Horizontal and vertical movements of white marlin, Kajikia albida, tagged off the Yucatán Peninsula

Abstract

The white marlin, Kajikia albida, is a highly migratory, prized sport fish of conservation concern. Improved understanding of white marlin ecology, including habitat use, will inform management measures. To improve white marlin movement knowledge in a region with limited information, we tagged 18 individuals off the eastern Yucatan Peninsula, Mexico with pop-up satellite archival transmitters. Tracks lasting 9-328 d, yielded data across 1277 d, and covered distances of 891-10 579 km. Horizontal movements varied greatly with ten individuals remaining in the Gulf of Mexico/northwestern Caribbean and eight individuals entering the western North Atlantic. Although white marlin experienced a temperature range of 10.0-33.6 °C, the majority of time was spent in waters >24 °C. Marlin displayed diel diving patterns with deeper dives occurring more frequently during the daytime. As water columns warmed, dive duration, maximum daily depth, and dive depth all increased. As a result, 18% of the time was spent at depths >100 m in the warmest water columns compared with <1% in the coldest water columns. Although the thermal characteristics of the water column greatly influence white marlin diving behaviour, the generally shallow distributions provide a way of separating white marlin from important fishery species.