Discovering the Hidden Biodiversity of the Gulf of California with DeepSee

Project Leaders from SIO

Brad Erisman MBRD, CMBC
Octavio Aburto MBRD, CMBC

Collaborating Researchers

John E. McCosker - Senior Scientist and Dept. Chair of Aquatic Biology, California Academy of Sciences

Introduction
The Gulf of California (GOC) houses an incredible variety of marine organisms and habitats, and the region is widely recognized as a biodiversity hotspot. Our understanding of this diversity is based primarily on observations and collections made at depths of 50 m or less, and almost nothing is known about organisms that dwell in the depths below. DeepSee, a custom-built submersible capable of exploring depths exceeding 475 m, is the key to unlocking the true marine biodiversity of GOC. It offers a 360-degree view of the undersea world, is equipped with a high definition video camera an array of HID lights that can produce  professional-quality films of organisms in their natural environment, and houses a mechanical arm capable of collecting specimens. DeepSee has performed over 300 dives at Cocos Island, where it has been used to identify a suite of undescribed species of fishes and invertebrates, document the behavior and habitat of rare organisms, and measure the distribution, biomass and diversity of deep reef fishes. DeepSee will allow us to achieve similar goals in the GOC.

Studying the marine habitats of the GOC with DeepSee will provide important information about the diversity, ecology, and behavior of organisms inhabiting these ecosystems and will reveal clues regarding the ecological connections between shallow and deep habitats of the marine environment. Although a major focus of this project will be on fishes, we will invite several SIO faculty members who are experts in other fields of research (i.e., biological oceanography, physical oceanography) to participate in this project. Several scientists and representatives from conservation groups from Mexico will also participate in this project. We will work together to create a more inter-disciplinary investigation into the biodiversity of the environment. Upon completion of this project, we will organize our results into a booklet that conveys the biodiversity of the Gulf in a manner that can be appreciated by the non-scientific community. We will also create a short movie that summarizes all the organisms and habitats observed during the trip. Both products can be used as educational tools to inform the community and the government about the importance and unique qualities of the marine environment of the GOC.

Knowledge of these habitats is also important for conservation measures. Commercial fisheries heavily exploit many fishes and invertebrates that inhabit the deep-water habitats of the GOC, and many of these species have shown dramatic population declines in recent years due to persistent overfishing. Surveys and collections of these organisms will allow us to gain insight into their essential adult habitats, their densities and abundances, and structure of their surrounding communities. All of these aspects are widely considered to be critical for conservation and management plans aimed at restoring healthy stocks and promoting sustainable fisheries.

 This ragged tooth shark was found by DeepSee researchers at a depth of 1,000 feet in the waters around Cocos Islands.  This rare species had never been observed in these waters prior to sightings by the submarine.

 
Photo Credit:  Steve Droggin

Results from this project will make a significant contribution to two current research projects focused on the conservation and management of fishes from the Gulf.  First, we are working with the David and Lucille Packard Foundation and several non-governmental organizations in Mexico (e.g., Pesca Artesanal del Norte del Golfo de California: Ambiente y Sociedad (PANGAS), Pronatura, Comunidad y Biodiversidad (COBI)), to document sites and study fishes that form spawning aggregations in the Gulf. This information will be used to design management policies to protect the overfished and declining stocks of aggregating fishes. Second, we are organizing a booklet (bi-lingual) on the ecology, fisheries, and conservation of groupers and seabasses from the Gulf. The purpose of this booklet is to summarize biological and fisheries information for commercially important species in such a way that it can be read by fishers, fisheries agencies, and conservation groups in Mexico and the United States. This booklet represents the first comprehensive summary of information on any fisheries in the Gulf of California and is the first step towards improving fisheries in the region.  For both studies, there are significant gaps in the knowledge necessary to improve management. Specifically, we have very little data on the habitat, community structure, and behavior of commercially harvested species that occur in deep-water habitats. DeepSee will provide us access to this information and thus will make a direct contribution to conservation of groupers, seabasses and other fishes of the Gulf.
In summary, we believe this project will make a significant contribution to our understanding of the marine biodiversity of the GOC and to the conservation of economically important organisms of the region. The scope and collaborative nature of this project reflect the multi-disciplinary approach of the CMBC, and we are confident that this project will further the success of CMBC and its mission to understand, protect, manage and restore biodiversity in the world s oceans.

Objectives
The overall objective of this project is to increase our understanding of the biodiversity, community structure and behavior of fishes and invertebrates from the Gulf of California
Specific objectives are as follows:

• Document the behavior and ecology of Humboldt squid, Dosidicus gigas, in their natural environment

• Identify and collect specimens of new and rare species of fishes

• Document geographic range extensions for fishes never observed in the Gulf.

• Describe community structure and estimate species diversity and biomass of fishes from 50 to 300 m, with an emphasis on economically important species

• Document changes in the above factors between shallow-reef (<50 m), deep-reef and seamount (50-150 m), and subphotic (150-300 m) communities

• Compare our results with those of pristine and degraded regions of the Pacific

Methods
Observations of deepwater habitat and organisms will be done while aboard the submersible, DeepSee. Dives will be made at seamounts, islands, and other sites near Santa Rosalia, Baja California Sur, Mexico. The Stationary Point Count (SPC) method will be used to conduct quantitative estimates of reef fishes at all sites. High-definition video will be used to document fishes and invertebrates (i.e., Humboldt squid) present at all depths and sites. Mechanical collection arms will be used to collect specimens of rare and unidentified species.

Anticipated Results

• First detailed observations of Humboldt squid, Dosidicus gigas, behavior in their natural environment

• Identification, collections and description of fish species unknown to science

• Identification and collections of fishes never before seen in the GOC

• Several scientific publications community structure, diversity, and biomass of deep-reef fishes of the GOC

• Outreach publication describing the biodiversity of deep-reefs and seamounts of GOC and their relevance to conservation and fisheries issues

• Short film on the marine biodiversity of the GOC

• Information on the ecology and distribution of economically important fishes, including spawning aggregations of groupers at deep reefs and seamounts