When whalers hunting more than 100 years ago tallied up their efforts they almost certainly didn't realise the data could be used to save the exact species they were killing.
Documents from the 1800s, detailing whalers' movements and slaughters, have been used by New Zealand scientists to better understand the habits and habitats of the endangered southern right whale.
Scientists from the National Institute of Water and Atmospheric Research (NIWA) have analysed historical documents compiled by the World Whaling History project to learn about the whale's present day distribution in Australasian offshore waters.
During the 1800s, whalers recorded their daily location and strikes of whales in vessel log books, allowing today's scientists to identify almost 2000 spots where whales were killed and about 23,000 areas where whalers' searches were futile.
The information has been used to model southern right whale patterns and locate areas where the species may be in danger from shipping traffic or climate change.
NIWA marine ecologist Leigh Torres describes the data as a "gold mine."
"There is very little modern information on the offshore habitats of southern right whales," she said.
Two key areas, the Chatham Rise off New Zealand and an area off Australia, have been identified through the research as areas where shipping traffic intersects whale habitats.
The endangered whale species was heavily hunted throughout the 19th and 20th centuries to near extinction.
Conservation efforts have replenished numbers to about 10,000 in southern waters.