communities based on the assumption that the community grows deeper - - PowerPoint PPT Presentation

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Aug 11, 2023 159 likes •224 views

Lower depth limit of macrophyte communities based on the assumption that the community grows deeper the more favourable the growth conditions are the depth limit should be measures at the depth where the community has a 10% coverage

SLIDE 1

Lower depth limit of macrophyte communities

based on the assumption that the community

grows deeper the more favourable the growth conditions are

the depth limit should be measures at the

depth where the community has a 10% coverage value

pre-core indicator
under development

SLIDE 2

Primary importance Secondary importance BSAP Segment and Objective Thriving and balanced communities of plants and animals Natural marine landscapes none stated MSFD Descriptors and Criteria 1.4 Habitat distribution 1.5 Habitat extent (area, only as proxy) 1.6. Habitat condition 4.3 Abundance/distribution of key trophic groups and species (habitat defining species) 6.1 Substrate characteristics Other relevant legislation: (e.g. WFD) Ecological status indicator for WFD in five HELCOM countries

Policy relevance of the pre-core indicator

SLIDE 3

GES-boundary concept

the reference value of lower depth limit to be

applied throughout the Baltic Sea due to the biogeographic and ecological differences between assessment units

WFD coastal types and water bodies are smallest

assessment units

GES-boundary is defined as 20% acceptable

deviation from reference value

community-specific reference values have to be

used between soft and hard bottom communities

SLIDE 4

Requirements

Indicator is not applicable if:

depth limit of macrophytes is limited by

substrate (e.g. lack of hard substrate in exposed areas)

no dense macrophyte stands naturally occurs

in an assessment unit

assessemnt unit is not deep enough

SLIDE 5

Applicability

applicable in all coastal areas
usable in soft, hard and mixed bottoms

– in all cases specific reference conditions needed – in suitable areas with soft or mixed bottoms depth limit of charophytes or higher plants to be used

SLIDE 6

Preliminary asssessment unit specific GES-boundaries

set by Estonia and Germany

ID HELCOM_ID Assessment unit name Macrophyte community type preliminary GES-boundaries [meter] 15 EST-003 1 mixed (soft and hard bottom) 5,6 16 EST-004 2 mixed (soft and hard bottom) 2,8 17 EST-005 3 hard bottom 8,4 18 EST-006 4 hard bottom 8,4 19 EST-007 5 mixed (soft and hard bottom) Not applicable 20 EST-008 6 hard bottom 6,7 ID HELCOM_ID Assessment unit name Macrophyte community type preliminary GES-boundaries [meter] 112 GER-002 B2b_MV soft bottom 6,0 113 GER-003 B2b_MV soft bottom 4,4 114 GER-005 B2a_MV soft bottom 5,1 115 GER-006 B3b_MV soft bottom 7,0 116 GER-007 B1_MV soft bottom 2,4 117 GER-008 B1_MV soft bottom 2,4 137 GER-029 B4_SH hard bottom 17,6 138 GER-024 B2a_SH soft bottom 2,2 139 GER-033 B3b_SH soft bottom 7,0 140 GER-036 B3b_SH soft bottom 7,0