Recovery of the sea otter population and conflicts with shellfish users in Southeast Alaska Ginny Eckert 1, Zac Hoyt 1, Sean Larson 1, Verena Gill 2, Sunny Rice 1 1 School of Fisheries & Ocean Sciences, UAF & 2 USFWS
1988 2,167 otters Jameson 1989
23 5,845 otters, 6.6% annual increase since 1988 Esslinger and Bodkin 29
21 ~ 13, otters,~12% annual increase since 23
Collecting local knowledge Outreach meetings Website Final meeting Semi-directed interviews Do you have information about the history of sea otters in our area? If so, we would like to interview you Current information on how the sea otter population has expanded in southern Southeast Alaska is limited to aerial surveys done in 1988, 23 and 21. These surveys only provide "snapshots in time" and don't necessarily cover the entire impacted area. In order to make predictions about how the otters will move in the future, we need to get more detailed information on how they have moved in the past. We are conducting 3-6 minute interviews with people that have long-term knowledge of areas that have been recolonized by sea otters. All information will be kept confidential Sunny Rice, Alaska Sea Grant Contact Sunny Rice 772-3381 or sunny.rice@alaska.edu
Examples of observations as recorded in Google Earth colorcoded by year of observation Observations to date
Local knowledge study outline Contact participants in earlier outreach meetings/ media Interview self-selected participants Snowball sampling Targeted subjects based on location Synthesis, create timeline Follow-up meetings with participants Early June Winter 213 Spring/ Summer 213 Workshop Early 214 June - present
Fisheries affected in southern SE AK Dungeness crab, Cancer magister Red sea urchin, Strongylocentrotus franciscanus California sea cucumber, Parastichopus californicus Geoduck clam, Panopea abrupta
Dungeness crab impacts ADF&G subdistricts no longer commercially viable ADF&G subdistricts still commercially viable ADF&G subdistricts with little fishing effort or currently unaffected by sea otters Preliminary, do not distribute. Source : ADF&G 211
Dungeness crab impacts 5 Sub-district 19-42 Sub-district 15-31 Catch (x1, pounds) 4 3 2 1 1985 199 1995 2 25 21 Fishing Year (Apr-Mar) ADF&G subdistricts no longer commercially viable ADF&G subdistricts still commercially viable ADF&G subdistricts with little fishing effort or currently unaffected by sea otters Preliminary, do not distribute. Source : ADF&G 211
Sea otter persistence and viability of the commercial Dungeness crab fishery appear spatially correlated 1988 sea otter distribution 23 sea otter distribution 21 sea otter distribution ADF&G subdistricts no longer commercially viable ADF&G subdistricts still commercially viable ADF&G subdistricts with little fishing effort or currently unaffected by sea otters Preliminary, do not distribute. Source : ADF&G 211, Esslinger et al. 29 and USFWS 211.
a) 1994 After Sea Otters 5 1 15 *** 15 b) 23 c) 21 * ** Sea cucumber impacts 2 4 6 8 1 12 5 1 *** Mean +/- 95% CI Sea Cucumbers per m Shoreline 2 Before Sea Otters With Sea Otters Without Sea Otters Larson 212 MS Thesis, Larson et al. in review
a) 1994 After Sea Otters 5 1 15 *** 15 b) 23 c) 21 * ** Sea cucumber impacts 2 4 6 8 1 12 5 1 *** Mean +/- 95% CI Sea Cucumbers per m Shoreline 2 Before Sea Otters With Sea Otters Without Sea Otters Larson 212 MS Thesis, Larson et al. in review
a) 1994 * After Sea Otters 5 1 15 *** 15 b) 23 c) 21 * ** Sea cucumber impacts 2 4 6 8 1 12 5 1 *** Mean +/- 95% CI Sea Cucumbers per m Shoreline 2 Before Sea Otters With Sea Otters Without Sea Otters Larson 212 MS Thesis, Larson et al. in review
1 8 6 4 2 Mean +/! 95% CI Sea Cucumbers per Meter Shoreline Mean +/95% CI Sea Cucumbers per m Shoreline Sea cucumber density 1988 1988 1997 23 21 1997 23 21 NoNone otters Confirmed Sea Otter Occupation Confirmed Sea Otter Occupation Larson 212 MS Thesis, Larson et al. in review
Foraging data collection
Preliminary Foraging Observations from the 21, 211, and 212 field seasons 6117 foraging dives 9 sampling areas 699 foraging bouts Foraging observations Sea otter distribution 21-11 23 1997 1988 1975 Sea otter habitat (depth < 6 m) 1968-1969 Sea otter release sites Hoyt et. al in progress.
.45.4.35.3.25.2.15.1.5 Preliminary diet composition 21-212 Commercially important species as a function of sea otter colonization 1968 1988 23 21 Hoyt et. al in progress
.45 Preliminary diet composition 21-212 Non-commercially important species as a function of sea otter colonization.4.35.3.25.2.15 1968 1988 23 21.1.5 Hoyt et. al in progress
Animals are currently being relocated via fixed wing aircraft and small vessel. Sea otter movement study 3 otters (16 males and 14 females) captured and instrumented with VHF transmitters in May 211
Preliminary, do not distribute. Hoyt et. al in progress Pinta Rocks Capture locations female male Relocations female male Gill Harbor
Much information still needed! 1. Other roles of sea otters a. role in kelp forest ecosystem b. positive fishery impacts (ex. herring, rockfish, salmon) c. tourism 2. Are areas without otters suitable otter habitat? Where are they likely to expand? 3. Standing stock biomass of Dungeness crab in the region 4. Changes in fisheries e.g. compression of Dungeness fleet 5. Otter distribution and abundance pre-fur trade & shellfish distribution and abundance at that time