Harvesting callos (pen shells) on the Tiburon Island
by Mateja Nenadovic -- April 7th, 2011
Written by SEC Team (Kirby, Luke, and Mateja)
What are the necessary ingredients for a perfect gazpacho? Apparently, a pack of coyotes at the Tiburon Island near our camping site have figured it out. They have successfully browsed through our food supplies and “borrowed” tomatoes, cucumbers, bread and a few gallons of water – basically all the essential ingredients. I was quite impressed with their decision to make some gazpacho, as well as with our ability to provide them with all the ingredients in a timely manner. As you might know, gazpacho is greatly enjoyed and appreciated during hot, sunny days – much like our time on the island.
This kind of a summer-like feast on the coyotes’ part forced us to supplement our food reserves through hunter-gatherer activities. We knew that the sea in front of our camp was able to deliver a bounty of fish and shellfish to local fishing communities. However, we were not sure whether the local ecological knowledge that we had patiently collected through talking to local people and reading scientific journals over the previous five days would allow us to successfully accomplish this activity. Luckily, our Seri hosts were willing to guide us in the right direction. And in this case, geographic direction was exactly what we needed. Their knowledge appeared to be a crucial resource since our initial decision to go and search for food in the little bay in front of our camp- according to one of our Seri hosts- would have resulted in a complete debacle. If we hadn’t talked to them, we would have ended up getting wet, tired, cold, and above all of that we would have stayed hungry! One of the things we learned was that five days was not enough time to obtain sufficient ecological knowledge that would allow us to fill our plates and satisfy our bellies.
Picture 2: Gancho
Our hunting-gathering team (Luke, Kirby, and I) armed with a single gancho (see picture) and, driven by a noise of our empty stomachs, started sweeping the area in a well organized and coordinated way. However, after we successfully completed the mission our supporters on the shore described us as a rather confused and lost group of inexperienced snorkelers who struggled to remain on the ocean’s surface (see picture). Regardless of the perceived appearance, we were able to spot, extract, and collect two full bags of callo de hacha (CDH) or pen shells (see picture).
CDH is a valuable commercial fishery in the Infernillo Channel, providing a critical source of income and employment to the Seri. The majority of CDH we harvested were a species called callo redondo (Pinna rugosa) (see picture). Part of the reason we were able to get so many was related to how they bury in the substrate, as a noticeable portion of their shells remain above the seafloor. This makes them easier to see and extract – or in our case, painfully rip – from the bottom than their pen shell relatives, callo riñón (Atrina tuberculosa). Callo riñón are barely visible on the sea floor, with only the small gap between their two shells usually visible on the sediment surface. Despite this, their abundance has traditionally made them the primary target species by local fishermen, and their kidney-shaped muscles are valued for their delicious, sweet flavor. Callo redondo, on the other hand, have slightly larger, more round-shaped muscles that taste similar, but arguably not as desirable as callo riñón. Desirability, in financial terms, translates into callo riñón having almost two times higher market price than callo redondo. Only due to a very recent spike in local populations has callo redondo supplanted callo riñón as the primary pen shell fishery – both commercially, and, in our case, for subsistence.
Let me tell you a little bit more about how a successful SEC operation (stands for spot, extract, and collect) works: as you are snorkeling you look for the unmistakable identifier of CDHs – gaping valves that protrude from the sediment’s surface. Once you identify CDH, you insert the gancho in between the valves making sure not to damage the central muscle, twist it so it wedges against the shell, and pull the shell out. Without using the gancho, you definitely get a free hand peeling which removes more than your dead skin cells. However, the experience of extracting CDH with your bare hands is unique. Byssus threads (silky fibers made of proteins) that the animal uses to secure itself to the substrate can be quite challenging to break. Commercial divers for the CDH use weights to anchor themselves down so that they can simply walk – in rubber boots – along the seafloor rapidly harvesting shells with a gancho (see picture). Divers can stay down for extended periods of time – Xavier had mentioned once clocking a diver harvesting underwater for 7 hours! They use neoprene wetsuits to keep them worm and jeans to protect the wetsuit from wear and tear. Air is supplied to the diver using hookah (i.e., breathing device), which is often cobbled together from an old air compressor attached to a garden hose (see picture).