Feather mercury levels in Magellanic Penguin (Spheniscus magellanicus) at southeastern Buenos Aires province, Argentina during the non-breeding season

GÓMEZ-RAMÍREZ M; SECO PON JUAN PABLO; QUADRI ADROGUÉ AGUSTINA; GARCÍA GERMÁN OSCAR; GARCÍA-FERNANDEZ A; MIGLIORANZA KARINA

Cartagena

Congreso; 13va Reunión Bienal SETAC Latinoamericana.; 2019

SETAC

Mercury (Hg) is a persistent, toxic and non-essential heavy metal, whose presence in fish, birds and marine mammals is the culmination of a process through the food chain due to its bioaccumulation and biomagnification. Birds feathers constitute a useful non-destructive tool for Hg detection since they excrete Hg through the quill during the premolt. The Magellanic Penguin (Spheniscus magellanicus) is amongst the most abundant warm water penguin species breeding in the Atlantic and the Pacific oceans. The species is listed as ?Near Threatened? by the International Union for the Conservation of Nature (IUCN) chiefly due to declines observed in several breeding colonies. In this context, the aim of this work was to determine levels of Hg in feathers of beached juvenile Magellanic penguins and establish the relationship between accumulation and sex, during the species? non-breeding season in Buenos Aires province, Argentina. Feathers of 26 individuals (11 males and 15 females) were analyzed. Hg was analyzed in a Milestone DMA-80 direct mercury analyzer by atomic absorption spectrophotometry with a detection limit of 0.005 ng. Hg levels, considering both, females and males together, ranged between 265.5-1515.52 ug/kg. These values were higher than those found in juveniles of the same species from Brazilian (wintering grounds) and Argentine Patagonian (breeding grounds) coasts, and below the levels associated with negative effects on seabirds (5000 to 65,000 ug/kg dry weight). Hg concentrations were not significantly different between sexes (GLM, p>0.05) (mean ± SD: 568.34 ± 308.2 and 824.59 ± 480.71 ug/kg, for females and males, respectively), probably because juveniles are sexually immature and females do not excrete Hg by egg laying yet.Hg levels found in this study, were one order of magnitude greater than those values found in 2012, for the same species from breeding grounds. Thus, the present study provides relevant information indicatinga possible increase in Hg pollutionin Magellanic penguin from Buenos Aires province. Moreover, these results alert on a potential increasing of Hg pollution in the Southern region of the Atlantic Ocean and thus incentive for the development of monitoring programs and regional strategies to improve the conservation status of this species. Further investigation would be useful in order to test the influence of age on Hg accumulation.