Researchers used the instrument to capture images of coral turf wars and a previously unknown phenomenon dubbed "coral polyp kissing."
Researchers from the Scripps Institution of Oceanography at UC San Diego have developed a diver-operated underwater microscope that can examine small-scale biological processes on the ocean floor. Referred to as the Benthic Underwater Microscope (BUM), this revolutionary tool is able to take photographs and videos of microorganisms in their native habitats without interfering with their natural settings. Prior to the development of the BUM, scientists were forced to remove organisms from the ocean in order to analyze them with microscopes, preventing them from fully understanding the context of ecological processes.
Oceanographer Jules Jaffe led the team that developed the microscope, and he considers the instrument essential to conducting research in the ocean. “To understand the evolution of the dynamic processes taking place in the ocean, we need to observe them at the appropriate scale,” Jaffe explained.
Jaffe and his team brought the BUM to coral reefs off the coasts of Maui, Hawaii and in the Red Sea to test it in the field. While using the microscope in the Red Sea, the researchers observed corals of different species firing string-like filaments from their stomach cavities towards one another in a “coral turf war.” The filaments secreted enzymes that dissolved coral tissue in an effort to reduce competition from neighboring species. The researchers also observed individual coral polyps on a single colony embracing each other, a previously unknown phenomenon they dubbed “coral polyp kissing.”
Off the coast of Maui, the team used the BUM to observe coral bleaching, a phenomenon that occurs when waters are too warm. The change in water temperature puts stress on corals, causing them to expel algae that live in their tissue and turning them completely white. The microscope revealed a previously undiscovered honeycomb pattern formed by expelled algae as it grew on the surface of the bleached coral.
Jaffe and his team published their observations in the journal Nature Communications and also produced a video describing their research. Watch Andrew Mullen, one of the authors of the study, explain how the BUM works and see some of the beautiful footage below.