- Red gorgonian, San Clemente Island. Copyright Phillip Colla.
Corals, sponges, and other animals that provide living structure to the seabed are essential to the diverse, complex seafloor ecology. Deep sea corals are found at depths of 100 to 10,000 feet in areas of rich nutrient flow along the shelf and slope. They are among the oldest living animals on the planet.
Individual corals, or polyps, grow together to form colonies. Corals support themselves by capturing small food particles with nematocysts, which are like tiny harpoons. Colonies of polyps share food among themselves, which allows the colony to grow higher into currents to get more food. Some coral gardens contain more than one hundred species of corals and sponges. Setting the ecosystem foundation, these complex seafloor structures support areas of high biodiversity in coastal and offshore waters.
- Juvenile crabs and basket stars adorn bubblegum coral
Corals are literally the cradle of life for the oceans. On the ocean floor, corals provide shelter, protection from strong currents, protection from predators, nurseries for juveniles, feeding areas, spawning areas, resting areas, and breeding areas for marine life.
These rich habitats take hundreds of years to develop. Deep sea coral and sponge populations grow at extremely slow rates and are particularly sensitive to disturbance. These minute animals can live for centuries and congregate in spectacular colonies towering up to ten feet tall; yet they advance at a rate of only half an inch each year.
- Large, fragile Gorgonian coral off Sitka, AK. Courtesy Victoria O'Connell (ADF&G)
Recent studies revealed lush vibrant deep sea gardens that have a host of life as great in variety as many tropical reefs. These same studies revealed irreparable damage to the coral habitat by the indiscriminate fishing practice of bottom trawling, which essentially strip mines the seafloor, destroying nearly everything in its path.
Oceana's Approach to protect living seafloor habitat uses science and law and an open public process to engage policymakers, the press, and the public to protect and preserve this essential seafloor habitat while maintaining vibrant fisheries for sustainable oceans.
