N.C. State students and staff members recently traveled to the Gulf of Mexico for a multi-year project in partnership with Oregon State University and Duke University to explore the mysteries of cold seeps at the bottom of the ocean.

A cold seep is a shallow area on the ocean floor where gases can accumulate, often in the form of a pool. 

David Eggleston, N.C. State biologist and director of the Center for Marine Sciences and Technology, said the scientific community knows very little about cold seeps, and there are so many questions that scientists want answered regarding the rare life-forms in the communities. 

Doreen McVeigh, a graduate student at N.C. State, added that it is vital to learn more about the cold seeps because they are often the site of mining and drilling operations, and there still so much to learn about them.

Cold-seep communities are unique in that they do not rely on photosynthesis for the base of their food web because they are located where there is no exposure to sun rays. Instead, these communities use chemosynthesis and consist of giant tube worms and giant mussels that harbor bacteria. 

The bacteria and the seep organisms share a symbiotic relationship in which the bacteria metabolize methane and hydrogen sulfide for the organism. The seeps are similar to hydrothermal vents. However, instead of an episodic delivery of hydrogen sulfide and very hot water, seeps have very cold water with a consistent flow of hydrocarbons that serve as the base of their food web. 

N.C. State researchers concentrated on predicting currents that are deep in the ocean and monitoring larval dispersal by creating computer models from their observations.  Researchers want to know how seep sites in the Gulf of Mexico, Barbados and the coast of the Carolinas are connected genetically and how the larvae are physically dispersed. They used many methods, covering several science disciplines. 

“The strength of this project is that we are bringing a lot of different disciplines together to focus on how these seep communities are connected,” Eggleston said.

Eggleston said researchers are trying to learn what allows these communities and populations to persist over time and how new seep sites become populated. Researchers used molecular techniques and looked at the DNA to see whether or not organisms in different parts of the world are related.

They also had the opportunity to use the Alvin, a submersible robot, to collect organisms at different locations to get a genetic analysis. They deployed moorings, which are weighted cables that are connected to a float and then submerged in the water with a variety of tools on the cable to measure the flow of currents through the water column to hear what the seep communities sound like and to collect larvae to help validate the larval dispersal models the scientists have engineered. 

McVeigh was responsible for creating biophysical models of the ocean currents and the larvae.  This was break from her specialty, which is genetics, but McVeigh said she gained a lot from this interdisciplinary approach to researching the seeps. 

 “It is really rewarding to have a wider knowledge base,” McVeigh said. “Constantly push yourself into new areas. It is a risk but, it is usually rewarding!”  

The impact of this research has the potential to broaden the scope of knowledge scientists have about the sea. 

“Antarctic species, which have evolved under similar cold conditions as the organisms in the cold-seeps, have promising anti-cancer properties,” McVeigh said. “It is entirely possible that a key factor in how to stop cancer or prevent cancer cells from taking over could be in these species.” 

McVeigh said deep-sea organisms are a bit of an anomaly because they have never been found with cancer or tumors.

 “It’s not that they are immune, they just have a property that other organisms don’t, and it is definitely worth looking into,” McVeigh said.  

There are health benefits in the deep sea to be discovered, as well as economic benefits from harvesting oil. It is impossible to know the effects hat mining a drilling for natural resources will have on the cold-seep communities.  

“We shouldn’t destroy the deep sea before we even have a chance to look at it,” McVeigh said. 

So far, the researchers have begun to understand deep sea currents, which is something scientists have had trouble understanding in the past. 

“Definitely still a work in progress, so stay tuned,” McVeigh said.