The last few days of SOCAL-12 have seen some excitement and interesting observations but mixed weather. The offshore weather has been deteriorating but we found some windows to get things done on a range of species. Plus today we had a little bit of luck.
When the offshore winds were down, we focused our efforts on beaked whales that live and dive in the deeper basins off southern California. Fortunately we were able to get one (of a new species for us – Baird’s beaked whale) a few days ago, but when those winds picked up to beyond the conditions we could tag these animals, we moved inshore to focus on other priority species.
Fin whales have been fairly scarce off southern California so far this trip, but we found a large, healthy adult just off Pt. Vicente on the Palos Verdes Peninsula. One of our small boats managed to get a suction cup acoustic tag along with a separate GPS positioning tag on him and we conducted a behavioral response experiment to this animal along with a tagged blue whale. We include multiple tagged animals in our experiments when possible to be able to look at differential responses of different individuals.
Adult fin whale with a suction cup acoustic tag (photo credit: A. Friedlaender – taken under NMFS permit #14534-2)
We found several aggregations of feeding blue whales off Long Beach, including some in the behavioral lunge feeding modes we are most interested in studying this year. This was our first effort on blue whales this year and we managed to attach several different types of suction cup tags on three individual blue whales, including an older calf in the mom-calf pair pictured below. We have very specific protective protocols and permit requirements to avoid tagging or conducting response studies with young calves. But it is important that we try and test responses in animals of different sex/age classes, including older calves, as opposed to just studying a subset of adult animals. The point of this is to fully sample the responses of animals within the population that are all exposed to real human sounds in their environment. Our time with this pair was complicated to some extent, as is often the case in the busy waters off California, by some over-eager pleasure boaters driving (within the legal range) around the animals and a very near passage of a massive tug boat and barge.
Mom-calf blue whale pair – the calf is on the right (photo credit: Cascadia Research, E. Falcone – taken under NMFS permit #14534-2)
Finally, at the end of the day yesterday we had something pretty unusual happen. We have had good luck on this trip seeing and hearing one of our highest priority species – Cuvier’s beaked whales – relatively close to Catalina Island. Early in the day our separate team towing passive listening recorders again detected these particularly sensitive species in this area. Working in tandem between these resources, the high visual platform from the central research vessel Truth, and the two tagging boats, we ultimately found a group of five Cuvier’s beaked whales. These species almost always require extremely calm conditions to even see, much less track, but we were able to stay with them over multiple “short” (30 min) diving bouts and later in the day were able to get two tags attached briefly, despite ~15 mph winds and a white-cap chopped swell. This is extremely unusual but you can get lucky if you are in the right place. Unfortunately neither tag stayed on the whales long enough to complete our response study protocols. However, it was important to find larger groups in this promising area and useful in demonstrating the efficacy of our approach using integrated teams to track and tag these very challenging animals.
We have three days left in the first leg of SOCAL-12. The offshore conditions remain unworkable for areas around the Navy range off San Clemente, but we will continue to try to work these near-shore deeper water areas near Catalina until moving back up through the northern Channel Islands to Santa Barbara. We have tagged nearly 20 individuals of seven cetacean species so far, and the data from the earlier deployments and response studies is looking good and quite interesting, though the detailed analysis takes considerable effort.
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One final shout-out that I have not given this year but like to do when folks are following our from-the-field blog is to www.dosits.org. The Discovery of Sound in the Sea website is a really great resource of information for those interested in the sounds of the ocean, animals, and people. It has information, animation, and resources for students, teachers, and those interested in ocean sound of all ages. Check it out.