Afant News

Shark Researchers need your Help

SHARK RESEARCHERS NEED YOUR HELP

As part of a study of freshwater and estuarine sharks around the Northern Territory (NT), who better to ask for information than the fishers who frequent these waters? Currently, researchers from Charles Darwin University, the Australian Institute of Marine Science and NT Fisheries are trying to assess the abundance and distribution of the relatively common bull and pigeye sharks, as well as the supposedly rare freshwater sharks, and their potential interaction with fishermen.

Little is known about the freshwater and estuarine sharks of the Northern Territory (NT). To better understand these species the scientists are asking you to answer a short questionnaire on whether you have caught sharks while fishing in these areas, and which species you may have caught. The questionnaire is very short and easy, and should take less than five minutes to complete.

The questionnaire can be filled in online, or printed out and returned to NT Fisheries by post or fax (08 8999 2002). All of the questions are related to fishing in freshwater and estuarine areas around the NT. Please answer all questions and provide specific information where requested. We emphasise that it is vital to answer all the questions, as even not catching sharks is valid and important information. A simple identification guide for the three sharks of interest is provided along with an overview presentation of the project. More information can be found at the following website: http://www.cdu.edu.au/ser/FreshwaterEstuarinesharks.htm

Although bull and pigeye sharks are relatively common, little is known about their distribution and abundance in NT water. The speartooth and northern river sharks (Glyphis spp.), are currently listed as critically endangered, although their true numbers are unknown. What is known is that they have been found in rivers and open water along the NT coastline, and the two species and bull sharks are similar in appearance. Small specimens around 60 – 80 cm are found in brackish waters in the upper reaches of tidal rivers but larger ones of up to 3m in estuaries and coastal regions. They were originally named because of the shape of their teeth in the bottom jaw that can be seen even when the mouth is closed (for images see the Identification guide ).