Fragile ecosystems Flashcards
Factors that affect the distribution of mangroves
Temperature: Mangroves require warm temperatures, usually around 27C to thrive, limiting them to tropical and sub-tropical regions
Salinity: Need saline water
Tidal range: Grow in intertidal zones, where tidal fluctuations expose their roots to both air and water
Sediment: Thrive in muddy, nutrient-rich sediments
Value of mangroves
Coastal Protection
Carbon storage
Biodiversity
Threats to mangroves
Deforestation for aquaculture: mangroves are often cleared to make way for shrimp farms and other farms
Coastal Development: expanding coastal towns, cities, and tourism facilities often damage mangroves, reducing their size and health
Pollution: Industrial and agricultural runoff contaminate mangrove ecosystem, causing eutrophication
How can mangroves be managed
Establishing protected areas
Reforestation and restoration projects
Factors that affect the distribution of coral reefs
Temperature: Corals need warm water, usually between 23–29°C, so they are found in tropical and sub-tropical waters, minimum 18 degrees
Salinity: Require stable salinity levels, generally found in oceanic conditions
Light: Need sunlight for photosynthesis (through symbiotic algae), so they grow in shallow, clear waters
Water clarity: Suspended sediments and pollutants reduce sunlight and can smother coral
Depth: Typically found at depths less than 25 meters due to light requirements
Value of coral reefs
Biodiversity: Support around 25% of all marine species despite covering less than 1% of the ocean floor
Coastal protection: Act as natural barriers against storms and erosion
Tourism and fisheries: Attract tourists and support fishing industries, providing economic value
Medical research: Source of new medicines and biomedical discoveries
Threats to coral reefs
Climate change: Rising sea temperatures cause coral bleaching and stress
Ocean acidification: Increased CO₂ lowers pH, weakening coral skeletons
Overfishing: Disrupts ecological balance and can lead to algae overgrowth on reefs
Pollution: Runoff with nutrients and chemicals causes algal blooms and degrades water quality
Destructive fishing practices: Such as blast fishing or cyanide fishing, physically damage reefs
How can coral reefs be managed
Marine protected areas (MPAs): Limit human activities and allow ecosystems to recover
Reef restoration projects: Includes coral farming and transplantation
Reducing carbon emissions: Helps combat climate change and ocean acidification
Sustainable tourism and fishing: Educating communities and enforcing regulations
Monitoring and research: Helps track reef health and guide conservation strategies
Factors that affect the distribution of salt marshes
Sheltered coastline: Usually form in estuaries and behind spits where wave energy is low
Tidal conditions: Require tidal flooding to bring in sediment and nutrients
Sediment supply: Need fine sediment (like mud and silt) to accumulate and create marshy land
Vegetation: Pioneer plants (e.g. cordgrass) help trap sediment and stabilise the area
Value of salt marshes
Biodiversity: Provide habitats for birds, fish, and invertebrates
Coastal protection: Absorb wave energy and reduce erosion and flooding risk
Carbon storage: Trap and store large amounts of carbon in sediment and plants
Water purification: Filter pollutants from water flowing through the marsh
Threats to salt marshes
Land reclamation: Drained for agriculture, industry, or development
Pollution: Agricultural runoff and industrial waste can damage ecosystems
Sea level rise: May submerge salt marshes if sediment accumulation doesn’t keep up
Disturbance: Human activity, including trampling and boating, can destroy vegetation and habitats
How can salt marshes be managed
Managed retreat: Allowing controlled flooding to restore natural marshes
Legal protection: Designating areas as Sites of Special Scientific Interest (SSSIs) or nature reserves
Restoration projects: Reintroducing native vegetation and reconnecting natural tidal flow
Monitoring: Regular checks to track health and changes in the marsh ecosystem
Factors that affect the distribution of sand dunes
Supply of sand: Large amounts of dry sand are needed, usually from nearby beaches
Wind: Strong, onshore winds move sand inland to form dunes
Vegetation: Pioneer plants like marram grass trap sand and stabilise dunes
Obstacle: Dunes begin forming when something (e.g. driftwood or vegetation) disrupts wind flow and causes sand to settle
Value of sand dunes
Habitat: Support a range of specialised plant and animal species
Natural barrier: Protect inland areas from storm surges and coastal flooding
Recreation: Used for walking, tourism, and education
Scenic value: Contribute to coastal beauty and attract visitors
Threats to sand dunes
Trampling: Foot traffic damages vegetation and leads to erosion
Development: Construction for tourism and housing can destroy dunes
Invasive species: Non-native plants can outcompete native dune stabilisers
Climate change: Increased storm activity and sea level rise threaten their structure
How can sand dunes be managed
Boardwalks and fencing: Limit trampling and protect fragile areas
Planting vegetation: Marram grass planted to stabilise dunes and encourage growth
Zoning and access control: Direct visitors to certain paths to reduce pressure
Education: Informing the public about dune importance and how to protect them
