Gray Whale Research
Eastern North Pacific gray whales (Eschrichtius robustus) migrate annually between winter breeding grounds in the lagoons of Baja California, and summer feeding grounds in the Arctic. This migration follows the coast of North America, and overlaps with areas of heavy coastal shipping, fisheries and resource exploration. Evaluation of risk from these activities requires fine scale data on precise migration routes.
In March of 2012, SWFSC scientists and Mexican collaborators - Dr. Jorge Urban Ramirez ( Universidad Autonoma de Baja California Sur, Mexico) and Dr. Lorenzo Rojas-Bracho and Gustavo Cardenas-Hinojosa ( Instituto Nacional de Ecologia, Mexico) - deployed small satellite dart tags on adult gray whales (see Figure 1) in order to monitor their fine scale migration route through the coastal waters off Baja California, Mexico, and southern California.
This project was made possible by funding provided by the NMFS West Coast Regional Office. Additional support was generously provided by Baja Ecotours and by the International Fund for Animal Welfare, which supplied 4 of the satellite tags planned for deployment.
Figure 1: A small satellite LIMPET tag (49g) deployed on the dorsal ridge of an adult gray whale: note the deployment bolt rebounding, leaving the tag attached. For comparison, this whale likely weighs ~ 40,000 kg (44 tons), almost a million times the mass of the tag
The map below displays the whales' past movements
The team successfully placed tracking transmitters to 19 gray whales. Great job team!
The final transmission was received on April 01, 2012.