Bimini Biological Field Station - shark research & marine biology internships

Tiger Beach is a dive name given for a site 25 miles north of Grand Bahama Island. Located on the edge of the Grand Bahama Bank, an area of sandy bottom lies not far from the deep drop off of the Gulf Steam . This area is frequented by very large sharks including tiger, lemon and great hammerhead. It has become famous as a dive site with a number of live aboard dive boats that offer shark excursions to the area. It gets the name Tiger Beach from the rather impressive tiger sharks that are often seen there. It should rightfully be called Lemon Beach because there are far more adult lemon sharks then tiger sharks. The lemon sharks often out number the tiger sharks ten to one. The Bimini Biogical Field Station naturally became interested in research possibilities on the lemon sharks found there. The Sharklab has been working in Tiger Beach since June of 2008.

In the late spring of 2008 our Princpal Investigators, Tristan Guttridge and Steve Kessel were invited by the dive vessel Gulf Steam Eagle. The purpose of the trip was to obtain DNA samples from the many lemon sharks found there. Tristan and Steve were able to gather a number of DNA samples using a specially designed DNA pole puncher right off the back deck of the Gulf Steam Eagle. The sample are a valuable research tool not only to identify individual sharks in the area without having to use highly visible dart tags, but also to compare DNA samples from Bimini, Marquesas Key and Jupiter, Florida. Are there any sharks that are associated with multiple sites? This quesiton could be answered through DNA analysis not only for specific individuals, but also for their offspring.

June 2008 marked the second Tiger Beach trip by the Sharklab. Dr. Samuel Gruber, Matthew Potenski and Steven Kessel all made the trip from Bimini aboard the vessel M/V Dolly operated by Pete Lindgren of Lindgren-Pitman. An underwater receiver was installed and fixed to the bottom to record the presence of any transmittered sharks. Two adult lemon sharks were caught and implanted with acoutic transmitters. The installed VR2 receiver would now be able to keep a watchful "ear" on these two sharks. That information will help us learn if the individual sharks frequent the area on a regular basis, if the sharks periodically leave and return, or if they leave and never return. The VR2 receivers also has the ability to listen for sharks with transmitters implanted in Bimini or Jupiter, Florida that may end up at Tiger Beach. Additional DNA samples were collected to expand our database of known individual sharks found at Tiger Beach.

Our first PAT Tag was placed on a lemon shark in November of 2008 during the "Deadly Sixty" film crew. The PAT tag is a specially designed tag used to track the movements of species that don't normally come to the surface. SAT tags are often placed on sea turtles and marine mammals all of which need to come to the surface to breath. When these animals are at the surface the antannae of the SAT tag is able to trasmit current locations and additional information. Because sharks and other fishes don't normally surface, a PAT tag is used. The PAT tag collects water temperatures, light levels and depth ratings at user defined intervals. It is the preset to "release" on a certain time frome, where it will float to the surface and transmit its information.

Lemons around a receiver

The PAT tag deployed on the Deadly Sixty, was observed on the shark by dive vessels in the area in November and December of 2008. It was later retrieved by the crew aboard the dive boat run by Jim Abernethy's Scuba Adventures Inc. The Pat tag was sent back to the manufacturer where the full data was retrieved off the tag. Not very often are the acutal tags retrieved after they are set out. This was great news for the Sharklab. In March of 2009 another PAT was set out by Steve Kessel and Joe Deppen, during a brief trip departing from Florida.

A Tiger Beach trip was also done for the purpose of filming for "Shark U", produced by Original Productions. Future trips are planned to Tiger Beach whenever possible. The distance from Bimini and Florida make daily trips impossible but the Sharklab is keen to continue on with work in this location. Additonal tags and transmitters need to be deployed. Underwater receivers need to be downloaded and additional ones set out. The overall goal is to look for any connections between the adult sharks found in Tiger Beach and those found in Bimini and Jupiter. Anyone interested in support this unique project is asked to contact Dr. Samuel Gruber or Dr. Tristan Guttridge. Vessels, fuel and bait are the major expenses for these trips.