St. Johns & Putnam counties 1994-1995 Manatee Distribution Survey Theoretical Flight Path

Aerial distribution surveys are used by marine mammal biologists from FWC and other agencies to determine the seasonal distribution of manatees. Most surveys are conducted from small, four-seat, high-winged airplanes (Cessna 172 or 182) flying at a height of 500-1000 ft at a speed of 70-90 kts. Small helicopters may be used instead of fixed wing aircraft in urban areas or where waters are particularly opaque and hovering may be required. Surveys are flown along a standardized, theoretical flight route, which was designed to cover all likely manatee habitats in the study area. This "theoretical flight path" indicates the area that was covered during each survey, but it may not be the actual flight route flown on every survey. GPS tracklines recorded during surveys may be available for some flights. The survey area includes all waters of St. Johns River in Duval, Clay, St. Johns and Putnam counties from the southwestern portion of Duval County south to the Cross-Florida Barge Canal, which is south of Palatka and Little Lake George. Doctors Lake, Julington, Durbin, Black, Trout, Six-Mile, Deep, and Rice creeks; the Cross-Florida Barge Canal; and creeks and waterways around the Seven Sisters Islands and Murphy Islands were included in the survey.来自佛罗里达鱼类与野生动物保护委员会（FWC）及其他相关机构的海洋哺乳动物生物学家，借助航空分布调查来确定海牛的季节性分布格局。绝大多数调查均采用四座高翼小型固定翼飞机（塞斯纳172或塞斯纳182）开展，飞行高度设置为500至1000英尺，飞行速度为70至90节。在城市区域或水体透明度极低、需要悬停作业的场景中，可使用小型直升机替代固定翼飞机。调查沿标准化理论飞行航线开展，该航线的设计覆盖了研究区域内所有潜在的海牛栖息生境。该“理论飞行路径”划定了每次调查所覆盖的区域范围，但实际执行时，每次调查的飞行航线未必完全与之重合。部分飞行任务会留存调查期间记录的GPS航迹数据。本次调查区域涵盖杜瓦尔、克莱、圣约翰以及普特南县境内的圣约翰河全段，范围从杜瓦尔县西南部向南延伸至位于帕拉特卡与小乔治湖以南的跨佛罗里达驳船运河。多克托湖、朱灵顿溪、德宾溪、布莱克溪、特劳特溪、六英里溪、迪普溪以及赖斯溪；跨佛罗里达驳船运河；以及七姐妹群岛与墨菲群岛周边的溪流与航道，均纳入本次调查范围。