The coast and its adjacent areas on and off shore is an important part of a local ecosystem as the mixture of fresh water and salt water in estuaries provides many nutrients for marine life. The coastal and marine human activities helps to understand which human activities are affected by certain coastal issues or impacts. Subcategories include from coastal urban development, aquaculture or maritime transportation to coastal defence or heritage management.
Beach nourishment is the process of dumping or pumping sand from elsewhere onto an eroding shoreline to create a new beach or to widen the existing beach. A beach is an unstable environment which exposes plants and animals to changeable and potentially harsh conditions. Some small animals burrow into the sand and feed on material deposited by the waves. Crabs, insects and shorebirds feed on these beach dwellers. The endangered Piping Plover and some tern species rely on beaches for nesting. Sea turtles also lay their eggs on ocean beaches. Sea grasses and other beach plants grow on undisturbed areas of the beach and dunes.
Many beaches are very popular during on warm sunny days. Many flock to beaches such as Joss Bay beach in southern England despite its reputation for unpredictable and wet summers. In the Victorian era, many popular beach resorts were equipped with bathing machines because even the all-covering beachwear of the period was considered immodest. This social standard still prevails in many Muslim countries. At the other end of the spectrum are top free beaches and nude beaches where clothing is optional or not allowed. In most countries social norms are significantly different on a beach in hot weather, compared to adjacent areas where similar behaviour might not be tolerated.
A walk along the beach is also popular, including a long walk in the case of a long beach, for example from one seaside resort to the next. When and where the sand is not too hot, people often walk barefoot on the beach, because of the pleasant feeling of sand on their soles and between their toes. The best beach walking areas typically are near the shoreline, where the sand is wet and more comfortable to walk in. A person will also enjoy walking with their bare feet in the water. In more than thirty countries in Europe, South Africa, New Zealand, Canada, Costa Rica, South America and the Caribbean, the best recreational beaches are awarded Blue Flag status, based on such criteria as water quality and safety provision. Subsequent loss of this status can have a severe effect on tourism revenues.
Because of being attractive tourist spot beaches are often becomes dumping grounds for waste and litter, necessitating the use of beach cleaners and other cleanup projects. More significantly, many beaches are a discharge zone for untreated sewage in most underdeveloped countries; even in developed countries beach closure is an occasional circumstance due to sanitary sewer overflow. In these cases of marine discharge, waterborne disease from fecal pathogens and contamination of certain marine species is a frequent outcome.
Nourishment restores and widens the recreational beach. Structures behind beach are protected as long as the added sand remains. When erosion continues, beach nourishment does not leave hazards on the beach or in the surf zone. This is a big advantage when compared with "hard" beach stabilization structures like seawalls or groins. Seawalls may protect structures behind the beach, but they almost always cause the beach in front of the wall to become narrower. If erosion breaches the seawall, then debris from the wall will be left on the beach and in the surf. Since beach nourishment only puts sand on the beach, no debris is left when it erodes.
Beach nourishment sand often erodes faster than the natural sand on the beach. A good rule of thumb is that nourished beaches erode two or three times faster than natural beaches. Erosion rates can differ widely, however. The biggest factor for the lifetime of a nourished beach is the number of storms that affect the beach. Storms are unpredictable, so nourished beach lifetimes are unpredictable too. The amount of sand added per yard of beach length and the sand placement design determine the new beach width. Wider nourished beaches last longer.
Beach nourishment is expensive, and must be repeated periodically. Except on very small beaches, the minimum expenditure is usually $1-$2 million dollars; larger, longer-lasting projects often cost much more (e g, $100 million-1 billion). The beach turns into a construction zone during nourishment. The process of nourishment may damage, destroy or otherwise hurt marine and beach life by burying it, squishing it under bulldozers, changing the shape of the beach, or making the water near the beach too muddy.
In recent decades, a variety of plants, insects, turtles, shorebirds, and other animals have become threatened or endangered as a result of human alteration of beach environments. Many of these organisms rely on storms and other natural beach processes (such as dune formation by wind) for the creation and/or maintenance of their habitats. Because of their dependence on natural beach processes, nourishment projects can affect the survival of certain species. For example, beach nourishment can modify a beach by making it too steep and/or too compacted for sea turtles to climb up and bury their eggs. Another example involves filter-feeding marine organisms, such as certain species of clams that are accustomed to relatively clear water.
These organisms can be particularly hard hit by the extreme muddiness produced by nourishment, and they can die-off in large numbers. The sand added to the beach is often different from the natural beach sand. It can be hard to find a perfect match. This means that the new material may have smaller or larger diameter sand grains than the natural beach. Such differences in "grain-size" affect the way waves interact with a beach. This will affect surf conditions and bars on the submerged part of the beach, and will also change the shape of the "dry beach", which is where people spread their towels and go for strolls. Fine-grained sand generally erodes faster than coarse-grained sand, so grain-size influences the replenished beach's "lifetime".
Although many factors have to be considered in coastal sites for tourism, recreation, aquaculture, fishing geomorphology remains basic as long as coast is a necessary resource. Site analysis has to assess various types of coasts and its various zones. As coastal tourism caters to a widening demand, coastal sites for resorts are also being assessed for their suitability for other demands such as golf courses, marinas, oyster culture, and other related types of development.
In the future, resort sites are likely to extend beyond the usual sandy coast and rock headland and include more adaptive use of the mangrove coast which has a potential for coastal ecotourism. Coastal sites are also likely to incorporate better technology not only for resort construction and infrastructure but also for coastal protection against erosion and beach management.
The writer is environmental analyst and associate member, Bangladesh Economic Association
