The Water Framework Directive (Classification, Priority Substances and Shellfish Waters) Regulations (Northern Ireland) 2015

Boundary values for aquatic plants and animals in transitional and coastal waters

This section has no associated Explanatory Memorandum

14.  The Department must apply, as applicable, to any transitional water or part thereof, the “high”, “good”, “moderate”, “poor” or “bad” fish boundary value for transitional waters specified in Table 18 below.

Table 1
Benthic invertebrate fauna Walley Hawkes Paisley Trigg (WHPT) boundary values (WHPT Average Score per Taxon) for rivers
Boundary values for the degree to which the annual mean sensitivity to disturbance of the observed taxa differs from the annual mean sensitivity of the taxa expected under reference conditions
Ecological quality ratio
High0.97
Good0.86
Moderate0.72
Poor0.59
Bad< 0.59
Table 2
Benthic invertebrate fauna Walley Hawkes Paisley Trigg (WHPT) boundary values (WHPT Number of TAXA) for rivers
Boundary values for the degree to which the annual mean number of disturbance-sensitive taxa differs from the annual mean number of taxa expected under reference conditions
Ecological quality ratio
High0.80
Good0.68
Moderate0.56
Poor0.47
Bad< 0.47
Table 3
Phytobenthos (Diatom) boundary values for rivers
Boundary values for the degree to which the relative annual mean abundances of nutrient-sensitive and nutrient-tolerant groups of diatom taxa differ from the relative annual mean abundances of these groups of taxa expected under reference conditions
Ecological quality ratio
High0.80
Good0.60
Moderate0.40
Poor0.20
Bad< 0.20
Table 4
Macrophyte boundary values for rivers
Boundary values for the degree to which the annual mean abundances of disturbance-sensitive and disturbance-tolerant macrophyte taxa differ from the annual mean abundances of those taxa under reference conditions
Ecological quality ratio
High0.80
Good0.60
Moderate0.40
Poor0.20
Bad< 0.20
Table 5
Freshwater Fish FCS2 (Ireland) boundary values for rivers
Ecological quality ratio(1)
(1)

FCS2 (Ireland) is the Fisheries Classification Scheme 2 (Ireland) model developed for WFD Ecoregion 17 which is the island of Ireland

High0.845 < EQR<= 1.0
Good0.54 < EQR <= 0.854
Moderate0.12 < EQR <= 0.54
Poor0.007 < EQR <= 0.12
Bad0 <= EQR <= 0.007
Table 6
Phytoplankton boundary values for lakes – chlorophyll a
Boundary values for the degree to which the biomass of phytoplankton taxa (as represented by the annual mean chlorophyll a concentration) differ from the biomass of those phytoplankton taxa (annual mean chlorophyll a concentration) expected under reference conditions
Ecological quality ratio
Column 1Column 2Column 3Column 4Column 5Column 6
Lake Type

High alkalinity, shallow

Marl shallow

High alkalinity, very shallow

Moderate alkalinity, very shallow

Low alkalinity, very shallow

Marl very shallow

Moderate alkalinity, deep

Moderate alkalinity, shallow

Moderate alkalinity

shallow humic

Low alkalinity, shallow

Low alkalinity, shallow humic

Low alkalinity deep
High0.550.630.500.640.64
Good0.320.300.330.290.33
Moderate0.160.150.170.150.17
Poor0.050.050.050.050.05
Bad< 0.05< 0.05< 0.05< 0.05< 0.05
Table 7
Phytoplankton boundary values for lakes – plankton trophic index
Ecological quality ratio
Column 1Column 2Column 3Column 4Column 5Column 6
Lake Type

High alkalinity, shallow

Moderate alkalinity very shallow

Low alkalinity very shallow humic

Marl very shallow

High alkalinity very shallow

Moderate alkalinity, deep

Moderate alkalinity shallow

Low alkalinity, shallow humic

Low alkalinity very shallow Clear

Marl Shallow

Low alkalinity

Deep Clear Water

Low alkalinity shallow Clear Water

Low alkalinity shallow humic
High0.930.910.950.980.96
Good0.820.800.840.870.85
Moderate0.700.680.720.750.73
Poor0.580.560.600.630.61
Bad<0.58<0.56<0.60<0.63<0.61
Table 8
Phytoplankton boundary values for lakes – cyanobacteria biomass
Ecological quality ratio
Column 1Column 2Column 3
Lake TypeAll Low and Moderate alkalinity and Marl LakesHigh alkalinity Lakes
High0.470.63
Good0.320.43
Moderate0.230.34
Poor0.130.21
Bad< 0.13< 0.21
Table 9
Phytobenthos boundary values for lakes
Boundary values for the degree to which the relative annual mean abundances of nutrient-sensitive and nutrient-tolerant groups of diatom taxa differ from the relative annual mean abundances of these groups of taxa expected under reference conditions
Ecological quality ratio
Column 1Column 2Column 3
High and Low alkalinity lakesModerate alkalinity lakes
High0.920.93
Good0.700.66
Moderate0.460.46
Poor0.230.23
Bad< 0.23< 0.23
Table 10
Aquatic macrophyte boundary values for lakes
Boundary values for the degree to which the annual mean abundance of disturbance-sensitive macrophyte(1) taxa differ from the annual mean abundance of those taxa expected under reference conditions
(1)

The term “macrophyte” refers to larger plants, typically including flowering plants, mosses and larger algae, but not including single-celled phytoplankton or diatoms.

