New method uncovers hidden chemical signals of coral reef health

Photo byPhoto by Ishan @seefromthesky on Unsplash

Researchers have developed a new method to identify chemical indicators of coral reef health by analyzing substances released into seawater by marine organisms. Coral reefs are complex environments with various compounds, making it challenging to detect and analyze these chemical signals. Traditional methods, which use sticky membranes to concentrate and collect dissolved compounds, often miss essential nitrogen-, oxygen-, and sulfur-containing metabolites due to their low concentrations and poor attachment to the membranes.

To address these limitations, scientists from the Woods Hole Oceanographic Institution employed a technique that modifies metabolites in seawater, making them more compatible with membrane materials. They filtered water samples from five coral reefs around the U.S. Virgin Islands and used chemical reactions to attach a benzoyl group to the metabolites. This modification allowed for better concentration and analysis using liquid chromatography-mass spectrometry.

Their analysis revealed 23 previously undetected metabolites near coral reefs, such as amino acids, amines, pyrimidine nucleosides, and organosulfonic acids, which play roles in photosynthesis and organismal growth. The study found that diseased coral, macroalgae, and crustose coralline algae significantly influenced metabolite compositions. Some compounds, like the organosulfonic acid DHPS, were consistently high across all locations, indicating their association with coral and related organisms. Notably, three metabolites—homoserine betaine, tryptophan, and γ-aminobutyric acid—varied significantly among the reefs, reflecting differences in marine environments and organisms.

Overall, this study highlights a new approach to detecting ecologically relevant compounds in coral reef ecosystems, which could improve monitoring for climate change impacts, natural disturbances, and disease.