Aerial Surveys of Juvenile Herring, Prince William Sound, 2010-2017, EVOS Herring Program

• Main Authors: Pegau, Scott, Brown, Evelyn
• Format: Dataset
• Language: English
• Published: Axiom Data Science 2019
• Subjects: Evelyn; Orca; Alaska
• Online Access: https://dx.doi.org/10.24431/rw1k330; https://search.dataone.org/#view/10.24431/rw1k330

These data are part of the Herring Program of the Exxon Valdez Oil Spill Trustee Council (EVOSTC), which is a multi-faceted study to determine why herring populations in Prince William Sound (PWS) remain depressed since the early 1990s. Flying 1000 feet in the air, following the contours of the Prince William Sound shoreline, schools of juvenile herring are easily identified and measured during the long summer days. Surveying from the air has the benefit of covering a large geographic area while minimizing the disturbance of herring. Aerial surveys cover waters that are too shallow for acoustic survey vessels to access. Aerial surveys were conducted from 2010 to 2012 during the months of June, July, and August as part of the PWS Herring Survey program by Evelyn Brown (EVOSTC project number 10100132-F). Beginning in 2013 (under EVOSTC projects 12120111-O, 14120111-R, and 16120111-O) surveys have been conducted in June focused on age-1 herring and in July in support of the project entitled Forage Fish Distribution, Abundance, and Body Condition in Prince William Sound, 2012-2015: Gulf Watch Alaska Pelagic Component (EVOSTC projects 12120114-O, 14120114-O, and 16120114-O). Each monthly survey takes about 10 to 12 days, 3 to 5 hours each day, in a Cessna 185 float plane. This dataset is a comma-separated value (csv) file containing the total number of age-1 herring schools by size (small, medium, large, and x-large) as determined from the 2010-2017 aerial surveys. When multiple surveys of an area were conducted only the first set of observations were used in the calculation of numbers of schools. During the course of the survey, the aerial flight tracks, numbers of fish schools, species of fish, school size, marine mammals, marine birds, and notes about unusual oceanographic sightings were recorded electronically and on paper. The raw aerial survey data files (csvs, gpx flightlogs, shapefile flightlogs, text notes and photos) are available from the Principal Investigator upon request. Formats of the raw datasets changed over the years of the survey (refer to Usability Report section) and include related files containing time, location, school extent, number of schools, species, herring estimated age, and observations of whales (orca, humpback, minke, grey, and fin). GIS software is necessary to view raw data from all years.