Steller Sea Lion Critical Habitat Dr. Randall Davis Texas A&M Univ. Mr. Don Calkins Alaska SeaLife Center Ms. Holly Briggs Texas A&M University

Collaborators Mr. Jason Waite –Alaska SeaLife Center Dr. Robert Leben –The Colorado Center for Astrodynamic Research, University of Colorado, Boulder

What is Critical Habitat? Critical habitat is defined in the US Endangered Species Act as: –“(i) the specific areas within the geographic area occupied by the species, at the time it is listed in accordance with the provisions of section 4 of this Act, on which are found those physical or biological features (I) essential to the conservation of the species and (II) which may require special management considerations; and –(ii) specific areas outside the geographic area occupied by the species at the time it is listed in accordance with the provisions of section 4 of this Act, upon the determination by the Secretary that such areas are essential for the conservation of the species.”

Critical Habitat Study Critical habitat definition 1992 Recovery team –Recommended 3 aquatic foraging areas –Aquatic areas 3000ft seaward of rookeries and major haulouts 1993 NMFS –Designate 3000ft zones seaward, landward and upward of all rookeries and haulouts in Alaska and seaward and upward of all rookeries in CA and OR –Designated 20 nm zones seaward of all rookeries and major haulouts west of 144 o Courtesy National Marine Fisheries Service

Critical Habitat Designation Courtesy National Marine Fisheries Service

What habitats are critical? What do we know? Adult females at rookeries forage predominately within 20 nm of rookeries while attending pups June to November. Weaned juveniles and adult females move around a great deal and may forage as far as 500 km offshore. They utilize areas out to the continental shelf.

Critical Habitat Study Objectives 1. To monitor Steller sea lion movements and diving behavior using satellite telemetry To characterize Steller sea lion habitat associations by combining tracking and dive data with bathymetry, and TOPEX/POSEIDON and ERS satellite remote sensing of hydrographic features. To compare areas shown to be important or critical to sea lions in this study to those areas currently protected as designated critical habitat by NMFS. Photo by J. Waite

Methods Critical Habitat Study Methods Capture sea lions 1.Dart Capture 2.Hoop net capture 3.Dive Capture 4.Floating trap Bring aboard boat and anesthetize

Sample captured animals –Blood –Tissue biopsies Blubber Skin Flipper punch Tooth Nasal, oral and genital swabs Muscle Critical Habitat Study

Glue on Transmitters –SLOT Glued to head Transmissions limited to surface times Photo by R. Davis

Glue on Transmitters –SDR Photo by J. Waite Critical Habitat Study

Release –Animal allowed sufficient time to recover from anesthesia –Released back into area of capture Photo by J. Waite

Data collection Monitoring –Service ARGOS System 2 sun-synchronous Polar orbiting TIROS-N Weather Satellites Three consecutive UHF transmissions from the tag Location calculated by Doppler shift of tag transmissions created by the speed of the satellite Accuracy depends on number and time between received messages during the satellite pass Previous 6 hours of dive data transmitted each time Polar orbiting satellites carrying receivers

Argos System Satellite Telemetry

Critical Habitat Study

Location data will be plotted and compared to hydrographic features: –Bathymetry 4 categories 1.Continental shelf <200 m 2.Upper continental slope 200 – 1,000 m 3.Lower continental slope 1,000 to 2,000 m 4.Abyssal >2,000m

Critical Habitat Study Comparisons to hydrographic features continued –Sea Surface Height Anomaly 1.Anticyclone (warm- core) eddies 2.Cyclonic (cold-core) eddies 3.Confluence 4.other

Critical Habitat Study What have we done? –Applied for Permit –Purchased equipment Capture Skiff Dive Equipment Dive skiff Satellite Transmitters –Received and prepared