pacific islands report_NU.indd - Whale and Dolphin Conservation ...

(5), and unidentified dolphins/porpoises (33). Thisinformation did not include condition of the animaland once again, it overlaps in content with Lawson’s(2001) review.c. Drift-netsA few records exist for drift-net fishing, although theglobal moratorium (on high-seas drift-net fishing)as well as concern by South Pacific countries ofthe navigational hazards, and prevalence of ‘ghostnet’ fishing has largely limited this fishing practice(Wright and Doulman 1991). In one case prior to themoratorium, four Taiwanese drift-net vessels wererunning a trial fishery for squid in New Zealand’s EEZin early 1981. Inspection of the vessels during theirfishing operations documented a frozen commondolphin and southern pilot whale in addition to shark,tuna and mackerels aboard the vessel. As a result,licences were suspended. In a second case, there aregeneral reports of hourglass dolphin (Lagenorhynchuscruciger) deaths in South Pacific driftnets, althoughspecific geographic information is not available(Goodall et al., 1997). Little is known about theincidental catch of marine mammals in historicaldriftnet fishing for tuna in the Pacific region (Sharpleset al. 1991, Richards 1994).d. Gill-netsInformation on gillnet fisheries throughout mostof the South Pacific Ocean is inadequate to judgeeffects on marine mammals although some assertthat bycatch is relatively probable in areas wherecetacean habitat intersects with gillnet deployment(Nitta 1994). However, it is reported that from1984 to 1988, at least 230 Hector’s dolphins werekilled in groundfish gillnets by commercial andamateur fishermen in the Canterbury region, NewZealand. Over 90% of catches occurred duringthe austral summer, and younger animals wereparticularly vulnerable to entanglement (Dawson1991). Based on a sensitivity analysis, Martien et al.(1999) predicted the extinction of the North Islandpopulation within the next few decades unless gillnetfishing effort was substantially reduced (Dawson etal. 2001). Entanglement in fishing gear, especiallygillnets in deep water (e.g., for billfish and tuna), iscited as one of the most significant threats to ziphiids,including Cuvier’s beaked whales (Reeves et al. 2003).Human-related mortality of Orcaella brevirostris innorth-eastern Australian waters is largely attributed todrowning in inshore gillnets set across creeks, riversand shallow estuaries for barramundi and threadfinsalmon (Parra et al. 2002).e. Other gear typesRelatively recent reports show that both long- andshort-beaked common dolphins are also capturedin New Zealand commercial nets (Duignan andJones 2005) and bottlenose dolphins have beenobserved entangled and stranded on the shore.Hector’s dolphins, bottlenose dolphins and commondolphins are reported to be taken in both trawland set net fisheries in New Zealand waters andnumbers reported by fishermen are believed tobe underestimates (Cawthorn 1988). In fact, it isbelieved that up to 100 Hector’s dolphins were takenand not reported in some fisheries/regions (Cawthorn1988). Fisheries capture of Tursiops sp. in a set-netmesh and an inshore finfish fishery has taken place inthe Gulf of Carpentaria, Australia (Haines and Limpus2001, Limpus et al. 2002). Finally, a few Hourglassdolphin individuals were reported to be taken in setnets off New Zealand (Goodall et al. 1997), and atleast four humpback whales have been entangledin crayfish pot lines off Kaikoura between 2003 and2006 (SPWRC 2004, M. Donoghue pers. comm.).f. Unspecified gear types and general concernsDawbin (1972) reported that Irrawaddy dolphinswere taken accidentally in fishing nets in the Gulfof Papua, and that false killer whales had beentaken between Papua New Guinea and Australia.Some mortality of spectacled porpoises Phocoenadioptrica occurs in fishing gear, but the scale ofthis mortality relative to abundance and populationrecruitment is unknown (Reeves et al. 2003). Smallnumbers of Peponocephala are taken in nets andby harpooning throughout the tropics (Reeves etCURRENT STATE OF KNOWLEDGE OF CETACEAN THREATS, DIVERSITY, AND HABITATS IN THE PACIFIC ISLANDS REGION 27