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Implementing the Water Environment and Water Services (Scotland) Act 2003: Development of environmental standards and conditions limits - phase II: A Consultation

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ANNEX 12: SURFACE WATER BIOLOGICAL STANDARDS - BIOLOGICAL STANDARDS FOR TRANSITIONAL WATERS AND COASTAL WATERS

Table A: Benthic invertebrate standards for coastal waters (1)

Standards 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

Ecological quality ratio

Vas Deferens Stage Index ( VDSI)

Column 1

Column 2

Column 3

High

0.95

0.3

Good

0.33

4

Moderate

0.17

5

Poor

0.00

6

Table B: Benthic invertebrate standards for transitional (salinity > 20) and coastal waters (2)

Standards 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 the annual mean number, diversity and the ratio of disturbance-sensitive and disturbance tolerant taxa expected under reference conditions

Ecological quality ratio

Column 1

Column 2

High

0.75

Good

0.64

Moderate

0.44

Poor

0.24

Table C: Indicators used in calculating the standards for the condition of benthic invertebrates in Table B.

Observed Simpson's evenness index divided by the maximum expected Simpson's evenness value expected under reference conditions

(Simpson's evenness index gives a measure of the proportion of individuals that each taxonomic group contributes to the total number of taxa in a sample)

Observed number of taxa in a sample divided by the maximum number of taxa expected under reference conditions

Observed AZTI Marine Biotic Index ( AMBI) divided by the maximum AMBI expected under reference conditions

AMBI describes the ratio of disturbance-sensitive to disturbance tolerant invertebrate taxa

Table D: Fish standards for transitional waters

Standards for the degree to which the annual mean composition and abundance of disturbance-sensitive fish taxa differ from the annual mean composition and abundance of disturbance-sensitive fish taxa expected under reference conditions

Ecological quality ratio

Column 1

Column 2

High

0.8

Good

0.6

Moderate

0.4

Poor

0.2

Table E: Aquatic angiosperm (i) standards for transitional waters and coastal waters

Standards relating to the degree to which the annual mean shoot density in, and spatial extent of, sea grass beds, differ from the annual mean shoot density in, and spatial extent of, sea grass beds expected under reference conditions

Ecological quality ratio

Column 1

Column 2

High

0.8

Good

0.6

Moderate

0.4

Poor

0.2

Note to Table E

(i)The term 'angiosperm' refers to the flowering plants. In transitional waters and coastal waters, angiosperms include sea grasses and the flowering plants found in salt marshes.

Table F: Phytoplankton (i) standards for transitional waters and coastal waters

Standards relating to mean of the results for each of the indicators of the condition of phytoplankton in Table G

Ecological quality ratio

Column 1

Column 2

High

0.8

Good

0.6

Moderate

0.4

Poor

0.2

Note to Table F

(i)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.

Table G: Standards for different indicators of the condition of phytoplankton in transitional waters and coastal waters used in calculating the phytoplankton standards in Table E

Indicators of the condition of phytoplankton

Column 1

Column 2

Column 3

Column 4

Column 5

Biomass indicator

Bloom indicator

Species succession indicator

90-percentile chlorophyll a concentration (µg/l)

90-percentile chlorophyll a concentration (µg/l)

Elevated phytoplankton abundance (a)

Deviation from the pattern of taxonomic functional group succession expected under reference conditions (b)

North Sea waters

Atlantic waters

High

10

5

15

0.85

Good

15

10

30

0.75

Moderate

20

15

40

0.6

Poor

25

20

50

0.5

Notes to Table G

(a)Elevated phytoplankton abundance is represented by the mean of:

(i) the percentage of the total number of samples taken in the period April to September in which the counts of any individual phytoplankton species (other than Phaeocystis species) exceed 10 6/l;

(ii) the percentage of the total number of samples taken in the period April to September in which the counts of Phaeocystis species exceed 10 6/l;

(iii) the percentage of the total number of samples taken in the period April to September in which the total count of all phytoplankton species exceed 10 7/l; and

(iv) the percentage of the total number of samples taken in the period April to September in which the concentration of chlorophyll exceeds 10 µg/l.

(b)Percentage of time during a year in which the number of individuals in each of the following taxanomic groups; diatoms, dinoflagellates, microflagellates (excluding Phaeocystis sp.) and Phaeocystis sp, is consistent with the number expected under reference conditions

Table H: Aquatic macroalgae (i) standards for transitional waters(1)

Standards relating to the degree to which the annual mean penetration of different fucoid communities from the seaward toward the freshwater end of an estuary differs from their annual mean penetration expected under reference conditions

Ecological quality ratio

Column 1

Column 2

High

0.8

Good

0.6

Moderate

0.4

Poor

0.2

Note to Table H

(i)The term 'macroalgae' refers to multicellular algae such as seaweeds and filamentous algae.

Table I: Aquatic macroalgae standards for transitional waters and coastal waters(2)

Standards calculated from the combined results of the different indicators of macroalgae specified in Table J

Ecological quality ratio

Column 1

Column 2

High

0.8

Good

0.6

Moderate

0.4

Poor

0.2

Table J: Standards for different indicators of the condition of macroalgae in transitional waters and coastal waters used in calculating the macroalgae standards in Table I

Indicators of the condition of macroalgae

Column 1

Column 2

Column 3

Column 4

Column 5

Column 6

Mean % cover of available intertidal habitat

Total extent of the bloom across available intertidal (hectares)

Average biomass on available intertidal habitat (g/m 2)

Average biomass on affected intertidal habitat (g/m 2)

Percentage of quadrats with algae growing > 3 cm into the underlying sediment

High

5

100

100

100

5

Good

15

500

500

500

20

Moderate

25

1,000

1,000

1,000

50

Poor

75

2,500

3,000

3,000

75

Table K: Aquatic macroalgae standards for coastal waters(3)

Standards calculated for the combined results of the different indicators of macroalgae in Table L and relating to the degree to which the annual mean species richness and diversity of red, green and brown seaweeds on rocky intertidal areas differs from that expected under reference conditions

Ecological quality ratio

Column 1

Column 2

High

0.8

Good

0.6

Moderate

0.4

Poor

0.2

Table L: Standards for different indicators of the condition of macroalgae in transitional waters and coastal waters used in calculating the macroalgae standards in Table I

Indicators of the condition of macroalgae

Column 1

Column 2

Column 3

Column 4

Column 5

Column 6

Species richness (number of taxa)

Proportion of Chlorophyta taxa (%)

Proportion of Rhodophyta taxa (%)

Ratio of late succession or perennial taxa to opportunist or annual taxa

Proportion of opportunist taxa (%)

High

55

25

47

0.65

15

Good

35

30

42

0.5

22

Moderate

20

40

32

0.35

35

Poor

5

60

15

0.1

45

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Page updated: Thursday, June 26, 2008