GLOSSARY

Active LakeWatch lakes - Lakes that have been sampled within the last six months by a LakeWatch Volunteer. All City lakes are also sampled quarterly by the City's Environmental Specialists. See Lakes in the City.

Aeration - the process of supplying air to a lake; promotes degradation of organic matter.

Aquashade® - Aquashade® is a blend of blue and yellow dyes specifically designed to screen or shade portions of the sunlight spectrum (red-orange and blue-violet) required by underwater aquatic plant and algae growth in lakes and ponds.  It is not toxic to fish, and is not an algaecide, but rather, is designed to prevent the growth of aquatic plants and algae.  Aquashade® can be added to maintain a pond or lake.  Lakes or ponds treated with Aquashade® tend to appear aqua-blue in color.

Chlorophyll-A - one type of chlorophyll, the green pigment found in plants.  Measurements of the chlorophyll concentrations in water samples are used to estimate algal biomass in a water body and to assess a water body's biological productivity.

Eutrophic - one of the four trophic state categories, the eutrophic state is defined as having a high level of biological productivity, second only to the hypereutrophic category.  A eutrophic water body is capable of producing and supporting an abundance of living organisms (plants, fish, and wildlife), but the system can be deficient in dissolved oxygen.  

Equivalent Residential Unit (ERU) - based on a typical Single Family Residential Parcel of 7760 square feet with 2000 square feet of impervious surface area. A parcel's ERU equivalence equals the amount of impervious area (measured in square feet) divided by 2000.  See Stormwater Utility Fee.

Grass Carp - a herbivorous (plant-eating) species of fish (Ctenopharyngodon idella) native to Africa.  Sterile, non-breeding populations have been introduced into some Florida water bodies to control undesirable plants. 

Hypereutrophic - one of the four trophic state categories, the hypereutrophic state is defined as having the highest level of biological productivity.  The prefix "hyper" means over abundant.  Hypereutrophic water bodies are among the most biologically productive in the world. Characterized by frequent and severe nuisance algal blooms and low transparency.

Inactive LakeWatch lakes - Lakes that are in the LakeWatch program but have not been sampled by a LakeWatch Volunteer within the last six months. All City lakes are sampled quarterly by the City's Environmental Specialists. See Lakes in the City.

Mesotrophic - one of the four trophic state categories, between oligotrophic and eutrophic, it is defined as having a moderate level of biological productivity.  The prefix "meso" means mid-range. A mesotrophic water body is capable of producing and supporting moderate populations of living organisms (plant, fish, and wildlife).

Nitrogen - an element that, in its different forms, stimulates the growth of aquatic plants and algae in water bodies.

Non-ad Valoremcharges  - Stormwater utility fess not based on the value of the property.  See Stormwater Utility Fee.

LakeWatch lakes  - Lakes that have never been sampled in the LakeWatch Volunteer Program. All City lakes are sampled quarterly by the City's Environmental Specialists. See Lakes in the City.

Oligotrophic - one of the four trophic state categories, describes a lake with clear water, low nutrients, but rich in dissolved oxygen, and characterized by few water quality problems.  Is capable of producing and supporting relatively small populations of living organisms (plants, fish, and wildlife). Trophic State Index value below 50.

Phosphorus - an element that, in its different forms, stimulates the growth of aquatic plants and algae in water bodies.

Secchi depth - (pronounced "secky") a measurement that indicates water clarity.  Traditionally, the transparency or water clarity of a water body has been measured by using an 8-inch diameter disc called a "Secchi disc," that was named in honor of its inventor. To use the Secchi disc to measure water clarity, it's lowered into the water to find the depth at which it first appears to vanish from the observer's sight.

Trophic State - the degree of biological productivity of a water body.  Biological productivity generally relates to the amount of algae, aquatic plants, fish and wildlife a waterbody can produce and sustain.  Image below from: http://lakewatch.ifas.ufl.edu/. 

Trophic State Index - a scale of numbers from 1 to 100 that can be used to indicate the relative trophic state of a water body.  Low TSI values indicate lower levels of biological productivity, and higher TSI values indicate higher levels.  

Urban Ponds - Ponds that have been intensively managed since 1991 to provide good action for beginners and/or those wanting to eat fish.  Usually have good bank access, fish feeders, fish attractors, and aeration.  Routinely stocked with catfish and on occasion hybrid striped bass and adult largemouth bass. See Fishing In Orlando.

Watershed - the area from which water flows into a water body.  Activities in a watershed, regardless of whether they are natural or man-made, can affect the characteristics of a water body.