Biodiversity impacts can be seen in freshwater, oceanic, and water-adjacent habitats. Sand dredging in water kills organisms that reside there and makes the habitat less suited for other marine life, often changing the overall composition of the area. The deepening, widening, and changing the course of rivers leads to less area available on land and a change in available food and water sources who fauna who rely on it.
The main risk factor is the disruption of habitat. According to the IUCN, “85% of species on the IUCN Red List are threatened by habitat loss and degradation, making it the most significant risk to global biodiversity”. The composition of the soil deposits in water bodies is altered through dredging, disrupting the natural habitat of many creatures and organisms. As a result, these aquatic organisms lose the ability and grounds to spawn, feed and grow. The fine balance of the ecosystem is upset, and the negative effects snowball as smaller creatures dying off cause larger predators to starve.
Sand dredging often leads to the contamination of water bodies and modifies the overall composition of the dredged area. The deepening and widening of rivers leads to less area available on land and depletes available food and water sources the nearby fauna relies on. Indirect factors such as increased vehicle traffic can also be damaging to the water-adjacent ecosystem.
The impact on biodiversity is as much a global issue as it is a localised one, as sand dredging in different geographical areas will have a vast range of effects. For instance, sand dredging in Malaysia annihilates nesting sites of the critically endangered terrapin, a river turtle. These turtles usually return to the same beaches to lay eggs each year, and may not be able to adapt to the destruction of their habitat.
Marine creatures ingest metals, chemicals and other dredging waste, which effectively leads to slow poisoning. For instance, 61% of mud crabs taken from a dredging site in Queensland, Australia, displayed shell disease due to high levels of ingested metals such as copper and aluminum. This varies from the 7% of crabs displaying shell disease a mere 32 km away. The year following the initiation of dredging demonstrated a 37% decrease in the number of mud crabs caught by fishing fleets.
These examples are just a sample of the many instances of biodiversity loss or endangerment linked to sand dredging. The lack of cohesive, geographically-specific research on the effects of sand dredging throughout the world prevents us from evaluating the full impact of sand dredging on biodiversity, but even the limited amount of case studies is alarming in its own right.
Sources:
https://d2ouvy59p0dg6k.cloudfront.net/downloads/sand_mining_impacts_on_world_rivers__final_.pdf https://www.sciencemag.org/news/2018/03/asias-hunger-sand-takes-toll-endangered-species
https://www.theguardian.com/environment/2013/jul/30/gladstone-harbour-dredging-link-mud-crab-disease
https://www.marineinsight.com/environment/effects-of-dredging-on-the-marine-environment/
The main risk factor is the disruption of habitat. According to the IUCN, “85% of species on the IUCN Red List are threatened by habitat loss and degradation, making it the most significant risk to global biodiversity”. The composition of the soil deposits in water bodies is altered through dredging, disrupting the natural habitat of many creatures and organisms. As a result, these aquatic organisms lose the ability and grounds to spawn, feed and grow. The fine balance of the ecosystem is upset, and the negative effects snowball as smaller creatures dying off cause larger predators to starve.
Sand dredging often leads to the contamination of water bodies and modifies the overall composition of the dredged area. The deepening and widening of rivers leads to less area available on land and depletes available food and water sources the nearby fauna relies on. Indirect factors such as increased vehicle traffic can also be damaging to the water-adjacent ecosystem.
The impact on biodiversity is as much a global issue as it is a localised one, as sand dredging in different geographical areas will have a vast range of effects. For instance, sand dredging in Malaysia annihilates nesting sites of the critically endangered terrapin, a river turtle. These turtles usually return to the same beaches to lay eggs each year, and may not be able to adapt to the destruction of their habitat.
Marine creatures ingest metals, chemicals and other dredging waste, which effectively leads to slow poisoning. For instance, 61% of mud crabs taken from a dredging site in Queensland, Australia, displayed shell disease due to high levels of ingested metals such as copper and aluminum. This varies from the 7% of crabs displaying shell disease a mere 32 km away. The year following the initiation of dredging demonstrated a 37% decrease in the number of mud crabs caught by fishing fleets.
These examples are just a sample of the many instances of biodiversity loss or endangerment linked to sand dredging. The lack of cohesive, geographically-specific research on the effects of sand dredging throughout the world prevents us from evaluating the full impact of sand dredging on biodiversity, but even the limited amount of case studies is alarming in its own right.
Sources:
https://d2ouvy59p0dg6k.cloudfront.net/downloads/sand_mining_impacts_on_world_rivers__final_.pdf https://www.sciencemag.org/news/2018/03/asias-hunger-sand-takes-toll-endangered-species
https://www.theguardian.com/environment/2013/jul/30/gladstone-harbour-dredging-link-mud-crab-disease
https://www.marineinsight.com/environment/effects-of-dredging-on-the-marine-environment/