I don't think there is anything more exciting than seeing a large flock of waders wheeling about in flight over the expanse of an estuary. I'm sure we've all had that experience and have also to admit that it never pales in its effect ! Over the years a large amount of time and energy has been directed towards such sites by conservation bodies, ever conscious of their importance to shorebirds moving on their migrations over various parts of the globe. Certainly in the UK the RSPB has put in a huge amount of work and resources aimed at gaining the recognition and designation of such sites and the BTO continues to place emphasis on their importance by organizing counts of birds under the WeBS ( Wetland Bird Survey ) and, in particular, the Low Tide Counts scheme. Similar work is carried out around the world by differing organizations.
One of the imperatives which continues to focus attention on such sites is that they are favoured for expansion by the petrochemical industry, hydroelectric schemes and a whole plethora of other industrial interests that require vast spaces on which to base their operations. This , of course, is often the precursor to the alteration of the areas "reclaimed" which, in turn , can have a knock on effect as far as adjacent areas are concerned.
For the first time details have emerged of how important these areas really are. It's not enough to presume that birds displaced by such industrial activities simply seek out and then continue to use some alternative. Research carried out linked with the East Asian - Australasian Flyway and, in particular, associated with the Saenmangeum reclamation scheme in South Korea has unearthed some disturbing results that show birds don't automatically switch to alternative sites and, as a consequence, pressures emerge on that particular population , with disastrous results. Here is an abstract of the research concerned kindly provided by Niall Moores
Saemangeum in the Republic of Korea (ROK, “South Korea”) was one of the
most important shorebird staging sites in the Yellow Sea. It supported at least
330,000 shorebirds annually in 1997-2001 including ~ 30% of the world population
of Great Knot (Calidris tenuirostris) during both northward and southward
migration. Construction of a 33km long seawall was completed in April 2006. We
show that shorebird numbers at Saemangeum and two adjacent wetlands decreased by
130,000 during northward migration in the next two years and that all species
have declined at Saemangeum since seawall closure. Great Knot was among the most
rapidly affected species. Fewer than 5,000 shorebirds were recorded at
Saemangeum during northward migration in 2014. We found no evidence to suggest
that the majority of shorebirds of any species displaced from Saemangeum
successfully relocated to other ROK sites. Instead, by 2011-2013 nearly all
species had declined substantially in the ROK since previous national surveys in
2008 and 1998, especially at more heavily reclaimed sites. It is likely that
these declines were driven by increased mortality rather than movement to
alternate staging sites given that other studies have revealed concurrent
declines in numbers and survival on the non-breeding grounds. This is the first
study in the East Asian – Australasian Flyway to confirm shorebird declines at a
range of geographical scales following a single reclamation project. The results
indicate that if migratory shorebirds are displaced from major staging sites by
reclamation they are probably unable to successfully relocate to alternate
Moores, N., Rogers, D.I., Rogers, K. and Hansbro, P.M. 2016. Reclamation of
tidal ﬂats and shorebird declines in Saemangeum and elsewhere in the Republic of
Korea. Emu, 116, 2: 136-146. Published by CSIRO.
It would appear that the importance of all such Flyway sites in an international context is paramount to the future survival of many shorebird bird species and that renewed vigilance and targeted protection needs to be the order of the day !!