Dear MARMAM community, My coauthors and I are pleased to announce our new paper: Marón CF, Budge SM, Ward RE, Valenzuela LO and others (2020) Fatty acids and stable isotopes (δ13C, δ15N) in southern right whale Eubalaena australis calves in relation to age and mortality at Península Valdés, Argentina. Mar Ecol Prog Ser 646:189-200. The paper is available online for users only at https://www.int-res.com/abstracts/meps/v646/p189-200/ ABSTRACT: Baleen whales accumulate fat reserves during the summer to sustain reproduction while fasting in the winter. The southern right whale Eubalaena australis population that calves off Península Valdés, Argentina, experienced high calf mortality events from 2003 to 2013 and poor nutritional states of mothers could be a contributing cause. Previous studies found that the population’s reproductive success is influenced by prey availability. Mothers unable to build sufficient fat reserves or feeding on prey with different nutritional value may fail to meet the demands of lactation. Milk is the only source of nutrients and energy for calves at Valdés, so their fatty acids (FAs) and stable isotopes should reflect their mother’s diet and feeding-ground locations. Here, we compared FA profiles and C and N stable isotopes of dead calves with those of living calves to evaluate the potential impact of maternal nutrition on calf survival. We found no differences in the FA composition of blubber in dead and living calves, indicating similar maternal diets. Likewise, the isotopic values of living and dead calves imply that their mothers had similar foraging ranges. However, FA composition was greatly affected by calf length, indicating effects of calf age and duration of nursing. These findings suggest that mothers of dead calves did not feed on different diets or feeding grounds compared to mothers of living calves. Future research should further assess the overall health and body condition of the Valdés southern right whale calves. Please do not hesitate to contact me (carimaron@gmail.com<mailto:carimaron@gmail.com>) if you have any queries regarding to this article or to request a PDF copy. Cheers, Cari Marón