Chapter 11

Marine Shores

Hubert Engelbrecht

Abstract

Interferences of elevated human pressure at marine coasts, and contaminants transported by marine currents and rivers contribute to forced degradation of littoral environments. Additional impairment has occurred due to inappropriate technical constructions to protect built-up areas against floods caused by sea level rise. Delta subsidence due to upriver damming, on and offshore hydrocarbon extraction, beach sand mining, onshore ground water pumping, and soil compaction and loading because of coastal urbanisation has resulted in accelerated sea level rise, marine ingressions, and considerable land loss. Nutrient-rich runoffs, produced by intensified agriculture, effected the origination of - partially temporary - hypoxic coastal water bodies. Eutrophication and degradation of littoral waters also result from industrial aquafarming. Harbour mud dredged for navigational purposes has been contaminated with toxic metals. Oil and gas developments and havaries have caused severe hydrocarbon pollution in littoral areas several times. Toxic legacies exist in the form of waste-filled river and coastal impoundments, now exposed to sea level rise. Because of the mobilisation of toxic leachates and submarine discharge of contaminated plumes (e.g. in estuaries), redistribution of toxic metal species and their bioaccumulation occurs. Saline brines, discharged from desalination plants in arid climate zones to compensate for water scarcity, negatively impact water quality of ambient littoral regions. Accidentally dispersed nuclear weapon material contaminated the inner shelf area off Thule Airbase.

Total Pages: 120-128 (9)

Purchase Chapter  Book Details