Persistent organic pollutants in living southern right whale (Eubalaena australis) mothers and calves at Península Valdés, Argentina

MARON, CARINA F.; HUED, A.; CECCHETTO, FRANCO; VAZQUEZ, NICOLAS D.

Bled

Jornada; Sub-Committee on Environmental Concerns on April 2023 of the Scientific Committee of the International Whaling Commission?s Document SC/69A/E02; 2023

Committee of the International Whaling Commission

Southern right whales off Península Valdés, Argentina, have experienced high newborn calfmortality in some years since the 2000 ́s. Between 2003-2013, calf mortality averaged 55 deathsper breeding season, almost seven times more than the numbers recorded in the previous decade(1993-2002). In this context, assessment of persistent organic pollutants in mother-calf pairs atPenínsula Valdés has been proposed as one of the priorities for research, since transfer ofpollutants from reproductive females could be compromising calf health. We analyzed persistentorganic pollutants in the blubber of 35 mothers and calves, and in 14 juveniles and non-calvingadults. A total of 16 organochlorine pesticides were found. In calves, the mean pesticideconcentration was on average two to 13 times higher than in mothers, and in adults and juvenilesthe concentration were two to ten times higher than in reproductive females. This finding suggeststhat mothers eliminate some of these chemicals through gestation and lactation. All pesticidesreported here in whales are already banned for agricultural use, and are thus environmentalresiduals and/or indicate current use of these chemicals. These findings are relevant sincepersistent pesticides could affect calf physiology and health and potentially reduce survival, thusaffecting the population dynamics.