Impacts of Sand Mining on Ecosystem Structure, Process & Biodiversity in Rivers 4
Total Page:16
File Type:pdf, Size:1020Kb
1 IMPACTS OF REVIEW SAND MINING 2018 ON ECOSYSTEM STRUCTURE, PROCESS & BIODIVERSITY IN RIVERS REPORT BY LOIS KOEHNKEN Impacts of Sand Mining on Ecosystem Structure, Process & Biodiversity in Rivers 4 EXECUTIVE SUMMARY WWF is a solution-oriented advocate of clean flowing rivers that believes that by better understanding and communicating the impacts of sand mining – aggregate extraction encompasses sand, gravel, pebbles or cobbles, but is collectively referred to as sand mining – on rivers, the organisation can influence key decision-makers to ensure that extraction is done sustainably. To do this, a strong evidence base for past, current and potential impacts of sand mining on rivers and their ecosystems is required. This report aims to provide an authoritative Sand and gravel are used in a wide range of review and summary of the available scientific applications, but of reported uses, the vast literature associated with sand mining impacts, majority is consumed in construction materials a context for this information with respect to such as cement. Global demand has increased global sources, demands and trends, and an rapidly over the past two decades and has largely understanding of what the estimated present been driven by growth in the Asia Pacific region, status and perceived associated impacts of sand particularly in China. China is the largest cement mining are on a global scale. producer in the world, accounting for 58% of global production. It is predicted that the per capita Two evidence-based research approaches consumption of concrete in China may decrease, have been used in this review. A Quick Scoping but demand in other developing countries is also Review (QSR) was used to survey the scientific rapidly increasing. India is projected to surpass literature describing the impact of sand mining China in population within the next five to ten on ecosystems. This highly structured objective years and the combination of this population approach involved reviewing papers obtained by growth and increased urbanisation could searching scientific databases using terms relevant quadruple its demand for concrete and aggregate to the question ‘What evidence is there of impacts if it follows a similar trajectory to China. The of aggregate mining on ecosystem structure, demand for aggregates in other developing nations process and biodiversity in rivers, floodplains and in Asia and Africa is also expected to increase estuaries’. All papers that were relevant to the dramatically in the coming years. central question were categorised by geographic location, system type, inference method, type of mining, scale of mining, end use of mined product, geomorphic impacts, social impacts and INTEGRATING THE QUICK presence and interaction with other stressors. The other parts of this review consisted of a SCOPING REVIEW RESULTS web-based literature review that included media WITH THE HIGH AND INCREASING articles, government reports and websites. Investigated topics included the trends in sand use DEMAND FOR AGGREGATE and availability, expected future trends, regulation IN DEVELOPING COUNTRIES and governance, and the prevalence of sand mining activities not captured in the scientific STRONGLY SUGGESTS THAT literature, including illegal activities. Many of the views and conclusions of these pieces are opinions THIS DEMAND CANNOT and inferences, as hard facts are in short supply. BE MET ON A SUSTAINABLE Potential avenues for future research, community engagement and communication are provided. BASIS FROM RIVERS. Impacts of Sand Mining on Ecosystem Structure, Process & Biodiversity in Rivers 5 In addition to construction, land reclamation species and increases in invasive alien species, is a major use of sand and aggregate, with but few had long-term data sets to confirm Singapore being the world’s largest importer. this. There is limited evidence that rivers Neighbouring nations have officially banned can sustain sand extraction if the extracted the export of sand, but a thriving illegal trade volumes are within the natural variability is reported in the mainstream media of the sediment load of the system, based on one year of extractions, but no studies have The QSR analysis showed that most demonstrated the sustainability of sustained investigations into the impact of sand extractions over prolonged time frames. mining on ecosystems has been completed in temperate rivers in western countries A significant finding of the QSR is that the where sand mining occurred historically, but countries and rivers for which there is science- has since ceased. These countries now have based evidence related to the impacts of sand strict regulations governing the extraction of mining are not the countries that are rapidly aggregate, and there is little active in-stream developing and where extensive illegal sand mining occurring. The scientific studies mining is reported by the media. The lack of overwhelmingly identified channel incision as scientific and systematic studies of sand mining the most common physical impact, but beyond in these rapidly developing countries prevents that, the physical responses of rivers differed accurate quantification of the volumes of depending on the characteristics of the material being mined, or the type, extent and river (underlying material, slope, catchment magnitude of impacts. An estimate of potential land use, etc.). Collectively the QSR papers impacts can only be made by inferring that highlight the decadal time-frames over which results from studies elsewhere can be applied rivers respond and recover from sand mining to locations without direct evidence. disturbances, and the importance of land use Integrating the QSR results with the high in determining river response. and increasing demand for aggregate in The QSR papers report ecological impacts developing countries strongly suggests that this associated with sand mining including the demand cannot be met on a sustainable basis direct disturbance and removal of habitats from rivers. in rivers, deltas and coastal areas, loss In most countries, sand mining is officially or changes to the vegetation structure of regulated through national mining and riparian zones, and increased or decreased environmental protection legislation, with downstream sedimentation affecting habitat authority for regulation devolved to the State quality. Sand mining was found to interfere or District level. Legislation is frequently with a number of ecological processes, such accompanied by non-binding guidelines to as macroinvertebrate drift, fish movements, improve the sustainability of the activity. abundance and community structures, and This governance structure results in food web dynamics. The studies often inferred many small administrative entities having impacts on populations, such as loss of native responsibility for implementing and enforcing these regulations, hampering management at the catchment level. The lack of enforcement of regulations is a common issue identified by the mainstream media. Options for reducing the construction industry’s dependence on sand mining identified through a literature review, included recycling concrete, fixing rather than replacing concrete, researching the suitability of waste materials as aggregate substitutes, and developing new construction materials and © Areeb Hashmi / WWF-India design approaches. Impacts of Sand Mining on Ecosystem Structure, Process & Biodiversity in Rivers 86 In contrast to the relatively low number RECOMMENDATIONS ARISING of scientific studies dedicated to impacts associated with sand mining, there is an FROM THIS REVIEW INCLUDE: abundance of media articles highlighting • Increasing public awareness of the the growing demand yet dwindling growing demand and finite supply availability of sand in developing countries. of sand is critical to effecting change The illegal extraction of river and coastal and is recommended. In the short sand is reported to occur in as many as 70 term, public awareness can increase countries, often with the support of complicit pressure on governments for stricter governments. The social impacts of the illegal regulations and governance, including trade are also widely reported, with violence the identification of off stream sources commonly reported against protestors or of aggregate. In the longer-term, public those who attempt to report illegal activities. awareness and acceptance will be Media reports highlight that impoverished required for any shift away from the communities engage in the illegal trade present market system whereby sand as it provides a higher income than other underpins all development, yet is the activities, even though they perceive that cheapest of commodities; sand extraction is destroying the rivers on • Research into economic incentives or which they depend for their livelihoods. certification schemes that could drive a reduction in the extraction of sand The conclusions of the review include: from rivers is recommended; • Developed countries with good governance • Scientific research in rivers where do not in general use rivers as a source in-stream sand mining is active is of aggregate. In these countries demand required to enhance understanding is met with terrestrial pits and a growing and quantification of impacts, reliance on marine resources. There is identify management and remediation growing social awareness of the impacts methods (if and where required) for marine sand mining has on beaches and rivers and underpin communication coastal