Modeling changes in baleen whale seasonal abundance, timing of migration, and environmental variables to explain the sudden rise in entanglements in California

Autor: Kaytlin Ingman, Piero L. F. Mazzini, R. Cotton Rockwood, Nadav Nur, Jaime Jahncke, Ellen Hines
Rok vydání: 2021
Předmět:
El Niño-Southern Oscillation
Climate
Marine and Aquatic Sciences
Social Sciences
Aquaculture
Oceanography
Geographical locations
California
Baleen whale
Humpback whale
Mathematical and Statistical Techniques
Psychology
Humpback Whale
Mammals
Climatology
Balaenoptera musculus
Multidisciplinary
geography.geographical_feature_category
Animal Behavior
biology
Statistics
Temperature
Eukaryota
Geography
Humpback Whales
Vertebrates
Physical Sciences
Medicine
Seasons
Research Article
Science
Gray Whales
Fishing
Marine Biology
Research and Analysis Methods
Ocean gyre
biology.animal
Animals
Atmospheric science
Statistical Methods
Marine Mammals
Ecosystem
Behavior
Pacific Ocean
Whale
Organisms
Whales
Biology and Life Sciences
Fisheries Science
Models
Theoretical
biology.organism_classification
Blue Whales
United States
Amniotes
North America
Earth Sciences
Balaenoptera
Upwelling
Animal Migration
People and places
Zoology
Mathematics
Pacific decadal oscillation
Forecasting
Zdroj: PLoS ONE, Vol 16, Iss 4, p e0248557 (2021)
PLoS ONE
ISSN: 1932-6203
Popis: We document changes in the number of sightings and timing of humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and gray (Eschrichtius robustus) whale migratory phases in the vicinity of the Farallon Islands, California. We hypothesized that changes in the timing of migration off central California were driven by local oceanography, regional upwelling, and basin-scale climate conditions. Using 24 years of daily whale counts collected from Southeast Farallon Island, we developed negative binomial regression models to evaluate trends in local whale sightings over time. We then used linear models to assess trends in the timing of migration, and to identify potential environmental drivers. These drivers included local, regional and basin-scale patterns; the latter included the El Niño Southern Oscillation, the Pacific Decadal Oscillation, and the North Pacific Gyre Oscillation, which influence, wind-driven upwelling, and overall productivity in the California Current System. We then created a forecast model to predict the timing of migration. Humpback whale sightings significantly increased over the study period, but blue and gray whale counts did not, though there was variability across the time series. Date of breeding migration (departure) for all species showed little to no change, whereas date of migration towards feeding areas (arrival) occurred earlier for humpback and blue whales. Timing was significantly influenced by a mix of local oceanography, regional, and basin-scale climate variables. Earlier arrival time without concomitant earlier departure time results in longer periods when blue and humpback whales are at risk of entanglement in the Gulf of the Farallones. We maintain that these changes have increased whale exposure to pot and trap fishery gear off the central California coast during the spring, elevating the risk of entanglements. Humpback entanglement rates were significantly associated with increased counts and early arrival in central California. Actions to decrease the temporal overlap between whales and pot/trap fishing gear, particularly when whales arrive earlier in warm water years, would likely decrease the risk of entanglements.
Databáze: OpenAIRE
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