SCIENTIFIC
Results of tagging project on Kenya’s striped- and black marlin By Sheena Carnie
T
HE black marlin is known as one of the fastest fish in the ocean, with sailfish and striped marlin other clear contenders for that title. Whoever takes the prize, black marlin swimming speeds as high as 129km/h have been recorded. But when you’re targeting a specific species, one of the most crucial questions is not how fast they swim, but rather, “What areas do they frequent?” Charter captains in Kenya wanted to know more about the movements of the
black- and striped marlin that inhabit the western Indian Ocean, so a few years ago they contacted the scientists from Marine Megafauna Found-ation (MMF) to formulate a plan. Together they undertook a tagging research project on black marlin (Istiompax indica) and striped marlin (Kajikia audax) off Kenya between 2015 and 2019. They hoped the results of this project would answer some of the questions surrounding the movements and habits of these highly migratory species. Marlin fishing boat captains
deployed the pop-up archival satellite tags, and the project was overseen by a team of MMF scientists, led by Dr Christoph Rohner. Forty-nine black marlin weighing between approximately 40and 227kg were tagged in this way. Only 34 of the black marlin tags transmitted data that could be used, but they provided a great deal of useful and interesting information. Forty striped marlin weighing between 8- and 100kg were tracked, with nine other tags not reporting data. The reasons tags didn’t transmit usable data included the fish presumably dying as they appeared to stay at a
