Chapter 8 Flashcards
encompass all water-based ecosystems, including freshwater (e.g., lakes, rivers) and marine (e.g., oceans, estuaries) ecosystems. These environments are characterized by the presence of water, which shapes the biological, chemical, and physical processes occurring within them.
Aquatic environments
refer to aquatic systems with low salt concentrations,
including rivers, lakes, ponds, and wetlands. These ecosystems are crucial for supporting a diverse range of plant and animal species and providing essential services such as water purification, habitat for wildlife, and recreational opportunities.
Freshwater ecosystems
is the process by which water bodies become overly enriched with nutrients (especially nitrogen and phosphorus), often due to runoff from agriculture and urban areas. This nutrient overload can lead to excessive algal blooms, which deplete oxygen levels in the water and result in hypoxic conditions detrimental to aquatic life.
Eutrophication
refers to the patterns and variability of water flow in aquatic systems over time, including factors like seasonal changes, storm events, and human alterations (e.g., dam operations). Flow regimes influence the physical and biological characteristics of rivers and streams, affecting habitat availability and species diversity
flow regime
describes the extent to which water moves through
different parts of an aquatic system, connecting various habitats (e.g., wetlands, rivers, lakes). This connectivity is vital for maintaining ecological processes, supporting species movement, and promoting nutrient cycling within ecosystems.
Hydrologic Connectivity
are transitional areas between terrestrial and aquatic environments, characterized by saturated soils, standing water, and distinct plant communities adapted to wet conditions. They serve essential functions, such as flood control, water purification, and providing habitat for diverse wildlife, especially migratory birds and amphibians.
wetlands
refer to the ecological regions at the lowest level of a water body, including the sediment surface and sub-surface layers. Benthic habitats are home to various organisms (e.g., worms, crustaceans, mollusks) that play critical roles in nutrient cycling and energy transfer within aquatic ecosystems.
Benthic environments
involves the active management and rehabilitation of
degraded coral reef ecosystems to restore their structure, function, and biodiversity. Techniques may include coral transplantation, habitat protection, and
reducing stressors (e.g., pollution, overfishing) to promote coral health and resilience.
Coral Reef Restoration
refer to the industry and practices associated with the harvesting of fish and other marine organisms from ocean waters. Sustainable management of marine fisheries aims to ensure the long-term viability of fish populations, minimize bycatch, and protect the health of marine ecosystems
Marine Fisheries
Threats to Aquatic Ecosystems
Freshwater Systems:
● Habitat destruction: Dams, drainage of wetlands, and water diversion projects alter
natural water flow and destroy habitats for aquatic species.
● Pollution: Agricultural runoff, industrial waste, and sewage introduce harmful chemicals,
nutrients (leading to eutrophication), and sediments into water bodies, degrading water
quality.
● Overexploitation: Overfishing, water withdrawal for agriculture, and the extraction of
aquatic species threaten biodiversity and ecosystem stability.
● Invasive species: Non-native species introduced by human activity can outcompete or
prey on native species, leading to declines in biodiversity.
Marine Systems:
● Overfishing: The depletion of fish stocks due to unsustainable fishing practices,
including bycatch (the unintentional capture of non-target species), is a major issue in
marine conservation.
● Pollution: Marine environments are particularly vulnerable to pollution from land-based
sources (e.g., plastics, heavy metals, oil spills) and marine activities (e.g., shipping,
fishing gear).
● Climate change: Rising sea temperatures, ocean acidification, and sea-level rise impact
marine species, coral reefs, and coastal ecosystems
- is the area of land where all the water drains into a
common water body, such as a river, lake, or ocean. - are critical for managing the flow of water, nutrients, and sediments into aquatic ecosystems.
watershed
aims to protect water quality and ecosystem health by
controlling land use, managing pollution sources, and maintaining natural vegetation in riparian zones (the areas along the banks of rivers and streams).
Watershed management
serve as buffers that protect aquatic ecosystems by filtering pollutants, stabilizing stream banks, and providing habitat for aquatic and terrestrial species.
● The protection and restoration of riparian zones are key strategies for improving water
quality and reducing the impact of human activities on aquatic systems.
Riparian Zones
are critical ecosystems that provide habitat for diverse species, especially birds, amphibians, and fish, and play a key role in water purification, flood control, and
groundwater recharge.
Wetlands
results from draining for agriculture, urban development, pollution, and invasive species.
Wetland degradation
