USGS
USGS Western Ecological Research Center

Number of Sea Otter Strandings, 1983-2002 and
Relative Number of Sea Otter Strandings, 1983-2002


The left graph below shows the actual number of sea otters that have stranded per year since 1983. The high number of strandings in 1983 and 1984 are believed to be due to incidental bycatch in a nearshore gill and trammel net fishery before it was restricted to deeper waters.

If the population of sea otters were increasing, the number of strandings would be expected to increase as well. Therefore a more meaningful figure (second graph) shows the number of strandings relative to our best index of the sea otter population in California - the annual spring range- wide count. This simply shows the number of strandings divided by the number of sea otters counted during the spring count times 100. Notice that from 1985 to 1994 - a period when the population was growing - the number of strandings was between 4% and 6% of the spring count. Since 1994 the number of strandings has been higher than 6% each year and averaged 8% of the spring count.

 
Graph of the number of sea otter strandings documented each year Graph of the number of sea otter strandings each year relative to our best index of the sea otter population in California

 

 
YearTotal
Strandings		Spring Count% of
Spring Count
198312012779.40
198412813039.82
19857013615.14
19867815864.92
19878416615.06
19888217254.75
19898818564.74
19909816805.83
19917819414.02
199211021015.24
199312522395.58
199412823595.43
199516123776.77
199618122787.95
199715222296.82
1998213211410.08
199918720908.95
200015323176.60
200118321618.47
200218121398.46
2003262250510.46

 

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Last update: 16 January 2003