Effects of Mobile Trawling Gear on the Nursery and Tilefish Habitats Associated with the Shelf Edge of the New York Bight  (Year 2 of 2) Project Number: MAB 2003-05 Principle Investigators: Cowen, R. K., K. W. Able, and M. P. Fahay Region(s):  Project Summary: Issues related to fish habitat have recently gained prominence in Fishery Management Plans, NOAA/NMFS reports, industry articles and the popular press with the enactment of the Magnuson-Stevens Fishery Conservation and Management Act of 1996. Yet, despite the growing acceptance that habitat-based insight is critical to effective management, knowledge of interactions between fisheries and critical life-stage habitats (most notably, nursery habitats) is poorly understood. One topic of increased focus is the impact of mobile bottom fishing gear (e.g. scallop dredges, hydraulic dredges, beam and otter trawls) on benthic fish habitats. An area of particular importance is the deeper portion of the continental shelf and upper slope (90-300 m) where impending regualtions are being considered that would impse significant gear restrictions (ie. Otter trawling) in order to protect tilefish (Lopholatilus chamaeleonticeps) habitat. This proposed project will evaluate important fish nursery habiatats and potential impacts of mobile fishing gear in deep waters at the edge of the continental shelf of the New York Bight. This work will directly assess habitat characteristics and nursery quality for shelf edge/upper slope fishes (with a focus on tilefish, goosefish, whiting) under varying conditions. Within this habitat framework, bottom features (particularly those associated with tilefish burrows) will be examined as potential settlement/nursery grounds and how otter trawling impacts the overall quantity and quality of these critical habitats. 1) Experimentally test chronic and direct impacts of trawling on the habitat structure/community inhabitants of the tilefish burrows and associated juvenile nursery habitat. 2) Determind environmental and habitat variables most critical in defining nursery habitat for the tilefish, goosefish, whiting and other common fish species inhabiting the outer shelf/upper slope. This two year study will incorporate both observational and experimental approaches, utilizing a combination of submersible technology, surface ship collections (beam trawl) and laboratory analyses in a balanced design to quantitatively address our objectives. Briefly, the spatial distribution of juvenile fish will be quantified with respect to habitat variables including depth, sediment type and structure (e.g. tilefish burrows), and biotic variables. Particular attention will be paid to associated species in and about tilefish communities. A balanced-design, experimental study of trawling impacts on this community will follow, taking advantage of areas where trawling activity has been extensive (Chronic impact) and limited (low impact). The initial survey of juvenile distributions (and associated measurements) will serve as the pre-treatment effort (2 replicates per site). Treatment will involve complete coverage by a commercial otter trawl of experimental sites nested within Chronic and Low impact locations (n=6 sites with 2 replicates per site). Post-treatment surveys will be completed 1-4 days, 8-12 weeks, and 1 year later.

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