Source: Society for Experimental Biology
Date: 2005-07-11
Do you enjoy eating oysters on a hot sunny afternoon? Make the most of it — it may not last forever. Research has shown that global warming increases the sensitivity of oysters to metal pollution, causing a deadly threat to populations in polluted areas.

Oysters are cold-blooded organisms so their body temperature changes with environmental temperature. Lannig observed that cadmium levels increased the basic metabolic rate (BMR) of oysters at 20?C and 24?. For oysters at 28?C, cadmium did not increase the BMR, but it significantly reduces its chances of survival. “One possible mechanism for this observation is increased damage of mitochondria in cadmium-exposed oysters with increasing temperature”, Lannig explains, “these organelles become significantly more sensitive to cadmium as temperature rises, so that cadmium levels which were not damaging to mitochondria at lower temperature become strongly toxic with increasing temperature.”
Cadmium circulates continually between air, water and soils. As it moves easily through the food chain, high levels are reported in seals. In humans, cadmium interferes with calcium metabolism and deposition in the bone. Accumulation over time can cause serious illnesses such as itai itai disease. Future research will focus on to what extent cadmium reduces thermal tolerance of cold-blooded species.
This story has been adapted from a news release issued by Society for Experimental Biology.