Physical Alterations and Destruction of Habitats (PADH)

Mining

Introduction

Mining is an expanding industry that can provide sustainable economic, environmental and social benefits to the communities and regions in which it operates. Achievement of these benefits to the full potential not only requires integrated and enabling policy frameworks but also depends heavily upon the commitment of the state sector and the industry to invest in high standards of environmental performance.

Coastal mining is diverse. It is undertaken at varying levels of intensity from large-scale enterprises to small-scale and artisinal mining and employ a variety of methods to mine a variety of minerals. Mining -extraction of sand and gravel (aggregate) from the seabed and beaches, as well as the exploitation of corals from reefs -is an expanding industry that has major impacts on coastal ecosystems. This also holds true for seabed mining of minerals such as diamonds and possibly gold in coastal waters. Mining in coastal areas also includes exploitation of bauxite and placer deposits of metals such as tin, chromium, manganese and titanium.

Increasing construction industry demands for sand, gravel, coral and shell as building materials, construction aggregate and filling material in land reclamation is one immediate consequence of the rapid expansion of urban areas in coastal regions. Corals are mined for lime production and collected for use in the construction and aquaculture industry, respectively.

A more recent development is large-scale offshore mining for sand for the increasingly popular beach nourishment programmes, as well as for restoration projects. With sand nourishment having been accepted as an approach to erosion management, especially when land-based resources of sand are scarce, the demand for sand from coastal and offshore areas has increased drastically. Although not as widespread, exploitation of coral reefs to provide construction material is an important issue, particularly in many developing countries, including many small island developing states.

Mining of sand and gravel is concentrated to estuaries, beaches, dunes, and near-shore areas. Sand mining from such areas affects the littoral sand budgets and result in erosion in nearby areas. Large-scale mining of sand and gravel is also conducted in offshore areas and in riverbeds. That, too, causes alterations in sediment mobilization and leads to increased coastal erosion. Changes caused by underwater dredging have immediate effects on near-shore patterns of waves and currents and rapidly leads to disturbances in the transport patterns of sand and, eventually, to changes in the shoreline morphology. Coastal mining can cause physical damage or destruction of habitats that are cleared, eroded, buried or crushed by mining activities. Increased turbidity and alteration of currents often lead to an extension of the areas affected well beyond the actual mining site. Coral reefs and sea grass beds are particularly sensitive to increased sediments loads and can be chronically or permanently degraded by coastal mining. Besides direct impact on reef ecosystems, coral mining also has major implications for coastal protection by reducing the buffering capacity of the reef against the impacts of waves and storms.

Although no global estimates are available, national estimates indicate increasing mining of sand and gravel in most countries. Technological advances have resulted in more efficient and powerful dredgers that can operate in locations that were not previously accessible. Global estimates on coral reef degradation do not indicate the extent to which this is caused by coral mining. However, estimates made in some countries, especially in East Africa, Caribbean, South Asia and Southeast Asia, indicate that coral mining continues at very high levels.

Location of mining activities and the methods used for extraction need to be carefully identified to minimize coastal erosion and effects on habitats and ecosystems. Many of the impacts of mining can be minimized by incorporating impact assessments in the planning phase and including reclamation and restoration into to the development and permitting process. Mining of sand, gravel and corals needs to be strictly regulated in order to minimize impacts, as mitigation can be very expensive.

The mining sector can have far reaching environmental and social impacts and invariably requires the dedicated use of coastal land for which there is obvious competing community demands. Hence an integrated approach is required to manage the sector and seek a balance between ecological integrity, social equity and economic development.

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