Humans began catching fish, shellfish and other marine mammals from 30,000 to 300,000 years ago, ten times earlier than previously believed, according to marine scientists conducting a years-long census of marine life, according to dpa. In a report issued Sunday, the researchers said they were re- calibrating their measurements of sea life based on historical studies dating back to written and paleontological records over the past millenia. The report is to be presented in Vancouver, Canada, from Tuesday to Thursday by international scientists at the Oceans Past Conference at the University of British Columbia. The researchers drew upon old ship logs, literary texts, tax accounts, mounted trophies, ice records and other resources to provide insight into marine diversity and how it's changed. The ongoing global Census of Marine Life is the first attempt to take stock of the world's oceans and their species, and has taken researchers into ocean regions rarely studied or visited. The census is to be published by 2010 in an online encyclopaedia with a webpage for every species. Scientist expect that there will still be more than 1 million unknown species at that point. The historical study is expected to "upend" ideas of natural marine life sizes, abundance, habitats and vulnerability, the Census team said in a press statement. Large freshwater fish started disappearing in medieval times as they steadily shrunk in size, sending fishers to sea, the researchers said. Net fishing began with the Romans, and was modernized with the use of pairs of boats dragging nets in the 1600s. "Human fishing and impacts on near-shore and island marine life ... apparently began in many parts in the Middle Stone Age - 300,000 to 30,000 years ago - ten times earlier than previously believed," the scientists wrote. Before systematic whale hunting began in the early 1800s, the waters around New Zealand sported an estimated 27,000 southern right whales, about 30 times today's numbers, the report said.
