GOALS Vessel Surveys June - July 2013

Original provider: HDR Environmental, Operations and Construction, Inc. Dataset credits: The U.S. Navy Marine Species Monitoring Program Abstract: Features in this feature class represent animal sightings that occurred during a line-transect vessel survey ("GOALSII") for marine mammals. Real-time acoustic monitoring and recording effort was also conducted using a towed-hydrophone array and sonobuoys around-the-clock to detect and localize vocally active cetaceans. The survey was conducted from 23 June to 18 July 2013 in the U.S. Navy's Temporary Maritime Activities Area in the central GoA, east of Kodiak Island. Work was performed under HDR task order TO 22 (IDIQ contract award N62470-10-D-3011, NAVFAC LANT). There are some discrepancies between the sighting totals in the GOALS II project report and this GIS dataset. For example, the report lists 91 humpback whale sightings (295 count) on-effort, and 15 sightings (36 count) off-effort, while this dataset contains 92 sightings (296 count) on-effort, and 19 sightings (250 count) off-effort. The reason for this discrepancy is that a large non-cohesive group of humpbacks was encountered and individual perpendicular distances could not be estimated for each of the subgroups. The first approach was to stay on effort and complete a “total count” estimate for whales in a specific quadrant until the ship had gone through the majority of the animals. Once completed, it was agreed that perpendicular estimation was needed for every subgroup of whales and the ship altered course and reran the trackline in the opposite direction for observers to get position fixes on as many of the animals/subgroups as possible. On the second pass, the density of whales was not as high and thus the numbers may have differed when compared to the first pass that was ultimately adjusted to be an “off-effort” sighting. Minor discrepancies also exist in sighting counts for other species, in most cases this is the result of how resightings were recorded (instances where the same animal group was observed more than once).

Citation: Ampela, K. and G. Miller-Francisco. 2017. GOALS Vessel Surveys June - July 2013. Version 1.0.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/80c82ab0.

Published: October 08, 2025 at 01:42

URL: http://ipt.env.duke.edu/resource?r=zd_1165