California has wildfire season. The southeastern states have a rainy season. Now, Oregon has a hypoxia season … and it’s killing fish in their lakes.

What is hypoxia in lakes, and what causes it?

Lake hypoxia occurs when the dissolved oxygen content in the water is too low to sustain marine life. The microorganism phytoplankton is at the base of the mechanism creating regions of hypoxic water. The number of nutrients in the water and water temperature are the main factors affecting the growth of these microorganisms.

They will continue to grow until either of these factors limits them. Increasing water temperature or the number of nutrients in the water can trigger massive phytoplankton blooms.

Though the growing phytoplankton population causes other problems in the marine microenvironment, it isn’t the root cause of lake hypoxia. The trouble begins when once these massive populations of the microorganisms die off. They sink to the bottom of the body of water, where bacteria decompose them.

This step of the food chain underlays the depletion of oxygen. Bacteria use up much of the oxygen in this deepest part of the water when digesting the dead phytoplankton. The more phytoplankton there are to decompose, the more oxygen the bacteria will use. Increased use of oxygen by the bacteria does not significantly change the natural rate at which dissolved oxygen is added to the body of water. Thus, oxygen concentration at this depth decreases, and other organisms in this habitat can die. 

Regions where hypoxia is prevalent

Hypoxia is not a new environmental condition. Runoff from farms contain fertilizers and high concentrations of nutrients. Wastewater from cities piped into rivers can combine with this. And when drained into lakes or oceans, it accumulates to create a great environment for microorganism growth. The Gulf of Mexico has low oxygen levels, especially where the Mississippi River drains into it, due to these factors.

In Oregon, however, the main cause of hypoxic water conditions is an increase in the water temperature. This is due to increased overall temperatures, ultimately attributable to climate change. Summers are especially bad times for phytoplankton growth, and because of this, summers have become Oregon’s “hypoxia season”. 

With decreased water oxygen content, many of the native fish species in Oregon are struggling. This is an even larger problem for marine life that is place-bound. In other words, in such scenarios, marine life cannot move to another place fast enough to get more oxygen. 

A temporary solution to help marine life?

Professor Mason Terry’s research group at the Oregon Institute of Technology is working to help increase oxygen concentration in Oregon rivers where endangered species live. Earlier this month, the group finished designs for and deployed a solar-powered aeration system in the state’s Upper Klamath Lake. 

The system is on a raft and obtains power from four 310-watt solar panels. The system is also equipped with a battery that can run the device for up to 32 hours. Hence, it can add oxygen to the lake even when the sun isn’t shining. 

Terry’s aeration system is essentially a much larger version of the smaller air pumps used in fish tanks. Two compressors take power from the solar panels and push air from the environment down into the lake. A hose helps ensure that the air is deposited at the bottom of the lake, where it is needed the most. 

While this will only help small portions of the lake, the raft has been placed at a spot the endangered species can gather at. 

While it is not possible to know the effectiveness of this system until the next fish counts, it is a step forward in helping sustain the diversity of animal life. 

Scalability of this solution

As climate change continues, rising air temperatures will lead to increased water surface temperatures and correspondingly lower levels of dissolved oxygen. It is possible that hypoxia in bodies of water could become an increasingly big problem in the future.

If this project from the Oregon Institute of Technology is successful, it will be a victory because it will show that humans can aid in helping marine life suffering from not having enough oxygen in the water.

However, we will also need to consider how to make this a more scalable device. This solution is still low-impact, but with increased research, there is a possibility of maintaining marine diversity.

Maddie Blaauw

Maddie is a Writer at The Rising and a Bioengineering, Materials Science and Engineering, and Behavioral Neuroscience student at the University of Illinois at Urbana-Champaign.

Zeppelins have come a long way since the early 1900s. Specifically, they are significantly faster, lighter, and largely fire-free compared to their modern airplane counterparts. They are also astoundingly safe. Even before the Hindenburg disaster, the airship casualty rate was half that of modern airplanes. The industry crashed with the Hindenburg, and these days seeing zeppelins is rare outside of advertisements and sporting events. Today zeppelins are simply a novelty, but they have surprisingly practical applications. Solar power could be the modern update that grants airships the comeback they deserve.

