-shaped shortfin mako shark, which can zip through the water at 31 mph, has more in common with the America’s Cup racing boats than is apparent to the naked eye.
The predator and the vessel are streamlined, have similar stabilizing fins and are fast as heck.
What they don’t have in common is the shark’s specialized sandpaper skin, with tiny dermal denticles that reduce drag. That feature was actually deemed an unfair advantage in the sailing races and banned in 1987 after an ingenious attempt to mimic the substance on the skin of a sailboat.
“There are so many things in nature that we look at to make the boat go faster,” said Manolo Ruiz de Elvira, the naval architect on the design team for Oracle Team USA, which is preparing its 72-foot catamaran for the America’s Cup finals, which will be held in San Francisco Bay in September. “We try to understand the principles of nature and really adapt the structures into our designs so that they work under sailing conditions.”
The California Academy of Sciences is highlighting this unique melding of evolutionary and technological design in its newest exhibition, “Built for Speed,” a collaborative program with Oracle that explains how and why the world’s fastest sea creatures are so speedy.
The America’s Cup, say the scientists at the academy, is a perfect example of human “biomimicry.”
“Competition has driven the evolution of the ocean’s fastest inhabitants, as well as the design of the world’s most extreme racing vessels,” said Greg Farrington, the executive director of the academy, which will open the exhibition Friday.
Ocean speedsters
The featured attractions are the mako; the Indo-Pacific sailfish, which can reach speeds of 68 mph; the yellowfin tuna, which tops 46 mph; the Humboldt squid, which can make a 15-mph burst, and the orca, which reaches 34 mph. Oracle’s 72-foot catamaran can reach speeds of 46 mph.
The exhibition also includes the skeleton of an offshore orca, or killer whale, that washed ashore on the Point Reyes National Seashore on Thanksgiving 2011 and is being put together by academy scientists. The exhibition also includes a 45-foot catamaran, which is hanging from the rafters.
Luiz Rocha, the assistant curator of ichthyology at the academy, said the fastest animals are all species that thrive in the open ocean, where there is no cover and speed is of the essence.
“The only way fish can get away from predators is if they swim fast,” Rocha said. “So the predators also have to swim fast.”
Most of the species have torpedo- or bulletshaped bodies and features that reduce drag and increase acceleration. The sailfish, for instance, has a retractable fin, Rocha said, and squids fill their bodies with water and use it as a jet propulsion system. Sharks have the denticles, or micro-teeth on their skin, creating tiny whirlpools that help propel them forward, he said.
Enormous skeleton
The orca, which is the fastest member of the dolphin family, uses powerful tail flukes, a large dorsal fin for stability and a layer of blubber that makes the skin smooth, reducing drag. The 18-foot orca on display at the academy was identified by its distinctive markings as a 12-year-old male known as 0319, because it was the 319th offshore orca that scientists had identified.
It is the first skeletal display of an offshore orca, a type of killer whale that primarily eats sharks, on the West Coast, said Moe Flannery, the ornithology and mammalogy collection manager at the academy.
The exhibition also includes displays about plastic garbage, toxic waste disposal and other issues affecting the health of fast and slowmoving ocean creatures. There is a jar full to micro-plastic pieces taken from the giant patch of ocean plastic known as the Pacific gyre for people to contemplate.
The main feature, Farrington said, is the opportunity for people to “explore the links between fast animals and fast boats — between natural selection in the wild and design optimization in the lab.”