MEPS 380:161-171 (2009)  -  DOI: https://doi.org/10.3354/meps07936

Complexity affects habitat preference and predation mortality in postlarval Penaeus plebejus: implications for stock enhancement

Faith Ochwada1,2,*, Neil R. Loneragan3, Charles A. Gray4, Iain M. Suthers1,2, Matthew D. Taylor1,2

1Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Science, University of New South Wales, New South Wales 2052, Australia
2Sydney Institute of Marine Science, Building 22, Chowder Bay Road, Mosman, New South Wales 2088, Australia
3Centre for Fish and Fisheries Research, School of Biological Sciences and Biotechnology, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
4Cronulla Fisheries Research Centre, NSW Primary Industries Science and Research, PO Box 21, Cronulla, New South Wales 2230, Australia

ABSTRACT: Global attempts to offset declines in fishery populations through stock enhancement have had varied levels of success due to the absence of preliminary studies to determine which habitats best support release species and the mechanisms controlling their distribution. Habitat preference was examined as a possible mechanism driving distribution of postlarval Penaeus plebejus, a current candidate prawn for stock enhancement in Australia. Occupancy of complex (artificial macrophyte) and simple (bare sand and mud) habitats by postlarvae was compared in the presence and absence of a choice between the habitats. Predation mortality was also compared amongst these habitats. P. plebejus settled into the different habitats randomly during the night, but actively selected macrophyte over the simple habitats during the day. Mortality caused by the predatory fishes Centropogan australis and Acanthopagrus australis was higher in simple habitats than in complex habitats, but was similar across habitats when large penaeid prawns, Metapenaeus macleayi (which are tactile rather than visual feeders), were used as predators. Postlarvae may select macrophyte habitats during the day to lower predation risk, but because nighttime foraging efficiency is reduced in their predators, which are primarily visual hunters, this may preclude the need of postlarvae to obtain shelter in macrophyte habitats at night. Predation mortality of stocked P. plebejus may be minimized by releasing postlarvae directly into macrophyte habitats. Studies such as these must precede all stock enhancement attempts because they identify optimal release strategies and allow ecological and financial costs of enhancement to be weighed against projected benefits, and thereby assess the practicality of enhancement as a management option.


KEY WORDS: Stock enhancement · Habitat · Predation · Macrophytes · Fisheries management · Prawns · Penaeid · Eastern Australia


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Cite this article as: Ochwada F, Loneragan NR, Gray CA, Suthers IM, Taylor MD (2009) Complexity affects habitat preference and predation mortality in postlarval Penaeus plebejus: implications for stock enhancement. Mar Ecol Prog Ser 380:161-171. https://doi.org/10.3354/meps07936

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