algae—Primitive, chlorophyll-containing, mainly aquatic, plant-like organisms that lack true stems, roots, and leaves. Algae can be green, yellow-green, blue-green, brown, or red.

blowhole—A hole created by the concentrated force of a ship's propeller as the vessel attempts to power off a coral reef.

benthic—Relating to or occurring at the bottom of a body of water.

berm—Mounds of coral rubble or substrate, either displaced from an excavated blowhole or plowed by a vessel's hull.

calcium carbonate— A colorless or white crystalline compound found in sea water and used by hard corals to create a hard, protective skeleton around soft, living polyps. It is the primary component of limestone.

catalyst—An agent that promotes significant change or action.

catastrophic event—A destructive natural occurrence, such as a hurricane.

coral head—A coral colony composed of thousands of coral polyps linked to their neighbors by connective tissue.

coral larvae—The early form of a coral. Pear-shaped and the size of a pinhead, a larvae is part of the ocean's plankton for a matter of weeks until it finds a suitable hard surface on which it can settle and morph into an adult coral polyp.

coral polyp—An individual adult coral animal attached to a hard surface. Polyps are cylindrical and elongated along their axis. The end of the animal bears a mouth that is surrounded by a ring of tentacles.

damages—Money collected from parties who are responsible for vessel-grounding incidents. These funds are used for restoration, monitoring, and paying damage assessment costs.

epoxy—A type of glue.

GPS (global positioning system)—A global satellite-based system for determining precise location.

hull—The frame or body of a vessel.

hydrological—Dealing with the properties, circulation, and distribution of water.

marine— Of or relating to the sea; native to, inhabiting, or formed by the sea.

nematocyst—A stinging cell found in coral tentacles. Nematocysts are used by corals to capture prey and defend themselves against predators.

nitrification—The oxidation of ammonium compounds in dead organic material into nitrates.

orphan site—A grounding site where a responsible party has not been identified.

phyla—A group that constitutes a phylum, which is a taxonomic grouping of species.

porous—Full of pores or holes; allowing gas or liquid to pass or diffuse through.

propeller scars—Shallow, bare trenches that result from the dredging and gouging effects of turning propellers as a boat travels over a shallow reef.

prop wash—Water movement that results from the turning of a vessel's propellers.

quadrat—A square frame used for ecological measurements, such as the calculation of number of species per unit area and the percentage of total area individual species occupy.

queen conch—A large, slow-moving marine snail found in the sand flats and seagrass meadows of the Florida Keys National Marine Sanctuary. Growing to 12 inches long and 5 pounds, conchs have long been harvested for their meat and beautiful shells. They are now protected in Florida, and efforts are underway to protect their native habitat and replenish their population.

rehabilitate—To restore to a former state.

relict coral—A remnant of an extinct or otherwise dead coral species.

salvor—A vessel that frees a grounded vessel from a reef.

sponge—Any of a category of water-dwelling, chiefly marine, invertebrate animals with porous body structures that belong to the phylum Porifera. Permanently attached to the sea floor as adults and lacking muscles, nerves, and internal organs, they are filter feeders, pumping water through their body and filtering out particles of food.

substrate—The underlying layers of rock, limestone, and calcium carbonate skeletons on top of which current generations of hard and soft corals, algae, and sponges grow.

symbiotic relationship (symbiosis)— A close, prolonged association between two or more organisms of different species that may (although not necessarily) benefit each member. The various forms of symbiosis include:

• Parasitism, in which the association is disadvantageous or destructive to one of the organisms.
• Mutualism, in which the association is advantageous to both organisms.
• Commensalism, in which one member of the association benefits while the other is not affected.

tactile—Perceptible by touch.

topography—The position of natural features and relief of a surface.

transect—A line that serves as a reference tool for assessing coral injuries.

zooxanthellae—Algae that live symbiotically in coral tissue and provide nourishment through photosynthesis.