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Welcome to MITZI's Glossary of Common Terms
Abiotic Factor: The physical, chemical and other non-living components of the environment that an organism lives in. These factors include all aspects of climate, geology, and atmosphere that affect ecological systems. Acre: An acre is an area of land equal to 4,840 square yards or 43,560 square feet. For comparison, a football field is 45,000 square feet, so one acre is a little smaller than a football field. Adaptation: Any change in the structure or function of an organism which makes it better suited to its environment. Anaerobic metabolism: Metabolism that can occur without the presence of oxygen. It involves a process of converting glycogen or glucose into ATP to be used as a fuel for the muscles. A faster process than aerobic metabolism, but good only for a short period of time and thus is used for higher intensity workouts (such as a full gallop in the case of a horse). Lactic acid is a by-product. Autotroph: An organism that synthesizes organic molecules from inorganic starting materials through photosynthesis or chemosynthesis. Autotrophs are ecologically important as primary producers as they ultimately provide energy for all heterotrophic organisms.
Bathymetry: The measurement of the depth of the ocean floor from the water surface; the oceanic equivalent of topography Benthic: Refers to ocean bottom. Benthic epifauna are organisms that live on the ocean floor or upon bottom objects sch as sea anemones and barnacles, whereas benthic infauna are organisms that live within the surface sediments such as clams and worms. Bioaccumulation: The process whereby pollutants are taken up, retained and concentrated in the cells of plants and animals (also know as biomagnification). Biodiversity: The variation in life on Earth reflected at all levels, from various ecosystems and species, to the genetic variation within a species. See also ecosystem diversity, species diversity, genetic diversity. Bioluminescence: The emission of visible light made by living organisms. Biomass: The total quantity of living organisms or all the species in a community, usually expressed as a unit of weight. Biotic Factor: A living component of the environment which arises from and affects living organisms (distinct from physical factors). For example, the interaction between predators and prey is a biotic interaction. Bivalve: A mollusk that has two shells hinged together, such as the oyster, clam, or mussel. Byssal thread: The term byssus (sometimes byssal thread, or byssus thread) denotes strong threads secreted by mussels to attach to rocks and large, generally heavy objects in the intertidal zone.
Carapace: The hard cover, or exoskeleton, which protects the internal organs of the head, thorax, and gills; it is made of chitin. Carnivore: An animal that feeds on other animals. (sometimes referred to as "meat eaters") Cerata: Soft, finger-like projections from the body of the sea slug Chemosynthesis: The process whereby chemical energy is used to make organic compounds from inorganic compounds. One example is the oxidation of ammonia to nitrite by nitrifying bacteria. Chitin: A hard, flexible, fingernail-like substance forming the outer covering of insects and crustaceans. Chromosome: A linear sequence of genes wound up with proteins into a single unit that is found in the nucleus of cells. Cirri: Small, flexible appendages present
on some invertebrates, including barnacles and annelids. Cobbles: Rock fragments that measure between 2.52 and 10.08 inches (6.4 – 25.6 cm) in diameter; a cobble is larger than a pebble and smaller than a boulder and has rounded edges due to natural forces such as water. Community: A naturally occurring group of plants and animals that live within a certain environment and interact with each other. Communities are often defined by a dominant species (e.g. kelp forest community) or the major physical characteristics of the area (e.g. mud flats). Competition: One of the biological interactions that occurs when two species vie with each other for the same resource. Can limit population growth.
Decomposer: An organism which gains energy by breaking down the final remains of living things. Predominantly bacteria and fungi, decomposers are important in freeing the last of minerals and nutrients from organics and recycling them back into the food web. See also decomposition; compare detrivore. Depth gauge: A device used to measure pressure and display the equivalent depth in water Dessication: Drying out or loss of water, usually due to subaerial exposure of a normally submerged environment. Detritus: Dead organic matter of plant or animal. Detrivore: An organism that feeds on large bits of dead and decaying organic matter. What detrivores leave behind is used by decomposers. Crabs and seabirds are examples of detrivores. Diatoms: Microscopic algae with plate-like structures composed of silica. Dioecious: Describes a plant which the male and female reproductive parts are located on different individuals. Diurnal: Having a daily cycle or occurring every day; especially pertaining to actions which are completed in 24 hours and are repeated every 24 hours Diversity - The richness and evenness of a group of species.
