CESIMAR - CENPAT   25625
CENTRO PARA EL ESTUDIO DE SISTEMAS MARINOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
No evidence of malnutrition in dead southern right whale calves off Argentina as inferred from blubber thickness measurements and lipid content analyses.
Autor/es:
MARIA CARLA LÁBAQUE; JON SEGER; BELTRAMINO, LUCAS; MARÓN, CARINA F.; MARCELA UHART.; MARIANO SIRONI; ALZUGARAY, LUCÍA; DI MARTINO, MATÍAS; VICTORIA J. ROWNTREE; FREDERICK R. ADLER; CHIRIFE, ANDREA
Lugar:
Bled
Reunión:
Conferencia; International Whaling Commission Scientific Committee; 2018
Institución organizadora:
International Whaling Commission
Resumen:
Marine mammals rely on their subcutaneous fat layer or blubber to store energy, insulate their bodies andprovide buoyancy and streamlining. Right whale calves are born with a thin blubber layer and needmaternal milk to increase lipid reserves and grow. From 2003 to 2017, at least 706 southern right whale(Eubalaena australis) calves died at Península Valdés (Argentina) calving ground. Malnutrition has beenconsidered as possible contributor to these deaths because it may negatively affect body condition ofcalves. However, anatomical signs of starvation were not evident during necropsies of calf carcasses. Wemeasured blubber thickness in nine body locations of 345 dead calves to determine whether their blubberwas thinner in years with high calf mortality (2003, 2005, 2007-2013) compared to low mortality years(2004, 2006, 2014-2017). Additionally, we asked whether blubber thickness changed with calf length, sex,state of decay and stranding location along the dorsal, lateral and ventral planes of the body. We alsoanalyzed whether the lipid content of the external blubber layer varies among living (n=16) and dead(n=67) calves of similar lengths. Contrary to what we expected, when controlled for calf length and state ofdecay, our data suggest that blubber was not significantly thinner in high mortality years compared to lowmortality years and its lipid content did not vary significantly among living and dead calves. The onlyvariable we found to affect blubber thickness was calf length as it increased as calves grew at all bodylocations. These findings do not suggest a decline in the blubber condition of calves over the periodexamined. Moreover, they do not support the hypothesis of reduced transfer of maternal fat reserves tocalves in high mortality years. However, this hypothesis should not be discarded, and additional studiesshould be conducted to further assess the overall health and body condition of right whale calves atPenínsula Valdés.