June 2004

Deep Sea Caregivers

Imagine a place of perpetual darkness, unlit except by the faint, glowing luminescence of a few animals.

Imagine a place of perpetual darkness, unlit except by the faint, glowing luminescence of a few animals
Deep Sea Caregivers
Three blob sculpin (Psychrolutes phrictus) attend nests of pinkish eggs on the sea bottom along the Mendocino Ridge (the fish on the left has a nest just off the left side of the photo). Unlike the surrounding rocks, the fish eggs are clear of sediment, which suggests that the parent fish may keep them clean by fanning them with their fins.
Three octopus (Graneledone sp.) brood their eggs on a rock outcrop along the Mendocino Escarpment, offshore of Northern California. The octopus are in a typical brooding position, with their heads down and arms curled outward. Their eggs are hidden underneath their bodies, which are about 16 cm (6 inches) across. Also on the rock are a deep-sea crab and several types of sea anemones. This photograph suggests some of the abundance and diversity of marine life found around the undersea nursery areas along the Gorda Escarpment off Northern California.

Imagine a place of perpetual darkness, unlit except by the faint, glowing luminescence of a few animals; temperatures that very from near freezing to boiling; and pressures up to a thousand times the pressure that we live in. This is the environment of the Earth's deep ocean, a place that is virtually unexplored.

To learn more about this mysterious world, scientists rely heavily on "ROVs", or "remotely operated vehicles." These probes allow researchers to get a glimpse of what is going on in the dark.

Much of the ocean's floor is relatively empty of life, but there are oases where there are dense communities of species- called "hot spots" by marine biologists. "Black smokers"- towering vents of hot fluids- provide the nutrient source for one such type of community... home to red tubeworms, crabs, clams, and many other animals. Equally interesting, "sea mounts"- underwater mountains- are a place that can look more like a coral reef than the deep sea, with sponges, soft corals, anemones, crabs, fish, and octopus.

Recently, marine biologists working at Monterey Bay Aquarium Research Institute (www.mbari.org) have discovered something never seen before in a deep sea species- what appears to be parental care. Both a kind of fish called the blob sculpin, and a species of octopus have nests of eggs in an area along the crest of the Gorda Escarpment (off the coast of northern California). The biologists hope to learn more about this behavior and what makes the area a desirable nursery.

Pulse of the Planet is presented by the National Science Foundation.