TermDefinitionKeywords (not displayed)
Abundancethe size or number of members of a population. GDEP is attempting to determine the number of common bottlenose dolphins who live in the tidal rivers and embayments between St. Catherine’s & Sapelo Sounds.
Barrier Islanda long, broad, sandy island lying parallel to a shore built up over time by the action of waves, currents and winds that protects the shore from the effects of the ocean.Where dolphins are found
Behaviorwe routinely record six dolphin behaviors using standard definitions. One or more behaviors by one or more dolphins may be observed during a sighting event. Behavior
The behaviors and their codes/definitions are:

  1. Traveling — directional movement, e.g., a dolphin or dolphins swimming down a river with apparent purpose,

  2. Milling — non-directional movement, e.g., a group of dolphins swimming in multiple directions without apparent purpose,

  3. Feeding — a dolphin observed with a fish in her mouth is considered to be feeding,

  4. Probable Feeding — a dolphin observed in pursuit of prey, but a fish is not seen in her mouth is considered to be probable feeding,

  5. Social — playing, tussling, chasing, sex, etc. are examples of social behavior,

  6. Other — other behaviors not specifically defined; examples include boat approach, begging, leaping, spy hopping, etc. Although considered as an “Other” behavior, begging is recorded separately, defined as a dolphin approaching the boat with her mouth open, apparently seeking food. GDEP does not feed dolphins or have any type of physical contact with them.

Birth ratethe rate at which a species or population produces offspring, often expressed as number of live births per year. Also referred to as “natality”.birth
Calving the act of a mother dolphin giving birth; young dolphins are referred to as “calves”.birth
Cetacean or Cetartiodactylathe taxonomic order that includes all whales, dolphins and porpoises.scientific name
Cetacean Morbillivirus (CMV)a virus in the same family of viruses that causes measles in human and canine distemper in dogs. In dolphins it is spread by the inhalation of respiratory particles and direct body contact. Symptoms include emaciation, respiratory problems, skin lesions, pneumonia, brain infections and abnormal behavior. Most recently it has been detected in the East Coast coastal migratory stock of dolphins in July 2013 that resulted in over 1,800 strandings. There is no evidence of infection in the estuarine population, but close monitoring continues. There is no evidence of transmission to humans.scientific
Distributionthe location of the members of a population within an environment. GDEP collects data on the location of common bottlenose dolphins in the tidal rivers and embayments between St. Catherine’s and Sapelo Sounds.dolphin distribution
DNR (Georgia Department of Natural Resources)the state agency with wide responsibility for managing and conserving Georgia’s natural, cultural and historical resources. As it relates to dolphins, GDEP collaborates with biologists in the Nongame Conservation Section of the Wildlife Resources Division to share life history and other information on dolphins and manatees and to assist with stranding response as needed.
Dorsal Finthe vertical fin on the back of a dolphin that provides stability while swimming. The dorsal fin also contains a specialized vascular system (arteries and veins) used in body temperature control. Markings from fishing line, crab pot ropes, interactions with other dolphins, etc, form a profile on the fin that is almost as unique as human fingerprints, allowing for the identification of individual dolphins.Part of dolphins, anatomy
El Niño-Southern Oscillation (ENSO)the ENSO is a recurring climate pattern involving changes in temperature of waters in the central and eastern tropical Pacific Ocean. On periods ranging from about three to seven years, surface waters warm or cool between 1℃ and 3℃, compared to normal. This oscillating warming and cooling pattern, referred to as the ENSO cycle, directly affects rainfall distribution in the tropics and can have a strong influence on weather across the US and other parts of the world. The ENSO cycle consists of three phases: 1) El Niño — a period of above-average sea surface temperatures (SST); low-level surface winds that normally blow east to west along the equator weaken or may start blowing in the opposite direction, 2) La Niña — a period of below-average SSTs; equatorial winds increase in strength, and 3) Neutral — neither El Niño nor La Niña; normal SSTs and wind direction/speed.climate
GIS (Geographic Information System) GIS is a framework for gathering, managing and analyzing data. Rooted in the science of geography, GIS integrates many types of data. It analyzes spatial location and organizes layers of information into visualizations using maps and 3D renderings. GIS is very useful for revealing geographic and temporal patterns and relationships in large datasets.G.I.S.
GPS (Global Positioning System)a satellite-based navigation system consisting of at least 24 satellites in orbit around the earth that was developed to provide precise positional and velocity data, as well as global time synchronization, for air, sea and land travel.G.I.S.
Habitat Utilizationways in which dolphins use the resources in the environment in which they live. For example, dolphins may use certain areas for feeding, resting, calving, etc.Ecology, found, dolphins
Home Range non-random movement of dolphins within a prescribed geographic area, e.g., St. Catherine’s Sound or Walburg Creekdistribution
Homodont all dolphins have a single type of tooth, a simple peg-like tooth that is used to grasp prey, which is then swallowed whole. This type of teeth of tooth arrangement is referred to as “homodont” dentition. Humans and many other mammals have multiple tooth types (e.g., incisors, molars, etc.), referred to as “heterodont” dentitiondentition
Lasagnathe scalloped trailing edge of a dorsal fin resembling a lasagna noodle; one attribute used to describe the profile of a dolphin fin.
Marine Mammal Protection Act (MMPA) first authorized by Congress in 1972 and amended in 1994, the MMPA protects all marine mammals, including cetaceans, manatees, pinnipeds (seals, sea lions & walrus), sea otters and polar bears in US waters. It established both national policy and procedures to monitor and protect marine ecosystems, marine mammals stocks and individual of dolphins
Marine Mammal Stranding Networka network of organizations, authorized by NOAA Fisheries, that responds to incidents involving injured, sick, dying and dead marine mammals. The Stranding Network includes trained responders and veterinarians who respond to and attempt to rescue and rehabilitate live stranded animals and investigate the cause of death of dead stranded animals. GDEP is a member of the Southeast US Marine Mammal Stranding Networkprotection of dolphins
Methylmercurya persistent environmental toxin. Elemental mercury is released into the atmosphere by combustion in industrial processes, distributed globally by wind currents and precipitated into the oceans as rain. This elemental mercury is then digested and methylated by bacteria in the ocean, which are in turn eaten by fish and progressively larger organisms, eventually working its way to the top of the food web. Methylmercury builds up in the blubber of dolphins and other marine mammals, causing a number of health problems, most notably with hormones involved in reproduction, the central nervous system and the immune system.toxin
Migrationnon-random periodic movement, usually seasonal, in response to availability of prey, reproductive requirements and/or environmental conditions.dolphin ecology
Mortalitythe rate at which a species or population loses members, often expressed as the number of deaths per year.death of dolphins
Mudding or strand feeding a feeding strategy in which one or more dolphins will swim rapidly towards a riverbank (the strand) pushing fish in front of them. The dolphins will follow the fish up onto the beach, putting as much as half of their bodies out of the water, to grasp and eat the fish. This behavior has been observed in a number of dolphin groups in Georgia, South Carolina and Mississippi. A prime example of social learning and culture, mother dolphins model this behavior for their calves, passing the technique on to the next generation.ecology of dolphins, how dolphins eat
Neonatea newborn dolphinbirth, baby dolphin
Nai’athe Hawaiian word for dolphin; (also the name of our boat)
NOAA (National Oceanographic and Atmospheric Administration) the federal government agency within the Department of Commerce that regulates and manages dolphins and other marine mammals in US waters. Multiple offices exist within NOAA, e.g., NOS (National Ocean Service, NMFS (National Marine Fisheries Service), NWS (National Weather Service), etc.
PCB (Polychlorinated Biphenyl) an organic chlorine compound once widely used in a number of manufacturing processes, especially electrical equipment. Highly toxic and persistent in the environment, PCBs are known to cause cancer in animals and are probable human carcinogens. Production of PCBs was banned in the US in 1978, but because of their longevity, PCBs are still in wide use and readily found in soil, water and air.

