Ns Ii Freshwater Pearl Mussel Sub-Basin Management Plans

NS II FRESHWATER PEARL MUSSEL SUB-BASIN MANAGEMENT PLANS

Report on Biological Monitoring of Surface Water Quality in Dereen River Catchment

September 2009 Conservation Services, Tullaha, Glenflesk, Killarney, Co. Kerry Tel/Fax 064 6630130 e-mail [email protected]

2 CONTENTS

1 INTRODUCTION...... 4

2 METHODOLOGY...... 6 2.1 HABITAT ASSESSMENT...... 6 2.2 INVERTEBRATE SAMPLING AND WATER QUALITY ASSESSMENT...... 7

3 RESULTS...... 9 3.1 DEREEN SITE A...... 11 3.2 DEREEN SITE B...... 12 3.3 DEREEN SITE C...... 13 3.4 DEREEN SITE D...... 14 3.5 DEREEN SITE E...... 15 3.6 DEREEN SITE F...... 16 3.7 DEREEN SITE 1...... 17 3.8 DEREEN SITE 2...... 18 3.9 DEREEN SITE 3...... 19 3.10 DEREEN SITE 4...... 20 3.11 DEREEN SITE 5...... 21 3.12 DEREEN SITE 6...... 22 3.13 DEREEN SITE 7...... 23 3.14 DEREEN SITE 8...... 24 3.15 DEREEN SITE 9...... 25 3.16 DEREEN SITE 10...... 26 3.17 DEREEN SITE 11...... 27 3.18 DEREEN SITE 12...... 28 3.19 DEREEN SITE 13...... 29 3.20 DEREEN SITE 14...... 30 3.21 DEREEN SITE 14A...... 31 3.22 DEREEN SITE 15...... 32 3.23 DEREEN SITE 16...... 33 3.24 DEREEN SITE 17...... 34 3.25 DEREEN SITE 18...... 35 3.26 DEREEN SITE 19...... 36 3.27 DEREEN SITE 20...... 37 3.28 DEREEN SITE 21...... 38 3.29 DEREEN SITE 22...... 39 3.30 DEREEN SITE 23...... 40 3.31 DEREEN SITE 24...... 41 3.32 DEREEN SITE 25...... 42 3.33 DEREEN RIVER MONITORING 1976-2009...... 43

4 CONCLUSIONS...... 46

5 REFERENCES...... 47

3 APPENDIX 1 HABITAT AT SAMPLING SITES

APPENDIX 2 SITE PHOTOGRAPHS APPENDIX 3 ‘SILT PLUME’ ASSESSMENT APPENDIX 4 NOTES ON Q-RATING IN MARGARITIFERA CATCHMENTS

4 1 INTRODUCTION

Conservation Services, Freshwater Ecological Consultants have been commissioned by RPS Group Ltd to carry out biological sampling and water quality assessment in accordance with EPA Q-rating methodology at the following 32 sites in Counties Wicklow and Carlow in the catchment of the Dereen River, a tributary of the River Slaney, for the NS II freshwater pearl mussel sub-basin management plans project.

Grid Reference Dereen A 29983 18356 Dereen B 29818 18106 Dereen C 29683 18076 Dereen D 29441 18028 Dereen E 28998 17796 Dereen F 28952 17469 Dereen 1 29968 18340 Dereen 2 29990 18330 Dereen 3 29944 18266 Dereen 4 29872 18308 Dereen 5 29827 18258 Dereen 6 29782 18159 Dereen 7 29771 18138 Dereen 8 29818 18106 Dereen 9 29828 18071 Dereen 10 29543 18082 Dereen 11 29538 18063 Dereen 12 29447 18053 Dereen 13 29454 17997 Dereen 14 29308 18064 Dereen 14A 29275 18165 Dereen 15 29271 18039 Dereen 16 29228 18034 Dereen 17 29102 17892 Dereen 18 29029 17925 Dereen 19 29006 17843 Dereen 20 29025 17690 Dereen 21 28940 17642 Dereen 22 28973 17487 Dereen 23 28915 17454 Dereen 24 28868 17459 Dereen 25 28755 17339

Location of sampling sites is shown on Map 1.

5 6 2 METHODOLOGY

Sampling was carried out on 24th July, 25th July, 14th August, and 18th September 2009.

