Methane bubbling from the seabed. Vast beds of mussels thriving in darkness. The remains of a manta ray providing a feast for deep-sea creatures. Sunken wood supporting life hundreds of metres below the surface.
And among it all, human debris.
For marine scientist Dr La Daana Kanhai, seeing these environments in Trinidad and Tobago’s waters firsthand was far different from reading about them in a textbook.
“Every single day of that expedition was mind-blowing for me!” Kanhai, of The University of the West Indies’ (UWI) Department of Life Sciences at St Augustine, told Guardian Media.
Now that the month-long Deep Wonders of Trinidad and Tobago expedition has ended, attention is shifting from discovery to what comes next. Kanhai believes some of the deep-sea environments documented during the voyage may warrant protection.
“Of the seven sites that we visited that were in Trinidad and Tobago’s Exclusive Economic Zone, there were certainly areas that were teeming with life and warrant protection,” she said.
Determining which areas should be protected, however, will require further scientific analysis.
“I think that once we’ve analysed the data and samples and gathered the evidence, we will be able to justify the selection of sites. However, this is something that must be undertaken in a systematic manner.”
The expedition, aboard the Schmidt Ocean Institute research vessel Falkor (too), ran from June 29 to July 28 and was the first locally led deep-sea mission of its kind in T&T.
The team returned with nearly 1,000 water, sediment and animal samples after exploring a largely unseen part of the country’s marine territory.
Scientists identified more than 25 active cold seeps, recorded around 20 organisms suspected to be new species and documented at least 54 species never before observed in T&T’s waters.
Three of the suspected discoveries may even represent entirely new genera, although confirmation could take years.
“I don’t want to speculate on a proposed time frame to confirming new species as this takes time,” Kanhai cautioned.
“However, the discovery of new species in any country is a first step towards better understanding a country’s biological diversity, which in turn can serve as a foundation for protection (either of species or ecosystems).”
Mapping what lies beneath
The expedition also addressed a major gap in knowledge about T&T’s marine territory.
Scientists mapped more than 11,335 square kilometres of previously uncharted seafloor, representing approximately 13 per cent of the country’s unmapped marine area.
Using those data, researchers identified 219 streams of bubbles rising from the seabed, possible indicators of cold seeps.
Unlike most ecosystems familiar to people on land, cold-seep communities do not depend on sunlight.
Instead, chemical energy, including methane emerging from the ocean floor, supports bacteria that sustain communities of mussels, clams, tubeworms and other organisms.
Using the remotely operated vehicle SuBastian, scientists visually confirmed 25 cold-seep ecosystems. One of the largest, spanning roughly half an acre, was densely covered with mussels and tubeworms.
But the voyage represented only the beginning of the scientific process.
“Each of the Principal Investigators and key collaborators will assemble their multidisciplinary teams and make plans to analyse their data and samples,” Kanhai explained.
That work will require both funding and personnel.
“Some teams will need to start preparing grant applications to secure funding to process their samples. Some teams will begin recruiting interested students to work on specific samples. We’re all going to be very busy with what we’ve collected.”
Kanhai said she hopes the research will deepen understanding of T&T’s marine biodiversity while providing greater insight into human impacts on the deep sea.
“Collectively, I’m also hoping that our findings will provide a foundation to guide the selection of marine protected areas,” she said.
Deep-sea discoveries come home to UWI
More than 700 specimens collected during the expedition will be housed at UWI’s Zoology Museum, increasing its deep-sea collection twelvefold.
For Kanhai, keeping those specimens in T&T is especially significant.
“By having these specimens in country, local scientists will be able to lead the way in marine conservation efforts as well as contribute to building marine scientific capacity locally and regionally.”
The expedition’s legacy will also quickly find its way into UWI classrooms.
Students studying Marine Ecology and Oceanography this semester will have access to imagery gathered during the voyage.
“Both the specimens as well as the imagery that were collected will serve as important resources for engaging our people (here at home as well as in the Caribbean region) about our deep-sea backyard,” Kanhai said.
For her, that “backyard” now looks very different.
“As a marine scientist, I had read about many of these things. Yet, to see them with my own eyes and to know that we Trinbagonians have such amazing biodiversity at these depths reignited a spark within me.”
What scientists ultimately learn from the hundreds of specimens, sediment samples and water samples collected during the expedition will take time.
So too will confirming whether the suspected new species are indeed new to science and gathering the evidence needed to identify areas worthy of protection.
But Kanhai believes the discoveries already made underscore the need for action.
“We have such incredible marine biodiversity and we need to take action now if future generations are even going to get a chance to bear witness to these deep wonders in the coming decades.”
