Southern right whale calf mortality at Peninsula Valdes, Argentina - are harmful algal blooms responsible?

Península Valdés (PV) in Argentina is an important calving ground for Southern right whales (Eubalaena australis). Since 2005 there has been a significant increase in right whale mortality at PV, with most of the deaths (~90%) being calves less than three months old. We investigate the potential involvement of harmful algal blooms (HABs) in PV right whale deaths by examining datasets that include the approximate timing of the right whale deaths, abundances of Pseudo-nitzschia spp. (a genus of diatoms), Alexandrium tamarense (neurotoxin that causes a human illness), shellfish harvesting closure dates, seasonal availability of whale prey at PV, biotoxins levels in tissue samples from dead whales, and satellite chlorophyll data for PV. While there is evidence of the whales' exposure to HAB toxins, we are unable to assign a causal role of HAB toxins in these deaths.

Speaker: Cara Wilson, NOAA