A new fauna intercalibration typology

Transcription

1 A new fauna intercalibration typology WFD Intercalibration - 2nd phase - Baltic GIG Auftraggeber: Landesamt für Natur und Umwelt Schleswig-Holstein Hamburger Chaussee Flintbe Author: Torsten Berg in cooperation with the fauna group of the Baltic GIG MariLim Gesellschaft für Gewässeruntersuchung mbh Heinrich-Wöhlk-Straße Schönkirchen Germany Version 4 2 October

2 Introduction The second round of the intercalibration within the Water Framework Directive (WFD; European Union, 2000) gives the possibility to change the typology of the waters for the purpose of the intercalibration. Until now, the fauna group within the Baltic GIG has been working with the following common intercalibration (IC) typology (Table 1): Table 1: IC typology for 1st intercalibration round (taken from technical report). Type Salinity Exposure Depth Ice days Other Characteristics psu CW B Sheltered Shallow > 150 Sites in Bothnian Bay (Northern Quark) CW B2 3-6 Sheltered Shallow > 150 Sites in Bothnian Sea CW B3 a 3-6 Sheltered Shallow Sites in the area extending from the CW B3 b 3-6 Exposed Shallow southern Bothnian Sea to the Archipelago Sea and the western Gulf of Finland CW B12 b Western 8-22 Sheltered Shallow - Sites at the Southern Swedish coast and the South western Baltic Sea open coast along Denmark and Germany Baltic Sea CW B Exposed Shallow - Sites along the coast of the Estonia, Latvia and Lithuania, the Polish coast and the Danish island Bornholm CW B Sheltered Shallow - Lagoons TW B Exposed Shallow Transitional water. Sites along the coast of Lithuania and Poland This typology is based on WFD system B and is following the Guidance document No 5 (Transitional and Coastal Waters - Typology, Reference Conditions and Classification Systems) of the CIS Working Group 2.4 (European Union, 2003), hereafter referred to as,cis guidance. This guidance lists a series of factors determining the typology within system B (Table 2). The obligatory factors are Latitude/Longitude (not listed in Table 2) - corresponds to the ecoregion,baltic Sea with brackish waters and mostly low hydrodynamic properties (compared to a European scale; see also Map B in the directive) Tidal range - only microtidal in the Baltic Sea Salinity - polyhaline to freshwater in the Baltic Sea It can be seen, that only the salinity is a varying obligatory factor, all others are constant. The distribution of salinity within the Baltic Sea is the major driver for differences in species assemblages and abundance distributions between different countries in the same intercalibration type. Although the surface salinity is similar in wide areas of the Baltic proper (Figure 1) and seems comparable, the bottom salinity which is important for the benthic communities (Figure 2) ranges from 6 to 22 reflecting largly the mesohaline salinity range. This means a huge difference in taxa numbers and taxa composition. This gave rise to different problems in comparability, meaning e.g. to compare benthic communities from Denmark and Estonia or from Sweden and Estonia on the same basis. Thus, especially the types B12b, B13 and B14 have a too broad salinity range to be compared without fundamental difficulties. Therefore, this paper proposes a new typology for the benthic fauna taking into account the experiences from the first intercalibration round. This affects only the above-mentioned intercalibration types, not the national typologies. However, the existing national types are utilised to build the new intercalibration typology. 2

3 *3*. 89:1.5- ;-::*<-: '( 06= & )*+,-./ Figure 1: Surface water salinity (0-5m) in the Baltic Sea based on data from the CHARM project (from Schernewski & Wielgat, 2004). "$% ( 3

4 Figure 2: Bottom salinity in the Baltic Sea (from Al-Hamdani & Reker, 2007) 4

5 Table 2: Factors recommended for typing surface waters according to the CIS guidance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eneral principle The general principle of the proposed intercalibration typology is to define the countries, who need to intercalibrate, as those countries sharing a coastline or sharing a natural water area. Natural water area means, that the countries are close neighbours, but are separated from each other by a stretch of water, which itself has homogenous properties with respect to the abiotic factors (salinity range etc.). This is illustrated in Figure 3. What is improving with respect to the current typology is that the huge area from Denmark to Finland for the mesohaline salinity range is splitted into smaller parts. 5

6 Figure 3: Neighbouring countries (connected by red arrows) sharing a coastline and countries sharing a natural water area (blue circles). These countries are proposed to intercalibrate in the 2nd round of intercalibration. The new types Based on the above principle, new types were defined and delineated. 9 types have thus been established (8 coastal types and 1 transitional type). The geographical core areas of these types expressed in national water bodies are shown in blue colour on the Figures 4 to 10. Similar to Table 1, the factors determining the 9 new types are given in Table 3 below. 6

