GEORGES BANK BENTHIC HABITAT Sample Clauses

GEORGES BANK BENTHIC HABITAT. Sedimentary composition of the ocean floor is highly variable in the Gulf of Maine, Georges Bank, and southern New England (Figure 9). Sediments differ in origin, texture, size, transport mechanism, and distribution. Bottom habitats in New England waters are heterogeneous, characterized by patchy surficial sediment composition and irregular topographic peaks. The following classification, excerpted from the NEFMC EFH Omnibus Amendment, 1998, is useful in forming an overview of habitat conditions in New England waters, based on habitat complexity. Its descriptions can support the information in Figure 7 and Table 4 in forming a picture of the surficial conditions in the affected environment: • smooth sand or mud: areas with no vertical structure • sand waves: troughs and peaks provide shelter from current; previous observations indicate species such as xxxxxxx position themselves on the downcurrent sides of sand waves where they ambush drifting demersal zooplankton and shrimp • biogenic structures: xxxxxxx, depressions, cerianthid anemones, hydroid patches; features that are created and / or used by mobile fauna for shelter • shell aggregates: provide complex small interstitial spaces for shelter; shell aggregates also provide a complex high contrast background which may confuse visual predators • pebbles and cobbles: provide small interstitial spaces and may be equivalent in shelter value to shell aggregates • pebbles and cobbles with attached megafauna: attached fauna such as sponges provide additional spatial complexity for a wider range of size classes of mobile organisms • partially buried boulders: while not providing small interstitial spaces or deeper crevices, partly buried boulders exhibit high vertical relief; the shelter value of this type of habitat may be less or greater than previous types based on the size class and behavior species • piled boulders: this habitat provides deep interstitial spaces of variable sizes. Emergent epifauna often contribute to the survivorship of marine organisms because of the increased cover and habitat complexity they provide (NEFMC, 1998). Bottom topography, along with sediment type, may also influence the distribution and abundance of benthic, demersal, and pelagic organisms. Geologic features such as submarine canyons, rock ledges, and topographic peaks are potential habitat components that are potentially important to a variety of marine organisms. Bottom topography is often associated with particular sedimen...