We had an AMAZING first full operational day on the water. We left Long Beach harbor in fairly dense fog, with visibility as little as 100m at times and running the fog horn. Both tag boats left ahead of us and had multiple sightings almost right away. Both got Dtags on blue whales within an hour of starting and conducted focal follow observations for the next several hours. The fog started lifting but was still heavy in spots and was far too limiting for the visual observation team on the Truth to commence operations and thus for us to consider commencing a playback.
Courtesy: C. Kyburg
After about 2.5 hours of baseline behavioral observations by each small boat of each tagged whale (and the other three in the general area), visibility expanded to 2-3 miles enabling us to move into CEE mode. Several fin whales were also in the area and continued to feed and track about 300-400m away from us, which was about half the distance to the focal blue whales. We deployed the source, but ultimately picked it up and moved away from them and repositioned about 1 km from the focal blue whale group. Once we determined all our pre-CEE conditions were met, we initiated sound transmissions while monitoring the focal group and all other animals in the area using our visual observers on the Truth and both RHIBs, while listening with monitoring hydrophones from the Truth and sonobuoys. There were multiple other vessels in the area at times relatively near the animals. In fact, we witnessed several more very close calls for collisions between whales and various boats throughout the day today. We completed the CEE in the specified 30 min period and monitored the focal whales until the tags came off mid-afternoon and we retrieved them very soon thereafter.
In the meantime, one of the RHIBs moved out into deeper water near some of the oilrigs to the east of Newport and managed to get two more monitoring tags attached to a blue whale. The Truth moved ~8 miles out to the tagged whale and scanned the area, joining the visual monitoring of baseline behavior being conducted by the RHIB. Once we determined that conditions were suitable for a CEE and we had several hours of baseline behavior, we moved into CEE mode for the focal whale, which we knew was not the same animals testing in the morning based on the distance and fact that we had just been monitoring them near Newport. In the figure to the left (which is a hot-off-the-press draft from our second playback today) you can see our GIS plots of the position of the Truth and our tagging RHIB (Ziphid) showing the visual detections of our focal whale group (coded "C"). This information is available to us in real-time showing where all our assets are in space relative to the animals. This helps us maintain the desired ranges and monitoring in a very dynamic situation, which is critical for decision-making. It was a textbook source deployment and CEE with visual and acoustic monitoring until about halfway through the sound transmissions a California sea lion that did not see previously popped up right next to the boat looking at us. We immediately terminated the sound transmissions, as required in our scientific research permit for any marine mammal or sea turtle within 200m.
It was still a very productive and useful first day, despite the complications from other vessels in the first CEE and the shutdown in the afternoon one and we were extremely pleased with our progress – 5 tags (of three different types) attached on 4 different individuals with two separate CEEs to 3 focal animals with visual and acoustic monitoring and a demonstrated ability to rapidly terminate transmissions when necessary. All in all, a resounding success for the first full field day of SOCAL-10. Tomorrow we hope for similar success, starting with the recovery of our two tags still riding around on blue whales out in the full moon somewhere this beautiful evening along the southern California coast.