Showing posts with label reef sharks. Show all posts
Showing posts with label reef sharks. Show all posts

Saturday, June 19, 2010

Bahamas' Sharks: a moment's scarcity with disturbing implications

I returned late Thursday night from a video assignment in the Bahamas as director of photography - hence, the lack of postings over the last few days. The crew was out there to film sharks but, as it turned out, we had to look far and wide to find what we were looking for. In the "usual places" where we would expect to find numerous lemon, tiger, and Caribbean reef sharks, we were being skunked - a highly unusual experience.

The boat captain made radio calls to other boats in the area only to find that they were also experiencing the same lack of sought-after quarry. So, we were not the only ones and apparently this had being going on for several weeks. Two possible theories were being bandied about - either of which raised concerns as they illustrated the fragility of a marine ecosystem.

Hunting for sharks:
One of the dive operators that regularly works the area off the Bahamas related a rumor that a tiger shark, possibly a pregnant female, was taken by a fisherman the week before. Had the sharks, in response, moved away from their usual haunts, perhaps deeper or farther out to sea? Possibly - although the theory demands a multi-species reaction to a singular event that may not be that plausible. But it's a tantalizing idea: what would be the response by schooling predators like lemon and tiger sharks to life-threatening events? No matter how much bait or chum was used, at sites where we would normally have so many sharks on hand, you could almost walk across the water on their backs, there were virtually none.

Rising temperatures:
The other theory, which we were experiencing first hand, was an increase in water temperature. We found the temperature in be in the mid-80's from the surface (which is to be expected this time of year) to as deep as 60 feet before it abruptly dropped about ten degrees. Could this abnormal wider range of warmer water have pushed the sharks to deeper and more comfortable depths? Several of the locations where one would typically be surrounded by sharks are in the 20-foot depth range - and we had no luck at those sites. Ultimately, on the last day of shooting, we came upon a small but suitable number of Caribbean reef sharks at 80 feet. My B-camera operator, Scott Cassell, commented to me that he also noticed a lot more algae growing on the reefs in the shallower, warmer depths, versus the more colorful sponges and corals.

In the end, the production crew was able to get the footage it needed, but it was challenging to say the least. And disturbing to think about the implications to a balanced and healthy marine ecosystem when normal conditions are disrupted. In the end, either of these two mitigating factors - fishing or water temperature - which impacted the number of sharks we encountered could be mere anomalies. But it did provide a disturbing indication as to the impact of shark fishing and climate change.

In a couple of weeks, all we experienced could be forgotten and the frequency and range of the Bahamas' sharks could return to normal. But it was sobering to think what the future may hold in store.

Sunday, January 17, 2010

Global Shark Diving: from Fiji to around the world, different strokes for different sharks

An article that ran in the New York Times on shark diving in Fiji has been making the rounds of several of the shark-related blogs, not because the article is some scathing expose but because it is a well-balanced look at shark eco-tourism as practiced at Beqa Adventure Divers.

What caught my attention was how the article, in a broad sense, highlighted the fact that shark eco-tourism (or shark diving, if you like) is a varied activity - something that proponents, and even opponents, need to keep in mind when discussing it. Unfortunately, it often is generalized under one heading: "You've gotta be crazy." But there's much more to it than that.

When discussing shark eco-tourism you have to consider the location, the species of shark involved, and the methods involved.

Location:
Shark diving should only take place in areas where there are recognized or resident populations of sharks. The anti-shark furor that occurred in Oahu several months back was initiated because someone wanted to start an operation in an area not known for sharks but highly populated by recreational beach goers. Bad business move.

In Fiji, the shark diving operations work in areas where the reefs are healthy and protected from overfishing (ie: a healthy reef includes resident sharks as part of a balanced marine ecosystem) and the boats keep an eye out to preserve what is a valuable source of tourism revenue for the islands.

Shark Species:
Great whites, tigers, lemons, bulls, Caribbean reef, Galapagos, whale, and many more species have been the center of attention with different operators around the globe. But each species has its own behavior, it's own level of interest or disinterest in the participants; and so each species requires its own set of protocols so as not to endanger the shark or the diver.

In Fiji, there are large groups of various reef sharks that can be active and put on quite a "show", but at deeper depths, bull sharks require more specific handling. And the great white sharks, that I have spent so much time with, require close attention not so much because of their size but their curiosity.

Methodology:
So, because of various behaviors presented by different species, the methods by which divers can be safely exposed to these animals can also vary. From open water experiences to using
chain mail suits to working within a cage - these decisions must be carefully considered to insure both the most educational and enlightening experience while also being the safest for the divers.

And there must be consideration as to any adverse or disruptive behavioral impact on the sharks and their surroundings. To date, the available research seems to indicate that, if carried out responsibly, there is, at worst, only a temporary effect on the shark's conditioning behavior and that there is nothing that indicates negative changes in their natural feeding or migratory behaviors.

Shark eco-tourism can be an effective way to communicate the importance of shark conservation whether to a specific audience of participants or to a non-participating public at large - if it is done right. And it must be done right because shark diving doesn't fly under the radar of media scrutiny.

Congrats to Beqa Adventure Divers for some well-deserved and balanced media coverage. One of these days, I'll get back to Fiji and you guys can introduce me to some of your sharky friends!

Read NY Times article.