The ARCUS Arctic Research Seminar Series held a seminar on the new ways of collecting and integrating critical environmental intelligence to develop resilience and adaptation strategies for dealing with ocean acidification. Dr. Jeremy Mathis, Director of the Arctic Research Program in NOAA’s office of Ocean and Atmospheric Research, gave a presentation on this topic.
Mathis said the environmental intelligence framework is being used to monitoring ocean acidification (OA) in the Arctic, and specifically offshore of Alaska.
As atmospheric carbon dioxide is absorbed by the ocean, ocean pH decreases, making it more acidic. Important carbonate ions can’t form in acidic conditions.
While acidification was previously thought about in terms of thresholds, where the aragonite threshold states, people concluded that impacts to organisms would occur when acidity reached a certain level. We know now that is not the case.
When these saturation states move outside of the natural range the organisms are used to living in, one can begin to see impacts whether they cross that threshold or not. Lots of examples of this can be seen in the lab, and some have already been seen in the environment, such as impacts on sea life and a decrease in the saturation state.
The posterchild for this has been the terapod.
The world’s ocean is not the same when it comes to ocean acidification. In the polar oceans, saturation states are naturally lower because the water is colder, and colder water can naturally hold more carbon dioxide than warmer water. Additionally, the higher amount of polar region freshwater—from icepack and glaciers—lowers the water’s buffering capacity, making it more susceptible to pH change and lower saturation states.
Because of this, before anthropogenic carbon was added into the environment, the polar oceans were already preconditioned to have lower saturation states.
Aside from the chemistry aspect of ocean acidification, there is also the human factor to take into consideration. Over one billion people derive their sole source of protein from the water.
In places like Alaska, important commercial and subsistence fisheries are located in the same places where OA-created big changes are starting to occur.
Mathis said he participated in a study that looked at the risk to Alaska’s commercial fisheries from OA. Researchers found that organisms in the wild environment—when transferred to laboratory settings—have a low tolerance to acidification. Their study ranked the ocean areas for three areas of vulnerability:
- Hazards, OA itself
- Exposure to OA conditions
- Vulnerability of the populations – size of the economy, industrial diversity, individual income, food accessibility, educational obtainment
This was in order to see how a region would respond to the loss of a fishery in a community. The results were not hugely surprising, but gave a roadmap for how to deal with the problem.
An OA observing network in the Arctic needs to be built on three pillars:
- Understanding of the processes and modeling scenarios and the ability to predict how the ocean will change.
- Observing – accumulating sustained data and making it cross-cutting so that we understand what is going on both chemically and biologically in the ecosystem.
- Responding – taking what is learned from understanding and observing and apply that to adaptation strategies, mitigation, and sustainability around the state.
This has to be done in an integrated way by thinking of it in terms of a nesting observing framework, so that observations are integrated more rapidly and researchers get faster feedback on the collected data. A nested observing framework starts out at a high level – the observing technology down to the human observer component – the communities they are serving and the knowledge that they can bring to the table, and the knowledge that they can take back from these studies to help them make good decisions in their communities.
This method is called environmental intelligence because intelligence has an immediate purpose, and the collecting cycle will occur as quickly as possible. This cycle has a goal of five days or less, where information is collected and used to quickly inform the next round of data collection.
The cycle is collection, transmission, corroboration, analysis, application, and then it starts all over again. This allows scientists to be responsive to the ecosystem as it changes.
The shellfish industry in Seward, Alaska was used as a case study. By deploying six different platforms simultaneously, researchers obtained the aragonite saturation state for three week periods, which provided a good understanding of how continental shelf waters, adjacent to the shellfish hatchery, were changing on a large scale.
The second component of the environmental intelligence gathering is a wave glider, which is remotely piloted from the Pacific Marine Environmental Laboratory in Seattle. It can track events such as glacial melt in the summer months. Scientists concluded that saturation levels worsened during the summer months, even if the amount of carbon dioxide deposited into the ocean stayed the same, because the high amount of glacier melt water lowered the water’s buffering capacity.
From a time series perspective, ocean acidification buoys are used. They collect data as they sit in one spot throughout the year.
Scientists also measured the water that came into the hatchery and was used to rear the shellfish larvae. They found that the water in this location would not be conducive for growing shellfish unless it is treated beforehand 30 years from now. The same concept can be applied to other regions in the Arctic where other valuable fisheries exist.
A vibrant benthic community is also being affected by these changes. Wide portions of ocean bottom water are already under saturated in aragonite, and some are being exposed to bottom waters that are corrosive to calcium carbonate bottom waters for at least a few months every year.
Autonomous vehicles need to be used more in the Arctic. Another under-development technology that will be a game changer in collecting environmental intelligence is the sail drone. It was deployed last year out of Unalaska, and sent to the Bering Sea on a 97-day mission.
With these two technologies, scientists can work to fill in the existing Arctic data gap. That comes back to the environmental intelligence cycle – researchers use the environmental intelligence platforms to fill in the more complex pictures. The direct effects of carbon dioxide on organisms can then be translated into the more complex questions about how those impacts could ultimately determine food web services and ocean services.
In conclusion, Mathis said that with all the progress being made, carbon dioxide concentration will continue to rise, even if all fossil fuel emissions were reduced dramatically.
Global and region projections show that the Arctic will undergo rapid transformations due to ocean acidification.
The surface waters in the Bering and Chukchi Seas are already under saturated for aragonite, and they will be perennially under saturated by 2075. Forty percent of the Chukchi Shelf bottom waters are under saturated in aragonite for at least part of the year.
Southeast Alaska’s fisheries and fishing-dependent coast communities are currently at the highest risk. Risk mitigation strategies could be applied immediately, but ultimately, the only thing to do to stop OA is stop emitting carbon dioxide into the atmosphere.