Glossary of Aquatic Vegetation Terms
Do you need a definition? Try our glossary of aquatic
- Conditions that result from human activities. "Anthropo-"
meaning human and "-genic" meaning produced from.
- A small, sedentary, marine invertebrate (chordate) having a
saclike body and a siphon through which water enters and leaves;
commonly known as sea squirts.
- Not contaminated by or associated with any other living
organisms. Usually used in reference to pure cultures of
microorganisms that are completely free of the presence of other
- Group of suspension-feeding organisms that usually live in
branching colonies and obtain food by using tentacles to collect
particles suspended in the water column. Bryozoans can use
seagrasses for support and in turn provide habitat for juvenile
fish and various invertebrates.
- A class of invertebrates including shrimps, crabs, barnacles,
and lobsters that usually live in water and breathe through gills.
They have hard outer shells and jointed appendages and bodies.
- Dead or decaying animal or plant matter.
- The process where solids, liquids, or gases are transported
(sometimes through a membrane) from a region of higher
concentration to an area of lower concentration.
- Dragging something along the ocean bottom, inadvertently or
intentionally removing and redistributing the sediment and other
materials found there. There are several specific definitions for
- To deepen waters to form channels or improve navigation, boats
or barges with dredges attached remove sediment from the bottom of
- To collect shellfish, an implement consisting of a net on a
frame, called a dredge, is used.
- When a boat drags its propeller through seagrass beds or other
bottom types, it is called prop dredging.
- Any animal belonging to the phylum Echinodermata, which
features radially symmetrical (radiating from a common center)
bodies; this includes starfishes, sea urchins, sea cucumbers,
- A non-parasitic plant that uses other plants as anchors.
- Flux rate:
- A change in the rate of flow. In reference to seagrasses, the
term refers to the rate of nutrient exchange between the sea floor
sediments and the overlying water column.
- Forams (Foraminifera):
- Single cellular organisms (protists) with a hard shell or test;
may be benthic or planktonic.
- GIS (Geographic Information System):
- GIS is a sophisticated computer-based tool that allows users to
produce simple maps from complex spatial data. Researchers can
overlay multiple data layers to perform a variety of tasks,
including generating a detailed view of the ecosystem, determining
changes over time, and predicting various scenarios in the future.
See the GIS and Mapping
section for more information.
- A state of higher-than-normal temperatures
- in situ:
- A Latin term meaning, "in its original position." In biology,
it refers to experiments or observations gathered in the natural
habitat, as opposed to those gathered in a laboratory.
- Organisms that live in the substrate of a body of water and
obtain their nutrients through digestion of ingested detritus or by
filtering particles out of the surrounding water. Common examples
include species such as clams, crabs, shrimp, sea cucumbers, and
- Light attenuation:
- Describes how light intensity decreases with distance from the
water surface. As water depth increases, less light is available to
organisms living on the ocean bottom. Light attenuation increases
with increased amounts of phytoplankton, dissolved organic matter,
and macroalgae and epiphytic microalgae.
- Algae species that can be seen without a microscope. In the
marine environment, this usually refers to seaweed.
- A specialized area within a plant where rapid cell division
occurs. Apical meristems allow for vertical growth.
- Algae species that cannot be seen without a microscope
- Use of tissue culturing methods to grow large numbers of plants
from very small pieces of plants, often single cells. Mudbank: A
shallow bottom area of shifting mud.
- An organism that can cause diseases in other organisms
Photosynthesis: The formation of carbohydrates in plants from water
and carbon dioxide-caused by the action of sunlight on the
- Microscopic plants that float in water and are transported by
the currents; often used as a food source by marine animals
- Phytoplankton bloom:
- An event in which the density of phytoplankton in the water
- The rate of production of biomass (which is the amount of
living matter in an area); primary productivity refers to the
biomass produced by the photosynthesizing plant components of an
- Increasing the number of plants through cuttings, seeds, or
- A diverse taxonomic kingdom that includes plant-like forms such
as algae (including seaweed); fungus-like forms such as slime molds
and water molds; and animal-like forms such as protozoans (Amoeba,
Euglena, Paramecium, etc.)
- An underground stem that can grow horizontally or vertically
and from which roots grow to provide anchorage for seagrasses. A
vertical rhizome is sometimes referred to as a short shoot;
horizontal rhizomes have longer internodes, or rhizome fragments.
For more details, see illustration in Seagrasses and Land Plants.
- The flow of water, usually from precipitation, which is not
absorbed into the ground. It flows across the land and eventually
runs into stream channels, lakes, oceans, and depressions or
lowpoints in the Earth's surface. Runoff can pick up pollutants
from the air and land, carrying them into the water body and
affecting the species that live there.
- Sediment porosity:
- The ability of water to flow through sediment. The degree of
water movement through sediment depends on sediment characteristics
such as type, grain size, and degree of compaction.
- Sediment resuspension:
- The remixing of sediment particles and pollutants back into the
water by storms, currents, organisms, and human activities such as
dredging or shipping.
- Aquatic animals with shells, such as oysters and clams.
- A culture that is derived from a culture.
- An exchange of molecules (and their kinetic energy and
momentum) across the boundary between adjacent layers of a fluid or
across cell membranes.
- In water bodies, the condition of having suspended particles
that reduce the ability of light to penetrate beneath the surface.
Soil erosion, runoff, and phytoplankton blooms can increase