Meeting Abstract

82.1  Friday, Jan. 6  Using behavioral data to identify potential marine protected areas for the endangered Southern Resident killer whale NOREN, D.P.*; HAUSER, D.D.W.; NOAA Fisheries; NOAA Fisheries

Southern Resident killer whales (Orcinus orca) are listed as Endangered under the U.S. Endangered Species Act (ESA). Both vessel disturbance and reduced prey availability have been identified as risk factors. Previous studies found that vessel presence reduced foraging and resting behaviors in resident killer whales and dolphins, respectively. The designation of marine protected areas where vessels are prohibited is one potential mitigation measure to reduce disturbance. For maximum benefits, protected area designation should be prioritized in regions where these animals engage in critical behaviors, such as foraging and resting. To better understand Southern Resident killer whale habitat use patterns in their ESA-designated core summer critical habitat, GIS analyses were conducted on behavioral data collected during summer months in waters surrounding the San Juan Islands, USA. Travel was observed during 70%, forage during 21%, rest during 7%, and social behavior during 2% of 571 scans. Directionality, spatial arrangement, and configuration of whales varied significantly across the four behavior states (P<0.0001). Dive duration, surface duration, ratio of surface duration to previous dive duration, and swimming speed also varied significantly across behavior states (P<0.001). Differences in diving and swimming patterns as well as directionality and spatial arrangements indicate that these behaviors likely serve distinct functions for the whales. Most behaviors occurred throughout the study area, though the occurrence of certain behavior states and spatial arrangements tended to vary geographically. In particular, foraging and resting predominantly occurred in localized regions within the core summer critical habitat. These regions could be candidate marine protected areas where killer whales are protected from vessel traffic and other human activities.