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. 🌱