CalCOFI Marine Mammal Monitoring Greg Campbell 1, Lisa Munger 1, Karlina Merkens 1, Dominque Camacho 2, Andrea Havron 2 and John Hildebrand 1 1 Scripps Institution of Oceanography, La Jolla 2 Spatial Ecosystems, Olympia, WA Sara Kerosky
Background Detailed knowledge of cetacean distribution, habitat use, density and abundance critical Importance for impact assessment/management. Status Cetacean habitat use and abundance in SOCAL are not clearly defined. Goals Characterize cetacean distribution and habitat, estimate population size/density, detect and compare vocalizations.
Approach Habitat Modeling Examine cetacean distribution relative to environmental variables to elucidate habitat use patterns. Distance Sampling Develop cetacean density and abundance estimates across seasons and years. Acoustic Monitoring Examine acoustical data for species and/or population specific calls. Assess acoustic line-transect methods.
Methods Visual Monitoring Visual monitoring conducted during daylight transits between CalCOFI stations. Two trained marine mammal observers on port and starboard, scanning 90 with 7-power 7 and 25-power binoculars. Species, group size, distance, angle and environmental data.
Methods Acoustic Monitoring Towed acoustic array deployed on transits between stations. Navy sonobuoys deployed during on-station sampling. Towed Array Schematic Navy Sonobuoy 9 kt 6 sensors 300 m 15 m Hydrophone 6-elements with 2-200 khz bandwidth 1-element: 0-26 khz
Habitat Modeling: Baleen Whales Habitat Modeling Visual Sightings SST and Zooplankton Thermal Fronts x r Distance Sampling Visual Sightings Density Abundance d Acoustic Monitoring Acoustic Detections Distance Sampling? Stock Structure
Habitat Modeling Baleen Whales Sea Surface Temp. Total Zooplankton Biomass Summer 2005 Spring 2005
Habitat Modeling Baleen Whales Sea Surface Temp. Total Zooplankton Biomass Winter 2006 Fall 2005
Thermal Front Activity Detection Dominique Camacho AVHRR (Advanced Very High Resolution Radiometer) Pathfinder 5.0 4km resolution satellite images from NOAAs NESDIS WIM (Windows Image Manager) SIED (Single Image Edge Detection)
Distance Sampling: Cetaceans Habitat Modeling Visual Sightings SST and Zooplankton Thermal Fronts x r Distance Sampling Visual Sightings Density Abundance d Acoustic Monitoring Acoustic Detections Distance Sampling? Stock Structure
Distance Sampling Density & Abundance Strip Transects Density = (# animals seen) / (area searched) D = n S 2 w L n = # sightings S = mean group size Abundance N = A D A = study area w L Line Transects x r trackline d = r sin x d Detection Probability 1 0.8 0.6 0.4 0.2 0 200 400 600 800 1000 1200 1400 1600 Distance from Trackline (m) D = Density n S 2 ESW L ESW = effective strip width
Abundance Estimation Baleen Whales Probability of detection with distance from track-line. Blue Whales Humpback Whales Abundance/Density Estimate: Pooled 2004-2009 Species Blue Fin Humpback n 37 67 68 N 191 338 426 95% CI 104-325 190-528 179-792 Density 1000 km 2 1.06 1.87 2.35 n=number of observations; N=abundance estimate Fin Whales Abundance Estimates: Stratified by Season 2004-2009 winter spring summer fall Species n N n N n N n N Blue 6 151 8 171 30 491 23 491 Fin 5 158 13 338 35 690 15 387 n=number of observations; N=abundance estimate Truncation Distance: 2 km
Acoustic Monitoring: Cetaceans Habitat Modeling Visual Sightings SST and Zooplankton Thermal Fronts x r Distance Sampling Visual Sightings Density Abundance d Acoustic Monitoring Acoustic Detections Distance Sampling? Stock Structure
Requirements for Passive Acoustics Density Estimation Detection Localization Species Recognition Group Size Estimation
Acoustic Monitoring Species Call Recognition 96 Risso s Dolphin Pacific White-Sided Dolphins Click Type B Click Type B Frequency (khz) 25 Freq (khz) 50 0 22 25 31 39 0 0.5 1.0 Time (hours) Bottlenose Dolphin Common Dolphin 0 0 Time (sec) 1.5 0 Time (sec) 1.5 37 26 22 0 0.5 1.0 Time (hours) BND CD 40 27.5 22 Click Type A DFA Classification Accuracy BND CD 90% 30% 10% 70% chance 50% 50%
Acoustic vs. Visual Detections: Humpbacks Visual Detections Inshore: Spring-Fall Sonobuoy Detections Offshore: Winter Visual Acoustic Los Angeles Los Angeles
Next Steps Habitat Modeling Expand habitat modeling analysis through integration of larger and more diverse sample of visual/environmental data. Distance Sampling Produce new density and abundance estimates for nine cetacean species. Acoustic Monitoring Improve acoustical census methods with advancements in localization software, species-id and group size estimation.
Acknowledgements Observers and Acousticians: Robin Baird, Jessica Burtenshaw, Annie Douglas, E. Elizabeth Henderson, Veronica Iriarte, Autumn Miller, Laura Morse, Erin Oleson Nadia Rubio Michael Smith, Melissa Soldevilla, Ernesto Vasquez, Katherine Whitaker, Suzanne Yin and Stephen Claussen. SIO & SWFSC CalCOFI Scientists: Dave Wolgast, Jim Wilkinson, Amy Hays, Dave Griffith, Grant Susner, and Robert Tombley CNO N45 and NPS Frank Stone and Curt Collins