Friday, September 11, 2009

White Sharks at Cape Cod: keeping the news in perspective

It was about a week ago that several shark blog sites, like SharkDiver's, started to post news about a congregation of white sharks appearing off Cape Cod in the northeastern U.S. While white sharks are not unheard of in this area, the higher than usual numbers were of interest - a statistical anomaly or evidence of a population increase (wouldn't that be nice, given their decline in numbers over the years)?

Scientists want to tag as many sharks as possible with satellite tags to hopefully accumulate data that might explain the concentration. And of course the media wanted to report this as another harrowing intrusion of malevolent ocean predators upon society. This morning, NBC's Today show reported on the efforts of the lead researcher and while their reporting was fairly even-handed (better than it has been in the past when it comes to sharks), they still referred to the scientist as a "shark hunter" rather than shark researcher or tracker. It's subtle but the title still invokes a man vs. man-eater image.

This past Wednesday, the Boston Globe reported that the spotter pilot who was assisting the researchers in locating and tracking the sharks claimed that several sharks made distinct threatening movements when a diver or surfer entered the water, as if to imply that the sharks were on the hunt for humans and as soon as a person entered the water the shark suddenly knew exactly where to go and what it would find. Here's a portion:

“They definitely knew they were out there,” Breen [the pilot] said of sharks sensing the swimmers. “Whether they’d bite them, I don’t know.”

Breen was hired to help the research team, which tagged three great whites on Tuesday, bringing to five the number of sharks tagged with tracking devices over the last week. The discovery of sharks off Chatham forced the indefinite closing of the town’s beaches, but some ignored warnings not to swim in the area.

In one near-miss, Breen said he watched as a shark approached a diver from a documentary crew making a film about the researchers. He said he was circling above the filmmakers’ boat when the diver jumped into the water to retrieve a piece of equipment.

“I saw a shark going real slow about a quarter-mile away, and then when the diver jumped in, all of a sudden I saw the shark head right for the boat, going from about 2 knots to 10 to 15 knots, in an instant,” Breen said.

He radioed the crew on the boat and told them to get the diver out -- right away. The diver was attached to a tether and he was pulled out.

“The shark definitely smelled something,” Breen said. “Their sensory perception is unbelievable. The shark was only about 100 feet when they pulled the diver out.”

I know, for those of you who know anything about sharks, you're doing a slow burn right now. Sharks don't "smell" people in the water, particularly at a quarter-mile away! A white shark has pretty good eyesight, but not that good. No, it's the shark's ability to "hear" or sense vibrations in the water (a trait shared by nearly all fish) that caught its attention as the diver jumped into the water. And these animals are naturally curious. I have been fortunate to have several close encounters with white sharks and these events came about not because I was the meal d'jour but because my presence peaked its curiosity; I was something out of the norm.

Sharks like the great white have a battery of sensory capabilities that, based on distance (far away to close) typically react in this order: vibrations/sound (lateral line and inner ear); smell; eyesight; electrical impulses (Ampullae de Lorenzini); and finally, taste.

If Breen had spoken with the research team who hired him before speaking with the press, he would have been set right and his sensationalistic story could have been diffused. But if you're looking for a hot story or a little attention, what good is that, eh?

Some of the beaches in the area have been closed which, dramatic as that may seem, might be prudent for a short while. The sharks are in an area with a seasonal breeding population of seals, which is probably what has attracted them. That there might be a slight uptick in the highly remote possibility wherein a swimmer could accidentally be mistaken for a seal - particularly if the swimmer is wearing a black wetsuit - may be sufficient reason to close a beach temporarily.

But let's hope that it doesn't inspire sportfishermen or even government officials to go on some wild hunting safari to clear the area of an animal who has more right to be there than we certainly do.

No comments: