Sharks At Risk In Australia: tagged sharks may be victims of Western Australia hysteria

Researchers in Australia are trying their best to foster calm and rational thinking in the wake of five fatalities in Western Australia due to great white sharks in the past 12 months.  As the number of human-shark interactions increased, so did the demand for some kind of action to be taken by the Australian government.

It's really a classic and unfortunate case of public concerns for safety mixed with businesses concerned over loss of potential business that has fueled, ala Jaws, demands for action ranging from protecting beaches with shark nets and drum lines to actively pursuing sharks that are spotted close to shore to culling sharks in the hopes of reducing the potential for deadly encounters.

The media is subtly fueling the hysteria with reports (see below) of sharks "lurking" off local beaches.  Yes, lurking.  Not swimming  as they have for hundreds of thousands of years in oceans that were always meant for their existence, but lurking.

According to a report in Australia's Herald Sun, in September the Western Australia government authorized $4 million to use drum lines and track any sharks that come close to beach swimmers.  This decision came, in contradiction, on the heels of a government-funded report by Queensland's Bond University that found that drum lines provided no discernible measure of safety from sharks and, in fact, would succeed in catching many other unintended species.  Drums lines are floating drums anchored to the bottom with baited lines attached.  The idea behind them is that, unlike shark nets which are designed to prevent sharks from entering an area or that inadvertently ensnare them, drum lines are specifically designed to hook and kill a shark.

The random killing of white sharks threatens the efforts of researchers who tag and track sharks using various telemetry devices that can provide information on the shark's location.  In fact, the Western Australia government has even voiced an interest in killing tagged sharks when their studied movements bring them close to populated beaches.  But with ongoing tracking information of Western and Southern Australia's white sharks (a population reported to be only around 1,000), scientists can learn more about their movements - seasonal patterns, migration routes, and more - and in so doing can best advise as to methods that would provide for public safety while also protecting the sharks as they roam within the environment nature intended.

"Killing tagged sharks is the worst thing we could do right now,'' said Tim Nichol, marine coordinator for the Conservation Council of Western Australia. "We need to learn more about white sharks and these are the sharks giving us information about their movements.  It is very expensive and difficult to tag white sharks and only a small proportion of the population is currently tagged.''

I can hear the voice of Amity mayor Larry Vaughn, "Now you do what you have to to make these beaches safe, but these beaches will be open for business." 

Source: Herald Sun

Are Sharks Social?: Australian researcher studies social interaction of Port Jackson sharks

A great white shark seems to keep its distance from its fellow white sharks.  Even when I have had the opportunity to have as many as five white sharks circling around me, they still keep a respectable distance from each other and rarely came close to each other.

Then on the other hand, you have hammerhead sharks that can be seen swimming in large schools.  Lemon sharks or various types of reef sharks congregating in the tens and sometimes hundreds.  And I have seen seasonal congregations of up to 4-5 foot leopard sharks and guitarfish in Southern California, presumably part of a breeding behavior.

The social interactions of sharks is not well understood.  Each species has its own type of behavior and while the general public thinks of sharks as somewhat solitary (which they often can be), in reality it is more likely a very complex relationship that revolves around feeding, breeding, and a predator's sense of territoriality (ie: survival). In Australia, one researcher is specifically focusing his efforts on understanding the social behavior of sharks.   Working in conjunction with the Taronga Zoo in Sydney, Australia, Nathan Bass intends to study the patterns of interaction between Port Jackson sharks, a smaller, predominantly bottom-feeding species similar to the horn shark found along the Pacific coast of the U.S.

“Port Jackson sharks have some really interesting interactions,” says Bass. “These types of sharks can be solitary, but they often occur in large groups around breeding time. They are apparently social while resting and seem to favour their resting sites, frequently with more than 30 individual sharks recorded together in one area alone.”

Bass will be attaching acoustic transmitters, known as "tags," to several sharks to track their movements.  Tags have long been used in shark research often to study the animal's regional hunting movements or longer migratory journeys.  By attaching tags to a large number of Port Jackson sharks, Bass hopes to be able to correlate their movements and possible interactions with seasonal events such as known breeding periods to determine possible social behavioral patterns.

“What we’d like to find out is whether Port Jackson sharks are frequently congregating with the same individuals for social reasons, and if they are, whether they prefer to socialise with individuals of the same sex and size or rather with individuals they’re related to,” said Bass.

An understanding of the social behavior of one species of shark does not necessarily  open the floodgates of enlightenment regarding sharks as a whole.  But it is a solid first step and provides a sort of baseline with a set of behavioral assumptions that can be tested with other species.  Insight into the social behavior patterns of sharks, no matter how social or anti-social these animals prove to be, will provide us with a better understanding as to their role in the maintenance of a healthy marine ecosystem and what the implications are with the loss of one or more of these important predators within a specific area.

Source: Phys.org

Adopt-a-Shark: corporate execs get hands-on treatment to study sharks

Getting people to make a personal connection with an endangered animal like a shark can actually be quite challenging. For most people, they are physically removed from the animal - the odds of them seeing a shark while wading at the beach are somewhat remote. So, many public aquariums and grass-roots shark conservation groups have established "adopt-a-shark" programs wherein people can make a donation to a specific shark species and feel, in a sort of charming and cute way, a connection with the animal.

However, at the University of Miami, Neil Hammerschlag, director of the university's RJ Dunlap Marine Conservation program, has taken the adoption a step further by having representatives of one of the program's key donors roll up their sleeves and get up close and personal with the recipients of their corporate generosity.

Hammerschlag has an adopt-a-shark program to help support his shark research. Price of adoption: $2,000 which pays for one satellite, or SPOT, tag destined to be attached to a bull, hammerhead, or tiger shark. While that might be a bit steep in price for most folks, to date Hammerschlag has had 20 adoptions/shark taggings. Wells Fargo Bank has been a major supporter of the research program, donating up to $40,000 to date.

Corporate donations are sometimes made, touted to the press, and soon forgotten, so to impress upon the people of Wells Fargo who were involved in the donation process the importance of his work, Hammerschlag invited a handful of Wells Fargo executives to assist him and several of his graduate students with the actual tagging of several sharks in Florida Bay.

Using baited circle hooks attached to weighted buoys (which allows a caught shark to continue breathing normally while swimming in a circle - a process less traumatic on the shark compared to reeling it in), a lemon shark was eventually snared and brought up alongside the boat.

As reported by the The Miami Herald, this is when the Wells Fargo execs were put to work.

"The professor and students would wrestle the shark onto a large, plastic litter and lift it into the stern of the boat. Sea water would be pumped through a hose in the shark’s mouth to enable it to breathe and, hopefully, stay calm.

One of the volunteers would use a syringe to squirt water into the shark’s eye to check its reflexes while another measured the animal. A small piece of dorsal fin would be clipped to check for toxins in its diet; Hammerschlag said there’s a link between cyanobacteria in the ocean and diseases such as Alzheimer’s, Parkinson’s and ALS, or Lou Gehrig’s Disease.

A fourth volunteer would have to extract a small piece of muscle for biopsy with a device that resembled a melon-ball scooper. Captain Curt Slonim would take a blood sample. Then a tag would be implanted in the dorsal fin.

The triage went flawlessly, with researchers and volunteers performing their assigned tasks in less than five minutes. The shark got an external streamer tag, but not the SPOT. [SPOT tags were reserved for bull, hammerhead, or tiger sharks.] Then the crew slid it off the transom into the bay."

“Working with sharks is a great opportunity to advance and promote ocean conservation,” said Hammerschlag. "Sharks are exciting. They are a rich addition to the resources on our planet. They bring attention to ocean-related issues.”

The Wells Fargo execs seemed to agree. Said Dale Rim of Wells Fargo's corporate communications department, “It’s great to be part of the environmental movement.”

Ireland's Basking Sharks: a high percentage of a rare species

As a follow up to my post on wobbegong shark behavior: researchers in Ireland are studying their resident populations of basking sharks and, as with the wobbegong studies, are able to draw conclusions on changing environmental conditions based on changes in animal behavior.

At the 14th European Elasmobranch Association conference held in Galway, Ireland, marine biologists and shark experts from across Europe gathered to discuss the state of shark populations and consider new research techniques to better understand the fate and future of sharks and rays worldwide. Irish researchers who have been working with Ireland's National Parks and Wildlife Service, presented their study which indicated that a high percentage of the remaining number of basking sharks move through Ireland's local waters.

Basking sharks are typically a cold water species and the second largest fish on the planet, topped only by the whale shark. Like the whale shark, the basking shark is a filter feeder, opening its cavernous mouth to strain hundreds of gallons of water, searching for zooplankton - a collection of tiny creatures including larval or minute juvenile forms of fish, mollusks, and crustaceans. Zooplankton are sensitive to changes in the aquatic environment, such as temperature changes due to global warming or changes in oxygen levels or pH, which can occur in response to acidification. Where the zooplankton go, so go the basking sharks.

“Tracking basking sharks may be far more effective than tracking zooplankton, and [may] provide one of the best indicators of the health of our seas and thus the planet,” said Dr. Simon Berrow, the study's group leader.

Extensive tracking of basking sharks has taken place off of Ireland, replacing the intense hunting that used to occur as the basking shark was prized for its sizable supply of shark oil. Worldwide estimates of basking shark populations have been placed as low as 20,000. Extrapolating population estimates from the 250 sharks that have been tagged, the study claimed that there are probably several thousand that frequent the cold waters off Ireland's coast, making the island nation a prime location and home for an increasingly rare shark species.

Read about the research in Irishtimes.com.

Bahamas' Deep Water Sharks: institute conducts research into little-known species

The Bahamas is known within the shark diving community as one of the top locations for seeing sharks. Tiger sharks, lemon sharks, and Caribbean reef sharks are three of the more common species, along with occasional bull, hammerhead, and nurse sharks. From Stuart Cove's Nassau shark diving operation to the boats that frequent popular Tiger Beach off Grand Bahamas, shark diving has flourished as a tourist activity in relatively shallow water.

But cruising in deep waters is another entire world of sharks, one that has largely remained out of sight from divers and scientists alike. There is much that we do not know about sharks, but with these deep water denizens we know even less. Over half of the documented species of sharks live below 200m (660 ft.) but only a handful have been studied to any appreciable degree.

To help fill that void in knowledge, researchers at the Cape Eleuthera Institute, along with scientists from Florida State and Stony Brooks Universities, are conducting research on several deep water sharks as part of the institute's Shark Conservation and Research Program. Utilizing satellite tags supplied by Microwave Telemetry, Inc. (including a new, next-generation of micro-tags more suitable for smaller sharks), the researchers have been quite successful in capturing and tagging 25 sharks from six different species, ranging from a 13-foot bluntnose sixgill shark to a petite sawtail catshark at 18 inches.

According to The Bahamas Weekly.com, Dr. Dean Grubbs of Florida State University was more than pleased. "I have conducted research on deep water sharks in a number of locations around the world including the central Pacific off Hawaii, the temperate western Atlantic off the east coast of the USA and in the Gulf of Mexico. Cape Eleuthera appeared to be an ideal location to expand my research however I never expected the incredible diversity and abundance of species we encountered these last few days. Twenty-five sharks from six different species on only six surveys is an incredible record." said Dr. Grubbs.

Realizing the impact of commercial shark fishing on these important predators and scavengers, in addition to appreciating their role as a component of the islands' tourist economy, the Bahamian government has been proactive in shark conservation, which includes a longline fishing ban in the 1990s, and enthusiastically supports the research taking place involving these deep water species.

"The absence of a commercial fishery of any significance for sharks in The Bahamas, along with a wide variety of marine habitats within close proximity to the facility makes the Cape Eleuthera Institute an ideal location for the pursuit of research into these important species," said the Department of Marine Resources director, Michael Braynen.

Best of success to the Cape Eleuthera Institute. The more light that can be shed on all members of the shark family, the better we will understand how they are woven into the fabric of the ocean ecosystem - not only as pelagic apex predators but as ocean citizens of a mysterious deep water community.

Read the article in The Bahamas Weekly.com.

Wintering White Sharks: possible migrations along U.S. east coast

A possible migration corridor has been identified for great white sharks on the east coast of the U.S. A satellite tagging study was initiated in the fall by the Massachusetts Division of Marine Fisheries and some of the early results are intriguing. It is possible that the great white sharks that appear off the New England coast during the summer months - suspected of feeding on seal populations there - travel south during the winter months based on the results of a tagged shark who has appeared as far south as Jacksonville, Florida.

Satellite tagging has been used on great whites and other shark species to record location, speed, depth, and ambient temperature. Typically, a well-placed tag will record data for 30 to as long as 90 days then release itself, float to the surface, and download its data to satellites overhead. Researchers must wait patiently then sift through a mountain of data when it is downloaded all at once. Satellite tags can provide more long-range data than regional telemetry tags (like those documented in my film, Island of the Great White Shark) but are also subject to being dislodged prematurely. A newer technique, SPOT tagging, bolts the tag to the shark to insure a significantly longer monitoring period, but requires that the shark be caught and brought on board; a technique that has raised considerable controversy because of the physical impact imposed on the shark during the procedure.

In the summer months, several species of shark inhabit the New England coastline, from basking sharks to thresher and blue sharks to the great white white (although not in significant numbers). This new tagging study is the first indication that, like their distant cousins throughout the world who exhibit distinct migratory patterns, white sharks could very well be moving up and down the east coast based on seasonal temperature changes and any changes in prey populations that those seasons impose.

Great whites have already been shown to migrate from the west coast Farallon Islands to the mid-Pacific; same for the white sharks at Isla Guadalupe. White sharks have been monitored moving from South Africa all the way to Australia and back. While there can always be the occasional exception, there is continuing evidence that these sharks and other pelagic species develop critical migratory patterns. Our concern would be, what would happen to these sharks if their migrations were intercepted by commercial fishing fleets? Or what would happen to the overall health of their populations with changes in ocean temperature due to global warming? How ingrained are these patterns and what would happen if external factors were altered - could the sharks successfully adjust?