Tectonic and glacial related seafloor geomorphology as possible demersal shelf rockfish habitat surrogates¡ªExamples along the Alaskan convergent transform plate boundary

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• 作者：H. Gary Greene^a ; ^b ; ^{greene@mlml.calstate.edu} ; Victoria M. O’ ; Connell^c ; Cleo K. Brylinsky^d
• 关键词：Surrogates ; Marine benthic habitats ; Tectonics ; Glacial ; Alaska ; Groundfish
• 刊名：Continental Shelf Research
• 出版年：2011
• 出版时间：15 February, 2011
• 年：2011
• 卷：31
• 期：2_supp_S
• 页码：S39-S53
• 全文大小：1K

文摘

Seafloor geology plays a major role in habitat formation and can be used to remotely identify key habitats for some commercially important fish species. We have used a combination of side-scan sonar mosaics, multibeam bathymetry, and backscatter data, and in situ observations and video from the submersible Delta to investigate marine benthic habitats in the Eastern Gulf of Alaska. The intent of this paper is to review the results of previous marine benthic habitat mapping efforts completed by us along the transform plate boundary of Alaska and to present new information that show how volcanic, plutonic, and glacial submarine geomorphology can be used to identify potentially important discrete habitat areas. Demersal shelf rockfish, a seven-species management complex of nearshore rockfish, including yelloweye rockfish (Sebastes ruberrimus), are found in rugged and highly rugose geomorphologic features. Eroded volcanic edifices, lava fields, and a pit crater, as well as a small shutterridge, deformed and differentially eroded sedimentary bedrock, and highly fractured and faulted plutonic rock outcrops are features that attract adult rockfish. Volcanic edifices that lie along the leaky (magma-conducting) Fairweather transform fault system intercept ocean currents, in turn producing upward eddies that bring nutrients to species residing on the features. We show that geologic processes such as fault deformation, volcanism, and glaciation are critical to the development of Essential Fish Habitats (EFH) for demersal shelf rockfish. Our work is the first attempt to determine a common geologic link between desperate commercial fishing areas in SE Alaska, USA, and to suggest how tectonic and glacial processes, including sea level rise and transgression, can be used to identify seafloor geologic characteristics as surrogates for marine groundfish habitats.