Center for Systems Integration and Sustainability

Baleen whale populations have increased around the world after the end of commercial whaling in the 1980s. Anecdotes from local inhabitants of the Falkland Islands tell of an increase in whale sightings after an almost com- plete absence. However, no long-term monitoring exists to assess such recovery. With increasing maritime activ- ities around the Islands, local managers need to understand the status and distribution of baleen whales to avoid impeding the potential recovery process. In the complete absence of scientific data, harvesting local ecological knowledge (LEK) from residents could provide means to assess whether whale numbers are increasing. We col- lected historical knowledge and mapped historical observations through structured interviews with 58 inhabi- tants and filtered observations for the highest reliability. We also collated existing historical catch and sighting data to compare species composition in inshore and offshore waters. A total of 3842 observations were compiled from the 1940s to 2015. This collation of information provided first-time evidence on the return of the whales in the Falkland Islands' waters. There was a clear increase in numbers of whales sighted, from no observations in the 1970s to 350 observations between 2010 and 2015 for similar effort, mostly of endangered sei whales (Balaenoptera borealis) and fin whales (Balaenoptera physalus). We mapped contemporary whale sighting hotspots to inform current marine spatial planning efforts. The use of LEK is highlighted here as a useful way to gain a better understanding of changes in the status of threatened species when no scientific monitoring has been conducted.