Last week, the Hook gave its readers links to stories about the disputes related to sand mining the coastal community of Xolobeni in the Eastern Cape.
This week we collected some facts from different sources to show how sand mining damages the environment, including fisheries.
For thousands of years, sand and gravel have been used in the construction of roads and buildings. Today, demand for sand and gravel continues to increase. Sand mining is a practice that is used to extract sand, mainly through an open pit. However, sand is also mined from beaches, inland dunes and dredged from ocean beds and river beds. Sand mining is regulated by law in many places, but is still often done illegally. (Wikipedia 2015)
Sand mining is a direct cause of erosion, disturbance of underwater and coastal sand causes turbidity in the water, which is harmful for such organisms as corals that need sunlight. Removal of physical coastal barriers such as dunes leads to flooding of beachside communities, and the destruction of picturesque beaches causes tourism to dissipate. It also destroys fisheries, causing problems for people who rely on fishing for their livelihoods.
Excessive instream sand-and-gravel mining causes the degradation of rivers. Instream mining lowers the stream bottom, which may lead to bank erosion. Depletion of sand in the streambed and along coastal areas causes the deepening of rivers and estuaries, and the enlargement of river mouths and coastal inlets. It may also lead to saline-water intrusion from the nearby sea. The effect of mining is compounded by the effect of sea level rise. Any volume of sand exported from streambeds and coastal areas is a loss to the system (The Ojos Negros Research group: Sand Mining Facts, 2015).
Excessive instream sand mining is a threat to bridges, river banks and nearby structures. Sand mining also affects the adjoining groundwater system and the uses that local people make of the river.
Instream sand mining results in the destruction of aquatic and riparian habitat through large changes in the channel morphology. Impacts include bed degradation, bed coarsening, lowered water tables near the streambed, and channel instability. These physical impacts cause degradation of riparian and aquatic biota and may lead to the undermining of bridges and other structures. Continued extraction may also cause the entire streambed to degrade to the depth of excavation (The Ojos Negros Research group: Sand Mining Facts, 2015).
Another major impact of beach sand mining is the loss of protection from storms surges associated with tropical cyclones and tsunamis. Some communities affected by the 2004 tsunami in the Indian Ocean had higher storm surges probably due to beach sand mining resulting in fatalities. Sometimes it is difficult to tell that a beach has been mined.
Sand extraction becomes difficult to recognize as the beach readjusts to a new profile after a few storms. But historic accounts of beaches in the Caribbean often reveal that beaches have been narrowed considerably. Mining is particularly senseless in a time of rising sea level when sand is sorely needed as a storm energy buffer (Coastalcare.org, 2015).