1. “FORGOTTEN SIGNALS IN FISHERIES MANAGEMENT” By, Deepak George Pazhayamadom Department of Zoology, Ecology and Plant Science (ZEPS) University College Cork (UCC), Cork, Ireland Emer Rogan (Department of ZEPS, University College Cork) Ciaran Kelly (Fisheries Science Services, Marine Institute) Edward Codling (Lecturer in Mathematical Biology, University of Essex)

2. Fisheries Management (Traditional approach) DATA Fisheries Management (Alternative approach) SSB, F [Estimated Indicators] (Stock abundance and Exploitation) MODELS (Assumptions) Monitor with Reference Limits (Acceptable, Precautionary, Limit) Regulate with output controls HCR (Eg: TAC) Other measures (Eg: Effort) Next Year Limit 10001.5 Precautionary 15000.8 Acceptable 20000.5 Statistical Process Control [Signal Detection Method] Statistical Signals [Stock Indicators]

3. Indicator Correlation Spawning Stock Biomass 80202 76328 79513 81415 75314 59943 50442 51140 54575 57047 57825 64478 62176 68199 70223 62100 60945 63634 59247 59088 54698 58995 74582 Year 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Catch Numbers Age 8 7749 8542 6419 4637 6490 8806 5453 3406 3601 2758 1916 2317 3397 3214 3979 4003 3616 4883 2328 2537 1949 3220 1306 Correlation = Degree of relationship 0.7 = Good 0.8 = Better 0.9 = Very good INDICATORS (Examples) Catch numbers from age group 1 Catch numbers from age group 2 Catch weights from age group 5 Catch weights from age group 4 Proportion of catch numbers Proportion of catch weights CN6 [BAD INDICATOR] r= 0.09310228 PATTERNS DONT MATCH CN11 [GOOD INDICATOR] r= 0.90395651 PATTERNS MATCH

4. ESTIMATED INDICATOR Spawning Stock Biomass ESTIMATED INDICATOR Spawning Stock Biomass STOCK INDICATORS (Age based catch numbers and weights) STOCK INDICATORS (Age based catch numbers and weights) TRADITIONAL APPROACH ALTERNATIVE APPROACH COMPARISON FOR WHICH YEARS ? 1. Cod (IS) 2. Megrim (CS & BB) 1. Cod (IS) 2. Megrim (CS & BB) Acceptable In Control Precautionary Limit Out Control

5. 6868 6969 7070 7171 7272 7373 7474 7575 76767 7878 7979 8080 8181 8282 8383 8484 8585 8686 87878 8989 9090 9191 9292 9393 9494 9595 9696 9797 989890 0101 0202 0303 0404 0505 0606 GOODBAD Irish Sea Cod (Gadus morhua) Reference Limits B pa B lim = 10,000t = 5000t CN4 = Catch number from age group 4 CW4 = Catch weight from age group 4 CWABOVE = Catch weight above age group 4 CNABOVE = Catch numbers above age group 4 I – 1970 II – 1978 III – 1990 I – 1970 II – 1978 III – 1990 OC 1995 Traditional Approach - Spawning Stock Biomass CN4 CW4 CWABOVE CNABOVE MATCH COLOUR CODES Traditional Approach - Fishing Mortality

6. 8485868788899091929394959697989900010203040506 GOODBAD Celtic Sea and Bay of Biscay Megrim (Lepidorhombus whiffiagonis, L. boscii) I – 1990 II – 2004 I – 1990 II – 2004 Traditional Approach - Spawning Stock Biomass CN8 CNPP6 CNPP7 CNPP8 Reference Limits B pa B lim = 55,000t = Not defined CN8 = Catch number from age group 8 CNPP6 = Proportions of catch numbers from age group 6 onwards CNPP7 = Proportions of catch numbers from age group 7 onwards CNPP8 = Proportions of catch numbers from age group 8 onwards Traditional Approach - Fishing Mortality

7. Pros and Cons Performance of CUSUM was found to be consistent with traditional traffic light approach CUSUM charts as real time monitoring technique for qualitative stock assessments Efficient to detect persistent changes in the system A handy monitoring tool for data limited fisheries Stabilize the catch - Objective Delayed signals occur for quick changes in the system Delayed signals might happen when recruitment to the fishery occurs before maturity