The Dorsal Fin

Bay of Fundy whale watchers report seeing a great white shark like this one, only MUCH larger.
(photo taken off Isla de Guadalupe, Mexico).

Canada’s The Chronicle Herald is reporting that a “scary big” great white shark was spotted by a boat of whale watchers last Wednesday (August 17, 2011) in Fundy Bay off of Brier Island, Nova Scotia. According to the report, Fulton Lavender, a Nova Scotia Bird Society naturalist claims that the shark was over 25′ in his personal opinion.

Initially, Fulton thought the shark to be a basking shark (Cetorhinus maximus), which can normally reach lengths of over 25′. However, after seeing photographs of the shark taken by a tourist aboard the whale-watching boat, Fulton said it was “definitely a great white shark.” Others aboard the boat reported that the shark had a white underside. While basking sharks do not characteristically have a white underside, white sharks (Carcharodon carcharias) do. Fulton also added that the photographs taken showed facial patterns and a dorsal fin more characteristic of a white shark.

The photographer who took the photos of the animal promised to provide Brier Island officials with a copy of a photograph of the animal but has yet to do so.

Adult white sharks are typically in the range of 13′-17′ in length, but reports of specimens reaching 20′, though somewhat rare, are not unheard of. A white shark exceeding 25′ in length would be extremely outside of the normal size range of the species.

Reid Gillis, a skipper for one of the whale watching boat says he saw the animal breach three times, but he could not identify the species as a white shark. The shark was also blamed by some of the whale watchers for a attacking a local humpback whale (Megaptera novaeangliae) who was seen with “crescent-shaped” wounds. Gillis who saw the wounds on the whale noted that he did not see the shark attack the humpback and could not determine whether the wounds were the result of bite marks.

Canadian shark researcher, Steven Campana, told The Chronicle Herald that it would be highly unusual for a white shark to attack a healthy adult whale.

Earlier this month a small white shark was captured inadvertently in a fisherman’s weir in the Bay of Fundy, putting an end to speculation that the species were currently present in the region.

A Long Island beach was closed yesterday due to multiple shark sightings. According to a CBS 2 report, a “pack of 18-foot sharks” was sighted “dangerously close” to the shore of a West Hamptons Dunes beach. While the report notes that some of the eyewitnesses thought the sharks were thresher sharks (Alopias vulpinus), the dorsal and caudal fins in the video do not appear to be consistent with that of common thresher sharks.

While I’m no expert on shark identification, the dorsal fin seen in the video looks more representative of a basking shark (Cetorhinus maximus) to me. If anybody can identify the sharks based on the footage, feel free to share your insight in the comments section.

On a related note, CBS 2 also reports that a seal carcass was found on the beach this morning. A connection between the seal carcass and the sharks is being investigated. (Basking sharks are filter feeders and don’t eat or attack seals.)

Today’s Google Doodle features an underwater scene to commemorate Jules Verne (author of 20,000 Leagues Under the Sea) on his birthday. A basking shark (Cetorhinus maximus) appears in the scene, which can be navigated via the joystick to the right of the Google logo. The basking shark is toward the right of the scene about half-way down the image (see video above).

YouTube user greatoutdoorsdublin recently posted the above video of a basking shark feeding among a group of kayakers. While most of the kayakers seem to appreciate the visit, one of them (identified as Eileen in the video information) can be heard expressing her apparent lack of enjoyment about it all.

Eileen’s worries are fortunately unnecessary as the basking shark (Cetorhinus maximus), despite its size, is a filter feeder and is relatively harmless to just about everything other than plankton.

The Vancouver Sun has an interesting article about the depletion of basking shark (Cetorhinus maximus) populations from British Columbia waters over the last several decades. It begins with the story of how basking sharks were targeted for slaughter by a federal fisheries vessel equipped with a blade designed specifically to slice open basking sharks and notes a one-day record of 34 confirmed kills. The sharks were targeted due to the fact that they were becoming troublesome for fishermen by getting entangled in commercial fishing nets.

The story then flashes forward to present day and a much different view of the basking shark, which is now endangered in the waters of B.C. Sightings of the sharks have become so rare, that federal shark biologist Romney McPhie compares basking shark sightings in B.C. waters to sightings of the mythical Sasquatch and Ogopogo. However, there have been some confirmed sightings over recent decades including an encounter that BBC filmographer, Florian Graner, filmed in July of 2009.

You can check out the entire article on basking sharks at the Vancouver Sun website.