CZS Sarasota Dolphin Program: 4/27/08

Friday, May 2, 2008

Franciscana Dolphins - Tracking Day #60

Two Month Tracking Goal Achieved
Today we achieved our goal of two months of tracking for all four tags. Kure/Tunken have moved a bit farther to the north, while Kona/Nahuel are together in in the mouth of Bahia San Blas.

Franciscana Dolphins - Tracking Day #59

The pairs continue yesterday's patterns.

Thursday, May 1, 2008

Franciscana Dolphins - Tracking Day #58

Both pairs remain outside the bay, with Kure/Tunken to the north of Banco Culebra, and Kona/Nahuel together and outside the mouth of Bahia San Blas. According to the tide tables, they have just experienced a set of somewhat extreme tides, that are now moderating.

Tuesday, April 29, 2008

Franciscana Dolphins - Tracking Day #57

Kure/Tunken remain together near the Canal Culebra to the northeast of Banco Nordeste, while Kona and Nahuel are together at the mouth of Bahia San Blas. Argentinean research assistants of AquaMarina Agustina Caride and Ignacio "Nacho" Bruno arrive in Sarasota tomorrow as part of an internship training program. Agustina will be here for about 10 days, and Nacho will remain through July.

Monday, April 28, 2008

Franciscana Dolphins Tracking Day #56

Kure/Tunken are together and northeast of Banco Nordeste, and Kona/Nahuel are together and in the mouth of Bahia San Blas.

Franciscana Dolphins Tracking Day #55

Kure/Tunken are together and headed north again, to the east of Banco Nordeste. Kona and Nahuel were together in the channel in Bahia San Blas yesterday, but do not appear to be together now.

Science as it Happens!

Ranging Patterns and Habitat Use of Franciscana Dolphins off Argentina: 2008

In March 2008, Chicago Zoological Society conservation scientists Randall Wells, Jason Allen, and Aaron Barleycorn returned to Bahia San Blas, Argentina, to work with Pablo Bordino and his dedicated team of students, colleagues, and fishermen, and a veterinary team from Disney’s Animal Programs, to conduct additional satellite-linked tagging of franciscana dolphins. Building on the tagging and tracking work during 2007 that indicated a high degree of residency to Bahia San Blas over periods as long as six months, the next phase of the project was designed to address specific questions about:

1) what part of the water column the dolphins use – if the dolphins show preference for water of particular depths, then fishermen might be able to set their nets at different depths in order to avoid the dolphins. Up to three satellite-linked transmitters with time-depth recorders (TDRs) will provide information on the depths of dives as well as locations.

2) developing correction factors for aerial and boat surveys for dolphin abundance that take into account the dive patterns of the animals – the TDRs provide information on dive durations and time spent at specific depths where the animals might be visible to scientists.

3) social patterns – deploying tags with identical duty cycles, it is possible to determine if the animals exhibit a stable or fluid pattern of social associations, through examination of their location data to see if they remain together or separate. In addition to the location data from the TDR tags, as many as 5 location-only tags may be deployed. Genetic samples collected during the tagging process will allow determination of relatedness of dolphins caught together.

The first two transmitters, both TDRs, were deployed on a juvenile male (#42483) and an adult female (#42485) on March 4, 2008. As data are received from these and subsequent transmitters, they will be displayed on this site, as maps showing dolphin locations.

The radio transmitter ("tag") was specially designed for dolphins and weighs only 15 grams. The expected battery life is approximately four weeks, and the tag naturally falls off some time later.

Major support for this project was provided by the Chicago Zoological Society and Disney’s Animal Programs, with tags and tag data processing assistance provided by Dolphin Quest.

CZS Sarasota Dolphin Program