2.1 HABITAT ASSESSMENT

Habitat assessment was carried out at each of the sites selected for invertebrate/water quality assessment. These sites were assessed in terms of:

· Stream width and depth

· Substrate type, listing substrate fractions in order of dominance, i.e. large rocks, cobble, gravel, sand, mud etc.

· Flow type, listing percentage of riffle, glide and pool in the sampling area

· Instream vegetation, listing plant species occurring and their percentage coverage of the stream bottom at the sampling site

· Dominant bankside vegetation, listing the main species overhanging the stream

· Estimated summer cover by bankside vegetation, giving percentage shade of the sampling site

Grid references were recorded at all sites using a GPS. Site photographs were taken using a digital camera.

7 2.2 INVERTEBRATE SAMPLING AND WATER QUALITY ASSESSMENT

A kick and stone wash invertebrate sample was taken at each site (ISO 7828:1985) using standard methodology employed by EPA. Each sample was retained in a large plastic bag at the sampling site. Sample processing and preservation was carried out under laboratory conditions within 24 hours of sampling. Mud was removed from each sample by sieving under running water through a 500μ sieve. Sieved samples were then live sorted for 30 minutes in a white plastic sorting tray under a bench lamp (ISO 5667-3:1994) and if necessary using a magnifying lens. Macroinvertebrates were stored in 70% alcohol. Preserved invertebrates were identified to the level required for the EPA Q-rating method (McGarrigle et al, 2002) using high-power and low-power binocular microscopes when necessary. The preserved samples were archived for future examination or verification. Based on the relative abundance of indicator species, a biotic index (Q-rating) was determined for each site in accordance with the biological assessment procedure used by the Environmental Protection Agency (Statutory Instruments No. 258 of 1998) and more detailed unpublished methodology (McGarrigle, Clabby and Lucey pers. comm.) It should however be noted that adult Margaritifera are not taken into account in the estimation of Q-ratings in the present survey; the rationale for this is outlined in Appendix 4.

8 Biotic Index Water Quality Quality Status Q5 Good Q4-5 Fair - Good Unpolluted Waters Q4 Fair Q3-4 Doubtful - Fair Slightly Polluted Waters Q3 Doubtful Moderately Polluted Waters Q2-3 Poor - Doubtful Q2 Poor Q1-2 Bad - Poor Seriously Polluted Waters Q1 Bad /0 Suffix applied when there is evidence of an additional toxic influence on the invertebrate fauna (t) Indicates tentative Q-rating due to suboptimal conditions for Q-rating.

9 3 RESULTS

Q-ratings are estimated on the basis of the biological data and the nature of the habitat at the sampling site. Data on habitat at each sampling location are tabulated in Appendix 1 and photographs of each sampling site are presented in Appendix 2. Photographs of sediment suspended after substrate disturbance at each site are presented in Appendix 4. Q-ratings for all sites are shown on Map 2.

Many of the sites sampled on the Dereen, particularly small streams with predominantly fine substrates (i.e. mud, sand and gravel), were found to have an abnormally low density of macroinvertebrates. Abnormally low densities were particularly evident in the upper part of the catchment where streams flow from the steep gradient of surrounding hills to a more gradual gradient close to the Dereen confluence. Abnormally low invertebrate density is usually indicative of toxic influence or heavy and persistent siltation. The only apparent explanation for this low density across so many sites and tributaries is the effect of one or more severe flooding events scouring a large proportion of the invertebrate fauna from the substrate in the weeks/months prior to the sampling. This interpretation is consistent with the time of sampling and Met Éireann data. The sampling of the Dereen River for the present project was carried out in late July, mid August and mid September 2009. This year had the “wettest July for at least 14 years generally and for more than 50 years in some places.” “Much of the rain that fell during the month was in the form of heavy showers or thunderstorms.” Localised flooding occurred in eastern areas, particularly early in the month. In Carlow 22.2mm of rain fell on 11th July. In Carlow the total rainfall for the month was c.300% the average for July. The final rainfall data for September are not available at the time of writing, however whereas the month has been generally dry, c.50% of the average rainfall for the month fell in the first week or so of the month. (Weather data from www.met.ie/climate/ monthlyBulletins/jul09_lores.pdf)

10 On a tributary of the River Araglin, County Cork, after a catastrophic flooding event in August 1986 Twomey & Giller (1991) recorded a reduction in invertebrate density to 5% of the pre flood density and a reduction of taxon richness to 50% of pre-flood levels. Such severe flood events will reduce the reliability of Q-ratings to some extent. Many of the Q-ratings below are therefore given the suffix “(t)” indicating a tentative Q-rating.

