Biodiversity and China's new Great Wall

Abstract

Coastal armouring and the reclamation of intertidal areas through the use of seawalls and other artificial structures has been practiced for thousands of years, but its recent expansion in China and elsewhere in Asia has been unprecedented in its rate and intensity. One result has been the recent loss of nearly two-thirds of tidal flats in the Yellow Sea, a globally unique ecosystem of high ecological value. The severe effects on biodiversity of the recent large-scale coastal land claim activities in China are well documented, yet some recent studies have emphasized the ecological opportunities provided by such artificial coastal infrastructure in China, in some cases suggesting that the ecological impacts of coastal infrastructure should be reconsidered due to benefits to some rocky shore species in a changing climate. This is cause for concern because, while studying the "new ecology" arising from coastal modification is useful, broad conclusions around the ecological role or conservation gains from seawall construction without adequate contextualization underplays the ecological consequences of large-scale coastal land claim, and could potentially undermine efforts to achieve biodiversity conservation. Here, we clarify the characteristics of seawall construction in China and summarize the environmental damage and some broadscale impacts caused by this type of infrastructure expansion on the endangered Yellow Sea tidal flats ecosystem. We also highlight the urgent need for all coastal development plans to consider how coastal wetlands and ecosystem functionality can be maximally retained within the development precinct. K E Y W O R D Sartificial infrastructure, ecosystem function, mudflat, reclamation, wetland

Multiple habitat use by declining migratory birds necessitates joined‐up conservation

“…In the EAAF, the scale and rate of intertidal habitat loss and degradation in Yellow Sea staging areas (Melville, Chen, & Ma, ; Murray, Clemens, Phinn, Possingham, & Fuller, ) are well accepted as the primary driver of severe population declines in multiple shorebird species (Amano, Székely, Koyama, Amano, & Sutherland, ; Piersma et al, Studds et al, ). This conservation crisis has prompted a focussed research effort to highlight negative consequences of coastal development and armouring on migratory waterbirds and the need to halt intertidal habitat loss (Choi et al, ; Ma et al, ; Murray, Ma, & Fuller, ; Piersma et al, ; Yang et al, ).…”

Conserving shorebirds in human-dominated landscapes

“…One driver of intertidal flat loss, particularly in East Asia, has been widespread land reclamation, which entails enclosure of coastal wetlands by a seawall to create new land, sometimes in enormous development projects that destroy many square kilometres of natural habitat at one time (Yang et al, 2011;Ma et al, 2014;Moores et al, 2016). Rapid shorebird declines have prompted a focussed research effort to highlight the negative consequences of land reclamation on waterbird populations and the wider ecosystem (Yang et al, 2011;Ma et al, 2014;Murray, et al, 2015;Piersma et al, 2017;Choi et al, 2018), and there is now widespread awareness of the damaging impacts of coastal land reclamation and the need to preserve and restore remaining intertidal flats.…”

“…However, in many parts of Asia, few intact natural coastal wetland systems now remain. In China and the Republic of Korea (ROK), for example, huge areas of intertidal flats have been reclaimed through seawall enclosure (Moores, 2006;Ma et al, 2014;Murray et al 2014;Moores et al, 2016;Choi et al, 2018). River damming has been extensive, and also contributes to intertidal flat loss through reduced sediment deposition (Murray et al, 2015).…”

“…In the EAAF, the scale and rate of intertidal habitat loss and degradation in Yellow Sea staging areas (Murray et al, 2014;Melville et al, 2016) are well accepted as the primary driver of severe population declines in multiple shorebird species (Amano et al, 2010;Piersma et al, 2016;Studds et al, 2017). This conservation crisis has prompted a focussed research effort to highlight negative consequences of coastal development and armouring on migratory waterbirds and the need to halt intertidal habitat loss (Yang et al, 2011;Ma et al, 2014;Murray et al, 2015;Piersma et al, 2017;Choi et al, 2018).…”

“…Substantial loss of intertidal habitat in China has occurred as a result of land reclamation for agriculture, aquaculture and industrial uses (Ma et al, 2014;Murray et al, 2014;Piersma et al, 2017;Choi et al, 2018;Duan et al, 2019). Reduced sediment discharge to coasts, changed hydrological regimes and sea level rise are also thought to have contributed to tidal flat loss (Iwamura et al, 2013;Murray et al, 2014).…”