San Diego scientists have built a new underwater microscope, and they've already used it to take unique close-ups of tiny ocean organisms in their natural habitat.
"When we show these to people who are experts in these areas, they think the resolution and quality of the pictures we're getting is unprecedented," said Scripps Institution of Oceanography research oceanographer Jules Jaffe, who led effort to build the microscope.
The researchers describe their microscope system in a new article published Tuesday in the journal Nature Communications.
The microscope consists of a long lens powerful enough to capture images on the scale of nearly one micron, or a thousandth of a millimeter. An array of LED lights surround the lens to illuminate dark underwater scenes. A scuba diver can operate the lens using a hand-held computer and a tripod to stabilize the lens on the ocean floor.
Scripps Ph.D. student Andrew Mullen helped build the microscope, and used it in recent dives. He focused on capturing new images of the millimeter-sized polyps that make up larger coral reefs.
In the Red Sea off the coast of Israel, the researchers saw polyps intertwine their tentacles, and even press their mouths together in a sort of kiss.
They also saw corals fighting. Two coral communities placed in close proximity competed for space by deploying extensions of their guts to waste away their competitors.
"They're basically digesting each other," said Jaffe.
"And when we looked the next morning, one coral had clearly been the victor," he said. "The other one was suffering from what we would anthropomorphically call a severe buzz cut."
Jaffe said it's important to view these creatures in their natural homes, because they don't behave exactly the same way in the lab as they do in the environment. He hopes this microscope will help scientists bring the lab to the ocean, instead of having to bring bits of the ocean back to the lab.
In another dive, Jaffe and his colleagues saw the damage done by coral bleaching, a process that can be triggered by events like ocean warming. Bleaching happens when coral polyps lose the beneficial algae that live inside them and help them gather energy from light.
The researchers collected images from reefs off the coast of Maui, which recently suffered one of the largest coral bleaching events on record. They found distinctive patterns in weakened corals that could give scientists a better understanding of the process of coral bleaching.
The researchers hope in future experiments their microscope will help scientists continue to better understand how small ocean organisms are responding to massive changes currently playing out in ocean ecosystems.
