by Kristen Green, Ichthyology Lab

September 2009: For the next three weeks, I am traveling to Cocos Island and the Las Gemelas Seamounts, which are located approximately 520 kilometers southwest of Costa Rica. Cocos Island is renowned for its marine biodiversity, and the island has been established as both a UNESCO World Heritage Site, and as a National Park in Costa Rica.

I will be working with scientists from the US National Geographic Society, University of Costa Rica, Ocean Research & Conservation Association, and the Monterey Bay Aquarium Research Institute to explore deep water habitats via manned submersible around Cocos Island and the nearby Las Gemelas Seamounts.

Manned submersibles are like miniature submarines; they allow scientists travel to ocean depths that would otherwise be inaccessible. We will be using the DeepSee submersible, which has room for a pilot and two passengers, and can travel to a maximum depth of 1,500 feet. We will use the submersible to record video images of the seafloor habitat, fishes, and invertebrates, as well as to collect invertebrate specimens from the seafloor.

In addition to the submersible dive operations, there will be several other research projects conducted during the research cruise. One team of scientists will be using SCUBA to identify and count fishes in shallower waters (less than 80 feet) around Cocos Island. Another team of scientists plan to catch sharks and implant them with sonic tags. These sonic tags transmit signals to receivers, which are like underwater listening devices. These receivers will be stationed all around the island. When a shark with a tag swims in the vicinity of a receiver, signals from the  transmitter will be detected by the receiver. The transmitter signals include information about the animal’s depth and location. These data will help scientists understand where and when the tagged sharks move around the island.