Can acoustic methods be used to monitor grenadier (Macrourid

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TitleCan acoustic methods be used to monitor grenadier (Macrouridae) abundance in the Ross Sea region?AbstractGrenadiers Macrourus spp. are the main bycatch species in the exploratory longline fishery for toothfish Dissostichus spp. in the Ross Sea, Antarctica. Ongoing monitoring tools are needed to assess stock status of grenadiers in the Ross Sea and to ensure ecological relationships are maintained. There may be potential to use fisheries acoustic methods to obtain estimates of grenadier abundance. Acoustic data collected during New Zealand's International Polar Year Census of Marine Life survey in February-March 2008 provide evidence that single targets close to the bottom over the Ross Sea slope are grenadiers. The acoustic target strength distribution of single targets was very similar to that predicted based on the measured size range of grenadiers. There are also positive correlations between acoustic backscatter and trawl and longline catches of grenadiers. Key uncertainties of the acoustic method are mark identification away from the bottom, and technical issues with low signal-to-noise ratio at depths greater than 1000 m and the acoustic dead-zone close to the bottom. AcknowledgementsThe research from RV Tangaroa was funded by the New Zealand Government under the New Zealand International Polar YearCensus of Antarctic Marine Life Project (Phase 1: So001IPY; Phase 2: IPY200701). We gratefully acknowledge project governance by the Ministry of Fisheries Science Team and the Ocean Survey 20/20 CAML Advisory Group (Land Information New Zealand, Ministry of Fisheries, Antarctica New Zealand, Ministry of Foreign Affairs and Trade, and National Institute of Water and Atmosphere Ltd.). Thanks to the officers, crew, and scientific staff on RV Tangaroa for their hard work, experience, and professionalism before, during, and after the survey. The research using data from industry vessels was funded by the New Zealand Foundation for Research Science and Technology Research Programme C01X1001: Protecting the structure and function of Ross Sea ecosystems, Antarctica. We thank the masters, crew, and scientific observers on the New Zealand toothfish vessels who collected acoustic data and to Graham Patchell (Sealord Group Ltd.) and Darryn Shaw (Sanford Ltd.) who made these data available. This paper was improved following detailed comments by three anonymous reviewers.

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1st AuthorO'Driscoll, R.AuthorO'Driscoll, R.Hanchet, S.Miller, B.Year2012JournalJournal of IchthyologyVolume52Number10Pages700-708DOI10.1134/S0032945212100098URLhttps://www.scopus.com/inward/recor.....6641041948a4c86d3bf95c33eKeywordsDissostichusMacrouridaeMacrourusMacrourus whitsoni, rank5Author KeywordsacousticsAntarcticagrenadiersMacrourus whitsonitarget strength

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TypeArticleCitationO'Driscoll, R., Hanchet, S. and Miller, B. (2012) Can acoustic methods be used to monitor grenadier (Macrouridae) abundance in the Ross Sea region? Journal of Ichthyology, 52(10): 700-708 doi:10.1134/S0032945212100098