2020 A Sustainable Method for The Rapid Assessment of the Extent and Causes of Metaphyton in Lake Tahoe

No Project associated with this Finding

Finding Details

Despite its massive size, the health of the lake is often judged by a narrow band of shallow water around its edge. The shore zone of Lake Tahoe is where the public interacts with the lake for the first time and where public opinion regarding the lake’s aesthetic character is determined by these first impressions. In recent summers, metaphyton (drifting patches of green filamentous algae) have been observed over the sandy bottom in nearshore waters along the south shore of Lake Tahoe. This algae, which is not attached to substrate, is highly visible in the nearshore and occasionally washes onto the beaches and subsequently degrade the aesthetic conditions of the beaches through its visual impact and the odors produced through decomposition.

Indications are that concentrations and the areal distribution of metaphyton have increased in recent years based on anecdotal reports from long-time users of the south shore; however, little data have been collected on metaphyton. The Lake Tahoe Nearshore Evaluation and Monitoring Framework report (Heyvaert et al., 2013) recommended that metaphyton monitoring should be included as part of nearshore monitoring.

This project had the primary goal of developing and demonstrating a regional (lake-wide) monitoring approach for the status and trend monitoring of summer metaphyton growth and distribution using a combination of aerial surveillance via a helicopter and an unmanned aerial vehicle (UAV) or drone, and a ground-truthing program. Through the project we have tested both aerial platforms and have refined our ground-truthing methodology.