The Mexican Pacific is an area which extends down from the border of the United states at Tijuana and runs all the way down to the tip of Baja California Peninsula. It encompasses a vast coastline with a number of islands such as Coronado Island, Todas Santos Island, San martin Island, San Jeronimo Island Cedros Island, Navidad Island and Santa Margarita Island, as well as oceanic Islands such as Guadalupe Island, Clipperton Island and the Revillagigedo Archipelago.

Project overview:

Fisheries in the Mexican Pacific have a detrimental impact on neonates and juvenile sharks, particularly on the scalloped hammerhead, mako and white sharks. However, little is known about the nursery areas of these species in this enormous region. The scalloped hammerhead shark (Sphyrna lewini) is in a critically endangered globally but lacks protective measurements in Mexico. This species is frequently captured in Mexican waters, and in certain areas it is the main target species. In the Mexican state of Sinaloa, 44% of the total capture are neonate and juvenile scalloped hammerheads. Mako and white sharks, on the other hand, are commonly captured in the artisanal fisheries of Bahía Vizcaíno off the northern Pacific coast of Baja California.

The main goals for this project are:

- Protect the nursery and aggregation areas of juveniles common hammerhead, white shark and shorfin mako sharks in the Mexican Pacific.

- Determine areas of successful reproduction between sites

- Implementation of technical inputs that assist in the design and management of public policies, based on the knowledge of the dynamic temporal space used by these species during their  most vulnerable states (neonates, juveniles and pregnant females).

Aggregation and nursery areas by species:

- Hammerhead shark: The Bay of La Paz, El Bajo Espiritu Santo Island, Boca de Camichin, Isabel Island, La Reforma, Revillagigedo Achipelago.

- White shark: Gudalupe Island, Vizcaino Bay, Cedros Island.

- Shorfin Mako: Vizcaino Bay, Las Animas and El Bajo.

Activities:

1. Ultrasonic tagging. We affix ultrasonic transmitters on different species of sharks. We use ultrasonic tags, which emit a specific code that is recorded by acoustic receivers (listening stations). The transmitters are placed externally in the base of the dorsal fin with a Hawaiian sling used for spearfishing by SCUBA or free divers. Transmitters are also put internally in the intraperitoneal cavity through capture and incision.

2. Listening stations. The stations consist of an underwater receiver VR2W (Vemco Ltd) that records acoustic pulses from the ultrasonic tags in a maximum range of 500 m. The stations are placed at depths between 20 and 40 meters at shark nursery areas and throughout the Mexican Pacific project area.

3. Satellite tagging. Satellite transmitters are designed to track the large-scale movements and behavior of fish and sharks. These transmitters are equipped with light, temperature, depth and accelerometer sensors, that either archives data in an on-board memory or transmits during deployment. We are deploying satellite transmitters in all three species of this project.

4. Genetics and isotopic signals. We collect skin biopsies for genetic and isotopic analysis to determine connectivity and habitat preference between the different species and life stages.

Other institutions participating in this Project:

- Centro Interdisciplinario de Ciencias Marinas-IPN

- Centro de Investigaciones Biológicas del Noroeste

- ECOCIMATI, A. C.

- Instituto de Ciencias del Mar y Limnología, Unidad Mazatlán, UNAM

Species under investigation: