[MARMAM] New publications on elephant seas vagrants and small cetacean strandings-Ecuador
Juan Jose Alava
jj_alava at yahoo.com
Tue Sep 11 20:02:29 PDT 2018
Please, find below a couple of new papers recently published by marine mammal researchers from Ecuador and international colleagues.
Páez-Rosas, D., Riofrío-Lazo, M., Ortega, J., Morales J.de D.,, Carvajal, R., Alava, J.J. 2018. Southern elephant seal vagrants in Ecuador: a symptom of La Niña events? Marine Biodiversity Records 11: 13. https://doi.org/10.1186/s41200-018-0149-y
AbstractBackgroundExtralimital observations of pinnipeds are important tounderstand the effects of changing climates on our oceans and the distributionof these species. The southern elephant seal (Mirounga leonina) is aknown vagrant species that moves over long distances. We report three newrecords of M. leonina in interior freshwater tributaries of the GuayasRiver Estuary Basin (Gulf of Guayaquil) and northern coast of Ecuador betweenOctober 2017 and January 2018 during a cold episode of La Nina event in thesoutheastern Pacific.ResultsThe elephant seals were identified according to their largesize (~ 5 m for adult and 2–3 m for juveniles/subadults), the head toneck size ratio, and the size and external morphology of the proboscis, whichwas used as a key trait to differentiate M. leonina from the Northernelephant seal (M. angustirostris). The observations of M. leoninain Ecuador highlight an extreme movement covering an assumed total distance ofapproximately 8000 km from the circumpolar region. The cold event “LaNiña” with sea surface temperature anomalies ranging − 1.5 °C to− 0.5 °C in October 2017 likely triggered the extralimital movements ofthese animals.ConclusionRecurring observations of M. leonina in the GuayaquilGulf suggest the importance of this highly productive region and tropicalestuarine-riverine habitats as temporary haulout sites for resting. These newfindings indicate that vagrant individuals influenced by oceanographic eventsand eco-physiological processes are reaching this region more frequently thanpreviously thought.
Date of publication: Published online on June 20, 2018Links:
Jiménez, P.J., Alava, J.J., Castro, C., Samaniego, J. and Fair, P. 2018. Stranding of Small Cetaceans with Missing Fins Raises Concerns on Cetacean Conservation in Ecuador: Bycatch or Targeted Fisheries?. International Journal of Fisheries Science and Research 2(1): 1006.
AbstractAmong anthropogenic threats to marine mammals, bycatch is one of the major and increasing concerns. Thisreport describes three species of small cetaceans, including a short-beaked common dolphin (Delphinusdelphis), a bottlenose dolphin (Tursiops truncatus), and two dwarf sperm whales (Kogia sima), which were found stranded with pectoral fins, dorsal fins and caudal fin removed. The dolphins were found at the beaches of San José de Las Nuñez and San Pablo, respectively (Santa Elena Peninsula Province on 14 August 2017), while the dwarf sperm whales were found in Puerto Lopéz and Crucita (Manabí Province) in July 2014 and August 2015, respectively. Possible explanation for the dolphins and dwarf sperm whales missing fins support the event as a possible case of fishery interaction or bycatch with systematic removal of their fins. Although remnants of artisanal gillnets were not found near the two dolphin species, one of the dwarf sperm whales showed marks of artisanal gillnets on the body as evidence of bycatch. Trade of dolphin carcasses and their parts for bait by fishers cannot be ruled out as there is some evidence of this practice in the past. Both dolphins species are vulnerable species at the national level and commonly involved in incidental captures with gillnets of artisanal fisheries in Coastal Ecuador. Cetacean bycatch is a grave conservation problem affecting several cetacean species in Ecuador’s waters. Fisheries and environmental authorities must be vigilant and enforce actions to proactively mitigate possible anthropogenic impacts and promote environmental education activities in fishing communities to conserve vulnerable dolphin species in Ecuador’s waters. Further, to comply with new rules and regulations of the US Marine Mammal Protection Act (MMPA) intended to reduce the bycatch of marine mammals in foreign commercial fishing operations that export fish and fish products to the United States, a regulatory program is urgently needed to mitigate and reduce fisheries interactions with marine mammals in Ecuador.
Date of publication: Published on May 1, 2018
Juan Jose Alava
Juan Jose Alava, PhD
Resource and Environmental Management, Faculty of Environment,
Simon Fraser University
8888 University Drive,
Burnaby, British Columbia V5A 1S6,Canada
E-mail: jalavasa at sfu.ca
Research Associate, Nippon Foundation- Nereus Program
Institute for the Oceans and Fisheries
Faculty of Science, The University of British Columbia
AERL 313.02-2202 Main Mall | Vancouver, BC V6T 1Z4 Canada
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the MARMAM