Intermediate trophic level organisms, small but mighty
All organisms within an ecosystem belong to a particular trophic level – essentially a label of where they fall in the food chain. ITL animals can range in size from tiny copepods to large jellyfish. They are moved by currents throughout the ocean, and can form massive swarms.
Penta said swarms around underwater acoustic equipment can render the equipment output unreliable. Swarms can be so dense that sound reflects and reverberates off of them, causing false readings and adding to ambient noise.
In addition to affecting sound, ITL organisms are known to flash.
“Many of these organisms emit light, called bioluminescence,” Penta said. “They do not light up all the time; usually it’s when they are stimulated or disturbed.”