This is a summary of count data and habitat assessment from the third spring-tide cycle of this years Saemangeum Shorebird Monitoring Program, a joint initiative of the domestic organization Birds Korea and the international Australasian Wader Studies Group (AWSG). These data and information will be refined further, for publication in the SSMP 2007 Report and in other papers, and can be cited freely by others (with proper acknowledgement and caveats).
Between April 30th and May 6th 2007, a total of 24 people counted or assisted counting shorebirds within the 40,100 ha Saemangeum reclamation area (until April 21st 2006, comprising the free-flowing estuaries of the Mangyeung and Dongin Estuaries), Gomso Bay and the Geum Estuary, three adjacent intertidal wetlands on the west coast of South Korea.
Data are here summarized from counts at Gomso Bay on May 1st; Saemangeum (Mangyeung area on April 30th and May 3rd, and the Dongjin area on May 3rd, including a nine hour boat-based count of all outlying tidal-flats of both areas the same day); and the Geum Estuary on May 6th (with additional counts in all areas throughout this period, and between April 20th and 30th).
At Gomso Bay, 726 shorebirds were counted on May 1st, with Whimbrel (368) the most numerous. While this count corresponds reasonably well with counts made in 2006, it is significantly less than the 2941 shorebirds recorded on April 19th this year. Of especial note, only 2 Great Knot were logged (down from 1664 on April 19th), indicating clearly that this sandy bay is largely unsuitable for the species.
Within Saemangeum, land-based counts of the Mangyeung on April 30th were followed by counts at the Dongjin on May 2nd and 3rd, with simultaneous boat-based counting on 3rd of shorebirds on outlying tidal-flats of both estuaries. In total, a minimum 54,010 shorebirds were counted during this period, with the majority of these (35,172) at the Mangyeung.
Most numerous at the Mangyeung were Dunlin (19,614), Great Knot (5089), Bar-tailed Godwit (2671), Grey Plover (1876) and Red-necked Stint (1310), with internationally important concentrations also of Terek Sandpiper (785), Ruddy Turnstone (336), Eastern Oystercatcher (172) and 6 Nordmann's Greenshank (Endangered). The Endangered/Critically Endangered Spoon-billed Sandpiper (2 on April 24th and 1 on April 27th) was not found during the main count period.
At the Dongjin, only 18, 838 shorebirds were counted (down from 39, 640 in the Second Count Cycle – leading to a Saemangeum-wide decline from 69,441 shorebirds counted in Mid-April). Much of the decline came through the apparent loss of a rich area of healthy-looking tidal-flat off Gyehwado in the Dongjin which had supported 18, 220 Great Knot on April 18th. With lower water levels in late April and early May, this island has expanded greatly in area, with most of the flats now dried out and littered with abundant dead shells. On May 3rd, only 1003 Great Knot remained at this site, and only 2348 Great Knot in total were found throughout the whole Dongjin, with the four other most numerous species there being Dunlin (11,460), Bar-tailed Godwit (1232), Terek Sandpiper (861) and Grey Plover (732). In addition, one Nordmann's Greenshank was found.
At the Geum Estuary, repeat counts at mainland sites were followed by simultaneous counts of the main roosts on the mainland (between Janghang and Janggu) and at Yubu Island, both on the afternoon of May 5th (561 cm high tide), and the early morning of May 6th (a 647 cm high tide), with a subsequent high tide count near the Geum Barrage in the afternoon of the 6th of three species consistently recorded in much higher numbers near the Geum barrage (where high-tide roosting likely in rice-fields), than at the other high tide roosts counted on both 5th and 6th (i.e. Black-tailed Godwit [830], Common Greenshank [389] and Sharp-tailed Sandpiper [371]). In total, a minimum of 91,119 shorebirds were counted on the 6th, with most numerous Dunlin (38,664), Great Knot (36,251), Bar-tailed Godwit (5,532), Grey Plover (3542), Mongolian Plover (2101) and Far Eastern Curlew (1387). In addition, 4 Spoon-billed Sandpiper and a conservative 19 Nordmann's Greenshank were counted (all on Yubu Island, where a total of 79,002 shorebirds were logged).
The Geum Estuary counts seem of great significance in at least three ways.
The first is that the counts there for the first time greatly exceed comprehensive counts throughout the whole of the Saemangeum system, emphasizing the Geum Estuary's extreme international importance, while highlighting the decline in value of Saemangeum.
The second is that a minimum total of only 80,281 shorebirds were counted through the whole northward migration period at the Geum Estuary during the SSMP 2006 (Moores et al., 2006). Considering an estimate of 50,000 Great Knot and 9,000 Bar-tailed Godwit also logged at Yubu Island in mid-late April this year, at least 110,000 shorebirds, with no allowance for turnover, will have been supported by this site so far this spring.
Third, of major concern, is that while Great Knot are considered likely to reach a peak in this region in mid-May before mass departure in mid-late May, their numbers recorded during the third count cycle have already fallen well below those counted in late April. While there has been no evidence of mass mortality (of this or other shorebird species), it can be understood that many Great Knot have been displaced by the Saemangeum reclamation, and have subsequently failed to stage through the remainder of the spring at either Gomso Bay or the Geum Estuary – contradicting the bland claims made by the Ministry of Agriculture and Forestry in 2003, that shorebirds displaced by the Saemangeum reclamation will simply move to Gomso Bay and the Geum.
Lacking evidence to the contrary, it seems most likely that these displaced Great Knot will still be somewhere in the Yellow Sea, staging at less optimal sites. Those birds that are unable to put on sufficient mass during the remainder of the month will likely be unsuccessful breeders, contributing to long-term declines in this species. Future research, including increased intensity of counts in Australia during the boreal winter and the 2008 SSMP, are well-placed to detect resultant significant declines at the population level of this species.
In addition to shorebird counts and leg-flag searches, SSMP participants and volunteers have been involved in a broad range of awareness-raising activities during this period. These have included presentations in Mokpo (on April 26th) with the local branch of KFEM (one of Korea's leading enviornmental organisations); visits to the British and Australian Embassies (on May 1st), where reports were handed over and discussions held relating both to Ramsar and the Korea-Australia Migratory Bird Agreement; interviews with media (most notably with the Korea Herald, also on May 1st); an informal photo exhibition at Wonkwang University (with photographs very kindly contributed both by participants and by the birdwatching group, KWBS), between May 1st and May 8th; a symposium at the same university (on May 4th), with an audience of over 60; and an open afternoon shorebird watching on May 5th.
As Birds Korea and the AWSG remain committed to making the SSMP data freely available in mailings and on our websites, we equally welcome receiving data on shorebirds and changes in ecological character of these wetlands from other individuals and organizations surveying the same or adjacent sites.
Field Participants in the SSMP between April 20 and May 6th included people from South Korea, Canada, The US, The UK, Thailand, Bangladesh, Australia and New Zealand: Geoff Styles, Andrew Patrick, Ju Yong-Gi, Nial Moores, Danny Rogers, Sarah Dawkins, Peter Nebel, Siriya Sripanomyom, Sajahan Sorder, Adrian Riegen, Keith Woodley, Nigel Millius, Kim Rakhyun, Richard Chandler, Ken Gosbell, Penny Johns, Maureen Christie, Charles Page, Park Meena, Lydia Slobodian, Seo Ji-Ah, Moon Ju-Hyeon, Tabitha Davis and Todd Schipper.
Birds Korea, May 6th, 2007