Status, Trends and Values of Wintering and Migrating Birds in Gialova Lagoon, Messenia, Greece

Institutionen för naturgeografi Status, trends and values of wintering and migrating birds in Gialova Lagoon, Messenia, Greece Viggo Norrby Examensarbete avancerad nivå Miljö- och hälsoskydd, 30 hp 2017 2 Förord Denna uppsats utgör Viggo Norrbys examensarbete i Miljö- och hälsoskydd på avancerad nivå vid Institutionen för naturgeografi, Stockholms universitet. Examensarbetet omfattar 30 högskolepoäng (ca 20 veckors heltidsstudier). Handledare har varit Håkan Berg och Giorgos Maneas, Institutionen för naturgeografi, Stockholms universitet. Examinator för examensarbetet har varit Salim Belyazid, Institutionen för naturgeografi, Stockholms universitet. Författaren är ensam ansvarig för uppsatsens innehåll. Stockholm, den 28 juni 2017 Steffen Holzkämper Studierektor Abstract Areas of wetland have for the last century declined globally, mostly as a cause of anthropogenic activitities. Since many bird species are depending on wetlands, this have affected their populations negatively, and today many of the remaining wetlands are protected. This study has investigated the status and trends of Gialova lagoon in Greece, both as a stopover for spring migrating birds and as a wetland for wintering waterbirds. This has been done by doing an own field inventory for two weeks in March, and by compiling and analysing data from winter censuses from the last thirty years. Results showed that Gialova supported many migrating birds during the inventory, and several of these are threatened in Europe. The eastern parts of the lagoon are the most important and sensitive areas, due to the suitable habitat for foraging and protection. The analysis of winter data showed that only one species was increasing, while the rest and the total amount of waterbirds were stable or decreased. The number of birds during winter did not reach thresholds for qualifying as a Ramsar-site of international importance. However, the wetland’s geographical location and context makes it a important area to protect for migrating birds, and it also has values for the local community in terms of different ecosystem services. Key words: Wetlands, waterbirds, bird migration, Greece, inventory, monitoring. 3 4 Contents Abstract ......................................................................................................................................................... 3 1. Introduction ............................................................................................................................................... 7 1.1 Purpose and study questions .............................................................................................................. 8 2. Method ...................................................................................................................................................... 9 2.1 Study area ............................................................................................................................................ 9 2.2 Previous research in the study area ..................................................................................................10 2.3 Evaluation of Gialova as a bird habitat ..............................................................................................11 2.4 Spring migration inventory ................................................................................................................12 2.5 Compilation and analysis of midwinter counting data......................................................................15 3. Results .....................................................................................................................................................16 3.1 Inventories in March .........................................................................................................................16 3.1.1 Number of species and individuals observed .............................................................................16 3.1.2 Species of higher conservation values .......................................................................................18 3.1.3 Birds spatial distribution within Gialova lagoon .........................................................................20 3.2 Midwinter counting data 1986-2015 ................................................................................................21 3.2.1 Long-term trend analysis of most common species...................................................................24 3.2.2 1% of flyway population .............................................................................................................25 4. Discussion ................................................................................................................................................26 4.1 Spring migration ................................................................................................................................26 4.2 Wintering waterbirds 1986-2015 ......................................................................................................28 4.3 Gialova’s values as a bird habitat ......................................................................................................29 5. Conclusions ..............................................................................................................................................30 Acknowledgement .......................................................................................................................................31 References ...................................................................................................................................................32 Appendix I: Swedish translation of some of the most mentioned species in the thesis ............................35 Appendix II: Species list from inventory, March 2017 ................................................................................36 5 6 1. Introduction In history, wetlands have been perceived as areas without greater values to offer the human society. Wetlands contribute to the spread of diseases like malaria, and the area that the wetland occupies could be used for something more valuable. This view of the wetland as something less valuable is the main reason why they for the last century have been disappearing at a high rate. Globally it is appreciated that since year 1900 64-71 % of all wetlands have disappeared (Davidson 2014). The rate and degree in which wetlands have vanished differs over the world, but Europe is a part where this negative trend is stated to have been one of the more significant (Zedler & Kercher 2005). During the 20th century two thirds of all European wetlands vanished, with a higher speed during the second half (Silva et al. 2007). The reasons for drying out wetlands in this region have to a large extent been for agricultural activities. Expanding fields for sowing and grazing, freshwater withdrawal for irrigation and new woodland creation are some of the major reasons why wetlands even today are declining in Europe, as well as in other parts of the world (ibid.). Much of the ones remaining are to a large extent also degraded by various, mostly anthropogenic, reasons such as eutrophication, salinization, pollution and by climate change (Zedler & Kercher 2005). The process of decreasing and degraded wetlands has caused large negative impacts on organisms dependent on this sort of environment. To this group of organisms birds is one of the major, where the subgroup waterbirds is the most apparent. Waterbirds are defined as “species of bird that are ecologically dependent on wetlands” (Ramsar convention 1994, art 1.2) including all waterfowl, seabirds and waders. For waterbirds wetlands are possibly the most crucial habitat, for breeding and not the least for migration. Migrating birds are dependent on wetlands both as wintering areas to stay in for longer periods but also as important “stopovers”. Stopovers, or staging sites, are areas which migrating birds make briefer stops at when they are migrating to or from their breeding grounds (Warnock 2010). They use these areas for resting and for foraging to refuel their fat reserves (ibid). Different birds have different migration routes which are more or less predetermined and evolved to pass by suitable stopover areas (Moore et al. 2005). When wetlands along a birds predetermined migration route disappear, the likeliness of the bird to complete its migration is strongly decreased (ibid.). The loss of wetlands has been stated to be one of the major reasons why populations of several waterbird species have shown a decline for the last century and into our days (Bortels et al. 2011, Morrison et al. 2001) The protection and conservation of wetlands and species connected to wetlands are today under a number of conventions and regulations. In the EU the most important regulation is the Bird- and habitat directive, where all member countries have agreed to protect habitats supporting birds listed in the Annex I (European commission 2016), forming the Natura 2000-network of protected areas. Wetlands and waterbirds are here central as habitats and species to protect. Wetlands in Europe are also protected under international conventions such as the Ramsar convention covering the large and most important wetlands (Ramsar convention 1994), and the by UNEP Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) with a focus on multilateral protection of migrating waterbirds and wetlands (AEWA 2017).

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