Scientists Use New Technology to Examine Health of Deep-Sea Corals, Find Suspected New Species

Issue 97 - June 2023, Ocean Literacy, Technology
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Multidisciplinary team of scientists utilizes new technology, SOLARIS, to determine health of Puerto Rican deep-sea corals

Brittle stars (or ophiuroids) are echinoderms, closely related to starfish. They can crawl across the seafloor – or up onto corals – using their five long, slender, and flexible arms for locomotion. Brittle stars can often be seen on our ROV dives atop corals. It is believed this relationship is a true symbiosis, wherein brittle stars get a “home” in which to hide and gather food, while the coral receives cleanings, being cleared of detritus as the brittle star coils its arms and moves around in search of food.

SAN JUAN, Puerto Rico – Scientists aboard Schmidt Ocean Institute’s R/V Falkor (too) have returned from an expedition to study the impact of climate change on deep water corals. Scientists from the mainland U.S. and Puerto Rico found greater biodiversity than previously known in Puerto Rican waters and may have identified several suspected new species of corals, collecting over 300 samples across 75 different species. Research will be conducted in the coming months to identify and name any new species.

The 20-day expedition included researchers from Woods Hole Oceanographic Institution (WHOI), Lehigh University, and the University of Puerto Rico, and aimed to assess the health of mesophotic corals, in low light from 200 to 500 feet (60 to 150 meters), to deep-sea corals from 60 to 6,500 feet (20 to 2,000 meters), utilizing a new technology called SOLARIS, which stands for Submersible Oceanic Chemiluminescent Analyzer of Reactive Intermediate Species.

This sensor measures molecules known as “reactive oxygen species (ROS),” which are both essential and detrimental to the health of all living creatures. ROS are difficult to quantify as they have short lifetimes, with some existing for only 30 seconds in the marine environment. SOLARIS is a first-generation sensor that will continue to be developed and used as a framework in building future technologies for assessing ocean health. An earlier shallow-water prototype, DISCO, helped to inform SOLARIS, and was developed by Colleen Hansel of WHOI, who served as the expedition’s chief scientist, with funding from Schmidt Marine Technology Partners.

A beautiful colony of Precious coral is documented on a rocky surface off the coast of Puerto Rico. Precious coral is the common name given to a genus of marine corals, Corallium. The distinguishing characteristic of precious corals is their durable and intensely colored red or pink-orange skeleton, which is used for making jewelry. The endoskeleton is composed of tiny stick-like calcium carbonate rods that fuse together to form a rigid structure which may be colored red, pink, or white.
A stunning mesophotic coral ecosystem is documented southeast of Vieques, off Puerto Rico. The expedition’s research focused on documenting the biodiversity of corals and measuring chemical signatures of their health and physiology.
A beautiful colony of Plumapathes is documented off the coast of Puerto Rico. Plumapathes is a black coral in the order Antipatharia, found in the tropical Indian, Pacific, and Atlantic Oceans in deep reef habitats where it forms part of a biologically diverse community. Black corals get their names from their dark brownish-black main axial skeleton. This colonial coral has a bushy form and can grow to 1.5 m (5 ft) tall with a similar width. The slender branches fork at intervals and divide pinnately, and the smallest pinnules are a few centimeters long and close together, forming a feather-like effect.

While it is widely known that shallow-water corals are struggling due to climate change, less is understood about the health of corals in deeper waters. The researchers investigated coral health by measuring their production of the ROS superoxide and hydrogen peroxide–chemicals that animals release for basic biological functions like eating and when responding to pathogens or environmental stress. The team found that the amount of ROS formed by corals surrounding Puerto Rico varied as a function of coral species and were substantially lower than those previously observed in the Pacific Ocean. This could provide vital insight into what species and regions are more vulnerable to stress and changing ocean conditions.

An unidentified cephalopod (most likely a sepiolid, aka Bobtail squid) is documented at 1800m deep by remotely operated vehicle (ROV) SuBastian off the coast of Puerto Rico. The area hosts several cephalopod species, but experts do not think this organism matches any of these known species very well.

Initial results within a controlled laboratory environment also indicate that some deep-sea corals release hydrogen peroxide when wounded, which could provide a diagnostic indicator of stress that scientists may utilize in rapidly assessing the health of deep-sea coral ecosystems.

