Interim report of the HELCOM CORESET project
Interim report of the HELCOM CORESET project
Interim report of the HELCOM CORESET project
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The policy decisions under different frameworks have possibly confl icting objectives. The Favourable Conservation<br />
Status under <strong>the</strong> Birds Directive may be diffi cult to reach, if <strong>the</strong> environment changes to more<br />
oligotrophic direction. However, decrease <strong>of</strong> by-catch, oil pollution and hunting would allow higher bird<br />
populations and may mitigate this confl ict.<br />
Provisional GES boundaries: Until modeling studies have confi rmed possible GES boundaries for <strong>the</strong> selected<br />
bird species, it is proposed that provisional GES boundaries are used. The GES is tentatively defi ned<br />
as a 50% deviation from mean <strong>of</strong> <strong>the</strong> reference period <strong>of</strong> 1992-1993 (based on available temporal trends<br />
in Skov et al. 2011).<br />
Ultimately, <strong>the</strong> GES could be set by modelling <strong>the</strong> population size based on <strong>the</strong> GES for eutrophication<br />
related core indicators, because <strong>the</strong> abundance <strong>of</strong> seabirds depends on <strong>the</strong> trophic state <strong>of</strong> <strong>the</strong> ecosystem<br />
and <strong>the</strong> objective <strong>of</strong> decreasing <strong>the</strong> eutrophication will affect <strong>the</strong> seabird populations.<br />
Assessment units for <strong>the</strong> seabird indicators<br />
The abundance <strong>of</strong> wintering seabird populations differs among Baltic sub-basins. Therefore <strong>the</strong> indicator<br />
should be assessed per sub-basin. That means that also <strong>the</strong> targets must be set for each <strong>of</strong> <strong>the</strong> sub-basins.<br />
Figure 2.14. Sub-basin assessment units in <strong>the</strong> Baltic Sea (blue lines).<br />
Sampling and data analyses<br />
See Skov et al. 2007 and 2011<br />
Gaps and weaknesses<br />
The indicator has currently a couple <strong>of</strong> weaknesses which must be addressed in near future:<br />
– not all wintering grounds are covered,<br />
– monitoring methods differ between <strong>the</strong> <strong>of</strong>fshore monitoring and national monitoring practices,<br />
– GES boundary is tentative, because <strong>of</strong> <strong>the</strong> uncertainty <strong>of</strong> interlinkages with o<strong>the</strong>r GES boundaries.<br />
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