Monitoring seagrass meadow health using coastal bird fecal fatty acid biomarkers

Lipids hold the potential to trace trophic interactions within ecosystems; however, their application has primarily been confined to predator/prey-scale investigations. A novel approach to strategically monitor the health and spatial distribution of hard-to-reach ecosystems, such as seagrass meadows, is explored in this study. These meadows serve as significant long-term carbon storage reservoirs on a global scale.

The researchers tested the hypothesis that lipids can be passively employed to monitor seagrass meadow health by analyzing fatty acids transferred upward through the food chain and deposited on nearby beaches via coastal bird droppings. By comparing seagrass-produced lipids with those generated by diverse microbial eukaryotes like diatoms and dinoflagellates, the analysis could differentiate between healthy and collapsed meadows, as demonstrated by the pilot dataset.

Furthermore, a metabolite generated by the pathogen responsible for seagrass wasting disease was also detected in the data, offering a potential diagnostic tool for assessing seagrass health. The non-invasive monitoring approach utilizing lipids offers several advantages, including the accessibility of beaches compared to seagrass meadows and the ability of birds to spatially sample a larger area than researchers could efficiently cover.

Despite the limitations of the pilot study in terms of sample size and field sites, the findings present compelling reasons to consider carnivorous fecal dietary lipids as a valuable source of ecosystem data.