Russ Vetter, Leg II SHARK CRUISE. Our third day of fishing on Leg II and all of the shark team, both veterans and new volunteers, are starting to fall into a routine. Suzy Kohin (who works in the Southwest Fisheries Large Pelagics Group and did blogging duties on Leg I of the Shark Cruise), Darlene Ramon (who works for Suzy as technical support and studies shark aging, among other things) and I are the veterans (I direct the Fish Ecology Group, which the Large Pelagic Group is part of). We get up at 4:00 a.m. to begin the day's work of firing up the CTD, checking with the ship's officers to discuss the plan of the day, thawing bait and getting the gear ready. At 5:30 a.m., the commuter rush begins as the rest of the crew pile out of bed. They grab their favorite morning beverage from the galley and assemble on the back deck to divide up the chores involved in setting the longline: sorting hooks, baiting hooks, and clipping hooks on a moving longline without losing fingers (that job's for the person who's most awake).

The invention of the iPod has changed shipboard life forever. Between the ship's crew and scientists, it is possible to find every variety of music, new and old, which can be broadcast across the back deck to make the zen of setting the longline almost fun.

Today we are sampling a block of ocean that is southeast of Catalina Island. On the first Leg, this was blue-shark country, but we start the day with a few makos. The weather is beautiful and the cook announces that dinner will be a Saturday barbeque on the back deck. For those who are unfamiliar with ship life, charcoal-grilling on a boat might seem odd. But the Saturday barbeque has a long tradition on most oceanographic boats. The barbeque is a way to break the monotony of the close quarters of ship life, not to mention that great food cooked on the grill.

It is a fact of life that we occasionally lose a shark to a bad hook, entanglement or for reasons we can't figure out. Today we lost a small mako. Nothing is wasted when we have a mortality, and many of the volunteers have been waiting to get various tissue samples. Two of our volunteers are masters-degree students who are studying shark blood and tissue chemistry. The brain is removed for MRI (magnetic resonance imaging) studies to examine its internal structure. (The Scripps Fish collection has an ongoing project to use MRI as a way of doing virtual dissection on rare specimens via MRI visualization.
This would be part of the ground truthing of that effort.) The stomach and pancreas go for diet studies. The gills go to a PhD student at Scripps Institute of Oceanography, and the eye and eye muscles are quickly frozen for a researcher at Cal State Fullerton. The rest of this particular fish was quickly integrated into the barbeque menu. Of all the sharks, mako is probably the best-tasting and compares well with swordfish.

Interest in sharks comes from many perspectives. Their conservation and management are of obvious interest to the general public, but the physiological and biochemical adaptations of these ancient, yet highly evolved, oceanic predators have always fascinated biomedical researchers and those interested in vertebrate evolution.

One easily visible adaptation in blue sharks is a special membrane that moves over the eye to protect this delicate organ when the animal attacks its prey. You can see it in the photo below. This is called the nictitating membrane.

As I mentioned yesterday, the skin of the female blue shark is also much thicker than the males. This is due to how the male bites the female during mating. As promised, I've included a photo of a female blue with a horrific but typical bite mark from a recent mating event. My gloved thumb is holding the trunk of the female in the center of the bite mark. The crosshatched pattern of tooth marks is extraordinary. ABOARD THE DAVID STARR JORDAN, Off Catalina Island, California.