Coastal Pollution

Persistent eutrophication and hypoxia in the coastal ocean

“…Also, of total estimated human sewage discharge in 2020, Asia (mainly South and East Asia) accounts for 50.3%, followed by South America, North America, Europe, and Africa with contributions varying from 8.9-14.3% (Table 1). Consequently, coastal eutrophication has emerged as a major environmental concern in the developing countries of Asia, South America, and North Africa (Wang et al, 2022).…”

“…Situated between the land and the open ocean, the coastal ocean (i.e., the areas from the shoreline to the continental shelf break influenced by the land-based runoff) possesses rich spatial, economic, and biological resources and diverse ecosystems, providing invaluable services for human society (e.g., Dai et al, 2022;Lu et al, 2018a;Winther et al, 2020). The land masses adjoining the coasts are home to over 50% of the world's population and are the world's most economically invigorating areas, driving global economic development, especially in Asia over the past 50 years, and producing approximately 50% of the world's gross domestic product (GDP).…”

“…Warming also decreases oxygen solubility, increases intensity and duration of stratification, and enhances microbial metabolism, resulting in an earlier onset, higher frequency, and increased severity of hypoxia in nutrient-enriched coastal systems (Altieri and Gedan, 2015;Breitburg et al, 2018). Furthermore, these negative consequences of increased nutrient loading and stratification might be partly, or temporarily, compromised by rising sea levels and stronger storms in low and mid-latitudes , and are further complicated by the superimposition of open ocean circulation and large-scale climate variability such as El Niño, the Pacific Decadal Oscillation, and the North Atlantic Oscillation (e.g., Dai et al, 2022).…”