ACS Research Committee Report

INTERACTIONS BETWEEN INDIAN RIVER DOLPHINS AND CRAB FISHERMAN
Source: Noke, W. D. and D. K. Odell. 2002. Interactions between the Indian River Lagoon blue crab fishery and the bottlenose dolphin, Tursiops truncatus. Mar. Mamm. Sci. 18(4):819-832

The study was conducted to investigate anecdotal reports from crab fisherman of dolphins following the commercial boats and then stealing the bait from the crab traps after they had been deployed. In the one year study, they found only 2.8% of 18,891 pots had evidence of dolphin/crab pot interaction. Interactions included: begging at boats, feeding on discarded bait fish, engaging in crab pot tipping behavior, and dolphin mortality from crab pot float line entanglement (1 occurrence). Overall, 16.6% of the 1,296 dolphins sighted interacted with the fishing boats. The only finding with significant statistical support is that increased door security on the traps would help reduce the negative impacts to the fishery and the dolphins involved.   

EFFECTIVENESS OF ACOUSTIC DETERRENTS IN REDUCING BYCATCH OF FRANCISCANA DOLPHIN IN ARGENTINA GILLNET FISHERY
Source: Bordino, P., S. Kraus, D. Albareda, A. Fazio, A. Palmerio, M. Mendez, and S. Botta. 2002. Reducing incidental mortality of Franciscana dolphin (Pontoporia blainvillei) with acoustic warning devices attached to fishing nets. Mar. Mamm. Sci. 18(4)833-842

This study examined the effectiveness of acoustic deterrents (pingers) in the artisanal gillnet fishery in Argentina at reducing bycatch of the Franciscana dolphin. Information on the number of dolphins captured, geographic position, depth, configuration of fishing gear, soak time, biomass of fish caught, and sea lion predation in a string/net producing any damage was recorded. Equal numbers of active and silent pingers were used. A total of 45 dolphins were caught in the silent nets, and 7 were caught in the active pinger nets. This shows a highly significant reduction in bycatch for this species. However, sea lions damaged the fish in the active pinger nets significantly more than in the silent nets, and the damage increased over the course of the experiment. So, although pingers show promise as a management tool for this species of cetacean, pinniped depredation suggests that higher pinger frequencies will be needed to avoid a "dinner bell" effect.    

EFFECTS OF ACOUSTIC HARASSMENT DEVICES ON HARBOR PORPOISES
Source: Olesiuk, P.F., L.M. Nichol, M.J. Snowden, and J.K.B. Ford. 2002. Effect of the sound generated by an acoustic harassment device on the relative abundance and distribution of harbor porpoises (Phocoena phocoena) in Retreat Passage, British Columbia. Mar. Mam. Sci. 18(4):843-862

This study found that there was a significant effect on the relative abundance and distribution of harbor porpoises when acoustic harassment devices (AHD) were used. Fewer porpoises were seen and spent less time in areas where AHDs were active. No porpoises were sighted within 200 m of an active AHD. The effect of AHD diminished with distance, however, their results indicated that the impact of the AHD extended beyond their maximum sighting range of 3.5 km.   

INTERACTIONS BETWEEN CETACEANS AND THE TUNA FISHERY IN THE AZORES
Source: Silva, M.A., R. Feio, R. Prieto, J.M. Goncalves, and R.S. Santos. 2002. Interactions between cetaceans and the tuna fishery in the Azores. Mar. Mam. Sci. 18(4):893-901.

Observations were made on the interactions between cetaceans (primarily common dolphins, Delphinus delphis) and the tuna fishery in the Azores from 1998 to 2000. Cetaceans were present for less than 10% of the observed fishing events. Their presence varied spatially and temporally, depending on the distribution of the fishing effort and the pattern of occurrence of each cetacean species in the region. Overall, cetaceans interfered in 5% of the fishing events. These interferences resulted in a higher proportion of events with no catches. During the study period, 49 dolphins were caught in the fishing lines, but were released alive, although it is impossible to determine if they survived the interaction. Overall, their results suggest a low level of interaction between cetaceans and this fishery.    

SATELLITE USED TO TRACK DISTRIBUTION AND MOVEMENT OF WHALES
Source: CNN.com/science and space.

A Japanese designed rocket was launched on December 14, 2002 from Tanegashima Space Center. The three Japanese satellites aboard included the Whale Ecology Observation Satellite, designed by a university to monitor the movements and behavior of whales over the next 1-2 years, and another probe to observe global warming and environmental change.