The fate of a popular fish found on the Great Barrier Reef could be in jeopardy, with a new James Cook University study highlighting the impact of marine heat waves on the Spanish Flag Snapper.

JCU researchers have discovered that while the species, commonly known as “Stripeys,” can recover from the effects of sharp rises in water temperature, catch-and-release fishing during these events may significantly impact their health and survival rates.

The study, led by former JCU Ph.D. student Shannon McMahon, collected mature adult Stripeys between Cairns and Cape Melville before transporting them to Townsville to simulate marine heat waves (MHW) across twelve 2500L outdoor tanks. The work is published in the journal Conservation Physiology.

“We all know that coral reefs are particularly susceptible to marine heat waves, which cause mass coral bleaching and mortality, but there was a real knowledge gap in the effects of MHW on coral reef fish,” Dr. McMahon said.

“Our results show that marine heat wave conditions cause direct physiological demands on adult coral reef snapper and residual effects can last for at least two weeks post these events. During a heat wave the fish are under a lot more metabolic stress, and we found that producing more hemoglobin was one coping mechanism during these events.”

Dr. McMahon said the species energetic needs were shown to increase up to 37 percent during MHW conditions.

“Climate change has led to the increasing frequency and intensity of MHWs, so there is an immediate need to understand the sensitivity of organisms both during and following these events,” he said.

Dr. McMahon, who is currently a Postdoctoral Scholar at Okinawa Institute of Science and Technology, said the increased demand for food from Stripeys could lead to increased predation of smaller reef organisms, which would have flow-on effects to wider reef ecosystems.

“If they can’t keep up their food intake to meet these stresses, these increased energy demands could mean a trade-off by decreasing other activities like growth or reproduction, which might influence population dynamics,” Dr. McMahon said.

“Fishing or capture puts them under pressure and when they are more vulnerable and really heat stressed, they could die easier following a catch and release.”

He went on to say that fishing restrictions during marine heat waves or advancement in catch and release protocols should be considered to limit or alleviate the effects on Stripeys and similar species.

“Further research on other coral reef fishes would give us a better idea of the effects future marine heat waves may impose on these vital ecosystems,” he said.

The paper was co-authored by JCU’s Marine Biology and Aquaculture Adjunct Professor Philip Munday and Associate Professor Dr. Jennifer Donelson.

Associate Professor Donelson said the study would help researchers better understand how larger reef fish responded to climate change, especially as marine heat waves continue to increase in frequency and intensity.

“Shannon’s passion for working on larger species of fish really drove his Ph.D.,” she said. “There hasn’t really been much research like this done on these larger reef fish before as they need big, purpose-built tanks but despite the challenges we were able to achieve original results at JCU Marine and Aquaculture Research Facility.”

On average, Americans spend about 90% of their time indoors, and the air we breathe at work, school or home affects our overall health and well-being.

Most air purification systems, however, are expensive, cumbersome and require frequent cleaning or filter replacement to function at optimum levels.

Binghamton University Professor Seokheun “Sean” Choi and Ph.D. student Maryam Rezaie are repurposing their research about bacteria-powered biobatteries—ingestible and otherwise—into a new idea for artificial plants that can feed off carbon dioxide, give off oxygen and even generate a little power.

They outline their results in a paper recently published in the journal Advanced Sustainable Systems.

“Especially after going through COVID-19, we know the significance of indoor air quality,” said Choi, a faculty member in the Thomas J. Watson College of Engineering and Applied Science’s Department of Electrical and Computer Engineering.

“Many sources can generate very toxic materials, like building materials and carpets. We breathe out and breathe in, and that builds up carbon dioxide levels. Also, there are risks from cooking and infiltration from the outdoors.”

Using five biological solar cells and their photosynthetic bacteria, Choi and Rezaie created an artificial leaf “for fun,” then realized the concept has wider implications. They built the first plant with five leaves, then tested its carbon dioxide capture rates and oxygen generation capability.

Although power generation of around 140 microwatts is a secondary benefit, Choi hopes to improve the technology to achieve a minimum output of more than 1 milliwatt. He also wants to integrate an energy storage system, such as lithium-ion batteries or supercapacitors.

“I want to be able to use this electricity to charge a cell phone or other practical uses,” he said.

Other upgrades could include using multiple bacteria species to ensure long-term viability and developing ways to minimize maintenance, such as water and nutrient delivery systems.

“With some fine-tuning, these artificial plants could be a part of every household,” Choi said. “The benefits of this idea are easy to see.”