As part of NZ Shark Week Te Papa hosted some free presentations from our leading shark experts. We were initially given an overview of sharks – what are they, how are they identified and who are their close relatives? New Zealand has ~110 shark species, ~70 rays and ~ 12 chimeras (ghost sharks). The exact numbers are unknown as the research is not complete and possible new species have yet to be described.
Malcolm Francis, Fisheries Scientist at NIWA, along with colleagues from other agencies, has been studying sharks for a number of years and is particularly interested in tagging and monitoring the movements of sharks.
One local study was run in Mana as this is known to be an important breeding ground for Rig Sharks. They tagged juvenile Rig Sharks and monitored their movement within the inlets – only one shark moved between the 2 arms of the inlet but preferences were shown for specific areas at various times which may be explained be feeding patterns. The study indicates that the entire inlet is used by the sharks and needs to be protected not just some areas within it.
Some of Malcolm’s more familiar work involves his studies on Great Whites at Stewart Island and at the Chathams, and he has presented some of his findings to our dive club in the past. Great Whites are not the cold water species we always imagined; Malcolm’s research shows that they also like to take a winter get away, often travelling 100km/day, as they head to the Great Barrier Reef, New Caledonia, Vanuatu, Fiji and Tonga! Each shark then returns to the islands they left. While travelling across open water the tags show the sharks diving to over 1000m but when around islands they stay much shallower. How they navigate is unknown and just one of several new questions arising from this research.
Mako sharks are also being tagged and their movements monitored. These sharks along with Blue Sharks and Porbeagles are often killed as by catch on Tuna lines so knowing their movements may allow for better fisheries management for all species.
Andrew Stewart, Collection Manager for fishes at Te Papa, highlighted the scarcity of knowledge of all species, but particularly sharks in our EEZ. With very little research having been conducted he is still being sent specimens from observers on fishing vessels, recreational fishermen and scientific expeditions that are as yet undescribed. Further research is being done to see whether these are new species or migrants from other areas. To be fair some of the deep water shark species are pretty ugly – including elephant fish, goblin sharks, longnose spookfish and frill sharks. However all species deserve to be protected and their roles in the ecosystem are currently unknown. It is thought that some of these species are threatened as a result of by catch from other managed fisheries.
Malina Palka from WWF came to represent the NZ Shark Alliance, a group of NGO’s and other interested groups who aim to ban the practice of shark finning in NZ waters. Shark finning is defined as the process of removing the fins off sharks at sea and dumping the bodies. 100 million sharks are killed every year or ~190 every minute, many just for their fins. Shark finning is still legal in NZ although the sharks must be killed first. We are one of the top 20 shark fisheries worldwide and a major exporter to Hong Kong. Finning generates ~$4.5 million in exports which is only 0.003% of our fishing exports. The government believes that sharks are protected under our Quota Management System (QMS) but with so little known on our shark species and current stock levels their survival cannot be guaranteed. The National Plan of Action (NPOA) for sharks is currently being reviewed and the NZSA is asking for your support to ban shark finning. Sharks can still be sustainably caught under the QMS as long as they are landed with ‘fins naturally attached’ – this is in line with other nations.
Visit www.nzsharkalliance.org.nz for more information and how you can help to ban shark finning in NZ waters.
