Color-Encoded Image of 3-m Gridded Hill-Shaded Bathymetry From Long Island Sound off Branford Connecticut (H11043_UTM18_3MBATHY.TIF, UTM)

The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology.

Anthropogenic wastes, toxic chemicals, and changes in land-use patterns resulting from residential, commercial, and recreational development have stressed the environment of the Sound, causing degradation and potential loss of benthic habitats (Koppelman and others, 1976; Long Island Sound Study, 1994). Detailed maps of the sea floor are needed to help evaluate the extent of adverse impacts and to help manage resources wisely in the future. Therefore, in a continuing effort to better understand Long Island Sound, we have regridded and interpolated this NOAA bathymetric survey into a complete-coverage acoustic image of the sea floor. The image presented herein covers a 41.1 km square area of the sea floor in north-central Long Island Sound off Branford, Connecticut and was produced from data collected during NOAA survey H11043.

This imagery may serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. This bathymetry may also serve as a base map for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretation of point measurements.

美国地质调查局（U.S. Geological Survey）与国家海洋和大气管理局（National Oceanic and Atmospheric Administration，NOAA）以及康涅狄格州环境保护部合作，针对美国东海岸大型河口湾——长岛海峡的海底完成了详细地质填图工作。该海峡毗邻美国人口最密集的区域。本系列研究基于1982年启动的康涅狄格州合作研究项目开展。当前研究阶段的核心方向包括海底沉积物分布、调控沉积物分布的动力过程、近岸环境问题，以及底栖群落结构（benthic community structures）与海底地质的关联。

受住宅、商业及休闲开发引发的人为废弃物、有毒化学品排放与土地利用模式改变的影响，长岛海峡的生态环境已承受沉重压力，导致底栖栖息地（benthic habitat）退化乃至潜在丧失（Koppelman等，1976；长岛海峡研究报告，1994）。当前亟需高精度海底地图，以评估不利影响的波及范围，并为未来资源的科学管理提供支撑。为此，为进一步深化对长岛海峡的认知，研究团队对NOAA的水深测量（bathymetric survey）数据进行了重新网格化与插值处理，生成了全覆盖的海底声学影像（acoustic image）。本次公开的影像覆盖康涅狄格州布兰福德附近长岛海峡中北部的41.1平方千米海底区域，数据源自NOAA的H11043号勘测任务。

该声学影像可服务于多重科研与管理目标：（1）刻画海底地质的空间变异性——这是调控底栖生境多样性的核心控制因素之一；（2）加深对调控海底沉积物分布与运移、底栖生境及相关内生群落结构分布的动力过程的理解；（3）为后续的研究、监测与管理活动提供精细化的基准框架。此外，该水深数据可作为后续沉积学、地球化学及生物学观测的基础底图，因为精准的环境背景信息对于采样点位的选取与单点测量结果的准确解读均具有重要意义。