The aquatic ecosystems of Doñana and those of its watersheds are highly threatened by multiple human pressures. Among them, the strong development of agriculture and the increase of population have been the main causes of the loss of quantity and quality of freshwaters during the last decades. Nitrate pollution is one of the main problems affecting both surface and groundwaters in Doñana and its surroundings. Previous studies have shown that the Doñana aquifer receives nitrates due to the...

Do parasites weaken their hosts’ resilience to environmental stress? Not always, according to this study. Rather than weakening its brine shrimp intermediate host, tapeworm infection enhances the shrimps’ ability to cope with arsenic contamination in the water, and the same holds true in the warmer waters predicted by climate change models.

A key goal for wildlife managers is identifying discrete, demographically independent conservation units. Previous genetic work assigned killer whales that occur seasonally in the Strait of Gibraltar and killer whales sampled off the Canary Islands to the same population. Here authors present new analyses of photo-identification and individual genotypes to assess the level of contemporary gene flow and migration between study areas, and analyses of biomarkers to assess ecological differences.

Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well-established dose-dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery.

Recent studies suggest that direct mortality and physiological effects caused by pollutants are major contributing factors to global amphibian decline. This study shows how sublethal concentrations of pollutants can disrupt the ability of amphibian larvae to recognize their natural predators, hence increasing the risk of predation in the populations.