Ecological quality ratio
Column 1Column 2
High0.90
Good0.68
Moderate0.42
Poor0.33
Bad< 0.33
Table 11
Freshwater Fish FiL2 boundary values for lakes
Ecological quality ratio(1)
(1)

FiL2 is the Fish in Lakes version 2 model developed for WFD Ecoregion 17 which is the island of Ireland

High0.76 < EQR<= 1.0
Good0.53 < EQR <= 0.76
Moderate0.32 < EQR <= 0.53
Poor/Bad0 <= EQR <= 0.32
Table 12
Benthic invertebrate fauna boundary values for IMPOSEX in coastal waters
Boundary values for the degree to which the annual mean occurrence and degree of tributyl tin (TBT) -induced imposex in the common dog whelk, Nucella lapillus, differs from the annual mean occurrence and degree of imposex expected under reference conditions using the Vas Deferens Stage Index (VDSI) (UKTAG Method ISBN 978-1-906934-35-4)
Ecological quality ratioVas Deferens Stage Index (VDSI)
High0.950.3
Good0.334
Moderate0.175
Table 13
Benthic invertebrate fauna boundary values for the INFAUNAL Quality Index (IQI) for transitional and coastal waters
Boundary values relating to the degree to which the annual mean number of benthic invertebrate taxa in soft sediments, the diversity of taxa, and the ratio of disturbance-sensitive and disturbance-tolerant taxa differ from that expected under reference conditions (UKTAG Method ISBN 978-1-906934-34-7)
Ecological quality ratio
High0.75
Good0.64
Moderate0.44
Poor0.24
Bad< 0.24
Table 14
Aquatic angiosperm boundary values in transitional and coastal waters
Aquatic Angiosperm(1) Boundary values relating to the degree to which the annual mean shoot density, and spatial extent of sea grass beds, differ that expected under reference conditions (UKTAG Method ISBN 978-1-906934-36-1)
(1)

The term “angiosperm” refers to flowering plants. In transitional waters and coastal waters, angiosperms include sea grasses and the flowering plants found in salt marshes, salt marsh tools have not yet been developed.

Ecological quality ratio
High0.8
Good0.6
Moderate0.4
Poor0.2
Bad< 0.2
Table 15
Phytoplankton boundary values for transitional and coastal waters
Boundary values relating to the degree to which biomass, taxonomic composition, bloom frequency and bloom intensity for phytoplankton(1) differ from that expected under reference conditions (UKTAG Method ISBN 978-1-906934-41-5 for Transitional waters and UKTAG method ISBN 978-1-906934-33-0 for Coastal Waters)
(1)

The term “phytoplankton” refers to solitary and colonial unicellular algae and cyanobacteria that live in the water column, at least for part of their lifecycle.

Ecological quality ratio
High0.8
Good0.6
Moderate0.4
Poor0.2
Bad< 0.2
Table 16
Aquatic macroalgae boundary values in transitional and coastal waters
Boundary values relating to the degree to which mean species richness, proportion of red, green and opportunist seaweeds and ecological status group ratio on rocky intertidal areas differ from that expected under reference conditions (UKTAG Method ISBN 978-1-906934-39-2)
Ecological quality ratio
High0.8
Good0.6
Moderate0.4
Poor0.2
Bad< 0.2
Table 17
Aquatic macroalgae boundary values in transitional and coastal waters
Boundary values relating to the degree to which opportunistic macroalgal(1) extent, biomass and entrainment differ from that expected under reference conditions (UKTAG Method ISBN978-1-906934-37-8)
(1)

The term “macroalgae” refers to multicellular algae such as seaweeds and filamentous algae.

Ecological quality ratio
High0.8
Good0.6
Moderate0.4
Poor0.2
Bad< 0.2
Table 18
Fish boundary values for transitional waters
Boundary values relating to the degree to which transitional water fish communities deviate from expectations in terms of species diversity and composition, species abundance, estuarine utilisation, and trophic composition using the Estuarine Multi-metric Fish Index (EMFI)
Ecological quality ratio
High≥ 0.92
Good0.65
Moderate0.35
Poor0.10
Bad< 0.10