Block 10 (The Impact Of Human Activity On Coastal Systems) Flashcards
What are the positive ways humans affect the coast?
- Conservation
- Sustainable management (managed realignment + soft e)
What is conservation?
The preservation + protection of nature
How can coastal conservation vary from extreme to limited?
- Extreme = total protection of an area
- Limited = reducing public access to an area
How does conservation happen on a global scale? Give an example
World Heritage Sites
- Protect cultural/natural sites that have ‘Outstanding Universal Value’
- E.g. Jurassic Coast, England
How does conservation happen on a national scale? Give an example
National Marine Reserves (‘Marine Conservation Zones’ in GB)
- Protected marine areas
- E.g Castle Espie, N.Ire
How does conservation happen on a local scale? Give an example
Sites of Special Scientific Interest (SSSIs)
- Small protected areas/features
- E.g. Ainsdale sand dunes, Lancashire
What is an integrated shoreline management plan?
Looking at all stakeholders across larger scale sediment cells, to consider the coast + its management holistically and sustainably
Why are integrated SMPs good?
- Ensure one area isn’t protected at the expense of another
- Try to be more sustainable + working with nature
What are the two management techniques that are actually helping the coast?
- Soft engineering
- Managed realignment
What is soft engineering?
Working with nature to try to reduce extent of natural processes (E.g. erosion)
How is a shift to soft engineering benefiting the coast?
- More environmentally friendly, by working with nature
- E.g. shift to beach nourishment > artificial structures
What is managed realignment?
Allowing the shoreline to move inland, in a controlled way, to a new line of defence
What coastal management strategies is soft engineering part of?
- Holding the line
- Advancing the line
Where is managed retreat implemented?
Areas with low development/land usage (so can be sacrificed to sea)
What is an example of managed realignment in the UK?
Pagham Harbour, Medmerry
What is an example of managed realignment abroad?
Florida + Louisiana (USA)
What factors influence the relative success of managed realignment?
- Current land use (high = less success, have to pay lots of compensation)
- Estuary size/shape/location
- Tidal regime
- Extent site has been researched (low = less success, must understand ecological processes there)
- Quality of site + how well this quality continues to be managed
How does managed realignment benefit the coast?
Reduced coastal squeeze
- Ecosystems (e.g mudflats + salt marshes) allowed to form naturally
- Habitats formed in these ecosystems, increasing biodiversity
Why is managed realignment also a good strategy for humans (non-environmental benefits)?
- Sustainable
- Cheaper than holding the line and maintaining hard engineering
- Tourism potential
What are the issues with managed realignment?
- Only solution for certain locations
- New technique (uncertain outcomes)
- Hard to plan around unpredictable tidal processes
- Compensation paid for land lost
- Locals may view as ‘giving up’
What conflict is emerging at the coast?
Conflict between need for coastal development + conservation
What are two negative impacts that humans have on the coast?
- Offshore dredging
- Sand dune erosion
What is offshore dredging?
Extraction of sand + gravel from the seabed
Why does offshore dredging occur?
- Aggregates for construction
(1/5 sand + gravel in UK construction is from seabed)
(Key ingredient in concrete)
(Often used for coastal defence - building hard structures + beach nourishment) - Removal to create channels for large ships + provide port access
Who provides licenses for offshore dredging? How do they personally benefit?
Government - Crown Estate
- Licenses are paid for
- They have earned £13 million over 1 year
How does offshore dredging negatively impact the coast?
- Destroys seabed habitats, interfering with marine food web
- Toxins can be released from seabed - harming organisms
- Nutrients can be released from seabed - algal blooms - produce toxins
- Increased erosion - offshore buffer lost, beaches starved
What kind of systems are sand dunes?
Dynamic (constantly changing) systems, that are very sensitive
What are the 4 ways humans can erode sand dunes?
- Conversion
- Removal
- Utilisation/overuse
- External factors
What is the conversion method of sand dune erosion?
Dune area used for urbanisation/development, including altering/removing veg, so dunes can’t function properly: break down
What is the removal method of sand dune erosion?
Sand from dune area is removed for industry or to improve beach access: break down dunes
What is the utilisation/overuse method of sand dune erosion?
Dunes used as they are as an amenity (e.g. tourism, training), veg slowly removed: break down
What is the external factors method of sand dune erosion?
Human activity elsewhere on coast affects dunes (e.g. groynes updrift starve dunes of sediment: break down)
What are the negative impacts of dune erosion?
- Habitat loss
- Biodiversity loss
- Increase of coastal erosion, leading areas vulnerable to coastal flooding
How can sand dune erosion be reduced?
- Complete reconstruction (in heavily damaged areas)
- Restoration + repair (of less damaged dunes, e.g. replanting veg, fencing off)
- Holistic management (tackle causes of erosion, e.g. access permits + removing external factors)