Researchers have used Marmite as bait to successfully attract fish from some of the world’s deepest lakes, potentially identifying a new species in the process. The investigation, led by Dr. Roe Stuart of the University of Otago in New Zealand, involved lowering baited traps on ropes hundreds of feet into the depths of four of the country’s deepest lakes.

The traps, coated with the yeast extract spread known as Marmite, were submerged overnight before being retrieved the following day. Each trap contained fish, including small, iridescent specimens resembling koaro. Koaro are known for their unique ability to climb steep waterfalls, and they are often harvested commercially as whitebait.

Dr. Stuart’s team plans to conduct genetic testing to determine if these caught fish represent a previously unidentified species. The use of Marmite, a product with a strong, distinctive scent, proved to be an effective lure. When asked about testing other similar spreads such as Vegemite, Dr. Stuart responded wryly, noting that she preferred not to take the risk.

This approach of using Marmite as bait marks an innovative method in freshwater fish research, particularly in challenging environments where deep-water sampling can be difficult. The findings could provide new insights into the biodiversity of New Zealand’s freshwater ecosystems and contribute to knowledge about species distribution in deep lake habitats.