Sonoma Man To Join Ocean Expedition to Study Endangered Sharks and Sea Turtles

Diver Greg Holzer of Sonoma, California,  has won a spot on a scientific expedition to study hammerhead sharks and endangered sea turtles in Cocos Island National Park, located in the Eastern Pacific Ocean half way between Costa Rica and the Galapagos Island, Ecuador. Cocos Island is famous for its large population and diversity of sharks, such as hammerheads, white tips, tigers, Galapagos sharks, and whale sharks, and for other marine wildlife including eagle rays, marbled rays and manta rays, and sea turtles.

“Truly, this is an opportunity of a lifetime,” said Holzer, who works as a mechanical engineer in San Francisco with Keithly Barber Associates, a consulting firm specializing in building commissioning.  “I know Cocos Island by its reputation as one of most incredible underwater places on the planet. To be able to assist in this important research, while also diving at one of Jacque Cousteau’s favorite dive sites, is an honor and a privilege.”

Holzer will join scientists and 12 other volunteer research assistants on a 10-day expedition March 13 to 23, 2011,  to tag hammerhead sharks with acoustic tags and place satellite transmitters on endangered green turtles. The research is sponsored by Turtle Island Restoration Network (TIRN) (  based in West Marin (Olema) and its sister organization PRETOMA (  in Costa Rica. Holzer will also help count the numbers of sharks and rays, and download tracking information from permanent receivers placed around the waters of Cocos Island.

“It’s great that Greg won the prize,” said Todd Steiner, biologist and executive director of TIRN, and the co-principal investigator of the expedition.  “It is gratifying that he won because he is an experienced and excellent scuba diver who volunteers his skills to ocean protection.” Holzer has volunteered his scuba skills for years to assist UC Davis’ Bodega Marine Lab, California Department of Fish and Game, and other organizations in the study and protection of marine species.

The goal of the research is to understand the relationships between shark and turtle migrations between Cocos, Galapagos and Colombia’s Mapelo Island in order to better protect these species through the creation of marine protected areas, as well as study the importance of Cocos Island as feeding and nursery grounds for these species

Research assistants, who normally pay their own way, support a large part of the costs of the expedition, but this year Turtle Island raffled off two spaces and Holzer was the lucky winner. The value of the prize was over $13,000, which included $2,000 cash for travel expenses to and from Costa Rica.   Steiner reported there are a few spots left for this trip for volunteers who can pay their own way, and he noted that expenses are tax-deductible, because participants are assisting a non-profit organization.

Similar studies on sharks are being conducted at Galapagos Island by a UC Davis research team and at Malpelo Island by Colombian researchers who are sharing their data and coordinating their activities through a program called MigraMar (, a network of marine research and conservation institutions working together to understand the dynamics of sharks and other pelagic species in the eastern tropical Pacific.
Costa Rica’s Cocos Island National Park is located in the eastern Pacific Ocean 550 km (340 miles) south of Puntarenas, Costa Rica, Rica and 630 km (394 mi) northeast of the Galapagos Islands of Ecuador. It was established as a National Park in 1978, and in 1987 a 15 km radius of the marine environment surrounding island was added for protection. The marine area was increased to 22.2 km in 2001. Regulations prohibit commercial and recreational fishing. In 1997, the Park was designated a United Nations World Heritage Site.
Cocos Island’s surrounding waters are best known for large populations of sharks, especially scalloped hammerhead and white-tipped sharks, and as a world–renowned scuba diving site captured in the IMAX movie, “Island of the Sharks.”  Jacques Cousteau discovered one of Cocos’ most amazing dive sites and named the seamount “Alcyone.”  Here groups of over 100 hammerheads congregate at a depth of around 100 feet at “cleaning stations” where small butterfly fish pick off parasites around the sharks gills.
Four species of sea turtles have been recorded inside the Park’s marine boundaries, though little else is known about the turtles of Cocos. Adult and juvenile green turtles are commonly seen foraging in the marine waters of Cocos Island, as are hawksbill turtles. The migration route of critically- endangered Pacific leatherback turtles leaving the most important nesting rookery in the East Pacific, located on Costa Rica’s mainland, migrate through the area. Presumably olive ridley turtles also migrate through the Park.
Todd Steiner said, “Clearly, Cocos Island is an important foraging area for both adult and green sea turtles, but we do not know if these turtles are part of populations emanating from the Galapagos Islands, the mainland of Central America or possibly even the west Pacific. Very little is known about juvenile green turtles or their foraging habitat, and even less is known about hawksbills in the East Pacific. These are some of the questions we hope to answer with our research and monitoring program, which will help discover and elucidate the migration routes to provide necessary policy recommendations to protect and restore the sea turtles and sharks of the East Pacific.”

Turtle Island is sponsoring two 10-day expeditions in 2011, and offers experienced scuba divers the opportunities to participate as volunteer research assistants.  Participants must pay their own diving and living expenses, though the expenses can be tax-deductible. For more information on the expeditions, visit .

Turtle Island Restoration Network, a non-profit conservation organization based in Marin County, CA, works to protect marine species and the oceans on which we all depend locally, nationally and internationally through research and monitoring, policy analysis, public education, advocacy, and strategic litigation.  For more information, see,,, and .