File Geodatabase Feature Class
Tags
abundance, oceans, mammal, harbor seal, coastal, trend, distribution, environment, haul-out, California, biota, monitoring, Phoca vitulina, population
The purpose of this project is to survey the abundance and distribution of harbor seals (Phoca vitulina richardsi) at all known haul-out sites in California coastal waters and offshore islands during the peak of the molt cycle.
In May of 2001, the California Department of Fish and Game (CDFG) conducted an aerial photographic survey of the California coast and the offshore Channel Islands to obtain a minimum estimate of the population of harbor seals (Phoca vitulina richardsi) living in California. The developed photographs were examined to count the number of harbor seals present and determine the location of each haul-out site by comparison to photos taken in previous surveys. This survey was successful in obtaining nearly complete coverage of all known haul-out areas. The 1995 survey was the last complete coverage. The total county for 2001 is 12,312 harbor seals. This result is the lowest ever recorded by CDFG for a combined count of the mainland and all offshore islands. The California Department of Fish and Game (CDFG) conducted two surveys in 2002 in an attempt to provide better coverage and to lessen the chances of weather related problems. A total of 16 days were scheduled for aerial surveys from May 19 to July 19, 2002. Total count for Survey 1 was 10,541 harbor seals, while that for Survey 2 was 8,374 harbor seals. Camera problems that produced un-readable film and poor weather conditions prevented a complete assessment by either survey. The lack of complete coverage by either Survey 1 or 2 limited the total number of harbor seals counted. This is especially true in areas where past surveys revealed high concentrations of seals such as the northern Channel Islands and Point Reyes - Sonoma County coast. The California Department of Fish and Game (CDFG) conducted two aerial surveys in 2003 in an attempt to provide better coverage and to lessen the chances of weather related problems. A total of 20 days were scheduled for aerial surveys from May 25 to July 20, 2003. Complete coverage was achieved in both surveys. This was the first time CDFG conducted these surveys using a digital imaging camera. Total count for Survey 1 was 17,415, while that for Survey 2 was 17,778 harbor seals.
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License: This work is licensed under Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ ). Using the citation standards recommended for BIOS datasets ( https://www.wildlife.ca.gov/Data/BIOS/Citing-BIOS ) satisfies the attribution requirements of this license.
Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.
Extent
West | -124.514073 | East | -116.925231 |
North | 42.008972 | South | 32.756047 |
Maximum (zoomed in) | 1:5,000 |
Minimum (zoomed out) | 1:150,000,000 |
License: This work is licensed under Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ ). Using the citation standards recommended for BIOS datasets ( https://www.wildlife.ca.gov/Data/BIOS/Citing-BIOS ) satisfies the attribution requirements of this license.
Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.