Potential Threats to Sandy Beaches
Threats
Zoning strategies and marine reserves, which have not been widely implemented in sandy beaches, could be a key tool for biodiversity conservation and should also facilitate spillover effects into adjacent beach habitats. Setback and zoning strategies need to be enforced through legislation, and all relevant stakeholders should be included in the design, implementation and institutionalization of these initiatives.
Stressors
Recreation
- Overwhelmingly concentrated on sandy beaches
- Effects of these pressures are particularly noticeable at scales ranging from weeks to months
- Beach management focuses on maximizing the recreational experience for beach users, which often results in ecologically harmful human interventions
- Nourishment
- Beach grooming
- Coastal armouring
- Destruction of dunes to construct tourism infrastructure
- Dune vegetation is vulnerable to mechanical impacts caused by trampling
- Light and sound pollution
Cleaning
- A common practice on beaches heavily used for tourism clears beaches of macrophyte wrack, litter and other debris by raking and sieving the sand, often with heavy equipment
- Removes not only unwanted material, but also propagules of dune plants and other species, and it perturbs resident organisms and roughens the sand, thereby exposing a greate surface area to the erosive effects of wind
Nourishment
- Beach engineering solutions, such as seawalls, breakwaters and groynes, are often ineffective to the point of causing the loss of the intertidal beach, beach nourishment (also called beach replenishment, restoration or nourishment), has increasingly been used to combat shoreline erosion
- Effects of this stressor can be noticeable at scales ranging from weeks to years
- Factors influencing the nature and extent of ecological impacts of nourishment include the mechanical process itself, its timing, and the quality and quantity of new sediment placed
- Effects may be direct, such as mortality of organisms when buried, or indirect, such as reduces prey availability for shorebirds
- Basic management recommendations include:
2) Careful timing or operations to minimize biotic impacts and enhance recovery
3) The selection of locally appropriate techniques
4) The implementation of several small projects rather than a single large project
5) Interspersion of nourished beach sections with unaffected areas
6) Importing sediments and creating beach profiles that match the original beach conditions
Pollution
- Most solid waste stranded on the shore is brought ashore by waves and currents
- Plastic is extremely persistent and it dominates the visible litter on sandy beaches worldwide
- Ingestion by and entanglement of vertebrates, such as seals, seabirds and turtles
- Risk increased when medical plastic wastes reach the shore from coastal dumping sites
- Economic losses can arise when tourist beaches are persistently contaminated by littler from land or ocean sources
- Oil spills are potentially the most destructive pollution source impacting sandy beaches, affecting all trophic levels
- Impacts can be acute and temporary, but they can also be more chronic, lasting for many months or even years
- Beach morphodynamics and exposure strongly influence the duration of contamination: the coarser the sediment the more rapidly and deeply oil penetrates, sometimes even reaching below the groundwater table
- Sheltered beaches are generally more sensitive to pollution than exposed beaches, even when sediments are fine and oil does not penetrate deeply, because they are less well flushed by wave action and subsurface oil persists much longer than surface oil.