Fish stocks are plummeting. From the Independent newspaper in London, 29th of September 2006: Cod catches in the Atlantic have dropped by 70% over 30 years.

Langoustines are caught in intensive bottom trawling operations, devastating large areas of the North Sea.

Land resources are also growing scarcer. Protein from meat takes 5 times the amount of water versus from rice. As an example, if everyone in India became carnivores, they wouldn't have enough landmass to feed the population.

The End of the Line by Charles Clover provides a frightening overview of how we are destroying our oceans.

'The Fish Guy' writes in the International Herald Tribune about both sustainability and the increase of harmful chemicals (including mercury and PCB's) can be ethically solved on a day to day basic: Eat fish that fits on your plate (without cutting, that would be cheating). Bigger fish are more endangered and contain more of the harmful chemicals since these fish themselves tend to be carnivores and have eaten other fish, increasing the amount of pollution in their flesh.