Ecology: The study of the physical and biological interactions between an organism and its natural environment. Ecological Niche: The role a plant or animal plays in its community. The niche of an organism is defined by what it eats, its predators, salt tolerances, light requirements etc. Two species cannot live stably in the same habitat if they occupy identical niches. Ecosystem: A community of plants, animals and other organisms that are linked by energy and nutrient flows and that interact with each other and with the physical environment. Rain forests, deserts, coral reefs, and grasslands are examples of ecosystems. Ecosystem Diversity: The diversity of biological communities and their physical environment. Diversity is determined by the species composition, physical structure and processes within an ecosystem. This is the highest level of biodiversity. See also biodiversity; compare species diversity, genetic diversity. Effluent: Industrial or urban waste discharged into the environment. Endangered: A species or ecosystem that is so reduced or delicate that it is threatened with or on the verge of extinction. Compare extinct, extirpated, threatened, vulnerable. Environment: All of the physical, chemical, and biological factors in the area where a plant or animal lives. Epilithic: A term for organisms that live attached
to rocks. Latin translation:epi = upon lith = rock Epiphyte: A plant which naturally grows upon another plant but does not derive any nourishment from it. Eutrophication: Enrichment of a water body with nutrients, resulting in excessive growth of phytoplankton, seaweeds, or vascular plants, and often depletion of oxygen. Evenness - A measure of the similarity of the abundances of different species in a group or community.
Fauna: The representative animal or other life of a specific region. Fauna can also be representative of a particular time because of changing weather and climate conditions. Fertilization: The joining or fusion of the male gamete (sperm) and the female gamete (egg) to form a zygote during sexual reproduction. See also gamete, zygote. Flora: The representative plant-life of a specific region. Flora can also be representative of a particular time because of changing weather and climate conditions. Food Chain: A linear sequence of organisms that exist on successive trophic levels within a natural community, through which energy is transferred by feeding. Primary producers capture energy from the environment (through photo- or chemo-synthesis) and form the base of the food chain. Energy is then passed to primary consumers (herbivores) and on to secondary and tertiary consumers (carnivores and top carnivores) (e.g. phytoplankton -> zooplankton -> herring -> salmon -> killer whales). Once they die, these organisms are in turn consumed and their energy transferred to detrivores and decomposers. Compare food web. Food Web: A non-linear network of feeding between organisms that includes many food chains, and hence multiple organisms on each trophic level. For example, both sharks and tuna eat herring, and sharks also eat tuna.
Gamete: A mature reproductive cell that is capable of fusing with another gamete of the opposite sex to form a zygote. Male gametes are typically known as sperm and female gametes a typically known as eggs. See also fertilization, zygote. Generalist: A species that can live in many different habitats and can feed on a number of different organisms. Genes: The hereditary material coded in cells that determine how an organism will look and behave. A gene is a single unit located on a chromosome and is thereby passed from one generation to the next. Genes are what make each species and individual unique. For example, genes are responsible for hair colour and texture in humans. Genetic Diversity: The genetic variation that occurs within a population or species. For example, there are several different colour dog whelk shells and sea stars. See also biodiversity. Gonophore: A structure bearing or consisting of a reproductive organ or part, such as a reproductive polyp or bud in a hydroid colony.
Habitat: The immediate space where an animal or plant lives and has food, water and protection. Habitat loss, which includes the destruction, degradation, or fragmentation of habitats, is the primary cause of decreasing biodiversity. Herbivore: A plant-eating animal. Sea urchins re a good example of a marine herbivore as they feed on kelp. See also heterotroph, primary consumer. Hermaphrodite: An animal that has both male and female reproductive organs. Nudibranchs (sea slugs) and barnacles are good examples of a hermaphrodite. Heterotroph: An organism that is unable to synthesize organic compounds (and thus its energy) from the environment and therefore fulfils its energy requirements by feeding on other organisms.
