Pa erns of Re-establishment of sea o ers in Bri sh Columbia
M. Boogaards • Mari me fur trade - 1778 • Ecologically ex nct – 1850s • Ex rpated as a species in BC - 1930
B. Gisborne Reintroduc on to Checleset Bay 1969 – 1972: Total 89 animals released K. Morrison • “[the] whole idea from the beginning was to return to the [Bri sh Columbia] coast an animal that we had destroyed” …during the same era
And in the US… • Endangered Species Act • Marine Mammal Protec on Act Sea otter range Vancouver Island sea o er popula on growth
10000
1000
18.6% per year to 1995 100
Number of ottersNumber of 8.4% per year therea er
10
1 1975 1985 1995 2005 2015 Year Central coast sea o er popula on growth 10000
1000
100
Number of ottersNumber of 11.4% per year 10
1 1975 1985 1995 2005 2015 Year • Extralimital sigh ngs. Mostly sigh ngs of single animals • Juan de Fuca Strait, Strait of Georgia, Haida Gwaii … Occupy exposed rocky coastal areas…for the most part At edge of occupied range, o en find male ra s Ra s of females (and pups) form and occupy habitats inside the established range Number of sea o ers increase in an area un l it reaches an equilibrium with available food.
Checleset Bay
Number of o ers Nuchatlitz Kyuquot
~1978 years ~now Popula on growth
10000
1000
100
Number of sea otters
10 1975 1985 1995 2005 2015 Year
Nichol et al. 2005 Diet changes in an area as popula on in an area grows to equilibrium density Sea Cucumbers are really chewy “how do I eat this!”
E. Rechsteiner Sea O er Survey 2013 Observer “A” team
Robin Abernethy Caitlin Blain Mike DeRoos Leah Honka Stan Hutchings Linda Nichol Erin Rechsteiner Leah Saville Jared Towers Jane Watson
M. Boogaards Wright Sound near entrance to Grenville Channel on July 10th, 1793 From the journal of Archibald Menzies aboard the HMS Discovery.
“We met in mid-channel with a vast crowd of sea o ers consis ng of several hundreds basking on the surface of the water with their young and moving with the de…. from the journal of Archibald Menzies aboard the HMS Discovery 1793. “Queen Charlo e’s Isles …. these islands and the shores adjacent have of late years afforded a more abundant supply of sea o er skins to the adventurous traders than any other part of the coast”. A er 1799 loca ons south of Skidegate cease to be men oned. Deple on of sea o er popula on in the south?
Places of trade men oned in ship logbooks 1787 to 1799.