Conserving unprotected important coastal habitats in the Yellow Sea: Shorebird occurrence, distribution and food resources at Lianyungang

Yong-Xiang Han,Sheena Suet-Wah Chung,Theunis Piersma,He-Bo Peng,Ying-Chi Chan,Lin Zhang,Jing Li

doi:10.1016/j.gecco.2019.e00724

Yong-Xiang Han, Sheena Suet-Wah Chung + Show 5 more

Open Access

https://doi.org/10.1016/j.gecco.2019.e00724

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Abstract

The Yellow Sea coastline in East Asia, an important staging area for migratory shorebirds in the East Asian-Australasian Flyway (EAAF), is rapidly deteriorating. Conserving the declining shorebird populations that rely on the Yellow Sea requires habitat protection and management based on sound ecological knowledge, especially on the seasonal occurrence of shorebirds, their daily movements and their food resources. However, in this region such ecological data are scarce, and expertise to collect them are less-established. Here we gather and assimilate such information for the coastal wetlands at Lianyungang on the Chinese Yellow Sea coast, an understudied and unprotected area where we found 27% of intertidal soft sediment habitats have been destroyed in 2003–2018 by reclamation. In 2008–2018, 43 shorebird species were recorded along this coastline, including 12 globally threatened or ‘Near Threatened’ species. In terms of number of shorebird species exceeding 1% of the EAAF population, with 22 species meeting this criterion, Lianyungang ranks highest among the >300 shorebird sites in East Asia. The benthic mollusc community of the intertidal flats were dominated by small soft-shelled bivalve species at very high densities, including 9399 individuals/m2 of Potamocorbula laevis, which are high-quality food for shorebirds to refuel during migration. Satellite tracked bar-tailed godwits (Limosa lapponica) and great knots (Calidris tenuirostris) stopped at Lianyungang for 5–30 days during northward and southward migration. The tidal movements of satellite-tagged birds indicated high-tide roosts and low-tide foraging areas, some of which are inaccessible on-ground. These movements can also be used to evaluate whether roosts and foraging areas are close enough to each other, and direct where to create new roost sites. Potential measures to increase the capacity of Lianyungang to support shorebirds include reducing human disturbances, creating roosts at undeveloped parts of the reclaimed land, and removing recently-built sea dikes to restore intertidal flats.

Highlights

The conservation of migratory shorebirds in the East Asian-Australasian Flyway (EAAF) has progressed in the past decades through field research that collected baseline information primarily on bird numbers (Bai et al, 2015; Barter, 2002)
Since land reclamation has reduced the area of intertidal flats in the Yellow Sea substantially (Murray et al, 2015), we describe coastal habitat changes along the Lianyungang Coast by measuring rate of coastal reclamation and mapping current status of the reclaimed coastal land from satellite images
43 shorebird species were recorded in the surveys, including 12 globally threatened or ‘Near Threatened’ species (Table 1)

Summary

Introduction

The conservation of migratory shorebirds in the East Asian-Australasian Flyway (EAAF) has progressed in the past decades through field research that collected baseline information primarily on bird numbers (Bai et al, 2015; Barter, 2002). This has resulted in the discovery and recognition of major staging sites, many of which are in the Yellow Sea (Conklin et al, 2014). Such knowledge is inadequate in many countries in East and Southeast Asia (Hua et al, 2015), the likely reason being the shorter history of science-based site management (Lee and Khim, 2017) and limited citizen science capacities (e.g. only one in about 65000 people in China are birdwatchers in 2010, Ma et al, 2013)

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