This tenderly named infrastructure is not very romantic. It is, however, a dreamy addition to a marine scientist’s toolbox: a cabled observatory that consistently relays exciting environmental information from the seafloor.
Text: Maja Sojtaric
LoVe Ocean Observatory, launched on August 25, will make it possible to consistently monitor the ocean off the coast of the Norwegian archipelago Lofoten and Vesterålen throughout the seasons. Thus, the enamoured acronym – LoVe. Several observatories are placed along 60-kilometre-long fibre optic and electric cables, making it possible for most of them to be operative 24/7, all year round.
CAGE is involved in the development and implementation of node 7 which is placed near an area of substantial methane seepage, close to a coral reef. The observatory will provide a long term, real-time observations of methane seepage from the ocean floor 270 meters below the surface. Methane is bubbling up in this area, potentially affecting the ecosystem.
First of its kind in Europe
Few cabled observatories exist in the world, and even fewer focus on natural release of the greenhouse gas methane. Which makes this observatory unique in its ability to provide crucial environmental information.
“We are very proud to be part of this success story, as we were actively involved since the first phase of LoVe in 2013. The observatory is the first of its kind in Europe and will mean a big leap towards understanding climate change and its effect on currents variations and ecosystems,” says Benedicte Ferré at CAGE.
Ocean Networks Canada and Ocean Observatories Initiative in the USA are similar observatory systems that include methane sensors. Norway is, however, the first country to have strategically built a cabled observatory in an area of high biological productivity, intense methane emissions, and with a vulnerable ecosystem.
“This provides us with a unique opportunity to investigate the impacts climate change will have on all these interconnected parameters. Conducting research on data from this area is the next step towards our understanding of environmental challenges in connection to climate change and potential industrial exploitation at the seabed,” says Ferré.
Remember phone books?
The long list of mounted sensors on node 7 reads like a phone book if you remember those: they measure greenhouse gases methane and CO2; water current data, temperature, salinity, and pressure; oxygen, nutrients (nitrate), pH and chlorophyll; turbidity, coloured dissolved organic matter and polycyclic aromatic hydrocarbon ( a mouthful, but a truly intriguing chemical compound).
In addition, a camera system coupled with a flash provides regular images of methane seepage, a hydrophone records the surrounding environment and the sound emitted by the bubbles as they escape the seafloor, and an echo-sounder records fish migration and long-range images of methane seepages.
Marine research has relied on research cruises, by ship, providing only a snapshot of current environmental conditions. However, the seasonal variations in methane release from the ocean floor can be significant. Which is not a small matter.
A recent paper by Ferré et al in-Nature geoscience showed that Climate gas budgets highly overestimate methane discharge from the Arctic Ocean. This means that the present climate gas calculations are disregarding the possible seasonal temperature variations.
Methane emissions also affect the biological and ecological environment in the nearby area, creating an unusual impact on local lifeforms.
An extraordinary landscape – above and below the water
“This area is exciting because of the fantastic life it hosts due to coastal waters mixing with Atlantic waters. The deep-sea corals abound, a large percentage of the cod population spawns here, and much of the herring stock travels through the area. The continental margin is also very narrow, making it possible for us to observe and monitor a plethora of environments in a relatively short distance from the coast, going down to almost 2500 meters in one area.” says project manager Espen Johnsen of Institute of Marine Research.
The first phase of the project began in 2013 as a collaboration between, among others, the Institute of Marine Research and Equinor. That involved putting out an observation platform by a coral reef off the village of Hovden in Bø Municipality in Vesterålen.
In 2015, the project received NOK 72 million in funding from the Research Council of Norway and several new partners. This has made it possible to install a total of seven observation platforms (nodes) covering the whole continental shelf from the coast out to the deep ocean.
“In due course, enormous amounts of data will become openly available through our webpage. We hope that many scientists from around the world will find them interesting. “ says Johnsen.