Understanding the role that an organism plays in a community, necessarily includes knowledge of what it eats, whether its prey change in time or space, and how much matter and energy individuals and populations consume. Past research has focused on the trophic biology or feeding ecology of deep-sea macrourid fishes. The macrourids (see photo) are among the largest, most diverse and widespread of all the deep-sea fishes. Studies of their diet show that they are among the top predators in their ecosystems and that they have the potential to exert significant pressure on their prey populations. But, not all rattails are scavengers and studies of several species along the Pacific coast of the United States suggests that they have separate trophic niches, effectively dividing the ecosystems food resources.
It has also been interesting to find from examing fishes stomachs, that several species consume a lot of carrion - animals such as fish, squid, and whales, which die at the surface of the ocean and sink to the seafloor in the deep sea. Current work is focusing on the use of stable isotopes and fatty acid biomarkers to determine the importance of carrion in the diets of abyssal species of rattails. See the video of rattails consuming bait at a video camera.
Other work has investigated the effects of seasons on their trophic biology. The difference between winter and summer are taken for granted in temperate coastal waters but in the deep-sea temperature and the absence of light and primary productivity are constants. Yet there are seasonal signals in some regions of the deep-sea. In the spring, blooms of phytoplankton in the surface waters occur and soon after due to predation by zooplankton and death of these organisms they slowly sink to the seafloor in a large pulse that sometimes blankets the deep-sea floor and provide a seasonal cue for the animals living there. Although these "pulses" dramatically impact bacteria, protests, and small animals living in the mud and on the seafloor our work suggests that rattails are too high in the food web to respond energetically.
Publications relating to this topic include: