Human Interaction With Coastal Environments

Human Interaction With Coastal Environments 🌊

  • This section covers:

    • Impact of recreational pressures 🤾‍♀

    • Coastal defence work 🚧

    • Conservation and management measures 🌱

  • The sea is a source of:

    • Food 🐟

    • Energy (gas, oil, wave power) ⚡

    • Transport 🚢

    • Leisure activities 🏖

  • People have historically settled near the coast. 🏘

Conservation and Management 🛡

  • Coastal erosion: A growing issue due to:

    • Rising sea levels 🌊⬆

    • Increasing storm frequency ⛈

    • Higher wave energy 🌊

  • Causes of erosion:

    • Human activities:

    • Disrupting natural processes like longshore drift via:

      • Sand removal 🚜

      • Dredging ⚙

      • Land reclamation for coastal defences 🧱

    • Natural forces:

    • Rising sea levels:

      • Predicted increase of 17–31 cm in 30 years. 📈

    • Lead to:

      • Faster erosion ⏳

      • Coastal defence breakdown 🚧

      • Flooding 🌊

      • Habitat loss (initially affecting the south and southeast) 🌵

  • Effective conservation and management strategies are crucial. ✅


Case Study: The Wexford Coastline 📍

  • Wexford coastline: Facing rapid coastal erosion for years, primarily due to human activity. ⚠

  • Historical disruptions:

    • Large-scale land reclamation in Wexford Harbour (1845–1855) 🏗

    • Construction of Rosslare Harbour (early 20th century) 🏗

  • Impact: Disrupted natural deposition processes. 🌊

  • Consequences:

    • Reduced beach size 🏖

    • Weakened natural coastal defenses 🛡

    • Property and infrastructure damage 🏠

  • Rosslare Strand protection:

    • Groynes were built to slow longshore drift. 🧱

    • Trap sediment on the updrift (south) side. ⏳

    • Widened the beach. 🏖

    • Caused erosion on the downdrift side. 🌊

    • Mitigation: Sloped groynes to reduce erosion impact on the downdrift area. 🚧

Beach Nourishment 🏖

  • Definition: A soft coastal defence method involving adding sand to beaches to combat erosion. 🛡

  • Example: Rosslare Strand

  • Advantages:

    1. Restores and widens beaches, improving coastal defences. ✅

    2. Protects infrastructure and property behind the beach. 🏠

    3. Alters wave dynamics, turning destructive waves into constructive ones. 🌊

  • Disadvantages:

    1. Artificially added sand erodes faster than natural sand, requiring repeated applications. ⏳

    2. Costly and temporary, as it does not halt erosion. 💸

    3. Disrupts local ecosystems, potentially affecting animals like turtles and clams, and can create a temporary construction zone. 🐢

  • Widely used method for beach protection and aesthetics but requires ongoing investment and environmental consideration. 🌱


Coastal Defences 🛡

  • Coastal defence structures: Used to manage erosion and protect vulnerable areas from wave activity. 🌊

  • Types:

    1. Groynes

    • Description: Concrete or wooden walls built perpendicular to the sea to prevent longshore drift by trapping sediment on the updrift side. 🧱

    • Advantages: Builds up beaches in specific areas. ✅

    • Disadvantages: Starves downdrift areas of sediment, contributing to erosion elsewhere. ⚠

    • Example: Rosslare, Co. Wexford. 📍


    1. Rock Armour

    • Description: Large boulders placed at the base of cliffs or sand dunes to absorb wave energy and reduce erosion. 🪨

    • Advantages: Effective at protecting cliffs and dunes. ✅

    • Disadvantages: Can be visually intrusive and expensive. ⚠

    • Example: Lahinch, Co. Clare 📍


    1. Sea Walls

    • Description: Sloped or curved walls built to protect coastal towns or economically valuable areas. They deflect wave energy and reduce erosion. 🧱

    • Advantages: Strong protection for urban areas. ✅

    • Disadvantages: Expensive to build and maintain, and can cause erosion at the base of the wall. ⚠

    • Example: Lahinch Co. Clare 📍


    1. Breakwaters

    • Description: Structures made of rock and rubble built offshore to reduce wave energy. They can be parallel to the coast or connected to the land. 🌊

    • Advantages: Calm waters behind the breakwater encourage deposition. ✅

    • Disadvantages: Can disrupt marine ecosystems and sediment flow. ⚠


    1. Gabions

    • Description: Wire cages filled with stones, placed in front of sand dunes or beaches to absorb wave energy. 🚧

    • Advantages: Affordable and effective for short-term protection. ✅

    • Disadvantages: Prone to corrosion and require regular maintenance. ⚠

    • Example: Lahinch Co. Clare 📍

  • Groynes, sea walls, rock armour, and breakwaters are classified as hard structure coastal defenses due to their durability and direct intervention in controlling erosion. 🛡

Erosion Management Case Study: Lahinch Co. Clare 📍

  • Lahinch, County Clare: Employs several coastal defence measures to protect its shoreline and community from erosion and storm damage. 🛡

  • Primary structures:

    • Concrete sea wall 🧱

    • Long series of Gabions 🚧

    • Rock armour 🪨

  • Location of structures:

    • Sea wall: Extends from the public car park in the north to the coastal cliffs in the south. 📍

    • Rock armour: Runs from the car park to the beginning of the concrete wall. 📍

    • Gabions: Run further north into the dunes. 📍

  • 2016 project: A €2.85 million coastal protection project was initiated post-2014 storm to enhance defences. 💸

  • Project inclusions:

    • Addition of extensive rock armour storm defences to the existing structure. 🪨

    • New concrete apron in front of the current seawall. 🧱

    • Refurbishment of existing steps and ramped access to the beach. 🪜

    • Development of a new universally accessible ramp at the north end of the promenade. ♿

  • Goals of coastal defences:

    • Protect human life, public infrastructure, and private property in Lahinch, including the Lahinch Golf Links course. ✅

    • Allow for future development of the area. 🏗

    • Prevent a recurrence of the damage experienced in 2014 and 2015. 🌊

Sand Dune Management 🌵

  • Sand dune management is essential to protect these fragile ecosystems from erosion and damage caused by wind, water, and human activity. 🛡

  • Recreational impact:

    • Activities like walking, quad biking, camping, and beach sports increase pressure on dunes. 🤾‍♀

    • Damaging vegetation like marram grass, which stabilises the dunes. 🌿

    • Uprooting marram grass leads to wind creating holes called blowouts. 💨

  • Tourism development impact:

    • Holiday homes, caravan parks, and golf courses contribute to increased foot traffic and dune degradation. 🏘

  • Strategies to protect sand dunes:

    1. Encourage visitors to use designated pathways and avoid walking over dunes. 🚶

    2. Prevent uprooting of plants and grass. 🌱

    3. Replant marram grass to stabilise dunes. 🌾

    4. Ban damaging activities like quad biking and horse riding. 🚫

  • Curracloe Beach, Co. Wexford:

    • Efforts by Wexford County Council to protect sand dunes include:

    • Planting grass and shrubs to stabilize dunes. 🌿

    • Installing timber pathways for beach access to reduce foot traffic on dunes. 🚶

    • These measures help maintain dune stability, protect the environment, and balance tourism with conservation. ✅

    • Using screens and fences to trap windblown sand and form new dunes. 🚧

Coastal Wildlife Conservation 🦉

  • Coastal wildlife habitats are vital ecosystems that support a wide variety of plant and animal life. 🐠

  • Sand dune flora:

    • Plants like sea rocket, marram grass, and lichens thrive. 🌿

  • Saltwater marshes:

    • Grasses grow in the muddy waters. 🌾

  • Sand dune fauna:

    • Provide shelter for animals such as rabbits, stoats, foxes, and badgers. 🐰

  • Protecting these habitats is essential because damage to coastal areas can disrupt the delicate balance of plant and animal life. ⚠

  • Conservation measures help maintain biodiversity and ensure the survival of these unique ecosystems for future generations. ✅

  • Efforts should focus on minimizing human impact, preserving vegetation, and managing tourism and development in coastal regions. 🌱