Fisheries related mortality of small cetaceans in neritic waters of Peru in 1999-2001. Scientific Committee document SC/54/SM10, International Whaling Commission, 26 April-10 May 2002, Shimonoseki, Japan
Van Waerebeek, K.; Alfaro-Shigueto, J.; Montes, D.; Ontón, K.; Santillán, L.; Van Bressem, M.-F.; Vega, D. (2002). Fisheries related mortality of small cetaceans in neritic waters of Peru in 1999-2001. Scientific Committee document SC/54/SM10, International Whaling Commission, 26 April-10 May 2002, Shimonoseki, Japan. International Whaling Commission: Shimonoseki. 5 pp.
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| Authors | | Top |
- Van Waerebeek, K., more
- Alfaro-Shigueto, J.
- Montes, D.
- Ontón, K.
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- Santillán, L.
- Van Bressem, M.-F.
- Vega, D.
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| Abstract |
Fifteen fishing centres on the northern and central coasts of Peru, including large industrial fishing ports and smaller fish landing sites were surveyed for cetacean landings periodically over 29 months, from January 1999-May 2001. Monitoring effort, measured in port-days (pd), was for northern Peru 61pd (1999), 73pd (2000) and 19pd (2001); for the central coast, 24pd (1999), 7pd (2000) and 2pd (2001). Effort was largely opportunistic to other shore-based studies, but some was dedicated to cetaceans. We here document evidence for a minimum of 471 small cetaceans (310 identified to species) encountered in and around ports and landing beaches. Species composition of identifiable specimens include (% in triennium sample): Burmeister’s porpoise Phocoena spinipinnis (42.6%), long-snouted common dolphin Delphinus capensis (24.2%), dusky dolphin Lagenorhynchus obscurus (20.6%) and bottlenose dolphin Tursiops truncatus (12.6%). The number of specimens tallied often were a composition of the visible fraction of animals landed that day plus remains of other animals butchered on earlier days, whence no per diem landing rates can be deduced. Moreover a dramatic change was noted in landing procedures contrasting with 1980s-90s. Depending on the port, entire cetacean carcasses were rarely landed for being illegal. New practices include butchering captured specimens at sea and landing concealed, filleted meat. Uses are still predominantly human consumption and bait for elasmobranch fisheries (both longline and gillnet). Important numbers of specimens were encountered in the form of meat and identification requires molecular genetic analysis. From now onwards, direct shipboard monitoring will be essential to estimate total mortality. Three Burmeister’s porpoises (and 12 green turtles) were incidentally taken in artisanal bottom gillnets (10-18 cm mesh size) in 10 supervised overnight fishing trips off northern Peru. Gillnets were set for a total duration of 163 hrs. Porpoise catch rate per hour of net soaking was 0.018 or 0.3 porpoises/boat/night. Data suggest that the predicted (Van Waerebeek, 1994) long-term relative decline of L. obscurus in catch composition continues, the cause for which is unknown. |
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