The Deep Ocean has no Borders


Journey with Diva Amon, a deep-sea biologist who has explored the deep ocean in Antarctica, the Atlantic and the Pacific. She has experience in chemosynthetic habitats and anthropogenic impacts on the deep sea. You can find out more via her Twitter (https://twitter.com/DivaAmon) and her website (https://divaamon.com/).

We now know that the seas around Trinidad and Tobago boast unique and ecologically important deep-sea methane seeps. It is useful that we have taken the first steps to answer the most basic of questions about the Caribbean deep ocean, “What lives there?” But what about even more complex questions such as “How do species find and colonize these relatively small and patchy chemosynthetic habitats in the huge expanse of the deep ocean?”
To get between islands, birds can fly, reptiles can raft over on flotsam, and many shallow water marine animals (fish, marine mammals, turtles, etc.) can swim the long distances, but what about deep-sea animals like the Bathymodiolus mussels, Alvinocaris shrimp and Lamellibrachia tubeworms that inhabit chemosynthetic habitats? Recent studies have shown that many of the species found at the deep-sea sites off Trinidad and Tobago have also been observed at sites on Kick’Em Jenny off Grenada, off Barbados, in the Cayman Trench and even as far as the Gulf of Mexico. But if many of these methane-seep inhabitants are unable to move, how do these far-ranging sites have these species in common?
The adults may be permanently attached (or sedentary) but their offspring are not! Many of the seep species release their young into the water column, where they hitch a ride in the currents. The Caribbean region boasts a predominantly easterly-north-easterly current suggesting that the seeps off Trinidad and Tobago may be a source of species for the more northerly chemosynthetic sites of the Caribbean. But how long would the epic journey from Trinidad and Tobago to the Gulf of Mexico take for a juvenile mussel? And is that even possible?! Well, that depends on the depth that the larvae travel at and the duration of the larval life span, of which very little is known. However, a recent study reported that the larvae of a seep mussel (Bathymodiolus childressi) and a seep snail (Bathynerita naticoidea) migrate into shallow waters (<100m depth) allowing them to take advantage of faster surface currents that may facilitate long-distance dispersal. Amazingly, it is estimated that B. naticoidea is able to disperse for 7–12 months, whereas B. childressi could migrate for up to 16.5 months. Additionally, it is thought that deep-sea larvae originating around Trinidad and Tobago had the potential of colonizing virtually the entire Caribbean area and even the southeastern Gulf of Mexico.
As some of the deep-sea animals found off Trinidad and Tobago have been found across the Caribbean and as far north as the Gulf of Mexico, having a regional understanding is essential. It reminds us that there are no borders in our deep ocean and is key to comprehending our current and future impacts in these areas. As a result, I will be exploring the deep sea of the Gulf of Mexico in the hope that we can gain a better understanding of those habitats and in turn that it will help to improve our knowledge of the Trinidad and Tobago and Caribbean deep sea. But even more excitingly, I hope that you will join me for the journey!

NOAA Ship Okeanos Explorer berthed at the NOAA Ford Island facility located in the middle of Pearl Harbor, Hawaii. The ship will be leaving from Key West, Florida for the upcoming expedition. Image courtesy of NOAA Office of Ocean Exploration and Research.
My upcoming expedition utilizes an incredible technological innovation called telepresence. Telepresence uses satellite technology to transmit live images and data from ships and ROVs at sea, providing a real-time portal into the excitement of deep-sea exploration and research for scientists, stakeholders, and members of the public (like you!) onshore. Yes, that’s right, every day from 30th November to the 20th December you can be a deep-sea explorer! We will be sending the ROVs Deep Discoverer and Seirios from the NOAA Ship Okeanos Explorer down into the depths to explore areas of the Gulf of Mexico that have never been visited, and beaming the images to you in your home, at work or anywhere you have an internet connection. There will be 21 dives including at potential methane seeps, shipwrecks, coral gardens and even some deep-sea canyons! Will they yield new and exciting life forms and landscapes? You’ll just have to follow along to find out! 
Please visit www.oceanexplorer.noaa.gov for the live video stream and more information about the expedition. ROV dives with live streaming will be conducted every day from approximately 8am to 4pm from 30th November to 20th December. You can also find the live video stream on NOAA Ocean Explorer Facebook and Youtube.
Bathymodiolus mussels (both dead and alive) are seen underneath a carbonate overhang. Also visible under this overhang is methane hydrate. Between the mussels, urchins and sea stars can also be seen. This site looks remarkably similar to seeps seen off Trinidad and Tobago. Image courtesy of the NOAA Office of Ocean Exploration and Research, Gulf of Mexico 2014.

 

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