Innovations to zeppelins

Recently Varialift Airships, a UK based aeronautical company, announced it had begun building a new prototype of its solar zeppelin design. They plan to address all the major problems that plague zeppelins as an airframe. The aircraft will be all-aluminum, wind-resistant, and entirely leak-free during normal use. Zeppelins are inherently slower than airplanes, averaging about double the travel time, but they have a distinct financial and practical appeal.

Varialift is specifically targeting the cargo market, where airships have historically been underused. Varialift airships will operate at approximately 10% of the cost of airplanes making expenses comparable with trucks or railways. Additionally, vertical takeoff and landing will allow access to hard to reach areas with no runways or additional infrastructure required. Their largest zeppelins will be capable of transporting 250 tonnes of cargo, nearly double the payload of a 747. Beyond their incredible weight capacity, Varialift airships also have no immediate size capacity, opening the door for outsize industry transport. 

The Varialift prototype will be finished in 9 months, but there are already solar airships in use today. The Yuanmeng, translated as “dream”, is currently China’s largest airship and uses solar power to run its electronics while airborne. It has been flying since 2015, and officials say it is capable of sustained flight for an incredible 6 months straight. The airship is currently used for communication and observation purposes.

Conclusions: the future for the solar zeppelin

Though it may take years for companies to leverage solar zeppelins for commercial use, the prospect is certainly enticing. If Varialift and its contemporaries succeed the zeppelin could reprise the futuristic sky cruiser image it held nearly a century ago. The idea of massive balloons running on solar to transport cargo is outlandish at best, but it is much more feasible than one might think.

Brian D'Souza

Brian is a writer at The Rising and a student in the pre-engineering program at University of Illinois at Urbana-Champaign

Over the last century mankind has impetuously emitted CO2 into the air, largely ignorant of its ill effects. Now, with the advent of a climate catastrophe, scientists are scrambling to take that carbon back and put it virtually anywhere else. Researchers at Japan’s Kyoto University, along with colleagues at the University of Tokyo and China’s Jiangsu Normal University, might have found a solution. Together they have developed a material that captures carbon and fixates it into useful organic compounds, which could be a game-changer in tackling carbon emissions.

Of course, there are several methods already available to sequester carbon, including the natural processes used by trees and algae. However natural sequestration is often slow, and artificial sequestering can be energy and cost intensive. Kyoto University scientists hope to address this shortcoming with the debut of their newly published polymer research. Here’s what you need to know.

How the technology tackles carbon emissions

In layman’s terms, the material uses a distinct molecular shape to selectively filter carbon dioxide out of the air. In distinctly not layman’s terms, the material is a porous coordination polymer, or PCP, made of zinc ions. It features a propeller-like molecular structure that causes CO2 molecules to rotate and become entrapped within the compound. You can pick whichever explanation you prefer; the end result is that the material uses no energy to filter carbon from air.

The material is extremely effective; it is approximately 10 times as efficient as similar polymers and can be reused indefinitely. During tests, it was found to maintain its initial carbon sequestration rate even after 10 cycles. The captured carbon molecules can then be converted into polyurethane which is used to make products ranging from clothing to cars. 

Why it matters

Polymer fixation offers an energy efficient and cost effective method to filtering carbon dioxide from air. Large scale implementation of polymer sequestering would counteract carbon emissions without the extensive infrastructure that other methods necessitate. 

Additionally, carbon’s potential to converted to useful chemicals makes PCP implementation economically appealing. Susumu Kitagawa, a material chemist from the Kyoto University group maintains that “one of the greenest approaches to carbon capture is to recycle the carbon dioxide into high-value chemicals.” This is important, as without a financial incentive it is hard for sustainable measures to make an immediate impact. Luckily PCP will be a technology that both environmentalists and economists can get behind.

Polymer sequestration technology truly has the capability to change how we approach carbon emission reduction, but it’s still one that needs to be followed and checked.

Brian D'Souza

Brian is a writer at The Rising and a student in the pre-engineering program at University of Illinois at Urbana-Champaign