Diego and the dolphins

A study by the Pritzker Laboratory and Stony Brook University’s Institute for Ocean Conservation Science found 33 different species of sharks have appeared in US food, commonly shark fin soup..

Shark fin soup is a popular delicacy in the Chinese culture for decades, but new information reveal sharks are turning up in many US restaurants. Prices for the shark fin soup are as high as $100 per bowl in the US.

“US consumers of shark fin soup cannot be certain of what’s in their soup,” said Stony Brook Biologist Demian Chapman, who co-led the DNA testing, “They could be eating a species that is in serious trouble.”

Among the sharks being served is the endangered hammerhead shark, according to the International Union for Conservation of Nature, however, it is not banned in the US or the Convention on International Trade in Endangered Species (CITES).

latinospost

Many severely depleted populations of baleen whales (Mysticeti) have exhibited clear signs of recovery whereas there are few examples in toothed whales (Odontoceti). We hypothesize that this difference is due, at least in part, to social and behavioural factors. Clearly, a part of the lack of resilience to exploitation is explained by odontocete life history. However, an additional factor may be the highly social nature of many odontocetes in which survival and reproductive success may depend on: (a) social cohesion and organization, (b) mutual defence against predators and possible alloparental care, (c) inter-generational transfer of “knowledge”, and (d) leadership by older individuals. We found little evidence of strong recovery in any of the depleted populations examined. Their relatively low potential rates of increase mean that odontocete populations can be over-exploited with take rates of only a few percent per year. Exploitation can have effects beyond the dynamics of individual removals. Four species showed evidence of a decrease in birth rates following exploitation; potential mechanisms include a deficit of adult females, a deficit of adult males, and disruption of mating systems. The evidence for a lack of strong recovery in heavily exploited odontocete populations indicates that management should be more precautionary