11 3.1 DEREEN SITE A

SITE CODE Dereen A

DATE OF SAMPLING 25/07/09

GRID REFERENCE 29983 18356

Q-RATING 3-4

INDICATOR GROUP TAXON Number Group A - Very Ecdyonurus sp. 1 Pollution Sensitive

Group B - Moderately None recorded Pollution Sensitive

Group C - Moderately Hydracarina 23 Pollution Tolerant Baetis rhodani 13 Ephemerellidae 33 Glossosomatidae 1 Hydropsychidae 1 Limnephilidae 3 Rhyacophilidae 3 Elmidae 24 Chironomidae (ex. Chironomus) 2 Simuliidae 25 Tipulidae 11

Group D - Very None recorded Pollution Tolerant

Group E - Most Tubificidae 3 Pollution Tolerant

Not assigned to an Enchytraeidae 3 indicator group Lumbricidae 16 Lumbriculidae 6

12 3.2 DEREEN SITE B

SITE CODE Dereen B

Q-RATING 4

INDICATOR GROUP TAXON Number Group A - Very Perla bipunctata 1 Pollution Sensitive Isoperla grammatica 1 Ecyonurus sp. 6

Group B - Moderately Leuctridae 14 Pollution Sensitive Baetidae (ex. Baetis rhodani) 3

Group C - Moderately Ancylidae 2 Pollution Tolerant Hydracarina 17 Baetis rhodani 41 Ephemerellidae 34 Hydropsychidae 5 Limnephilidae 4 Rhyacophilidae 13 Elmidae 29 Chironomidae (ex. Chironomus) 4 Simuliidae 11 Tipulidae 11

Group E - Most Tubificidae Pollution Tolerant

Not assigned to an Lumbricidae 12 indicator group Lumbriculidae 3

13 3.3 DEREEN SITE C

SITE CODE Dereen C

Q-RATING 3-4(t)

(t) Q-rating tentative due to limited sampling area due to high water levels and due to suspected flood scouring effects

INDICATOR GROUP TAXON Number Group A - Very Ecyonurus sp. 2 Pollution Sensitive

Group B - Moderately Leuctridae 5 Pollution Sensitive Nemouridae 2

Group C - Moderately Hydracarina 2 Pollution Tolerant Baetis rhodani 21 Ephemerellidae 30 Hydropsychidae 1 Rhyacophilidae 4 Elmidae 19 Hydrophilidae/Hydraenidae 1 Chironomidae (ex. Chironomus) 6 Simuliidae 28 Tipulidae 25

Not assigned to an Nematoda 1 indicator group Enchytraeidae 6 Lumbricidae 2 Lumbriculidae 2

14 3.4 DEREEN SITE D

SITE CODE Dereen D

Q-RATING 4(t)

(t) Q-rating tentative due to suspected flood scouring

INDICATOR GROUP TAXON Number Group A - Very Perla bipunctata 1 Pollution Sensitive Isoperla grammatica 1 Ecyonurus sp. 3

Group B - Moderately Leuctridae 12 Pollution Sensitive Sericostomatidae 1

Group C - Moderately Gammarus duebeni 39 Pollution Tolerant Hydracarina 2 Baetis rhodani 2 Ephemerellidae 19 Hydropsychidae 2 Rhyacophilidae 4 Elmidae 9 Chironomidae (ex. Chironomus) 2 Simuliidae 7 Tipulidae 38

Group D - Very Sphaeriidae 1 Pollution Tolerant Asellus sp. 1

Group E - Most None recorded Pollution Tolerant

15 3.5 DEREEN SITE E

SITE CODE Dereen E

Q-RATING 3-4

Group B - Moderately Leuctridae 2 Pollution Sensitive Nemouridae 1 Baetidae (ex. Baetis rhodani) 3 Lepidostomatidae 1

Group C - Moderately Gammarus duebeni 23 Pollution Tolerant Hydracarina 3 Baetis rhodani 8 Ephemerellidae 53 Glossosomatidae 3 Hydropsychidae 19 Rhyacophilidae 1 Elmidae 24 Chironomidae (ex. Chironomus) 8 Simuliidae 22 Tipulidae 1

