USGS BOEM PaCSEA GPS Data

To ensure comparable spatial and temporal coverage with similar historic datasets, we flew 32 east-west-oriented uniform transects (spaced at 15' latitude [27.8-km] intervals) when possible to the 2000-m isobath (includes shelf, slope, and rise waters). At the request of BOEM, we included six focal-area surveys nested within the overall broad transect survey area. Each focal-area survey consisted of ten 25-km, parallel transect lines targeting shelf waters and spaced at 6-km intervals. This pattern (broad survey lines and Focal Area survey lines) was surveyed during each oceanographic season: summer (June-July), fall (September-October), and winter (January-February) during 2011 and 2012. Aerial survey methods follow Mason et al. (2007) with slight modifications. Specifically, we recorded all sightings of marine animals, vessels, and floating objects from twin-engine, high wing aircraft (Partenavia P-68, Aspen Helicopters, Oxnard, CA, or Commander AC-500, GoldAero, Arlington, WA) along pre-determined 150-m (75 m per side) strip transects at 60-m above sea level. Surveys were flown at 160 km h-1, and we used a Global Positioning System (GPS) unit linked to a laptop computer that allowed us to simultaneously collect coordinates (WGS-84 map datum), sea surface temperature (SST, degrees Celcius [°C]) determined via a belly-mounted pyrometer, and ocean color data via an onboard radiometer (see Remote sensing methods).We maintained the same two trained observers throughout the study. During individual surveys, observers frequently verified strip widths using hand-held clinometers. Observations generally were discontinued when glare exceeded &amp;gt;25% of the field-of-view or if sea state exceeded Beaufort 5 (29-38 km h-1wind speed). Observations were recorded into hand-held digital audio recorders. The third (non-dedicated) observer assisted the pilot with navigation, monitored sensor data, and maintained the onboard computer. Observations of species or individuals identified to nearest taxon included number of individuals, time, pre-coded behaviors, flight direction, and interspecies or vessel associations. Digital recordings of observations were archived and used by observers after surveys to enter data into a customized Graphical User Interface in ACCESS (Microsoft). Observation data were proofed after transcription to ensure accuracy or to resolve inconsistencies. Species observations were linked with GPS-based tracklines generated at 1 to 3 second intervals. Based on variations in the lag-time between sightings and recordings, we estimate that observations have a nominal along-trackline spatial accuracy of 222 m, based on a five-second lag at 160 km hr-1survey speed.This file geodatabase table contains the flight track data from the aerial surveys. This data includes the date and time (DATETIME), the latitude (LAT) and longitude (LON), the number of observers (NOOBS), the left and right observers initials (LObs, RObs), the sea state condition (Baeufort), the sea surface temperature (SST), the focal transect number (FocTran), the broad transect number (BroTran), the lines flown between transects (DeadTran), and a unique ID number (NewIDNum).References:Bonnel, M.L., C.E. Bowlby, and G.A. Green. 1992. Chapter 2: Pinniped Distribution and Abundance off Oregon and Washington, 1989 – 1990. In: J.J. Brueggeman (Ed.) Oregon and Washington Marine Mammal and Seabirds Surveys. Final Report, OCS Study MMS 91-0093, Pacific OCS Region, Minerals Management Service, US Department of the Interior, Los Angeles, CA. Briggs, K.T., W.M. Breck Tyler, D.B. Lewis, and D.R. Carlson. 1987. Bird Communities at Sea Off California 1975 to 1983. Studies in Avian Biology No. 11. The Cooper Ornithological Society. 74 pp.Briggs, K.T., D.H. Varoujean, W.W. Williams, R.G. Ford, M.L. Bonnel, and J.L. Casey. 1992, Chapter 3: Seabirds of the Oregon and Washington OCS, 1989 – 1990. In: J.J. Brueggeman (Ed.) Oregon and Washington Marine Mammal and Seabirds Surveys. Final Report, OCS Study MMS 91-0093, Pacific OCS Region, Minerals Management Service, US Department of the Interior, Los Angeles, CA. Green, G.A., J.J. Brueggeman, R.A. Grotefendt, and C.E. Bowlby. 1992, Chapter 1: Cetacean Distribution and Abundance off Oregon and Washington, 1989 – 1990. In: J.J. Brueggeman (Ed.) Oregon and Washington Marine Mammal and Seabirds Surveys. Final Report, OCS Study MMS 91-0093, Pacific OCS Region, Minerals Management Service, US Department of the Interior, Los Angeles, CA.

Tags: biota, environment, oceans, seabirds-aerial-survey-flight-track, usgs-5577360be4b032353cba3c43
Organization: Department of the Interior