Franciscana Dolphins - March 11

Rough Seas
The winds were too high and the seas too rough to conduct any field work today, so we cleaned up the field station and prepared for our return trip. Two of the Argentinean students who have worked in our Sarasota lab over the past two years (Leo and Carpì) will remain in San Blas for another week to conduct photographic identification surveys, using the methodology they learned in Sarasota. They plan to return at intervals through the year to document identifiable dolphins and monitor our tagged dolphins.

Dolphins Remain Inside Bay
All four of the dolphins were again inside the bay this morning, with the first two we tagged, Tunken and Kure, moving together (the 2 red dots farthest to the left). The other two dolphins, the female, Kona (warrior in Mapuche) and the male, Nahuel (jaguar in Mapuche) were in the same general area, but did not appear to be together.

Franciscana Dolphins - March 10

Final Day of Tagging

Today was the final day to attempt tagging. We did not catch any franciscanas today, but we added several to our photo-identification catalog. In total, we have tagged four dolphins with satellite-linked transmitters. Their positions as of this morning are shown in the attached map, with the red dots being the most recent, and all occurring within the same minute or so. This shows that they are following similar movement patterns, but they are not together in the same group at this time, suggesting perhaps a fluid social structure. More data will be required to document how often individuals join and separate.

The three transmitters with time-depth recoding capability appear to be collecting data appropriately, but limitations of the internet site in San Blas preclude our being able to fully review the data in the field. If they are indeed functioning properly, then we will have accomplished our primary goal for this year´s tagging session.

Killer Whales Spotted

Today we had an added treat - two killer whales entered the bay and passed by our boats. They both had distinctive fins, and we will try to compare them to the existing identification catalog for Argentina. They appeared to be different from the pair we saw here last year - last year's orcas were not in the existing catalog for Patagonia.

Tomorrow will be our last day in the field. We will work with our colleagues from Argentina to refine the photo-ID abilities they have learned working with our Sarasota lab over the past two years, and we will search for distinctive dolphins, our current tags, and individuals tagged last year who should have shed their tags.

Franciscana Dolphins - March 9

Four Dolphins Near Sandbanks
Rain and high winds have kept us on shore today, but the satellite-linked transmitters show us that all four (4) tagged dolphins are moving through the bay as expected. This morning, all four were in the vicinity of the sandbanks where they were caught and tagged several days ago. The large red dots indicate the most recent position, and smaller white dots indicate older positions within the past 24 hours. As with any remote tracking, there is some imprecision, as demonstrated by the one white dot in a small cove to the south. Given the position of the animal immediately before and after this one, we can be pretty sure that it is anomalous.

Once the final data are obtained from Argos, we will run them through a filter program that will eliminate the biologically-impossible positions.