16 3.6 DEREEN SITE F

SITE CODE Dereen F

Q-RATING 3-4

Group B - Moderately Leuctridae 4 Pollution Sensitive Baetidae (ex. Baetis rhodani) 1

Group C - Moderately Gammarus duebeni 41 Pollution Tolerant Baetis rhodani 10 Ephemerellidae 65 Glossosomatidae 1 Hydropsychidae 16 Limnephilidae 1 Rhyacophilidae 1 Elmidae 7 Chironomidae (ex. Chironomus) 3 Simuliidae 243 Tipulidae 3

17 3.7 DEREEN SITE 1

SITE CODE Dereen 1

Q-RATING 3(t)

(t) Q-rating tentative due to suspected flood scouring indicated by abnormally low invertebrate density

INDICATOR GROUP TAXON Number Group A - Very None recorded Pollution Sensitive

Group B - Moderately Leuctridae 4 Pollution Sensitive

Group C - Moderately Baetis rhodani 1 Pollution Tolerant Ephemerellidae 3 Rhyacophilidae 4 Veliidae 7 Elmidae 3 Hydrophilidae/Hydraenidae 1 Chironomidae (ex. Chironomus) 1 Simuliidae 26 Tipulidae 7

Group D - Very Sphaeriidae 1 Pollution Tolerant

SITE CODE Dereen 2

Q-RATING 3-4(t)

INDICATOR GROUP TAXON Number Group A - Very Isoperla grammatica 1 Pollution Sensitive

Group B - Moderately Leuctridae 2 Pollution Sensitive Goeridae 5 Odontoceridae 1 Sericostomatidae 2

Group C - Moderately Hydracarina 2 Pollution Tolerant Baetis rhodani 10 Ephemerellidae 9 Hydropsychidae 4 Limnephilidae 9 Rhyacophilidae 3 Dytiscidae 3 Elmidae 17 Hydrophilidae/Hydraenidae 2 Simuliidae 4 Tipulidae 23

SITE CODE Dereen 3

Q-RATING 3-4(t)

Group B - Moderately Nemouridae 1 Pollution Sensitive

Group C - Moderately Limnephilidae 4 Pollution Tolerant Polycentropodidae 1 Veliidae 1 Helodidae 1 Chironomidae (ex. Chironomus) 1 Simuliidae 4 Tipulidae 7

Not assigned to an Enchytraeidae 1 indicator group Lumbricidae 3

SITE CODE Dereen 4

Q-RATING 3-4(t)

INDICATOR GROUP TAXON Number Group A - Very Isoperla sp. 1 Pollution Sensitive

Group B - Moderately Leuctridae 1 Pollution Sensitive Goeridae 8 Sericostomatidae 4

Group C - Moderately Baetis rhodani 3 Pollution Tolerant Limnephilidae 20 Dytiscidae 1 Elmidae 15 Chironomidae (ex. Chironomus) 2 Simuliidae 5 Tipulidae 26

Group D - Very Erpobdellidae 1 Pollution Tolerant

Not assigned to an Enchytraeidae 3 indicator group Lumbricidae 15 Lumbriculidae 3 Ceratopogonidae 1

SITE CODE Dereen 5

Q-RATING 2-3(t) to 4(t)

(t) Q-rating tentative and of little value due to suspected flood scouring indicated by abnormally low invertebrate density

Group C - Moderately Limnephilidae 12 Pollution Tolerant Rhyacophilidae 2 Haliplidae 1 Tipulidae 4

Not assigned to an Lumbricidae 6 indicator group

SITE CODE Dereen 6

Q-RATING 3-4(t)

Group B - Moderately Nemouridae 2 Pollution Sensitive

Group C - Moderately Baetis rhodani 9 Pollution Tolerant Limnephilidae 8 Polycentropodidae 1 Rhyacophilidae 5 Dytiscidae 3 Elmidae 2 Helodidae 2 Chironomidae (ex. Chironomus) 2 Simuliidae 3 Tipulidae 7

Group D - Very Glossiphoniidae 1 Pollution Tolerant

Not assigned to an Nematomorpha 2 indicator group Enchytraeidae 1 Lumbricidae 8 Lumbriculidae 3

SITE CODE Dereen 7

Q-RATING 3(t) or 3-4(t)

