Steller Sea Lions at Fort Ross
Joe Mortenson Prepared for Fort Ross Conservancy Marine Mammal Monitoring Program
Evolution in North Pacific Enaliarctos
From Mammal Evolution an Illustrated Guide Prehistoric Trends Present Steller Sea Lion Sites
Western Steller Sea Lion Stocks Historical Trends in California for STSL Map Drawn by Bonnet 1920 Central California STSL 1982-2009 Ano Nuevo and the Farallones
700
600
500
400
300
200
100
0 1982 1990 1991 1992 1994 1996 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 Stellers and California Sea Lions Stellers Down and Californias up
100000
90000
80000
70000
60000
50000 Eumetopias Zalophus 40000
30000
20000
10000
0 1927 1928 1930 1936 1938 1946 1947 1958 1964 1965 1969 1970 1980 1981 1982 1987 Is Fort Ross In Northern or Central California? Eastern Stock STSL Counts California Sea Lion Pups Increase 2001 Central California STSL Population at Sea and on Land Fort Ross Fort Ross Maximum Steller Sea Lions 1999 2002
45
40
35
30
25
20
15
10
5
0 Average Fort Ross Steller Sea Lions Over Months
25
20
15
10
5
0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average Fort Ross Bulls Over Months
9
8
7
6
5
4
3
2
1
0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average Fort Ross Stellers Over Hours
16
14
12
10
8
6
4
2
0 8 9 10 11 12 13 14 15 16 Average Fort Ross Pups Over Hours
3
2.5
2
1.5
1
0.5
0 8 9 10 11 12 13 14 15 16 Maximum California Sea Lions Over Hours
350
300
250
200
150
100
50
0 8 9 10 11 12 13 14 15 16 Maximum California Sea Lions Over Hours
Max Of Zalophus 350
300
250
200
150 Max Of Zalophus
100
50
0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Issues
• What is the trend for Fort Ross’ Steller numbers? • What is the relation between Californias and Stellers at Fort Ross? Do they compete for space? • Is Fort Ross a colony? Are there pups present, and if so, when? • What will global warming do to the sea lions?
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