A new study published in the journal Science has found that in many places the harvesting of small fish needs to be drastically reduced and monitored to protect the marine food chains. The international team of scientists further added that fishing cuts should even be buttressed by no-fishing zones in appropriate areas.

According to the study, even purportedly sustainable fishing levels of these key prey fish are harmful to marine ecosystems and species higher up in the food chain, the researchers concluded.

The experts determined that overfishing of smaller species has "significant effects on other parts of the marine ecosystems," explained Tony Smith, the lead author of the study at the Commonwealth Scientific & Industrial Research Organisation (CSIRO) in Australia.

He said the findings comprise the first wide-ranging analysis of how catching small fish and krill can interfere with marine food chains and ultimately trim down human food supplies. Because little fish eat mostly tiny plankton and are prey for large fish, whales or seabirds, small species play a crucial role. They make up more than 30 per cent of world fish production and many people in developing nations rely on them as a staple food source.

The scientists used computer models to study populations of small fish off Peru, the California current, southern Africa, the North Sea and Australia. They believe catches need to drop sharply if these stocks are to be saved, as some were harmed even by the maximum sustainable yield (MSY) of a stock.

"Halving exploitation rates would result in much lower impacts on marine ecosystems, while still achieving 80 per cent of MSY," the authors wrote.

The authors noted that small fish are often ground up into fishmeal and used as feed for livestock or farmed fish. Only around 10-20 per cent of small fish are actually reserved for human consumption. For more information check out the 25 July article from FIS: www.fis.com/fis/worldnews/worldnews.asp?l=e&id=44670&ndb=1. Also see the 25 July article from The Fish Site: www.thefishsite.com/fishnews/15263/small-fish-harvesting-unsustainable.