Ever wonder what it’s like to be a volunteer at the Aquarium—and swim with sharks? Great photo essay and profile from The Chronicle.
(Photo: Russell Yip, The Chronicle)
Meet the incredibles! Today and for a short while you can see spotted comb jellies in our Drifters Gallery. They’re incredibly rare, fragile, and we’re the only aquarium to display them. Our intrepid jelly wranglers have to collect these gems carefully, using plastic bags to gently surround the jelly. The species made its world debut here in 2002!
Leucothea is a Greek word meaning “white goddess.” Distinctive brownish-orange papillae cover most of the body. The large oral lobes can be as long as the body and are marked by complex patterns of meandering canals. It can reach lengths of 25 cm, and swims horizontally at a slow pace while feeding with the lobes spread open. A quartet of worm-like auricles aid in guiding copepods and other crustacean prey into the lobe area. Each lobe folds into a tube upon prey contact and brings the food to the oral tentacles for transfer to the mouth. A pair of long secondary tentacles trails from the mouth area.
Hope you get a chance to see them!
Here’s looking at you! This striped burrfish—as striking as it may be—is unwanted “bycatch” from the U.S. Gulf of Mexico shrimp fishery. It’s highlighted in our exhibit in the Open Sea wing called “An Accidental Catch.”
How do you FIN-gerprint a Great White Shark?
To the untrained eye, one shark fin cutting through the water probably looks like any other. Yet each great white shark dorsal fin gives our researchers and their colleagues important clues that will help to identify and protect them.
Like the swirls on a human fingerprint, the shape and notches of each white shark’s dorsal fin are unique, enabling scientists to catalog and track sharks across the oceans.
Building a Fin Photo Database
Since 1987, great white shark researchers at the aquarium, Stanford University, Point Blue, Montana State University and the University of California, Davis, have been photographing dorsal fins – first in waters off the Farallon Islands, and later at Año Nuevo Island and Tomales Point. They’ve created a photo database identifying 270 individuals over the past quarter century, providing the basis for the first-ever population estimate of adult and adolescent white sharks off the Central California coast.
This database helps scientists better understand where white sharks go and whether they return to the same waters on a regular basis. Fin IDs also help them estimate the number white sharks at these locations, and monitor the survival of individual animals.
Scientists have found that just as humans routinely travel between important locations — home, school, work — so too do great white sharks. White sharks congregate seasonally at spots along a migration route that takes them from the Central California coast, to the middle of the Pacific, and past southern California and Mexico.
Scientists use seal-shaped decoys to entice white sharks to the surface where it’s easy to photograph their fins. They also gather information such as size and sex when the sharks swim alongside their research boats. By comparing fin photos of the same sharks over the years, researchers concluded that – just as with our fingerprints, which remain the same over a lifetime – the overall shape of a shark fin remains fairly constant (with the exception of scrapes and scars).
In 2013, of the 80 individual adult white sharks photographed by researchers from the Aquarium and other institutions, nearly 65 percent had been seen in previous years. This suggests that the team is getting close to recognizing most of the adult great white sharks that frequent Central California waters.
Several have been coming back to the same waters for more than 20 years. One, a 16-foot male known as “Tom Johnson,” has been sighted for the last 26 years - the longest tracking period for any white shark on earth.
Hey, what’s going on here? Our clever photographer, Tyson Rininger, created this image that overlays high and low King Tides to give you an idea of just how much the depth has changed these past days. See the rocks of low tide under the water?
Yesterday we showed you some amazingly high King Tides at the Aquarium—but the last few days have also produced some extremely low tides, as you can see here. If you missed them, the King Tides will return at the end of this month!
Don’t worry, we haven’t washed away! King Tides are the highest and lowest tides of the year, and they’re occurring right now, and again at the end of the month. Here’s a shot of the high tides off our ocean-view decks! Beautiful to watch, but we wonder: Will rising sea levels make today’s King Tides tomorrow’s everyday tides?
Old man of the sea? We recently added a 10-pound Pacific spiny lobster to our Kelp Holdfast exhibit. These lobsters gain 1.5 pounds every 7-8 years, so this specimen could be decades old. And here’s the good news: California’s vast network of Marine Protected Areas is what helps them reach such ripe old ages!
Have a great holiday! We’d love to know your ideas for helping protect the planet and promoting conservation of our oceans in the coming year!