Group B - Moderately Leuctridae 2 Pollution Sensitive Sericostomatidae 3

Group C - Moderately Baetis rhodani 1 Pollution Tolerant Limnephilidae 3 Chironomidae (ex. Chironomus) 1 Simuliidae 25 Tipulidae 9

Not assigned to an Nematomorpha 1 indicator group Lumbricidae 4

SITE CODE Dereen 8

Q-RATING 3(t)

Group B - Moderately Goeridae 7 Pollution Sensitive Odontoceridae 2 Sericostomatidae 1

Group C - Moderately Baetis rhodani 4 Pollution Tolerant Limnephilidae 4 Rhyacophilidae 1 Elmidae 3 Hydrophilidae/Hydraenidae 1 Simuliidae 3 Tipulidae 17

Not assigned to an Enchytraeidae 1 indicator group Lumbricidae 11

SITE CODE Dereen 9

Q-RATING 3

Group B - Moderately Leuctridae 5 Pollution Sensitive Odontoceridae 5

Group C - Moderately Hydracarina 10 Pollution Tolerant Ephemerellidae 8 Limnephilidae 6 Polycentropodidae 1 Rhyacophilidae 9 Veliidae 1 Dytiscidae 2 Elmidae 25 Chironomidae (ex. Chironomus) 23 Simuliidae 1 Tipulidae 23

SITE CODE Dereen 10

Q-RATING 3

Group C - Moderately Ancylidae 1 Pollution Tolerant Gammarus duebeni 11 Limnephilidae 1 Rhyacophilidae 3 Dytiscidae 1 Chironomidae (ex. Chironomus) 2 Simuliidae 530 Tipulidae 1

SITE CODE Dereen 11

Q-RATING 3(t)

Group C - Moderately Hydracarina 1 Pollution Tolerant Baetis rhodani 2 Hydropsychidae 1 Limnephilidae 3 Dytiscidae 6 Chironomidae (ex. Chironomus) 45 Simuliidae 23 Tipulidae 5

Group E - Most Tubificidae 2 Pollution Tolerant Chironomus sp. 1

SITE CODE Dereen 12

Q-RATING 3-4(t)

Group B - Moderately Nemouridae 1 Pollution Sensitive Sericostomatidae 2

Group C - Moderately Potamopyrgus antipodarum 56 Pollution Tolerant Gammarus duebeni 1 Hydracarina 2 Limnephilidae 2 Rhyacophilidae 1 Veliidae 1 Dytiscidae 6 Gyrinidae 5 Haliplidae 1 Helodidae 1 Hydrophilidae/Hydraenidae 1 Chironomidae (ex. Chironomus) 3 Simuliidae 2 Tipulidae 4

SITE CODE Dereen 13

Q-RATING 3-4(t)

Group C - Moderately Potamopyrgus antipodarum 22 Pollution Tolerant Limnephilidae 8 Elmidae 2 Chironomidae (ex. Chironomus) 2 Simuliidae 6 Tipulidae 7

SITE CODE Dereen 14

Group C - Moderately Gammarus duebeni 3 Pollution Tolerant Hydracarina 1 Baetis rhodani 1 Ephemerellidae 1 Glossosomatidae 1 Limnephilidae 1 Elmidae 13 Chironomidae (ex. Chironomus) 1 Simuliidae 4

N.B. Because of extremely low faunal density in the sample and the importance of the tributary (Douglas River) an additional site was sampled further upstream (see Site 14A below) where cobble substrate and more normal faunal density was encountered.

31 3.21 DEREEN SITE 14A

SITE CODE Dereen 14A

Q-RATING 3-4

INDICATOR GROUP TAXON Number Group A - Very Ecyonurus sp. 1 Pollution Sensitive Rhithrogena sp. 2

Group B - Moderately Leuctridae 7 Pollution Sensitive Goeridae 6

Group C - Moderately Gammarus duebeni 14 Pollution Tolerant Baetis rhodani 18 Ephemerellidae 2 Glossosomatidae 1 Limnephilidae 1 Rhyacophilidae 15 Elmidae 7 Simuliidae 266 Tipulidae 3

Not assigned to an Lumbriculidae 2 indicator group

SITE CODE Dereen 15

Q-RATING 3-4(t)

