University Of Tasmania
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Environmental influences and ontogenetic differences in vertical habitat use of black marlin (lstiompax indica) in the southwestern Pacific

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posted on 2023-05-19, 13:23 authored by Williams, SM, Holmes, BJ, Sean TraceySean Tracey, Pepperell, JG, Domeier, ML, Bennett, MB
The black marlin (Istiompax indica) is a highly migratory billfish that occupies waters throughout the tropical and subtropical Indo-Pacific. To characterize the vertical habitat use of I. indica, we examined the temperature-depth profiles collected using 102 pop-up satellite archival tags deployed off the east coast of Australia. Modelling of environmental variables revealed location, sea-surface height deviation, mixed layer depth and dissolved oxygen to all be significant predictors of vertical habitat use. Distinct differences in diel movements were observed between the size classes, with larger size classes of marlin (greater than 50 kg) undertaking predictable bounce-diving activity during daylight hours, while diving behaviour of the smallest size class occurred randomly during both day and night. Overall, larger size classes of I. indica were found to use an increased thermal range and spend more time in waters below 150 m than fish of smaller size classes. The differences in the diving behaviour among size classes were suggested to reflect ontogenetic differences in foraging behaviour or physiology. The findings of this study demonstrate, for the first time to our knowledge, ontogenetic differences in vertical habitat in a species of billfish, and further the understanding of pelagic fish ecophysiology in the presence of global environmental change.


Publication title

Royal Society Open Science



Article number









Institute for Marine and Antarctic Studies


The Royal Society Publishing

Place of publication

United Kingdom

Rights statement

Copyright 2017 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0)

Repository Status

  • Open

Socio-economic Objectives

Fisheries - wild caught not elsewhere classified