Coastal Environments Notes

Changes in Coastal Environments

  • Increasing Populations:

  • Coastal areas see significant changes due to rising populations.

    • Examples include the construction of marinas, harbours, ports, and breakwaters.

  • Pollution:

  • Pollution from sources inland (farms, cities, industries) is transported to coastal areas via rivers.

  • Decreasing Freshwater Flows:

  • Water extraction for agricultural and urban use diminishes river flows, negatively affecting coastal lagoons and estuaries.

  • Intensive Farming:

  • Coastal flat, fertile land is often farmed intensively, which can disrupt local ecosystems.

  • Desalination Plants:

  • These facilities alter the salinity of nearby waters, impacting marine life.

  • Land Reclamation:

  • Some areas engage in land reclamation from the sea to create more usable land, particularly where flat land is scarce.

  • Overfishing:

  • Commercial trawling practices can lead to the depletion of fish species, disrupting natural ecosystems.

  • Harbour Dredging:

  • Dredging activities enable larger ships to access ports but can lead to habitat destruction.

  • Invasive Species:

  • Invasive species can be transported globally through ships' ballast water, severely affecting native ecosystems.

  • Impact of Coastal Visitors:

  • Activities such as snorkelling and scuba diving can harm coastal areas.

  • Climate Change and Sea Level Rise:

  • Sea levels are rising due to climate change, which increases coastal erosion, especially during storms and reduces native habitats.

  • Warmer Waters:

  • Fish traditionally found in cooler waters are moving to new locations, causing ecological imbalances and threatening coral reefs.

Coastal Degradation

  • Dynamic Nature of Coasts:

  • Coasts are constantly changing due to natural forces (waves, currents, tides) and human activities.

  • Both can contribute significantly to coastal degradation.

  • Observability of Degradation:

  • Local: Litter on beaches.

  • Regional: Oil spills affecting extensive coastlines.

  • Impacts of Coastal Degradation:

  • Loss of biodiversity, introduction of invasive species, and natural alterations (e.g., sand dunes eroding).

  • Forms of Coastal Degradation:

  • Toxic algal blooms and erosion altering coast shape.

Major Drivers of Coastal Changes

  • Key Drivers of Environmental Degradation:
  1. Climate Change
  2. Population Growth in Coastal Areas
  3. Economic Growth
  • Discussion Questions:
  • What changes are impacting coastal environments?
  • Are coastal areas near cities at a higher risk of degradation compared to remote areas?
  • Examine specific causes of coastal degradation and classify them according to the major drivers.

Energy and Matter in Coastal Environments

  • Inputs:
  • To understand the energy and matter dynamics in coastal environments, consider:
    • The various natural resources feeding into these systems, such as freshwater and nutrients, and energy inputs from solar radiation, tidal movements, and wind.

Sand Movement Evidence and Coastal Shaping

  • Movement of Sand:
  1. Types and evidence of sand movement, such as erosion and deposition patterns.
  2. Changes in the coastline’s shape and location due to ongoing sand movement.
  3. The concept of dynamic equilibrium: Analyze whether these changes signify a stable, balanced condition or ongoing alteration.