Of particular concern along the Georgia coast is the presence and persistence of Aroclor 1268, which was released for decades into tidal waters near Brunswick, GA. The contamination was sufficiently extensive in the release area for it to be designated an EPA Superfund Site. A number of studies have documented the transport of Aroclor 1268 to adjacent waterways in Georgia and the build up of the compound in dolphin blubber and plasma, negatively affecting the overall health, reproductive fitness and survival rates of dolphins in the area.

Pedunclethe area of a dolphin’s back behind the dorsal fin, including the tail fluke, that contains very powerful longitudinal muscles used to move the dolphin through the water.dolphin physiology, body
Populationin general terms, all of the members of a species. When applied to dolphins, of which there are many species distributed globally, the term loses significance. In US waters, NOAA refers to dolphins as “stocks”, which are defined by geographic range & morphology. NOAA currently recognizes three major stocks along the East Coast: estuarine (tidal rivers, embayments and nearshore around barrier islands), coastal migratory (dolphins that migrate seasonally up and down the coast within a few kilometers of the coast) and pelagic (offshore, usually east of the Gulf Stream). These larger stocks are divided into smaller units for management purposes, e.g., the Western North Atlantic South Carolina/Georgia Coastal Stock.ecology
Preythe various species of fish and other marine organisms on which dolphins feed are referred to as their prey.what do dolphins eat
Residencydolphins who are observed during surveys within the geographic range of the GDEP study area (St. Catherine’s to Sapelo Sounds) at least 6 months of the year are considered to be “resident” animals. We classify dolphins as “seasonal residents” if we sight them more than once a year at about the same time, usually Spring and Fall. The third class are “transients”, dolphins that we may see more than once, but not on any discernible schedule. More often than not transients appear in our photo catalog only once.where you can find dolphins
Salinity the concentration of dissolved salts in water, usually expressed as parts per thousand (ppt) by weight. Average ocean salinity is 35ppt. The salt in ocean water is mostly made up of the elements sodium and chlorine, which account for 85.7% of dissolved salt.salt
Site Fidelityremaining within or regular return to a generally well-defined geographic area, usually for breeding purposesdolphin ecology, distribution
Social Network/Network Analysisa conceptual framework used to describe and study the social organization of a species, e.g., a dolphin family group.