(t) Q-rating tentative due to depositing substrate and very small size of stream

Group C - Moderately Tricladida 2 Pollution Tolerant Potamopyrgus antipodarum 260 Planorbiidae 1 Gammarus duebeni 19 Hydracarina 1 Limnephilidae 7 Polycentropodidae 3 Dytiscidae 1 Helodidae 1 Chironomidae (ex. Chironomus) 5 Tipulidae 1

Group D - Very Asellus sp. 1 Pollution Tolerant

Not assigned to an Lumbricidae 25 indicator group

SITE CODE Dereen 16

Q-RATING 3

Group B - Moderately Sericostomatidae 1 Pollution Sensitive

Group C - Moderately Gammarus duebeni 150 Pollution Tolerant Limnephilidae 3 Dytiscidae 1 Elmidae 1 Helodidae 1 Chironomidae (ex. Chironomus) 1 Tipulidae 4

SITE CODE Dereen 17

Q-RATING 3

Group B - Moderately Leuctridae 6 Pollution Sensitive Odontoceridae

Group C - Moderately Tricladida 2 Pollution Tolerant Gammarus duebeni 1 Hydracarina 1 Baetis rhodani 19 Ephemerellidae 3 Hydropsychidae 1 Elmidae 3 Chironomidae (ex. Chironomus) 3 Simuliidae 114 Tipulidae 3

SITE CODE Dereen 18

Q-RATING 3-4

Group B - Moderately Leuctridae 2 Pollution Sensitive Nemouridae 10

Group C - Moderately Gammarus duebeni 31 Pollution Tolerant Baetis rhodani 8 Rhyacophilidae 1 Dytiscidae 15 Simuliidae 343 Tipulidae 18

Not assigned to an Lumbriculidae 7 indicator group

SITE CODE Dereen 19

Group C - Moderately Gammarus duebeni 22 Pollution Tolerant Baetis rhodani 1 Limnephilidae 1 Elmidae 1 Chironomidae (ex. Chironomus) 13 Simuliidae 5 Tipulidae 36

Group D - Very Glossiphoniidae 1 Pollution Tolerant

Not assigned to an Nematomorpha 10 indicator group Lumbricidae 9 Lumbriculidae 1

SITE CODE Dereen 20

Q-RATING 3-4

INDICATOR GROUP TAXON Number Group A - Very Ecdyonurus sp. 2 Pollution Sensitive

Group B - Moderately Leuctridae 7 Pollution Sensitive Goeridae 1

Group C - Moderately Gammarus duebeni 77 Pollution Tolerant Hydracarina 1 Baetis rhodani 5 Ephemerellidae 6 Hydropsychidae 2 Limnephilidae 1 Rhyacophilidae 1 Elmidae 25 Chironomidae (ex. Chironomus) 1 Simuliidae 4 Tipulidae 1

Not assigned to an Lumbricidae 1 indicator group Lumbriculidae 1 Ceratopogonidae 2

SITE CODE Dereen 21

Q-RATING 3

Group C - Moderately Gammarus duebeni 66 Pollution Tolerant Hydracarina 12 Limnephilidae 6 Polycentropodidae 4 Haliplidae 8 Chironomidae (ex. Chironomus) 40 Simuliidae 3 Tipulidae 22

Group D - Very Asellus sp. 12 Pollution Tolerant Sialidae 2

Not assigned to an Nematoda 2 indicator group Enchytraeidae 6 Ceratopogonidae 19

SITE CODE Dereen 22

Q-RATING 3

Group C - Moderately Ancylidae 6 Pollution Tolerant Gammarus duebeni 11 Hydracarina 1 Baetis rhodani 21 Ephemerellidae 17 Limnephilidae 1 Elmidae 36 Chironomidae (ex. Chironomus) 6 Simuliidae 1 Tipulidae 6

Group D - Very Lymnaea peregra 2 Pollution Tolerant Asellus sp. 3

Not assigned to an Lumbricidae 5 indicator group Lumbriculidae 2 Ceratopogonidae 1

SITE CODE Dereen 23

Q-RATING 3

Group C - Moderately Tricladida 2 Pollution Tolerant Gammarus duebeni 37 Hydracarina 4 Ephemerellidae 2 Limnephilidae 4 Polycentropodidae 2 Corixidae 1 Veliidae 1 Gyrinidae 2 Haliplidae 1 Chironomidae (ex. Chironomus) 45 Tipulidae 12

