Photos: Roving the floor of Crater Lake

Crater Lake is one of the clearest bodies of water in the world. There are few places on earth that command such overwhelming awe from observers. The clarity of this indescribably blue lake is primarily due to the extremely low concentration of suspended particles and nutrients to support algae and aquatic plant growth.

Mark Buktenica, Crater Lake National Park

A close-up of some of the sample moss pulled from the bottom of Crater Lake.

Steven Jessup, Southern Oregon University

Hidden far below the lake surface, a remarkable deep-water moss community (Depancladus aduncus) may represent the bulk of the biomass in the entire lake ecosystem. This thick band of moss encircles the lake at depths from 85 to 460 feet. This is growing moss hanging down from on the north wall of the caldera at 384-foot depth.

Mark Buktenica, Crater Lake National Park

Lush beds of moss cover the gentler slopes around Wizard Island. This photograph was taken during a night dive by Bob Collier from the submersible Deep Rover in 1988.

Bob Collier, COAS, Oregon State University

This moss was the first described and sampled during Deep Rover submarine program in the late 1980s by Crater Lake National Park biologist Mark Buktenica and colleagues at Oregon State University.

Bob Collier, COAS, Oregon State University

Further evidence of the moss distribution was uncovered during recent high-resolution multibeam sonar surveys. Since the moss beds do not reflect the sonar sound back to the surface as well as the hard surfaces of the caldera wall, Pete Dartnell (USGS) predicted the moss distribution throughout the lake using a model of sonar backscatter intensity.

NOAA

The USGS National Seafloor Mapping and Benthic Habitat Studies Project.

Pete Dartnell, USGS, Western Coastal and Marine Geology

Backscatter intensity: Dark areas may help identify moss.

Pete Dartnell, USGS, Western Coastal and Marine Geology

Photograph of Mark Buktenica

David Reinert, COAS, Oregon State University