A report from Trinidad’s Express.
For the first time, local marine biologists Drs. Diva Amon and Judith Gobin have investigated the deep sea off Trinidad and Tobago, discovering two new cold seeps hosting unique communities of animals.
The discovery, made almost a mile deep, reveals important information about the biodiversity of the deep ocean around Trinidad and Tobago. Additionally it enables comparisons with similar habitats elsewhere in the Caribbean.
“These communities are absolutely amazing: hundreds of thousands of 8-inch deep-sea mussels, as well as 3-foot tubeworms, crabs, shrimp, snails and fishes were found living at the seeps between 1000 and 1650 metres depth” says Dr. Amon, a postdoctoral researcher.
The information gained from this study is crucial to understanding Trinidad and Tobago’s almost entirely unknown deep ocean, especially given the increasing oil and natural gas exploration and exploitation”.
These habitats are home to at least 83 species of deep-sea animals, many of which have never been recorded in our waters.
Amon is lead author of a research paper reporting the work this week in the scientific journal Frontiers in Marine Science, in collaboration with Dr. Judith Gobin of the Department of Life Sciences at The University of the West Indies, and colleagues from Duke University, Scripps Institution of Oceanography, University of Southampton, and the Ocean Exploration Trust.
Eighty-three species of animals were recorded from extensive seep communities at four sites, two previously known and two new. The newly discovered seep sites have been named after two Trinbagonian female folklore characters: La Diablesse and Mama D’Leau.
One of the most remarkable discoveries was that during the surveys in this area, 85 further sites were detected off the east coast of Trinidad.
Cold seeps are areas where fluids rich in hydrogen sulfide and methane leak from the seafloor, similar to hydrothermal vents. This fluid provides the energy to sustain large communities of life in the harsh conditions that exist in the deep sea (no light, approximately 4°C temperature and more than 100 atmospheres of pressure).
At cold seeps, bacteria create food via chemosynthesis in the absence of light, using the chemicals in the fluid, in a similar way to plants, which use sunlight for photosynthesis.
The two new sites have been named after female folklore characters, La Diablesse and Mama D’Leau.
These microbes use the oxygen in seawater to oxidize the chemicals present in the seep fluids and form the basis of the food chain at these environments. These bacteria can form thick white mats or live inside many of the animals at these seep sites including the mussels, tubeworms and clams providing food directly. Other organisms such as snails and shrimp seen at the new sites may feed directly on the bacterial mats, in turn providing food for eelpout fish, crabs and other predators. As a result, cold seeps are oases of life, patchy areas of huge abundances of unique endemic animals.
“These cold-seep sites and the associated fauna, were an exciting find that I can now use as real samples of our own deep-sea, for my students” says Dr. Gobi.
“I am extremely pleased to be engaging in this cutting-edge exploration and science in Trinidad and Tobago waters” says Gobin.
Species of a purple octopus, a white sponge and an orange anemone were also discovered and being new to science, do not yet have names. Many of the animals are also poorly understood, such as a species of eelpout fish that lives amongst the mussels, Pachycara caribbaeum, that is known from only one other small site in the Cayman Trench.
85 further possible seep sites were detected indicating that these deep-sea habitats may be widespread in Trinidad and Tobago waters.
Unfortunately, these newly discovered areas are already under threat. These cold seeps, potentially Ecologically and Biologically Significant Areas (EBSAs), will likely be irreparably damaged by drilling and associated oil and gas activities. Scientific research in this area is struggling to keep up with such commercial activities and without targeted actions, these species and their habitats may be lost before they are even studied.
The authors list a number of recommendations for the stewardship and conservation of these deep-sea habitats. Drs. Amon and Gobin hope that this is just the beginning for deep-sea science in Trinidad
and Tobago. “Not only are we blessed with an amazing diversity of life on land and in shallow waters here in Trinidad and Tobago’,” says Amon, “but also down in the deep sea. Only when we understand what exactly exists in the depths of our waters will we be able to protect and manage this biodiversity”.
The findings presented in this study were as a result of a deep-sea exploratory mission on board the Exploration Vessel (E/V) Nautilus in 2014 that Drs. Amon and Gobin were selected to join. The E/V Nautilus is a 64-meter research vessel operated the Ocean Exploration Trust http://www.oceanexplorationtrust.com). The ship carries with it two Remotely Operated Vehicles (ROVs), Hercules and Argus, which explore the seafloor and can be viewed in real time online at www.nautiluslive.org.