Group D - Very Lymnaea peregra 3 Pollution Tolerant Sphaeriidae 5 Asellus sp. 15

Not assigned to an Nematoda 1 indicator group Naididae 14 Ceratopogonidae 9 Rhagionidae 1

SITE CODE Dereen 24

Q-RATING 3

Group B - Moderately Goeridae 1 Pollution Sensitive Sericostomatidae 5

Group C - Moderately Potamopyrgus antipodarum 2 Pollution Tolerant Gammarus duebeni 222 Baetis rhodani 5 Ephemerellidae 1 Glossosomatidae 1 Hydropsychidae 1 Limnephilidae 9 Rhyacophilidae 1 Elmidae 2 Chironomidae (ex. Chironomus) 7 Tipulidae 8

SITE CODE Dereen 25

Q-RATING 2-3

Group B - Moderately Goeridae Pollution Sensitive Sericostomatidae

Group C - Moderately Potamopyrgus antipodarum Pollution Tolerant Gammarus duebeni 12 Baetis rhodani Ephemerellidae Glossosomatidae Hydropsychidae Limnephilidae 2 Rhyacophilidae Corixidae 1 Gerridae 1 Dytiscidae 2 Chironomidae (ex. Chironomus) 78 Tipulidae 9

Group D - Very Sphaeriidae 3 Pollution Tolerant Asellus sp. 56

Group E - Most Tubificidae 12 Pollution Tolerant Chironomus sp. 1

Not assigned to an Naididae 8 indicator group Ceratopogonidae 10

43 3.33 DEREEN RIVER MONITORING 1976-2009

EPA DATA CS DATA

EPA CS 1976 1980 1883 1986 1989 1991 1994 1995 1998 2001 2004 2007 2009 Site No Site No.

12/D01/0120 A - - - - 5 2/0 3 - - - - - 3-4

12/D01/0200 B 5 4 4 4-5 4-5 3/0 4-5 - - - - 3-4 4

12/D01/0300 C - 3 3 3-4 3 3 - 4 4-5 4-5 4 4 3-4(t)

12/D01/0400 D 3-4 4 4 4 4 3 - - - - - 3-4 4(t)

12/D01/0500 E 4-5 3 4 4 4 4 - 4 4 4 4 - 3-4

12/D01/0550 F - - - - 4-5 4 - - 4 4 4 4 3-4

- 1 ------3(t)

- 2 ------3-4(t)

- 3 ------3-4(t)

- 4 ------3-4(t)

- 5 ------2-3(t) to 4(t)

- 6 ------3-4(t) EPA DATA CS DATA

- 7 ------3(t) or -3- 4(t)

- 8 ------3(t)

- 9 ------3(t)

- 10 ------3

- 11 ------3(t)

- 12 ------3-4(t)

- 13 ------3-4(t)

- 14 ------3(t) or 3- 4(t)

- 14A ------3-4

- 15 ------3-4(t)

- 16 ------3

- 17 ------3

- 18 ------3-4

- 19 ------3(t) or 3-

45 EPA DATA CS DATA

- 20 ------3-4

- 21 ------3

- 22 ------3

- 23 ------3

- 24 ------3

- 25 ------2-3 (t) = Tentative rating due to sub optimal Q-rating conditions EPA data from www.epa.ie/qvalue/webusers/

46 4 CONCLUSIONS

Of the six sites assessed on the main channel of the Derreen River, four merited a rating of Q3-4 and two merited a rating of Q4.

Of the twenty six sites assessed on the tributaries of the Derreen River, ten merited a rating of Q3-4, eleven merited a rating of Q3, and one site merited a rating of Q2-3. The remaining four sites could not be assigned a specific Q- rating value because of unsuitable conditions for Q-rating. 5 REFERENCES

Bauer, G. (1988). Threats to the freshwater pearl mussel Margaritifera margaritifera L. in central Europe. Biol. Conserv. 45, 239-253.

Lucey, J. et al (1999) Water Quality in Ireland 1995 – 1997. EPA

McGarrigle, M. et al (2002) Water Quality in Ireland 1998-2000. EPA.

Twomey, H & Giller, P.S. (1991) The effects of catastrophic flooding on the benthos and fish of a tributary of the River Araglin, Co. Cork. In: Steer, M.W. (ed.) 1991 Irish rivers: Biology and Management, pp59-81. Royal Irish Academy, Dublin.

