Before oil hunters in the early 1800s harpooned whales by the score, the ocean around New Zealand teemed with about 27,000 southern right whales – roughly 30 times as many as today – according to one of several astonishing reconstructions of ocean life in olden days to be presented at a Census of Marine Life conference May 26-28.
At about the same time, UK researchers say large pods of blue whales and orcas, blue sharks and thresher sharks darkened the waters off Cornwall, England, herds of harbour porpoise pursued fish upriver, and dolphins regularly played in waters inshore.
Using such diverse sources as old ship logs, literary texts, tax accounts, newly translated legal documents and even mounted trophies, Census researchers are piecing together images – some flickering, others in high definition – of fish of such sizes, abundance and distribution in ages past that they stagger modern imaginations. They are also documenting the timelines over which those giant marine life populations declined. For example, Census scientists say the size of freshwater fish caught by Europeans started shrinking in medieval times.