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Hydrogen peroxides at high levels as SOS in cultured seaweed

Measuring hydrogen peroxide (H2O2) concentrations could be used as a mitigation strategy in determining stress levels in seaweed aquaculture, according to a study.

“Monitoring hydrogen peroxide (H2O2) could be used as a health indicator in seaweed aquaculture and serve as an early warning sign of stress, said authors Lina Taenzer et. al in the study, “Assessment of hydrogen peroxide as a bioindicator of stress in seaweed aquaculture.” 

“Observations of increased production of H2O2 by plants as a stress response, along with its comparative stability and ease of quantification in seawater in comparison to other (reactive oxygen species), suggest that H2O2 could be used as an indicator of health,” they explained.

The protocol is seen as contributing towards the sustainability of the seaweed aquaculture industry, which has been identified as providing a “multi-faceted solution to the problems of hunger, nutrient deficiency, and alternative energy supplies.”

Keeping up with global demand for seaweed is stymied by challenges in production. Among these are environmental stressors that come with intensive farming. 

The study demonstrated how measurements of H2O2 provide information about seaweed health. “H2O2 has a sufficiently long lifetime allowing it to diffuse out and away from cells. This affords it the potential as a target for monitoring in the aqueous environment,” they explained.

With focus on temperate seaweeds, chlorophyte Ulva fenestrata and rhodophyte Palmaria palmata, tests were conducted on the effects of using major environmental stressors, specifically, acute heat shock, grazing, and desiccation, on H2O2 concentrations. An herbivorous snail (L. littorea) was included in the environment to evaluate the effect of grazing pressure.

Highest concentrations were observed in the grazing experiments and least, under the heat stress condition. 

At present, methods employed in monitoring stress in seaweed are “time- and labour-intensive”, they said. Among the ways are washing algal blades in acid solution, and visually monitoring stocks for epiphytes that are then removed by hand.

The article of the study was published in Scientific Reports.