Great White Sharks: There’s a New Sheriff in Town

 

There’s a New Sherrif in Town

Each fall the White Sharks return to the Marin shoreline and the Gulf of the Farallones. These enigmatic apex predators are returning after an epic ocean voyage, the course and destination that only recently have been discovered.  We know from biologists stationed on the islands that there is a local seasonal population of sharks at the islands. Photographs of fins have identified individuals returning to the Farallons, some two years apart, some every year.  As part of a long term observational and tagging study – the Shark Watch program- conducted by the Point Reyes National Bird Observatory, we know that the white sharks gather in the fall in the Gulf of  the Farallones and off Ano Nuevo in the Monterey Bay National Marine Sanctuary, and then dissapear a few months later.  Where do they go?  New sattelite tracking data from Stanford’s TOPP program has revealed that each year the sharks leave the Sanctuary and gather at an area thousands of miles away off Hawaii at a location called The White Shark Café.  A café is where we come to eat, linger, have a drink and maybe check out the opposite sex.  “That’s probably what the sharks are doing,” says Stanford shark specialist Dr. Sal Jorgenson in Sean Aronsen’s documentary The White Shark Café. It makes sense.  Like twenty year olds, sharks are either feeding or breeding, and in between sleeping they are looking for one of the two.

Now, thanks to the sattelite tracking, we know where the sharks are going, and we know where they return and when. The question is, why?  Altough sharing the waters of the Cafe’, genetics data is also revealing that the sharks of Guadalupe Island Mexico and the Ano Nuevo Group and Farallones Island population are probably distinct sub populations.

They’re back!

This July one of the earliest shark predation events at the Farallones was reported by the Shark Watch program consisting of biologists of the Point Reyes Bird Observatory program located on the island.  A few weeks ago, a large white shark nuzzled the bow of a kayaker off of Pigeon Point leaving a few teeth marks and a wide awake paddler.  A skipper reported two very large sharks off  Duxbury Reef and last week while we were on the opposite side of the Farallones, a white shark was observed feeding.

 “Shark feeding on a Sea Lion in Fisherman’s bay!”  The VHF radio crackled. The PRBO crew had witnessed the bright spot of blood, the struggling pinniped and then another hit as the shark claimed its victim.  Not witnessed by our boat observing whales in Mirounga Bay or by the two cage diving operations anchored in the bay of East Landing, the event gives an example of the randomness and good fortune one has to observe a white shark.  A shadow in the water, a splash, a pool of bright red blood, or the occasional shark breach is what little we see or experience of sharks. With the tagging and genetic information we are gathering more insight to population size and dynamics.  What this information is not telling us is how many white sharks are being caught on longlines or caught and finned illegaly in their long passage across the ocean.

Searching for Sharks, Seeing Whales & Dolphins

On one of the most fantastic days I have ever experienced on the Gulf, our group spotted our first Humpback whales feeding mid channel in calm sunny weather.  The standard surface swimming, followed by predictable shallow dives gave us a view of the twin blow holes, humpy dorsal fin and knobby tail characteristic of this baleen whale we have been seeing on every trip.  Motoring on, we were rewarded with two Blue whales lunge feeding, gasping, swimming and luching forward, and later by more Humpbacks to the south of the isalnd. Venturing around the point past the marine terrace, we entered Mirounga Bay, so called for the genus of Elephant seal which is one of the white shark’s favorite meals.

Suddenly there is a splash, and then another and a huge white beast breaks the water.  Nearby the ghostly shape of another lurks beneath the boat.  Several passengers shriek as the shutters click away. Are they White sharks?  No, we are surrounded by a huge school of Rizzo’s dolphins.  Also known as Grampus, and considered by old sailors to be ghosts of drowned shipmates, these large blunt-headed whales are scarred and bleached by time. All around us the large Grampus swim and breach, including several young dolphins. Among the Grampus swam Northern Right Whale Dolphins, Pacific White Sided Dolphins and Common Dolphins.  Captain Jimmy slowly steams through the middle of the pod and: whale ho!  More Humpback whales feeding.  We do not see a shark, but we know the sharks are here.

Sharktober

Local surfers call it Sharktober and when there is a shark sighting at Stinson Beach or Bolinas the news station and papers are quick to report it. When there is an attack, like that of local surfer Jonathan Kathrein, the papers and press go into a literal feeding frenzy.  Like the recent article in the San Francisco Chronicle, reports are loaded with adjectives like “grisly death”, and “white sharks swarming”.   What we don’t hear is the story: Man Bites Shark!  For every shark attack on humans, there are hundreds of thousands of sharks killed each year, every year.

We have a misconception of sharks extending from blind fear to the ironic but ignorant symbol of a shark with a red slash though it seen outside a local clothing store or on the bumpers of inlanders. Scientists have demonstrated that sharks play a vital role for a healthy ocean ecosystem. This week another study has been published on the benefit of sharks on Caribbean reefs, further reinforcing the ecological importance of sharks.  Sharks are the regulators of fish and marine mammals.  They cull the weak, the stupid and the sick, thereby strengthening the remaining population. The kill of the sea lion isnt a sad thing, it is a necessary event to help the population remain robust.   

Instead of no sharks, we should be saying Let Sharks Live!

White sharks are protected and the killing of sharks for fins is illegal in US waters.  However, there are loopholes in our laws that allow some sharks to be finned and making the anti finning law difficult to enforce.  Senator Kerry’s Senate Bill 950 is intended to help resolve these loopholes; a bill held up by one recalcitrant senator from Oklahoma.  We can protect our sharks in the Sanctuary, but little can be done when they enter international waters. Supporting our Sanctuaries, strengthening our existing regulations and stopping the consumption of shark products like shark fin soup can all help increase the protection of the pelagic sharks that visit our waters. 

This October, Sea Stewards will be celebrating the shark with special shark awareness events including Farallones tours with San Francisco Bay Whale Watching, emphsaizing the importance of sharks to the Bay and Sanctuary, as well as looking at the entire ecosystem of the Gulf of the Farallones from plankton to sharks. 

Sea Stewards will be leading several expeditions including Oct 2nd with White shark Advocate and Survivor Jonathan Kathrien, Oct 16th with Leatherback Sea Turtle expert Dr. Chris Pincetich, October 24th with Sherman’s Lagoon creator Jim Toomey, and culminating in a shark Halloween party on October 31st.  A percentage of the proceeds will go to Sea Stewards shark conservation and reserach program.

Visit sfwhalewatching.com or www.seastewards.org to find more information.

copyright 2010 Sea Stewards.org
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