River Derg and Tributaries Catchment Status Report 2008 Loughs Agency of the Foyle Carlingford and Irish Lights Commission RIVER DERG AND TRIBUTARIES CATCHMENT STATUS REPORT 2008 River Derg and Tributaries Catchment Status Report 2008 Report Reference LA/CSR/05/09 Headquarters 22, Victoria Road Londonderry BT47 2AB Northern Ireland Tel: +44(0)28 71 342100 Fax: +44(0)28 71 342720 [email protected] www.loughs-agency.org Regional Office Dundalk Street Carlingford Co Louth Republic of Ireland Tel+353(0)42 938 3888 Fax+353(0)42 938 3888 carlingford@loughs- agency.org www.loughs-agency.org Written and Prepared by: Art Niven Inside cover picture of hen salmon in breeding Rachel Scott dress courtesy of Atlantic Salmon Trust Declan Lawlor 2 RIVER DERG AND TRIBUTARIES CATCHMENT STATUS REPORT 2008 Table of Contents 1.0 INTRODUCTION ........................................................................................................................... 6 Figure 1.0 Main salmon producing rivers and tributaries in the Loughs Agency areas .................. 7 1.1 The Derg Catchment ............................................................................................................... 8 Fig 1.1 Upper section of the River Derg. ......................................................................................... 8 Fig 1.11 Foyle and Carlingford catchments illustrating the main rivers of the Foyle system. ........ 9 1.2 Atlantic Salmon and Sea Trout .............................................................................................. 10 1.3 Non Salmonid Fish Species .................................................................................................... 10 Fig 1.3 Sample of fish from the Foyle estuary ............................................................................... 10 2.0 ATLANTIC SALMON STOCKS ...................................................................................................... 11 2.1 Redd Counts .......................................................................................................................... 11 Table 2.1 Redd counts for Foyle system and Derg catchment 2004/05 – 2008/09 ..................... 11 Fig 2.1 Redd counts for Foyle system and Derg catchment 2004/05 – 2008/09 .......................... 12 Fig 2.11 Redd counts for Foyle system 1952/53 – 2008/09 ......................................................... 12 2.2 Juvenile Abundance .............................................................................................................. 13 Table 2.2 Loughs Agency semi‐quantitative electrofishing classification system ........................ 14 Fig 2.2 River Derg catchment salmony fr index 2001‐2008 .......................................................... 14 Fig 2.21 The mean abundance of salmon fry in 17 catchments in 2008 ...................................... 15 Fig 2.22 Salmon 0+ electrofishing site classification 2008 ............................................................ 16 3.0 TROUT STOCKS .......................................................................................................................... 17 Fig 3.01 River Derg catchment trout fry index 2001‐2008 ........................................................... 17 Fig 3.02 The mean abundance of trout fry in 17 catchments in 2008 .......................................... 18 Fig 3.03 Trout 0+ electrofishing site classification 2008 ............................................................... 19 4.0 MARINE SURVIVAL .................................................................................................................... 20 Table 4.0 Marine survival rates for the River Bush of 1SW grilse ................................................. 20 Fig 4.0 Marine survey areas for salmon in 2008 ........................................................................... 21 Fig 4a RV Celtic Explorer SALSEA research cruise 2008 ................................................................ 22 Figure 4b Picture from the Irish Research Vessel Celtic Explorer ................................................. 22 Figure 4c Rotary screw trap in position on the River Faughan ..................................................... 23 Table 4.01 Numbers and average weight and length of salmon smolts tagged ........................... 23 Table 4.02 Recapture data from River Faughan CWT programme.. ............................................. 24 3 RIVER DERG AND TRIBUTARIES CATCHMENT STATUS REPORT 2008 Figure 4d Salmon smolt run timing and abundance from rotary screw trap ............................... 24 Table 4.03 Age class of salmon smolts migrating from the Faughan catchment in 2004 ............ 25 5.0 ADULT ABUNDANCE .................................................................................................................. 26 5.1 Recreational Fisheries ........................................................................................................... 26 Table 5.1 Declared rod catch returns for salmon and trout ......................................................... 26 Table 5.11 Declared catch from the Derg catchment for salmon and sea trout 2001‐2008 ........ 27 Fig 5.1 Angler on the upper reaches of the Faughan River ........................................................... 27 5.2 Commercial Fisheries ............................................................................................................ 27 Table 5.2 Declared catch from the commercial salmon fisheries 1998‐2008 .............................. 28 Fig 5.2 Commercial Fishing ........................................................................................................... 28 5.3 Counters ................................................................................................................................ 28 Fig 5.3 Fish counting facilities at Sion Mills, River Mourne........................................................... 29 Table 5.3 Sion Mills fish counter figures 2002‐2008 ..................................................................... 29 Fig 5.31 Monthly fish counts on the River Mourne 2004‐2008 as recorded at Sion Mills ........... 29 Fig 5.32 Annual fish counts on the River Mourne 1987‐2008 ...................................................... 30 5.4 Conservation Limits/Spawning targets ................................................................................. 30 Table 5.4 Upstream of Sion Mills estimated egg deposition 2002‐2007 ...................................... 31 6.0 HABITAT MONITORING ............................................................................................................. 31 Fig 6.0 Life cycle unit ..................................................................................................................... 32 Fig 6.01 Examples of spawning, nursery and holding habitat ...................................................... 32 Fig 6.02 Habitat overview key for Derg Catchment ...................................................................... 33 Fig 6.03 Derg catchment habitat survey map 1 ............................................................................ 34 Fig 6.04 Derg catchment habitat survey map 2 ............................................................................ 35 Fig 6.05 Derg catchment habitat survey map 3 ............................................................................ 36 Fig 6.06 Derg catchment habitat survey map 4 ............................................................................ 37 Fig 6.07 Derg catchment habitat survey map 5 ............................................................................ 38 7.0 LAND USE .................................................................................................................................. 39 Fig 7.0 Derg catchment land use classification ............................................................................. 39 Fig 7.01 Derg catchment land use classification map ................................................................... 40 8.0 WATER QUALITY ........................................................................................................................ 41 Fig 8.0 Loughs Agency chemical water quality testing in the laboratory ..................................... 41 Fig 8.01 Derg catchment average suspended solids results 2008 ................................................ 44 Fig 8.02 Derg catchment Ammonia results 2008 .......................................................................... 45 Fig 8.03 Derg catchment phosphorous results 2008 .................................................................... 46 4 RIVER DERG AND TRIBUTARIES CATCHMENT STATUS REPORT 2008 Fig 8.04 Derg catchment Biological Oxygen Demand (BOD) results 2008 .................................... 47 Fig 8.05 Derg catchment Biological Monitoring Working Party results 2008 ............................... 48 Table 8.0 chemical GQA class limiting criteria .............................................................................. 49 Table 8.01 Biological GQA class limiting criteria ........................................................................... 50 Figure 8.06 Flattened mayfly nymph from the order ephemeroptera ......................................... 50 8.1 Favourable Condition Tables, Target Levels ......................................................................... 51 Table 8.1 Favourable condition targets for Atlantic salmon ........................................................