کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4532828 1325150 2010 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The spatial structure of local surficial sediment characteristics on Georges Bank, USA
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
The spatial structure of local surficial sediment characteristics on Georges Bank, USA
چکیده انگلیسی

Georges Bank is one of the world’s most productive marine ecosystems, but the lack of accurate broad-scale sediment maps presently limits habitat assessments and spatial fisheries management. From 1999 to 2009 we surveyed 36,669 km2 of Georges Bank using 2.8 and 0.6 m2 quadrats viewed with live underwater video (video quadrats). The sediment types observed in 61,604 quadrats were used to map and evaluate spatial structure of local surficial sediment coarseness, dominance, heterogeneity, and maximum size characteristics at a 1 km2 spatial resolution. Sand dominated sediment covered 62% of the study area, and there was a logarithmic decline in coverage by larger, coarser and more heterogeneous sediments. Gravel dominated sediments covered 38% of the study area and were more than twice as abundant as previously estimated. A 12,890 km2 swath of gravel dominated seabed stretched from Cape Cod to northeastern Georges Bank consistent with estimates of prehistoric glacial extent. Within the swath there were 14 large gravel outcrops (15–2743 km2) . This work increases the spatial resolution of sediment information available for habitat assessments and spatial fisheries management on Georges Bank by two orders of magnitude. The four sediment characteristics we evaluated support further detailed investigations of the Bank’s benthos, including the influences of surficial sediment characteristics on species and community distributions, and more spatially accurate estimates of seabed roughness. Finally, this work demonstrates the use of video quadrats as an alternative to traditional grab sampling and modern acoustic sampling for continental shelf-scale mapping.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Continental Shelf Research - Volume 30, Issue 17, 15 October 2010, Pages 1840–1853
نویسندگان
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