Aquatic Biodiversity

Plankton

small organisms that drift in water and cannot swim against currents

Zooplankton

animal plankton that feed on phytoplankton and other plankton

Phytoplankton

photosynthetic plankton that form the base of aquatic food webs

Nekton

strong-swimming aquatic organisms that can move independently of currents

Benthos

organisms that live on or in the bottom of aquatic environments

Euphotic zone

upper ocean layer with sunlight where photosynthesis occurs and nutrients are low to moderate

Bathyal zone

deep ocean layer with little sunlight and moderate nutrients

Abyssal zone

deepest ocean layer with no sunlight and nutrients that cannot be used for photosynthesis

Oligotrophic

low nutrients clear water low productivity and high dissolved oxygen

Mesotrophic

moderate nutrient levels and moderate productivity

Eutrophic

high nutrients high productivity frequent algal blooms and low oxygen

Hypereutrophic

extremely high nutrients severe algal blooms very low oxygen and fish kills

Estuaries and coastal wetlands

filter pollutants reduce flooding protect coastlines and provide nursery habitats

Mangrove forests

prevent erosion protect coastlines store carbon and provide fish habitat

Coral reefs

support biodiversity protect coastlines support fisheries and tourism

Inland wetlands

purify water reduce flooding recharge groundwater and provide wildlife habitat

Rivers

provide freshwater transport nutrients support ecosystems and generate hydropower

Source zone

fast moving narrow cold water with high dissolved oxygen

Transition zone

moderate water speed wider channel and warmer water

Floodplain zone

slow moving wide warm water with lower dissolved oxygen