MEPS 328:1-15 (2006)  -  doi:10.3354/meps328001

Use of acoustic telemetry for spatial management of southern calamary Sepioteuthis australis, a highly mobile inshore squid species

Gretta T. Pecl1,*, Sean R. Tracey1, Jayson M. Semmens1, George D. Jackson2

1Tasmanian Aquaculture & Fisheries Institute, Private Bag 49, and 2Institute of Antarctic & Southern Ocean Studies, Private Bag 77, University of Tasmania, 7001 Tasmania, Australia

ABSTRACT: The use of temporal and/or spatial fishing exclusions is a common approach in managing impacts of squid fisheries targeting spawning aggregations, although there are limited data for assessing closed areas as a management tool. We evaluated the degree of protection that 2 closed areas were providing to individual spawning Sepioteuthis australis and assessed the extent of exchange between these coastal regions, separated by only 25 to 32 km. VR2 acoustic receivers were placed along the boundaries of closed areas on the east coast of Tasmania, Australia, across smaller bays within these areas, and on individual seagrass beds. Over 77000 detection events were obtained from 46 individuals over durations of up to 129 d, demonstrating that individuals spawn over several months, traveling 100s of km within the spawning areas during this time. Squid were detected at closed area boundaries; however, most were detected again on other receivers within the closed area, indicating that although squid had moved within boundary vicinities, they had not actually left the protected area. Closures of critical spawning regions during times of heightened reproductive activity will therefore achieve the desired effect of protecting spawners and will allow for egg-laying. Clearly, inshore squid species can be highly mobile during an extended spawning phase and any assessment of the management benefits of closed areas needs to explicitly consider the temporal and spatial scales of the closed area in question.

KEY WORDS: Movement · Closed areas · Squid fisheries · Spawning behavior · Tracking · Reproductive effort · Spawning duration

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