Tag deployments off central California – May 2016

On 22 and 23 May 2016, Cascadia deployed six dart-attached archival tags on humpback and blue whales off the Bay area to examine whale diving behavior and movements and test a new medium duration acoustic tag design. These were also strategically deployed to gather information important for better understanding and addressing the impacts of ship strikes and entanglement. These deployments consisted of the following:

  • Two deployments on humpback whales feeding on fish close to shore between Half Moon Bay and the entrance to San Francisco Bay that were in among high densities of crab pots and lines. There has been a dramatic increase in the number of humpback whale entanglements in crab pot gear in recent years in this region and these tag will help understand the movement and diving behavior of humpback whales in the vicinity of this gear to better identify reasons for this entanglement and possible solutions.

  • Two deployments on humpback whales west of the Farallon Islands feeding on krill near the shelf edge. The ACCESS surveys conducted by the National Marine Sanctuary and Point Blue that examine distribution of whales and seabirds in relation to oceanographic conditions were completed the previous week and had identified high concentrations of whales in this area and the data from the tags will provide an important information on how deep and what the whales were feeding on.

  • Two deployments were conducted on blue whales to serve multiple purposes including the link mentioned above but in one case to examine whale behavior in the shipping lanes and response to ships (one whale was feeding in the western shipping lanes leading to San Francisco and we had to maneuver to avoid being in its path). One of these also represented the first deployment of a longer term archiving acoustic tag on a whale. The tag consisted of the Acousonde acoustic tag but with increased floatation and the addition of Fast-loc GPS and a satellite transmitter as well as small darts for attachment. Both of these tags will be used to also examine the vocalizing behavior and rate for blue whales to aid in developing a way to better infer density/abundance from remote detections of calls.

Map of some of the satellite hits on the humpback and blue whales tagged. Satellite based positions are not very accurate and GPS positions from tags

will provide more frequent and accurate positions once downloaded off recovered tags.

The first longer duration acoustic archival tag on a blue whale. This tag was on from 23 May to 2 June 2016.


Deployment of our medium duration archival GPS tag on a humpback whale on 23 May 2016 west of the Farallon Islands.

Two humpback whales that were with one of our tagged animals passing some crab pot gear off Half Moon Bay on 22 May 2016.

Tagged humpback whale off Half Moon Bay on 22 May 2016 feeding near crab gear.

Double trouble. A humpback whales showing scars from an injury caused by a boat propeller swims past crab gear off Half Moon Bay on 22 May 2016.