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Location Turkey, Istanbul
Central coordinates 28o 32.00' East  41o 5.00' North
IBA criteria A1, A4i, A4iii, B1i, B2
Area 5,118 ha
Altitude 6 m
Year of IBA assessment 2004

Doga Dernegi (Partner Designate)

Site description A freshwater lake situated west of Ýstanbul where the Karasu stream reaches the Marmara Sea. The stream was dammed to create a drinking water reservoir; during dry years less than 25% of the lake area remains flooded. Mudflats, sandbanks and reedbeds (Phragmites) have formed where silt deposition occurs. South of the dam is a brackish lake with reed fringes and islands. The lake is largely surrounded by arable land and, increasingly, industrial and residential development. Motorways cut across both ends of the lake.

Key Biodiversity This site is important for wintering and passage waterbirds. It also supports a range of breeding waterbirds. During autumn the arable land surrounding the lake can hold thousands of migrating Ciconia ciconia, which roost here before crossing the Boðaziçi (site 005). Species of global conservation concern that do not meet IBA criteria: Aythya nyroca (thought to breed).

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Red-breasted Goose Branta ruficollis winter  1998  75-80 individuals  A1, B2  Vulnerable 
Common Pochard Aythya ferina winter  1996  14,036 individuals  A4i, B1i  Vulnerable 
Larus cachinnans winter  1996  1,250-8,775 individuals  B1i  Not Recognised 
Mediterranean Gull Larus melanocephalus passage  1995  10,000 individuals  A4i, B1i  Least Concern 
Little Gull Hydrocoloeus minutus passage  1991  1,740 individuals  A4i, B1i  Least Concern 
A4iii Species group - waterbirds winter  1996  22,681 individuals  A4iii   

IBA Monitoring

2015 high near favourable medium
Medium - based upon reliable but incomplete / partially representative data

Residential and commercial development housing and urban areas happening now some of area/population (10-49%) moderate to rapid deterioration high

Wetlands (inland) Standing freshwater  0 0 good (> 90%) moderate (70-90%) near favourable

Most of site (50-90%) covered (including the most critical parts for important bird species)  A management plan exists but it is out of date or not comprehensive  Substantive conservation measures are being implemented but these are not comprehensive and are limited by resources and capacity  medium 


IUCN habitat Habitat detail Extent (% of site)
Wetlands (inland) Standing freshwater; Water fringe vegetation  100%

Land use

Land-use Extent (% of site)
water management 100%

Protection status National High International None2,850 ha of IBA covered by Drinking Water Reservoir (Büyükçekmece Gölü, 2,850 ha).

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Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Büyükçekmece Lake. Downloaded from on 25/10/2016

To provide new information to update this factsheet or to correct any errors, please email BirdLife