Inorganic: Part of or derived from non-biological material. A chemical compound that does not include a carbon chain. Intertidal: The area between the high tide mark and the low tide mark on a seashore Introduced Species: An organism that has been brought into an area, usually by humans, where it does not normally occur. Introduced species often compete with and cause problems for native species. Introduced species are also called exotic, nonnative, alien species, or invasive species. Invasive Species: An introduced species that out-competes native species for space and resources. An example of a marine invasive species in Maine is the Asian Shore Crab, Hemigrapsus sanguineas.
Keystone Predator: The dominant predator or the top predator that has a major influence on community structure. For example, sea otters are a keystone predator in kelp beds. Sea otters eat urchins that feed on kelp which house a huge diversity of other organisms. If sea otter populations are lowered in an area the kelp beds are generally reduced and urchin barrens appear. Keystone Species: A species that has a major influence on community structure.
MIxed tide: The type of tide in which a diurnal wave produces large inequalities in heights and/or durations of successive high and/or low waters. This term applies to the tides intermediate to those predominantly semidiurnal and those predominantly diurnal. Monecious: Male and female reproductive organs are found in the same plant or animal Morphology: The form and structure of an organism, in particular its outside features. Mutualism: Two species living together in a relationship in which both benefit from the association.
Native Species: A species that occurs naturally in an area (i.e. is not introduced). Natural Selection: The main mechanism of evolutionary change. In a given population of organisms, there are heritable traits that enable some members to contribute a larger number of offspring than others. If these offspring also have a greater reproductive success, then the genetic composition of the population is altered, thus evolution. Neap tide: The tide with the least variation in water level, occurring when the moon is one quarter and three quarters full. The lowest high tide and the highest low tide occur at neap tide. The opposite is the spring tide. Nonrenewable Resource: A resource that is in limited supply and can't be replenished by natural processes, at least not for thousands of years or more. Fossil fuels are nonrenewable resources.
Omnivore: An animal that eats both plants and other animals. Organic: Part of or derived from living organisms. Or a chemical compound that contains carbon as an essential component. Over-consumption: The use of resources at a rate that exceeds the ability of natural processes to replace them.
pH: The chemical p(potential) of H (Hydrogen) using a scale of 1 to 14 and is a measure of the activity of hydrogen ions (H+) in a solution. pH expresses how acidic or how alkaline a solution or chemical is. Pelagic: Refers to the plants and animals that live in the water column or in the open waters of the ocean rather than the ocean floor (see benthic). Life is found throughout the pelagic zone, however is more concentrated at shallower depths. Pelagic organisms can be further divided into the plankton and nekton. Pesticides: Chemical products used to reduce or eliminate unwanted organisms, regarded as "pests". Pesticides are often used on gardens, agricultural land, roadsides, and golf courses to eliminate species considered undesirable or damaging. Photic Zone: The surface layer of the ocean that is penetrated by sunlight. The photic zone is the layer of the ocean that has been explored the most as it is relatively easy to access with conventional diving equipment. In the photic zone phytoplankton flourish and it is where the fish, marine mammals, and marine invertebrates that most people are familiar with are found. Light can penetrate down to approximately 200m which marks the end of the photic zone. Photoautotroph: An organism that captures the sun's energy and uses it to make organic compounds from inorganic materials. Photosynthesis: A chemical process whereby plants and algae use a sun's energy to make sugars (organic compounds) from carbon dioxide and water (inorganic compounds). Phylum: After Kingdom. The broadest classification for animals. Phytoplankton: The plant and algae component of the plankton; the primary producers of almost all marine food webs. Plankton: Pelagic organisms that float through the water column, not attached to any substrate and unable to move against the currents and tides. Population: The number of individuals of a particular species that live within a defined area. Predator: An organism that captures and feeds on other organisms. Prey: An animal that is used by other animals for food. Primary Consumer: A heterotrophic, herbivorous organism that feeds directly on a primary producer. Urchins are a primary consumer as they feed on kelp. Primary Producer: An autotrophic organism that makes complex organic compounds from inorganic compounds through the process of photosynthesis or chemosynthesis. For example, phytoplankton synthesize sugars (organic compounds) from carbon dioxide and water(inorganic compounds) using energy from the sun. Phytoplankton is one example of a marine primary producer. Primary Production: Synthesis of organic matter by plants, which is the main source of energy and nutrition for other consumers in the ecosystem (e.g. herbivores). See also chemosynthesis, photosynthesis. Proboscis: In general, a proboscis (from Greek pro "before" and baskein "to feed") is an elongated appendage from the head of an animal. The most common usage is to refer to the tubular feeding and sucking organ of certain invertebrates like insects, worms, and mollusks.