“We believe reactive oxygen species are critical for acquiring food and fighting off pathogens,” said Hansel. “If these chemicals are protecting corals, then we may be able to help corals armor themselves from stress by better understanding the controls that promote their formation.”

The scientists also used Schmidt Ocean Institute’s underwater robot, ROV SuBastian, to explore the mesophotic and deep sea habitats, including Whiting Seamount and a canyon southwest of Vieques Island, where the team observed 6-foot-high bamboo coral.

At Desecheo Ridge, a part of the Desecheo National Wildlife Refuge west of Puerto Rico, scientists observed dense and diverse coral species outside the marine protected area. The team discovered much higher diversity of corals than previously observed in Desecheo National Wildlife Refuge and surrounding waterways. Before this expedition, the region was expected to have low diversity of corals based on the few observations previously done. The new findings could provide evidence for expansion of marine protected areas around Puerto Rico.

Eric Ryberg (Postdoc, WHOI) analyzes water samples for hydrogen peroxide using DISCO in a laboratory on Research Vessel Falkor (too). DISCO is a handheld sensor developed by Hansel and her team and is used to measure the reactive oxygen species (ROS) superoxide and hydrogen peroxide associated with corals in response to metabolic processes or stress. The lab-based data gathered is used to identify the controls and stressors that promote ROS formation in corals maintained in aquaria within a temperature-controlled room on the ship. These studies complement the in situ measurements and will help the team understand the importance of chemical compounds in coral health and physiology.
On the Research Vessel Falkor (too), the expedition’s science team goes over recent data in the ship’s Computer Electronics Lab. Readings from sensors were used to plan dives with the remotely operated vehicle (ROV), a robot submersible that is connected to and piloted from a Control Room on the ship.
Colleen Hansel (Chief Scientist, WHOI) and Scott Wankel (Principal Investigator, WHOI) work on samples for characterizing the water biogeochemistry in Research Vessel Falkor (too)’s Main Lab while the expedition is at sea.
Santiago Herrera (Principal Investigator, Lehigh University) and his team monitor video feeds in Mission Control during a remotely operated vehicle (ROV) dive. The ROV is tethered to the research vessel, sending video and data of the coral as the submersible explores.

This was the second expedition for Schmidt Ocean Institute’s newly launched Falkor (too)–a state-of-the-art global class ocean research vessel available to the international scientific community to conduct groundbreaking research and test new technologies at no cost in exchange for making their research and discoveries publicly available.

“Through technological advancement, Schmidt Ocean Institute catalyzes the discoveries needed to understand our ocean. We are delighted to assist in testing prototype sensors such as SOLARIS,” said SOI Executive Director Dr. Jyotika Virmani. “We also think it is important that scientists and students participate in expeditions that take place within their country’s waters and were pleased to welcome researchers from Puerto Rico on board R/V Falkor (too) to discover the wonders that lie hidden just off their coastline.”

About the Organizations

Schmidt Ocean Institute was established in 2009 by Eric and Wendy Schmidt to catalyze the discoveries needed to understand our ocean, sustain life, and ensure the health of our planet through the pursuit of impactful scientific research and intelligent observation, technological advancement, open sharing of information, and public engagement at the highest levels of international excellence. For more information, visit www.schmidtocean.org.

Woods Hole Oceanographic Institution is dedicated to advancing knowledge of the ocean and its connection with the Earth system through a sustained commitment to excellence in science, engineering, and education, and to the application of this knowledge to problems facing society. Learn more at https://www.whoi.edu/ .

Lehigh is one of the nation’s most distinguished private research universities. Through academic rigor, an entrepreneurial mindset and collaborative opportunities we challenge our students to become the leaders of the future. Visit https://www1.lehigh.edu/home to learn more.

The University of Puerto Rico, Mayagüez Campus (UPRM) or Recinto Universitario de Mayagüez (RUM) in Spanish, is a public land-grant university in Mayagüez, Puerto Rico. UPRM is the second-largest university campus of the University of Puerto Rico system. In addition to its status as a land-grant university, it is also a member of the sea-grant and space-grant research consortia. Learn more at https://www.uprm.edu/portada/

This piece was prepared online by Panuruji Kenta, Publisher, SEVENSEAS Media