Southern right whale (Eubalaena australis) calf mortality at Península Valdés, Argentina: Are harmful algal blooms to blame?

A concerning increase in southern right whale calf mortality at Península Valdés, Argentina—with 90% of deaths occurring in calves under three months old since 2005—may be linked to harmful algal blooms (HABs). Research identifies a statistically significant correlation between the density of the diatom Pseudo-nitzschia spp. and calf deaths, though no such link was found with the dinoflagellate Alexandrium tamarense. Evidence of whale exposure to HAB toxins includes trace levels of paralytic shellfish toxins (PSTs) and domoic acid (DA) in tissue samples, as well as Pseudo-nitzschia frustules in fecal matter. The study analyzed multiple datasets, including biotoxin levels, algal abundances, shellfish harvesting closures, prey availability, and satellite chlorophyll data, to assess the potential role of HABs in these mortalities.

Wilson, C., Sastre, A. V., Hoffmeyer, M., Rowntree, V. J., Fire, S. E., Santinelli, N. H., Ovejero, S. D., D’Agostino, V., Marón, C. F., Doucette, G. J., Broadwater, M. H., Wang, Z., Montoya, N., Seger, J., Adler, F. R., Sironi, M., & Uhart, M. M. (2015). Southern right whale (Eubalaena australis) calf mortality at Península Valdés, Argentina: Are harmful algal blooms to blame? Marine Mammal Science, 32(2), 423–451. Portico. https://doi.org/10.1111/mms.12263