Conservation deep sea Ecology Human impacts Ocean Exploration

Deep Sea: The Final Frontier

Da Ros, Zaira, Dell’Anno, Morato et al. “The deep sea: The new frontier for ecological restoration.” Marine Policy 108 (2019): 103642.

The UN has declared the next decade to be the decade of “Ecosystem Restoration.” Several organizations have already provided frameworks for comprehensive marine restoration, indicating that many have begun considering the breadth and importance of the resources the ocean provides. The deep sea is an exciting new frontier not only for exploration, but also for restoration. The beginning of a new decade provides the opportunity for a turning point in marine research efforts, allowing us to light up the secrets of the deep sea.

The deep sea is a fascinating place, but it is vastly understudied. Research cruises led by NOAA, the Schmidt Ocean Institute, Nautilus Live and MBARI routinely collect footage of the deep sea using remotely operated vehicles (ROVs) with cameras attached to them. Here’s a short clip of some footage from NOAA’s Okeanos research cruise near American Samoa from 2017.

Many scientists have written papers on the importance of marine ecosystems and the services they provide to society. To learn more about ecosystem services and the value of the ocean, check out these two posts from the Oceanbites archives on Human Health and Coral Reefs, and this one on Marine Conservation from Envirobites. In a 2019 paper, Da Ros and colleagues outline why the deep sea is in need of protection, and the potential for future research in the deep sea. They hope that this will produce a more thorough understanding of deep sea ecosystem processes, and by doing so, will illuminate ways to protect and restore the deep sea.

Impacts from humans:

While it may not seem like it, humans actually have a huge impact on the degradation of the deep sea. The three primary culprits are resource exploitation (trawling, mining, oil and gas extraction, etc.), contamination (sewage and coastal runoff, plastic debris, etc.), and climate change. Even research equipment, such as dredges, moorings, and other technical instruments that may affect benthic fauna, can impact this delicate ecosystem in localized places. To learn more about efforts to avoid harming deep sea ecosystems during research, check out this article about how robots may be able to help. With all these anthropogenic factors affecting the health of deep sea ecosystems, research and restoration are becoming more important than ever. And what’s a better time to start than the beginning of a new decade?

What’s slowing down the research?

It is clear that the deep sea is a valuable resource, but there are a couple of obstacles slowing down exploration and research. First, since deep sea regions can reach 1,000 times surface pressure, samples have to be collected in special containers to ensure they aren’t damaged as they are brought to the surface. Continued research will demand the development of more advanced technology in order to gain a better understanding of deep sea ecosystem functions and processes, as well as accurately study the uniquely adapted organisms that live there. However, better technology is a double-edged sword in this case. As the deep sea becomes more accessible, the potential for exploitative activities, like mining, also increases.

Second, deep sea ecosystems take a long time to recover. Da Ros et. al. reviewed several studies in which researchers attempted deep sea restoration following simulated mining operations in the area. They found that some species only began recovering after 37 years, mainly because it took a long time for species to return to the area of disturbance. While this is an extreme case, it demonstrates the fragility of these ecosystems and indicates that the restoration process may need to be more involved than simple passive restoration.

The third issue is cost. The authors estimate that restoration could cost between 0.8 to 1.6 million USD per hectare (1 km2 = 100 hectares). That’s pretty steep, considering shallow marine ecosystem restoration only costs about one-fourth as much.  And with the size and breadth deep sea ecosystems, procuring funding for further research and restoration could be a daunting task.

While the costs of deep sea restoration are somewhat easy to estimate, the direct benefits associated with deep sea restoration are harder to specify. The deep sea provides important supporting ecosystem services, but the socio-economic benefits associated with restoration may not be evident at first glance. The authors list several important supporting ecosystem services the deep sea provides, such as decomposing organic matter, supporting biodiversity and cycling nutrients.

Restoring the deep sea:

Based on these challenges, Da Ros et. al. outline a few possible actions for ways to restore deep sea ecosystems. Generally, they advocate for active restoration on a broad scale, stating that restoration projects need to implement solutions rather than simply protecting an area from further exploitation. Current active restoration projects mostly focus on transplanting and restoring deep-water coral populations. Projects like Marine Ecosystem Restoration in Changing European Seas (MERCES) perform valuable research while restoring coral habitats on the seafloor, and the authors believe more initiatives similar to MERCES will greatly improve international restoration efforts in the deep sea.

They also believe that the costs associated with restoration will go down as the technology improves. They state that equipment, such as ROVs, currently accounts for 80% of restoration costs in deep sea environments. The decreased costs could initiate important research on ecosystem services that may spur more research on restoration. Therefore, the authors call for increased research on deep sea species assemblages and ecosystem function as a means to proving the importance of deep sea function to current and future resources.

Finally, the authors target policy makers as important players in deep sea restoration. They advocate that policy makers should 1) avoid actions resulting in irreversible degradation, 2) plan ahead for the mitigation of impacts to deep-sea ecosystems and 3) assess the costs for restoring the degraded habitats. Based on these three considerations, the authors urge policy makers to engage in international collaborative research in order to ensure the deep sea will remain a priority in the coming years.

Looking to the Future:

At the end of the article, the authors are optimistic that combined efforts to restore marine ecosystems, accumulate knowledge from scientific research, and perform environmental baseline studies will greatly improve the future of deep sea ecosystems. With the start of a new decade, there’s no better time to optimistic about the future of our oceans. If you’re looking for inspiration for a New Year’s resolution, take a look at this post on 101 Ways to Make a Difference by protecting the oceans.

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