Cabo Pulmo is a National Park (marine reserve) situated on the southeast coast of the Baja California peninsula, approximately 100 km north of Cabo San Lucas, and is home to the oldest reef in the American coast of the Pacific Ocean. This marine reserve was established in 1995 thanks to the joint effort by the local community, scientists, non-government organizations and government that pushed to protect this area of 71 km2. In 2005 it was declared as an UNESCO World Heritage site and in 2008 it was listed as a Ramsar wetland site of importance. In the last decade the Park has seen a dramatic increase in marine life, which has driven the local community to protect and ensure the sustainability of this area. Cabo Pulmo has become an international example of marine conservation with the participation of the community, which has encouraged a truly sustainable touristic development model.

Project overview:

Cabo Pulmo holds the only coral reef in the Gulf of California in a unique setting where protection in the form of a marine reserve has brought a massive 400% percent recovery of fish biomass and the return of top predators. Sharks are now abundant and diverse in small marine reserve in the East cape region. Sharks in Cabo Pulmo have not been studied sufficiently, even though several species have been observed in high abundance in recent years.

The overarching goals at this location are:

- Understand movement patterns and residency of bull, blacktip and lemon sharks using acoustic telemetry

- Examine abundance and diversity of sharks using aerial (Drones), land and underwater surveys, Baited Remote Underwater Video Systems (BRUVS), and photo ID

- Understand connectivity of sharks to other areas in the Gulf of California and long-distance migratory movements using acoustic and satellite telemetry

Activities:

1. Ultrasonic tagging. We affix ultrasonic transmitters on different species of sharks, particularly bull, blacktip and lemon. 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 a small surgery.

2. Listening stations. The stations consist of an underwater receiver VR2W (Vemco Ltd.,) that record 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 aggregation sites in Cabo Pulmo. We have 13 listening stations distributed in the Park.

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 blacktip and bull sharks.

4. BRUVS. We use benthic (bottom) BRUVS to record the behavior and diversity of sharks visiting the shallow reefs. We also use pelagic (midwater) BRUVS to study the abundance and diversity of sharks in open water.

5. Surveys and photo ID. Surveys are carried out in different ways: aerial with drones, underwater by SCUBA diving, and from observation points on land. Also, photos are taken of each individual bull shark to develop a photo ID catalog.

Other institutions participating in this Project:

- Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE-La Paz)

- Florida International University

Species under investigation: