Gulf of Alaska | Mammals
When gray whales hit a snag: What we can learn from gray whale entanglements in Alaska Presenter: Sadie Wright , sadie.wright@noaa.gov, NOAA Fisheries, Protected Resources Division, Alaska Region Suzie Teerlink , suzie.teerlink@noaa.gov, NOAA Fisheries Ed Lyman , ed.lyman@noaa.gov, NOS Hawaiian Islands National Marine Sanctuary Gray whales ( Eschrichtius robustus ) are primarily benthic feeders that tend to use shallow, coastal waters to forage while on the Alaskan summer feeding grounds. They follow coastal migration corridors to the Mexican breeding and calving grounds where they prefer the protection of shallow inland waters. Gray whales feed on benthic and epibenthic invertebrates by sucking ocean floor sediment into their mouths and filtering out the food. Their feeding strategy may make them susceptible to interacting with fixed gear they encounter and becoming entangled. A review of confirmed reports received since 2000 shows gray whales were reported entangled in Alaska (whether in Alaska-set gear or otherwise) in low numbers, ranging from 0-3 animals annually. Seventeen gray whales are confirmed to have been entangled in Alaska over the 22-year period. Entanglements ranged in severity and outcome; from minor events to fatal events; at least 3 of 17 whales died as a result of entanglements. Some entangled gray whales appeared malnourished, or thin, likely due to the entanglement inhibiting their ability to feed and resulting in increased energetic expense. Entangling materials included crab pot gear, salmon gillnet, and other unknown net or lines. However, these data are limited to those entanglements that were noticed, reported, and confirmed, and thus represent the minimum number of gray whales impacted by entanglements in Alaska. Many entanglements are not observed or reported, and a number of unidentified large whale entanglements were reported in Alaska during this time period that could have been gray whales. Several disentanglement efforts occurred to free gray whales from life-threatening entanglements. At least four gray whales were completely disentangled, while several animals were partially disentangled. Interventions hopefully increase the odds of survival for those individuals disentangled, but do not address the root cause or help to prevent future entanglements. We encourage the marine on-water community to diligently monitor fishing gear and other lines and remove gear from the water when not in use. Please submit any information you have regarding entangled whales in Alaska to our 24/7 hotline: 1-877-925-7773.
Alaska Marine Science Symposium 2023 244
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