What threatens coastal sand dunes?
Coastal sand dune systems are highly vulnerable to disturbance by trampling. Pedestrians and motor vehicles can compact the sand and crush vegetation; for example, Native Dune Grass dies when its roots are crushed. Without the stabilizing vegetation, the sand is blown away and dunes disappear. This can leave the shoreline more prone to damage from storm surges.
Invasive species are a major concern for the ecology of sand dunes. Scotch Broom and European Beachgrass are two common examples. Because they are not native to the region, they often have no natural predators or other controls. Therefore, invasive species can create dense monocultures that crowd out other species. As they did not evolve along with all the other species in the area, they provide limited habitat values. Some invasive species are so well-established that their eradication is not feasible without substantial cost and effort.
Sand dunes can be destroyed when structures are built too close to the shoreline. As the coastline naturally erodes, these structures become threatened, and people often respond by building “protective” reinforcements such as seawalls. This can further degrade the beach habitat, and even distant seawalls can starve downdrift beaches of sediment (see also coastal sediment processes and altered shorelines).
Dune habitats are often affected by alteration of shorelines in other areas. For example, bluffs composed of glacial till provide sediment that is eroded by waves and transported by longshore currents to the sand dune beach, where it is deposited. If the bluffs are armoured to prevent erosion, with cement or rock, this sediment supply is cut off and the beach is gradually depleted of sand.
How can I help protect coastal sand dunes?
When walking on beaches with sand dunes, try to stay on the seaward side of the dunes, where the sand has been compacted by the tides. Stay on marked or established trails or boardwalks, when walking through dune vegetation, and observe signs.
Keep dogs under control and don’t let them dig in dunes or chase wildlife.
Plant native vegetation along your shoreline property, to help prevent erosion and increase wildlife habitat. Learn about other options for reducing erosion that use natural shoreline development techniques instead of hard structures.
Leave driftwood in place, rather than “cleaning up” the beach. Logs help to stabilize sand dunes, and provide hiding places for wildlife.
Get involved with a local community stewardship group that works to protect and restore sand dunes.
See other tips to help protect shorelines in general.
(Source: Capital Regional District)
We can all make a difference when it comes to the protection and preservation of our delicate coastal sand dune ecosystems. One for all and all for fun!
Have a great day at the beach!
This week’s WordPress Weekly Photo Challenge theme is “Delicate.”