Isla Natividad Divers: Better Organized, but Still Diving Dangerously

The Cooperative of Divers and Fishermen cares for harvesting divers as a family

In Mexico's Isla Natividad divers work at depth to harvest from sea, regularly exceeding the limits of any dive table. Even so, these harvest divers do not have the same level of health problems observed in the divers in Moskitia, Honduras. The key difference: organization.
The Cooperative of Divers and Fisherman was established nearly 60 years ago. Diving and fishing support approximately 400 people on the island, each changing jobs with the dive season. There are approximately 25 divers (buzos) who harvest abalone, caracole, sea cucumber and a specific red algae, depending on the season. From mid-September until the middle of February, they also trap lobster.

The remainder of the people on the island work to support those divers. They work as pump men, captains (bomberos) and dive tenders (cabo-vidas) on the boats. They clean and prepare the catch for export on a small processing plant. They have offices on the mainland in Bahia Tortuga and Ensenada to manage their exports and negotiate for the best price. Members of the cooperative also maintain the island's infrastructure like the water desalination and electric plants. The Isla Natividad cooperative is a very successful example of how divers can work together to support and protect themselves.

Exclusivity plays a large role in the cooperative's success. They have the exclusive harvesting rights to all commercially viable invertebrates around Isla Natividad. No one else can come to the island and harvest lobster, abalone or anything else. This allows the cooperative to protect its resources and control harvesting levels. It also allows the harvesters to place traps in the water and leave them overnight or for longer periods to catch lobster. In Honduras, where there is no security and lobster harvesting is done well offshore, it's neither practical nor possible for the divers to leave traps in place. Instead, they must dive to pick up the lobster by hand—putting themselves at greater risk for injury.
DAN and the Cooperative
Dr. Matias Nochetto, the medical coordinator for Latin America, and I were invited to visit Isla Natividad recently by Reef Check Worldwide. Reef Check is working with the divers, through the Mexican non-governmental organization Comunidad y Biodiversidad (CoBi), to help them find alternate sources of income for the island, such as expanding into ecotourism.

Reef Check has trained several of the harvesting divers to work in a scientific capacity monitoring the health of a Marine Protected Area that covers approximately four percent of the island's fishing grounds. The cooperative set these fishing grounds aside to help them decide whether fully-protected reserves should be a part of their management strategy in the future. Using established transects and performing counts of the area's kelp and sea life, the Reef Check-trained divers regularly monitor the health of the island's kelp forest.

Nochetto and I had three goals for the trip to Isla Natividad. Our primary function of the visit was to complete a risk assessment of the recompression chamber, used by the cooperative to treat their divers, and to determine its readiness to treat recreational divers who may visit the island as part of the ecotourism initiative. The secondary goal was to learn more about the diving processes on the island and compare them to harvesting diving activities in other locations. Finally, we planned to offer educational safety lectures for the divers.
Dive Accident
It was the last week of the sea cucumber harvesting season—the cooperative planned to dive for only a few more days to collect the invertebrates exported mainly to Asia. The teams met early in the morning, as they do six days a week to get their assignments and set off for the fishing grounds. The dives had been moving progressively deeper all season as they cleared out the catch from shallower sites.

A typical dive ranges from depths of 60 to 120 fsw, for one-and-a-half to two or more hours. They dive using surface supplied air, called hookah rigs and literally run across the bottom collecting their catch. Wearing wetsuits in the 65 degrees Fahrenheit water, they wear double the amount of lead a diver who hopes to float would wear. They pick up their catch and place it in a game bag or a bucket, sending it to the surface when it is full.

That afternoon, we were told two divers were in the chamber receiving hyperbaric treatment. Between Jan. 1 and July 17, 2010, the cooperative treated 48 divers. With a diving population of 25, it indicated that several went to the chamber more than once. With the chamber on the island, and the dive sites no more than 45 minutes away, a diver presenting with symptoms of decompression illness can be delivered to the chamber quickly. In this case, the response time was swift, and the two divers were back under pressure within 20 minutes of surfacing.

The more severely affected diver had serious neurological symptoms, with an impaired ability to walk and to urinate and parasthesia affecting his arms and legs. Dr. Nochetto began consulting with the doctor on the island and the chamber crew to make sure the diver received the best care possible. Typical presentation for one of the cooperative divers is pain-only symptoms that resolve with a single treatment. A diver facing severe neurological impairment was not something the rest of the divers had ever seen before. By the end of the week, after a total of nine hyperbaric treatments, the injured diver had recovered much of his mobility. Since leaving the island, Nochetto has learned that the diver has reportedly regained most of his lower extremity strength, and walks assisted only by a cane. He is currently undergoing physical therapy and is likely to end up with little to no significant disability.

In response to the severity of this diver's injury, the cooperative managers decided to discontinue diving for sea cucumbers for the season.

During our visit, Nochetto and I organized educational programs for the divers and the rest of the dive teams. The first lecture focused on decompression sickness and the potential risks they face. After a short presentation, the divers proceeded to ask questions for nearly two hours. The divers also attended workshops on oxygen first aid use, signs and symptoms to look for and basic care to provide a diver while getting them into the local medical system.
Results and Progress
DAN Medicine, Education and Research continue to study ways to help harvesting divers around the world dive more safely. The Isla Natividad divers currently perform decompression stops following their dives along with relatively slow, controlled ascents, but these are untimed and not on any official dive schedule—typically they are limited by the diver's ability to withstand the cold. By studying and comparing diving practices of different locations and populations of harvest divers, DAN hopes to develop collaborative solutions that may help these groups lower their risk for injury.

Note: In spring 2010, DAN staff made a trip to La Moskitia, Honduras to research and assist another group of harvesting divers. Read all about it and view the Harvesting Divers photo gallery.

© Alert Diver — Fall 2010