From Shark Teeth To Shark Cage: some interesting items in the news

As we approach Discovery's Shark Week, here are a couple of interesting shark items that have been traveling the Internet.

First, a study by chemists from the University of Duisburg-Essen found that the teeth of mako sharks and tiger sharks contain the mineral fluoroapatite (fluorinated calcium phosphate).  Humans' and other mammals' teeth contain an inorganic, bone-like compound, hydroxyapatite.  as we all known from or fluoride toothpaste, mouthwash, and water, there is an advantage to having some fluoride protecting our chompers.

“In order to make teeth more acid resistant, toothpaste often contains fluoride,” Matthias Epple, a professor of inorganic chemistry at the University of Duisburg-Essen, told Discovery News. “In the surface of human teeth after brushing, a small amount — much less than 1 percent — of hydroxide is exchanged by fluoride. In contrast,(the surface of) shark teeth contains 100 percent fluoride. In principle, sharks should not suffer from caries. As they live in water and as they change their teeth regularly, dental protection should not be a problem for sharks.”

So, sharks have built-in cavity protection.  And, as the professor mentioned, they replace their teeth regularly.  A shark can contain as many as several hundred teeth in it's jaw at any one time, with rows of fresh new teeth ready to come to the fore as older teeth are pushed out.  Which brings me to the second interesting shark item.

Many of you have seen images of the white sharks at Seal Beach, South Africa leaping out of the water attempting to either bite down on an unsuspecting seal - or a seal decoy placed in the water by crews hoping to grab some spectacular video or still photos.  South Africa's Chris Fallows has built a respected career out of documenting white sharks going airborne with videos like the "Air Jaws" series and some amazing photographs.

Australia's The Daily Telegraph ran a brief article on Seal Beach with photographer Dan Callister taking his own memorable photographs of airborne white sharks.  As dramatic as his shots were, what caught my eye in several rapid-fire images of a shark grabbing a seal decoy was the clear evidence of the shark shedding a tooth.  You can see it airborne in the image below.

Lastly, for those of you who have ever wondered what it would be like to see a great white shark up close, but decided you had to be an experienced diver or half crazy, Kevin Richberg wrote in The Huffington Post's Travel Blogs his experiences cage diving in Australia as part of his 30 Postcards Project.  What caught my attention was how he described the experience.

When doing any public speaking about white sharks, I often recall the word that first came to mind when I saw my first great white shark.  Serene.  There is a calm majesty to these animals; not a frantic, teeth gnashing demeanor at all.  And that was exactly how Richberg saw it.

"What surprised me was that following the initial excitement of seeing the sharks up close, my mood turned quite quickly to being calm and peaceful. I know you're probably thinking that 'peaceful' is the last word you'd use to describe a great white shark encounter, but for me it was true."

Source: Discovery News
Source: The Daily Telegraph
Source: The Huffington Post

Shark News: not a couple of good weeks if you're a shark

It hasn't been a particularly good couple of weeks for sharks.

First there was the large 20-foot, 4000-pound female white shark that was caught in the Sea of Cortez.  Reportedly caught accidentally in the fishing nets of some local fishermen, it garnered media attention because of its massive size.  As it turns out, it apparently had a research tag showing it had traveled from the coast of central California.  Conjecture is that it traveled to the Sea of Cortez to give birth as this is a popular theory being proposed and studied by researchers.

The Sea of Cortez is an area that is being heavily fished by local fishermen and several species are being hard hit by the overall level of the catch.  If juvenile white sharks are being taken - evidence of which has been seen in local fish markets - and females are being caught, either accidentally or deliberately, for a slow-reproducing animal like the great white shark, this is not good news.

Next up was the unfortunate fatal attack on a bodysurfer in South Africa.  There have been fatal attacks throughout the years, but what raised the hackles of locals and caught the attention of the media was the fact that a film production company/research group was in the area apparently chumming to attract sharks for tagging purposes.  South African government officials, who had issued the permits to allow the research, pulled those permits and from there it's been a media communications nightmare of accusations and a lot of CYA.

The production company had been filming in the past for National Geographic Channel's Shark Men series, but Nat Geo issued a response saying that they had not been working with this particular company for some time.  South African government officials are being accused of faulty vetting of the operation in issuing the permits, but it's been said that there were scientists on board to ensure that no reckless behavior for the sake of dramatic film footage was taking place.  And the production company claims that their actions were well within acceptable practices.

Then along comes a preliminary research study from Australia that says there may be a causal link between chumming used by shark diving operators and behavioral changes in white sharks.  The report itself says it's not conclusive and does not imply that, because of chumming, white sharks are purposely seeking out humans, but it certainly added fuel to the fire of the anti-shark locals.  It's quite a media mess and at this point it's hard to tell what the final results might be as to whether we'll see some knee-jerk reactions against the sharks by officials trying to placate those who believe they have greater rights to the seas than do the sharks.  At the very least, it's bad P.R. for the sharks; the spectre of shark nets or a crack down on all shark diving operators always looms in the background.

Finally, the media outlets have been jumping all over a new study from the University of Hawaii and British Columbia's University of Victoria which says that Pacific reef shark populations have declined by as much as 90 percent or more in the past few decades.  This decline has been noted in other studies, but this particular study had an interesting twist to it, as reported by The Washington Post's environmental writer, Juliet Eilperin.

The researchers study shark populations over 46 islands in the Pacific and not only found a decline but, conversely, found increases in shark populations wherever human populations decreased over the years and the productivity and temperature of the ocean increased.

“Our results suggest humans now exert a stronger influence on the abundance of reef sharks than either habitat quality or oceanographic factors,” said the researchers. 

Many of the islands involved in the study have laws and regulations in place to protect sharks but, as is the case with many conservation regulations worldwide, enforcement is lacking either due to lack of resources or political will.

Julia Baum, assistant professor at the University of Victoria and co-author of the study, said, “To me, enforcement of these islands is a major unsung conservation challenge, and I suspect that if this is not effectively addressed [as soon as possible], the reef sharks on these islands will be fished out within the next 10 years.”  

The Muppets' Kermit the Frog once sang, "It's not easy being green."  It's not easy being a shark either.  We need our green puppets for comic relief; and we need our sharks for something far more important: the preservation and natural balance of the sea's marine life.

Source: Sacramento Bee
Source: Mail & Guardian Online.  
Source: The Washington Post  
Photo: Brian Skerry

It's the Summer of the Shark: yaawwnnnn. . .

It's summertime in the U.S., folks are vacationing, heading to the beaches (well, maybe not the Gulf, unfortunately) to frolic in the surf. And like clockwork, the media reports begin to pile up, one after another: sharks reported cruising the coast, increases in sharks, attacks on the rise, it's the revenge of the evil elasmobranch . . . ad nauseam.

Following a very successful week of programming for the Discovery network (this year, Shark Week brought in its highest ratings ever at over 30 million viewers), there have been reports of white sharks seen along Southern California beaches along with indications that the population of white sharks in California is increasing; surfers are having close encounters of the third kind; shark incidents in Australia are filling the news pages of sites like Underwater Times; and South Africa has issued a coastal shark warning. I think it peaked last week but there was a moment where it seemed like the world was about to be swallowed up.

It's not the individual reports that are necessarily the problem - I'll give the reporters the benefit of the doubt that what they are writing is researched and factually accurate. And there have been some very good articles from the likes of Pete Thomas, as an example (although, Pete, you succumbed to the "summer of the shark" title temptation). My concern is the collective result of all this reporting and the impact it has on the general public's view towards sharks and, by extension, shark conservation. It makes for titillating summer media but without the all-important ingredient: context, context, context.

Sharks migrate along the California coast, giving birth in the deep coastal canyons. And this happens elsewhere in the world. Ergo, we get juveniles cruising the coastline, feeding and fattening up before the migratory impulse hits them and off they go on their annual journeys. It happens every year. Perhaps there might be a spike in sightings, maybe in actual number, but those have always been considered anomalies. Is the California population actually increasing? Well, if it is, as recently reported, then that would be GREAT! But still no reason to fear, statistically-speaking.

And speaking of statistics, we all know that with more people in the water, the chances of a sighting or an encounter goes up. Drastically? Well, no - but that always seems to get glossed over.

So, the bottom line is: this shark activity is all VERY NORMAL! Time of year, migratory and birthing patterns, increased numbers of people in the water - with these factors there is bound to be an increase in sightings or encounters. Sharks just don't need the accompanying hysteria when its whipped up by the media. Shark conservationists are having a tough enough job as is.

BTW: Regarding shark conservation, there is some interesting headway being made in Hong Kong, where Asian-based conservation groups are promoting anti-finning policies. Read the latest from The Daily Caller.

Shark Nets: Thomas Peschak reports on the past and future

Shark Nets - long standing shark "deterrents" strung along some of the more popular beaches in South Africa and Australia - have become a source of concern among conservationists. It's a concern perhaps not as widely shared among the general population, or beach goers in particular, because of a fundamental lack of understanding as to what the nets can or cannot do.

In an excellent article in Africa Geographic, written by premier underwater photographer Thomas Peschak, chief photographer for the Save Our Seas Foundation, the history and issues regarding South Africa's shark nets are detailed.

As Thomas, a South African himself, points out, the nets have been in place in his country for over 40 years, totaling some 27 miles by the late '80s. The problem with the nets is that they actually don't deter or keep out the sharks - they catch and kill them. The Natal Sharks Board reported that nearly 34 thousand sharks were caught in these nets from 1978 to 2008, the majority of which were species that posed no threat to humans. Interestingly, for those who felt safe from any "killer" shark, a large percentage of the sharks were caught on the beach side of the net, as the shark was making its way out of the area.

But the nets - basically gill nets by design - are random killers, catching turtles, dolphins, and even whales. This unintended bycatch has fueled the conservation debate and the trend in South Africa is slowly moving towards the use of drum lines (baited hooks) and even a possible reduction of the use of any nets or deterrents at all in less populated beaches.

Peschak takes the realistic position that we can not expect all nets or deterrents to disappear any time soon; as long as there are large numbers of beach goers - representing a sizable tourist economy - then the priority of providing a "safe" beach will probably prevail. But he asks the proverbial question: if science can make such advances as cancer cures and moon landings, could we not come up with a method of shark deterrence that is less destructive? I concur. The methods have not changed much in 3 to 4 decades and have only reinforced both the idea that humans have a greater right to the oceans than its inhabitants and that sharks as a whole are dangerous and must be dealt with severely (an attitude illustrated in the Australian press regarding the government policy to hunt down and slaughter any shark reported to have been involved in biting a human).

Click here to view a great video of Thomas Peschak discussing the history and status of SA shark nets (contains a PDF download link to his Africa Geographic article).

CNN's Planet in Peril: discusses shark issues on December 11th

In early October, I posted information about CNN's Planet in Peril series (Oct. 10 posting). They will be covering several important shark issues, among other important environmental topics. The show will air on December 11 (check your local listings for exact times).

It appears that the show will cover shark finning/shark conservation and shark ecotourism. The video previews available on the shark finning segment cover familiar ground for those of you familiar with shark conservation issues. Hopefully it will enlighten some of the less informed. Of course, the biggest issue in saving sharks is finding effective ways to change the cultural midset regarding shark fin soup and other related products. Much like the criticisms hurled against the ineffectiveness of the "drug wars", we must wrestle with the demand for the product with equal attention and force.


The other shark issue that CNN touches on is shark ecotourism. They look at a South African operation and then touch on whether baiting white sharks is teaching them to attack surfers and swimmers (it makes for an exciting story). It's an argument often used by opponents, but in my experience and from what I have learned from respected scientists who have studied these animals for a lot longer than I have spent filming them, it just doesn't hold water. These sharks are more discriminating than most uninformed people give them credit for. Attracted to fish chum and chasing/biting hangbait consisting of tuna, bonito, or something similiar, does not make a white shark suddenly develop a taste for human flesh and begin seeking out surfers or swimmers as their next prey. Surfers have been and probably will always be subject to mistaken identity for the large pinnipeds (seals, sea lions) that white sharks feed on.


I did find it noteworthy that the South African shark diving operation CNN chose to film had an incredibly small cage that fit the divers in like slices of bread in a toaster (a cameraman could barely fit a decent video housing in there) and they dragged the hangbait right up to the cage, causing the shark to bang up against the cage - dramatic fun for the tourists but potential harm for both the shark and the divers. This is not responsible shark ecotourism.