Estuaries (17)

Estuary

An inlet of the ocean that extends into a river valley as far as the upper limit of the tide, serving as a transition zone between freshwater and seawater ecosystems.

Coastal Plain Estuary

An estuary formed by glacial melt raising the sea level, flooding low-lying rivers and plains (e.g., Chesapeake Bay).

Tectonic Estuary

An estuary formed when an earthquake causes land to sink, allowing seawater to cover it (e.g., San Francisco Bay).

Bar-built Estuary

An estuary formed when sediments deposit at the river mouth, creating a barrier between river and ocean (e.g., Pamlico Sound).

Fjord

A deep, narrow estuary formed by glacial activity, filled with water after the glaciers retreated (e.g., Saanich Inlet, Bonne Bay).

Salinity Gradient

The variation of salinity levels within an estuary, ranging from freshwater close to river input to saline water near the ocean.

Biological Oxygen Demand (BOD)

A measure of the amount of oxygen that microorganisms will consume while decomposing organic matter in the water, often limiting in estuarine sediments.

Detritus

Organic matter that is broken down into smaller pieces and forms the base of estuarine food webs.

Osmoregulator

An organism that can maintain the concentration of salts in its body tissues, allowing migration between freshwater and seawater (e.g., salmon, striped bass).

Suspension Feeders

Organisms that feed by filtering suspended particles from the water, important in controlling phytoplankton populations (e.g., bivalves like oysters).

Hypoxia

A condition of low oxygen availability in water, which can negatively impact estuarine ecosystems.

Estuarine Food Web

A complex network of interactions among organisms in an estuary where detritus is the base, supporting various trophic levels.

Human Impacts on Estuaries

Activities such as high nutrient inputs, overfishing, and introduction of invasive species that negatively affect estuarine ecosystems.

Brackish-water Benthic Fauna

Aquatic organisms that exist in brackish water conditions (salinity 5 - 18) distinct from freshwater and true seawater.

Epifauna

Organisms that live on the surface of the substrate in an estuary, often good osmotic regulators.

Infauna

Species that live buried within the sediment of the estuary, experiencing less salinity variation.

Nutrient Runoff

The flow of nutrients from freshwater into estuaries, which can enhance primary productivity but also lead to problems such as hypoxia.

Detritivore

Organisms that feed on detritus, playing a key role in the nutrient cycle of estuarine ecosystems.

Estuarine Biology

The study of the diverse biological communities and ecosystems found within estuaries, highlighting their productivity and species interactions.

Estuarine Species

Organisms that have adapted to live in both freshwater and saline environments within estuaries.

Nutrient Cycling

The movement and transformation of nutrients within estuarine ecosystems, involving processes such as decomposition, uptake by plants, and mineralization.

Trophic Levels

The hierarchical levels in an ecosystem, each representing a different position in the food chain, including producers, consumers, and decomposers.

Wetland Buffer Zones

Areas surrounding estuaries that absorb excess nutrients and pollutants before they enter the ecosystem, enhancing water quality.

Estuarine Stratification

The layering of water in estuaries, often due to differences in temperature, salinity, and density, which affects circulation and habitat conditions.

Invasive Species Impact

The effects of non-native species introduced to estuaries, which can outcompete native species and disrupt ecological balance.

Ecosystem Resilience

The ability of an estuarine ecosystem to recover from disturbances while maintaining its essential functions and processes.

Fish Migration Patterns

The seasonal movements of fish species to and from estuaries for breeding, feeding, or as part of their life cycle.

Sediment Quality Assessment

The evaluation of sediment in estuaries to determine levels of pollutants, which impacts the health of the ecosystem.

Ecotones

Transitional zones between different ecosystems, such as freshwater and saltwater habitats found in estuaries, which support unique biodiversity.

Salinity Adaptation Strategies

Mechanisms employed by estuarine species to survive in variable salinity conditions, such as physiological and behavioral adaptations.

Estuary Zonation

The distinct ecological regions within an estuary based on factors such as salinity, vegetation, and tidal influence.

Biomagnification

The increase in concentration of toxic substances in organisms at higher trophic levels within an estuarine food web.

Tidal Energy and Dynamics

The natural forces that influence estuaries' water levels and currents, shaping their physical and ecological characteristics.

Phytoplankton Role

Microalgae that form the base of the food web in estuaries, providing oxygen and serving as primary producers.

Restoration Ecology

The scientific discipline focused on restoring degraded estuarine environments to enhance biodiversity and ecosystem services.

Water Quality Monitoring

The systematic assessment of water parameters in estuaries to gauge health and ecological integrity.

Disturbance Regimes

Patterns of disturbances, such as storms and floods, that can significantly shape estuarine habitats and species interactions.

Hydrodynamics in Estuaries

The study of water movement and flow patterns, which influence nutrient distribution, habitat structure, and species behavior in estuaries.

Benthic Community Dynamics

Interactions and relationships among organisms living in the sediment of estuaries, which play a key role in nutrient cycling.

Ecosystem Functioning

The natural processes and interactions that occur in estuarine ecosystems, contributing to biodiversity and human benefits.