7 Table 3: List of types in the new IC typology used for 2nd intercalibration round. New type name Countries involved Bottom Salinity Exposure Ice days Old types Remark BT1 PL, LT 0-5 very sheltered B13 (TW) oligohaline transitional BC1 FI, SE 1-6 exposed B0, B2, B3 exposed oligohaline BC2 DK, DE, PL 2-6 very sheltered B14 lagoon BC3 EE, FI 3-6 sheltered sheltered oligohaline BC4 LV, EE 5-6 sheltered <90 B12a sheltered lower mesohaline BC5 PL, LT, LV 5-8 exposed <90 B13 exposed lower mesohaline BC6 SE, DK 7-11 sheltered <90 B12b sheltered mid mesohaline BC7 DE, PL 8-11 exposed <90 B13 exposed mid mesohaline BC8 DK, DE sheltered <90 B12b upper mesohaline The new types are named starting with B for Baltic followed by C for coastal or T for transitional waters. Following these letters is a number that is increasing with increasing salinity as the main factor for benthic fauna in the Baltic Sea. The original tyes have been spread into different types in the mesohaline salinity range. Originally, this comprised 6-22 psu in one type, now there are types for the lower, the mid and the upper mesohaline range, better reflecting the different fauna communities occuring in the Baltic Sea. The depth (shallow waters) has not been used in the new typology, since it is the same for all countries and has not changed in comparison to the old typology. Also, the types were differentiated on the exposure, just as the old types, using new exposure data from the EU SeaMap project. Some inconsistencies have been removed with this new typology: The communities in the old types B0, B2 and B3 did not differ so much differentiate the oligohaline range into 3 different types. The new typology has only one type BC1 for this. The original type B14 only contained DK and PL. The lagoons in DE were ignored. The new type BC2 now also includes the DE lagoons. EE and FI did not share a type in the old typology, although these two countries are very close together (much closer than EE and SE, who did share a type). The new type BC3 is now comprising these countries. It should be noted that the new types in fact nest with the old ones. This means there are no overlaps and the new types, where they have changed the area, are either subtypes of the old ones (BC4 - BC8) or supertypes (BC1 only). This is important because it means the new types can co-exist with the old types when other quality elements (phytoplankton, angiosperms, macroalgae) still use the old typology. An example case is the old type B12. In the new typology, it is subtyped into BC4, BC6, and BC8. The core area of type BC4, however, does not cover the exposed waters of Estonia. These are still part of B12 but are not considered for the benthic fauna IC. The following maps show the geographical extent of the new 8 coastal types. 7

8 Figure 4: The new type BC8 between Denmark and Germany. It comprises Kiel Bight, the Lillebælt area, and parts of Storebælt. Figure 5: New type BC7 between Germany and Poland. It comprises the German coast from the Darss sill and most of the Polish coastline with the exception of the transitional waters at the mouths of some rivers. 8

9 Figure 6: The new type BC5 between Poland, Lithuania, and Latvia. It comprises the exposed coast of Latvia, the part of the Lithuanian coast that is not transitional (excluding the plume of the Curonian lagoon), and the northern part of the Polish coast. Figure 7: The new type BC4 between Latvia and Estonia. It comprises the coastal part of the Gulf of Riga. The large water body in the south-east of the Gulf of Riga is a transitional water and therefore left out. 9

10 Figure 8: The new type BC3 between Estonia and Finland. It covers the complete Gulf of Finland, that is not part of Russia. Figure 9: The new type BC1 between Finland and Sweden. It comprises the Bay and Gulf of Bothnia. 10

11 Figure 10: The new type BC6 between Sweden and Denmark. It covers the Danish Køge Bight and Faxe Bight and the southern coast of the Swedish Skåne. The northern part of the Øresund is covered by the NEA GIG. Intercalibration sites All country pairs have national water bodies that are close to each other or even share a border. These are the best suited areas to do the intercalibration in. It should be avoided to compare areas, that are far apart, eg. an area from northern Latvia with an area in southern Lithuania. There are, however, not always good enough data from these close areas, so a compromise has often to be applied in order to fulfil the requirements. Transitional waters The countries having transitional waters (type BT1) in the Baltic Sea are Poland, Lithuania, Latvia, and Sweden. The two neighbouring countries Lithuania and Latvia have the Curonian lagoon (LT) together with its plume outside the lagoon, and the inner part of the Gulf of Riga (LV). These two areas are comparable with respect to salinity, but not with respect to exposure, ice cover, sediment, and slope. Thus, currently, it seems not feasable to intercalibrate these. Lithuania also is in the same region as Poland, where the Curonian lagoon (LT) has similar properties as the Vistula lagoon (PL). For salinity, this has not yet been investigated in depth, so there may be differences here. Additionally, LT has a plume of transitional waters outside the lagoon and has no counterpart in PL. However, Poland lacks data for the Vistula lagoon and does not participate in the intercalibration anymore (lack of funding) and therefore intercalibration is not currently possible there. The transitional waters of Sweden are restricted to a comparably small area in the inner part of the Stockholm archipelago and have no counterpart elsewhere in the Baltic Sea. Thus, for Sweden there will be no intercalibration possible in transitional waters. Since Sweden applies the BQI in both the coastal and transitional waters, it is however secured, that the method itself is being intercalibrated. Lagoons The countries in type BC2 having lagoons (a coastal, oligohaline type) are Denmark, Germany, and Poland. Since both Poland and Denmark don t have finished methods yet, and Poland has not sufficent data and is not participating in the IC exercise any longer, no IC is possible for this type. 11

12 References European Union, DIRECTIVE 2000/60/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 23 October 2000 establishing a framework for Community action in the field of water policy. Official Journal of the European Communities, L 327, 72. European Union, Common Implementation Strategy for the Water Framework Directive (2000/60/EC). Guidance document No 5. Transitional and Coastal Waters. Typology, Reference Condions and Classification Systems. Schernewski, G. & Wielgat, M., Towards a Typology for the Baltic Sea. Coastline Reports, 2, Al-Hamdani, Z. & Reker, J., Towards marine landscapes in the Baltic Sea. BALANCE interim report No