Body condition of right whale calves at Península Valdés: a preliminary study

MARON, CARINA; WARD, ROBERT; VALENZUELA, LUCIANO O; SIRONI, MARIANO; CHIRIFE, ANDREA; DI MARTINO, M; ROWNTREE, VICTORIA; SEGER, JON

Sausalito, California

Conferencia; 44th Annual Conference of the International Association for Aquatic Animal Medicine (IAAAM); 2013

An animals reproductive success can be affected by a decline in food availability. Southern right whale females that calve off Península Valdés (PV), Argentina, have experienced high rates of calving failure as indicated by: a) having fewer calves than expected (longer calving intervals), and b) high calf mortality on their PV nursery ground. Previous studies found that the PV whales experience longer calving intervals following El Niño events, when the abundance of Antarctic krill (a primary prey for the whales) declines. However, it is still unknown whether malnutrition is playing a role in the large numbers of calves that have died at PV since 2005 (501 dead calves). Krill contain essential polyunsaturated fatty acids (PUFA) that mammals require for gestation and lactation.The nutritional value of Patagonian copepods, an alternative prey of the whales, remains unknown. A goal of my research is to determine whether calves that die at PV show signs of malnutrition. Fatty acid profiles and blubber thickness of calves were compared between calves that died in years with low (2003, 2004 and 2006) and high mortality rates (2005, 2007-2012). The proportion of PUFA increases with calf length, regardless of whether calves died in years of low or high mortality. This result indicates that the nutritional condition of calves improves during their first months of life. Calf blubber was thinner in high mortality years suggesting a decline in prey abundance in these years.