Quadrat: An ecological sampling unit that consists of a square frame of known area. The quadrat is used for quantifying the number or percent cover of a given species within a given area. See also transect.
Recruitment: The addition of new members to a population through reproduction or migration. Renewable Resource: A resource that can be replenished through natural processes within a human life span, if it is soundly managed. Richness - The number of different species in a group or community.
Salinity: A measure of the quantity of dissolved solids in ocean water. A salinity of 35 ppt means 35 pounds of salt per 1,000 pounds of seawater. Open ocean salinity is generally in the range from 32 to 37 ppt. Salinity is now measured as practical salinity units (psu). Sea level: The height of the surface of the sea midway between the average high and low tides Secondary Consumer: A heterotrophic, carnivorous organism that feeds on a primary consumer. Herring feeding on zooplankton are an example of a secondary consumer. See also food chain, heterotroph, primary consumer. Selection Pressure: A measure of the effectiveness of natural selection in altering the genetic composition of a population. See also natural selection. Semi-diurnal tide: The type of tide having two high waters and two low waters each tidal day with small inequalities between successive high and successive low water heights and durations. Sessile: Refers to an organism that is permanently attached or fixed; not free-moving. Specialist: A species with a very narrow range in habitat or food requirements. Speciation: The evolution of one or more species from an existing species. Species - A group of organisms that have the ability to interbreed. Species: A group of organisms that differ from all other groups of organisms and that are capable of breeding and producing fertile offspring. This is the smallest unit of classification for plants and animals. Species Diversity: A measure of both species abundance and species richness. An area that has a large number of species and many representative individuals from each species is more diverse than an area that has only a single species. Species Abundance: The total number of individual of a species within a given area or community. Species Richness: The number of different species that exist within a given area or community. Spring tide: A tide higher than normal which occurs around the time of the new and full moon. Stipe: The stem-like part of a seaweed thallus. Substrate: The material upon or within which a plant or animal live or grows (e.g. rocky or sandy substrate). Sustainable: A sustainable way of life is one in which human needs are met without diminishing the ability of other people, wild species, or future generations to survive. Symbiosis: An interaction between two different species where either both, one or neither of the organisms benefit from the relationship. Many symbiotic relationships are obligatory (e.g. tropical reef building corals and their algal symbiont, also lichens). Systematics: The area of biology that deals with the diversity of living organisms, their relationships to each other through evolution, and their classification. Can also be referred to as taxonomy.
Taxonomy: The theory and practice of describing, naming and classifying plants and animals. Threatened: A species likely to become endangered if limiting factors are not reversed. Tide: The alternating rise (flow) and fall (ebb) of the ocean water in response to the gravitational attraction of the sun and moon. Tide pool: A small body of trapped water created on rocky shores along the ocean when the ocean recedes during low tide. Transect: A straight line placed on the ground along which ecological measurements are taken. If an ecologist wanted to sample the diversity of intertidal organisms in the intertidal, he/she would place a number of transects perpendicular to the shore and take samples at predetermined interval lengths. Trophic levels: The energy levels or steps in a food chain or food web: primary producer, primary consumer, secondary consumer, tertiary consumer etc.
Water Cycle: The continuous circulation of water from the atmosphere to the earth, including the ocean, and back to the atmosphere through condensation, precipitation, evaporation, and transpiration.
Zooplankton: Animal component of the plankton that feed on phytoplankton and other zooplankton (primary consumers). Zygote: A fertilized egg. Or the diploid cell that results from the joining of two haploid gametes (sperm and egg) during sexual reproduction, that will cleave to form an embryo. See also fertilization, gamete. |
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