48 APPENDIX 1

HABITAT ASSESSMENT AT SAMPLING SITES APPENDIX 2

SITE PHOTOGRAPHS APPENDIX 3

‘Silt Plume’ Assessment The amount of fine interstitial sediment in the river substrate is regarded as an important factor influencing the health of Margaritifera populations; it also provides an indication of the scale of suspended solids pollution in the preceding weeks or months. Typically the kick sampling method used for macroinvertebrate sampling disturbs the substrate to a depth of 5 – 10 cm and re-suspends the fine particles that are present, forming a visible silt plume, the density and transparency of which is proportional to the amount of fine sediment present. To provide a rough, qualitative index of the interstitial silt, the silt plume observed at the invertebrate sampling sites was photographed and classified arbitrarily into three categories, i.e. ‘not significant’, ‘moderate’ or ‘heavy’.

The results, along with the Site Q-rating, are tabulated in Table A below and mapped in Map 3.

TABLE A

SITE Q-Rating Silt Plume

A 3-4 Not Significant

B 4 Not Significant

C 3-4(t) Not Significant

D 4(t) Not Significant

E 3-4 Not Significant

F 3-4 Not Significant

1 3(t) Not Significant

2 3-4(t) Moderate

3 3-4(t) Not Significant

4 3-4(t) Moderate

5 2-3(t) to 4(t) Moderate

6 3-4(t) Moderate

7 3(t) or -3-4(t) Not Significant

8 3(t) Not Significant SITE Q-Rating Silt Plume

10 3 Not Significant

12 3-4(t) Heavy

13 3-4(t) Moderate

14 3(t) or 3-4(t) Not Significant

14A 3-4 Moderate

15 3-4(t) Moderate

16 3 Moderate

17 3 Moderate

18 3-4 Not Significant

19 3(t) or 3-4(t) Moderate

20 3-4 Not Significant

21 3 N/A

22 3 Not Significant

23 3 N/A

24 3 Moderate

25 2-3 N/A N/A: Silt plume assessment not applicable because of muddy substrate APPENDIX 4

NOTES ON Q-RATING ASSESSMENT IN MARGARITIFERA CATCHMENTS Prior to 1997 M. margaritifera was not included by EPA in the list of macroinvertebrate indicator groups used for Q-rating assessment (see Lucey et al 1999); since 1998 Margaritifera has been included in the EPA list of Group A Sensitive Taxa (see McGarrigle et al 2002). The inclusion of Margaritifera in the EPA list did not necessitate retrospective revision of the Q-ratings prior to 1997 as the Q-value is accurately reflected by other Group A taxa i.e. Plecoptera and Ephemeroptera, regardless of the presence of Margaritifera.

As notified to EPA in 2005, Conservation Services does not include adult Margaritifera in the calculation of Q-values. The reasons for not including adult Margaritifera in the calculation of Q-values are as follows:

1. If Margaritifera are absent from a river site for biogeographical reasons, or due to unsuitability of habitat, or due to historical water quality problems (now rectified), the other Group A taxa i.e. Group A Plecoptera and Ephemeroptera will nevertheless clearly reflect the water quality. A Q5 or Q4-5 rating will therefore be clearly indicated by the presence in adequate diversity and density of Group A Ephemeroptera and Plecoptera without the use of adult Margaritifera.

2. Bauer (1988) states: "Pearl mussels are most vulnerable to human influences at the stage where they leave the host fish and establish in the sediment. This stage will die out completely if even a slight degree of pollution is present. The juveniles are also far less tolerant than the adults, and persistent intermediate levels of eutrophication could prevent long-term recruitment, resulting in aged stocks”. It is therefore clear that (a) persistent intermediate levels of eutrophication will in the long term eliminate a Margaritifera population primarily by terminating recruitment rather than by directly eliminating adult mussels and that (b) adult mussels may therefore be found in waters with intermediate levels of eutrophication. 3. As we are not aware of any evidence of substantial niche overlap between Margaritifera and Group A Plecoptera and Ephemeroptera, there is no reason to believe that the presence of Margaritifera will reduce the density of other Group A invertebrates. Therefore if the abundance and diversity of Group A Plecoptera and Ephemeroptera are not indicative of high water quality i.e. Q5 or Q4-5, the Q-value is based on this fact regardless of the presence of adult Margaritifera.