Seagrass Sampling Methods in a Community-Based Setting, a Comparative Analysis

Effective monitoring of seagrass is essential for the conservation of this critical marine ecosystem. The choice of monitoring method depends on balancing accuracy, efficiency, cost, and accessibility, especially in contexts requiring community engagement and ownership. This study evaluates and compares three seagrass monitoring methods, including video, quadrat, and point count, at a field site in Kenya to assess their suitability for community-led monitoring in resource-limited settings. The video method, used as a benchmark, demonstrated high precision with moderate resource demands, requiring 18 samples to detect a 20% change in cover with 80% statistical power. However, its technical complexity and initial setup costs could limit community adoption. Quadrat sampling, while labour-intensive, provided reliable estimates of species richness and total cover, although it required a larger sample size (36) than the video method to achieve the same power. Point count, the least resource-intensive method, was time-efficient but consistently overestimated seagrass cover. These results support the widely used SeagrassNet and Seagrass-Watch sampling methods. These accessible methods can both supply accurate data and help to foster local ownership and capacity. The findings highlight trade-offs between the methods, suggesting that combining technical training with simplified tools such as automated analyses and accessible data interpretation frameworks could enhance the applicability of advanced techniques like the video method in community settings. While accessible technological advancements might improve accuracy and efficiency, such benefits need to be balanced against wider community engagement in monitoring and conservation. Nevertheless, quadrat sampling emerges as the most suitable method for immediate community use, given its reliability and accessibility, while the integration of video methods could be pursued where resources and training permit.