14BIM02_SBB_tracklines: Shapefile of the Single-beam Bathymetry Tracklines Surveyed in 2014 near Breton Island, Louisiana

As part of the Barrier Island Monitoring Project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off Breton and Gosier Islands, Louisiana, in July and August of 2014. To assist the United States Fish and Wildlife Service (USFWS) with restoration planning efforts, the USGS was tasked with answering fundamental questions about the physical environment of the southern Chandeleur Islands, including the geology, morphology, and oceanography. Baseline data needed to answer these questions was either insufficient or missing in the area. The USGS conducted a comprehensive geologic investigation in the summer of 2014 by collecting geophysical and sedimentological data.
Breton Island, located at the southern end of the Chandeleur Island chain, Louisiana, was recognized as a natural and globally important nesting sanctuary for several bird species and was established as the Breton National Wildlife Refuge (NWR) in 1904. The aerial extent of Breton Island has diminished 90% since 1920. Land loss is attributed to ongoing relative sea-level rise, diminished sediment supply, and storm impacts. The bird population on Breton Island has also declined over the years, most notably after Hurricane George in 1998 and Hurricane Katrina in 2015, which completely submerged the island. Despite the decreasing habitable acreage, migratory seabirds continue to return and utilize Breton Island. To prevent the island from being completely submerged in the future and to protect, stabilize, and provide more nesting and foraging areas for the birding population, the USFWS is proposing a restoration effort to rebuild Breton Island to its pre-Katrina footprint.
This Data Series serves as an archive of processed interferometric-swath, single-beam bathymetry, and side-scan sonar data collected in the nearshore of Breton and Gosier Islands, NWR, Louisiana. The data were collected during two USGS cruises (USGS Field Activity Numbers 2014-314-FA and 2014-317-FA) in July and August 2014. Geographic Information System data products include: a 100 meter-cell-size interpolated bathymetry grid surface, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee (FGDC) metadata.

作为屏障岛监测项目（Barrier Island Monitoring Project）的组成部分，美国地质调查局（U.S. Geological Survey, USGS）圣彼得堡海岸与海洋科学中心的科研人员于2014年7月至8月，在路易斯安那州布雷顿岛与戈西尔岛近岸海域开展了近岸地球物理勘测。为协助美国鱼类及野生动物管理局（United States Fish and Wildlife Service, USFWS）推进修复规划工作，USGS承接了针对尚德利尔群岛南部物理环境的基础研究任务，研究内容涵盖地质学、地貌学与海洋学相关方向。该区域此前用于解答此类问题的基线数据要么存在不足，要么完全缺失。2014年夏季，USGS通过采集地球物理与沉积学数据，完成了一次全面的地质调查工作。

布雷顿岛坐落于路易斯安那州尚德利尔群岛链的南端，是多种鸟类的天然全球重要筑巢栖息地，并于1904年被设立为布雷顿国家野生动物保护区（Breton National Wildlife Refuge, NWR）。自1920年以来，布雷顿岛的陆地面积已缩减90%，土地流失主要归因于持续的相对海平面上升、沉积物补给减少以及风暴冲击。多年来布雷顿岛的鸟类种群数量持续下降，尤以1998年乔治飓风与2015年卡特里娜飓风过后最为显著，后者曾完全淹没该岛。尽管可栖息面积不断缩减，迁徙海鸟仍会返回并利用布雷顿岛。为防止该岛未来彻底被淹没，并保护、稳定该区域，同时为鸟类种群提供更多筑巢与觅食区域，USFWS正提议开展修复工程，将布雷顿岛恢复至卡特里娜飓风前的范围。

本数据集系列作为经处理的干涉测量条带测深、单波束测深与侧扫声呐数据的存档，采集自路易斯安那州布雷顿岛与戈西尔岛国家野生动物保护区的近岸海域。数据由USGS两次科考航次（USGS野外活动编号：2014-314-FA与2014-317-FA）于2014年7月及8月采集完成。地理信息系统数据产品包括：100米网格分辨率的插值测深栅格表面、测线地图与点数据文件。附加文件涵盖误差分析地图、野外活动采集系统日志，以及正式的联邦地理数据委员会（Federal Geographic Data Committee, FGDC）元数据。