1. JUVENILE HAMMERHEAD SHARK TAGGING
The goal of this research project is to determine where the juvenile hammerheads, born in and around the Sea of Cortez, live as adults. To accomplish this goal, we are tagging baby sharks (Fig. 1) with archival tags in order to identify where they go as they grow into adults.
On January 9, 2006 Mauricio Hoyos, was able to tag two healthy scalloped hammerhead juveniles (a 89 cm female and a 91 cm male) with the help of local fishermen in Mazatlan. Two types of tags were placed on the sharks: an external tag called a spaghetti tag (Fig. 2) and a surgically implanted archival tag MK 9 (Fig. 3-4). The spaghetti tag contained the tag number and the instructions for the fishermen who recapture the shark. The internal archival tag will digitally record the depth, temperature, and geographic position of the shark for up to 5 years. After being tagged, the sharks were checked to make sure they were in good condition and were released.
When fishermen eventually re-capture the sharks, the returned tags will contain a wealth of information about hammerhead’s essential habitat and environmental preferences. This information will help identify where the sharks can be most effectively protected. Also, the information will help determine, for example, whether adult hammerhead populations from other regions depend on the Sea of Cortez area as a pupping ground. Last year in December one of these archival tags was recovered and almost one year of data was retrieved. Currently that information is been analyzed.
2. REVILLAGIGEDO ARCHIPELAGO PROJECT
Many shark species appear to display a high degree of fidelity to very specific sites. Also a certain degree of connectivity between shark populations was found between Cocos, Malpelo and Galapagos (www.migramar.com). The aim of this project is to investigate the residency patterns of the shark populations in Revillagigedo Islands and the degree of connectivity between this islands and other locations of the Pacific with the use of acoustic telemetry and genetic analysis.
In April 2008 we started with the project in Revillagigedo by supporting the Santa Rosa University in the giant manta tagging program. The information recorded with the receivers will be shared by both Institutions.