General Fisheries Commission for the Mediterranean Scientific Advisory Committee Sub-Committee on Statistics and Information OPERATIONAL UNITS A Preliminary Study by Matthew Camilleri1 Salvatore R. Coppola2 J. Ignacio De Leiva Moreno3 April 2000 1 FAO / COPEMED Consultant; Department of Fisheries and Aquaculture, Malta 2 FAO, Fisheries Resources Division, Fisheries Department 3 COPEMED (APO); FAO, Fisheries Resources Division, Fisheries Department THIS STUDY HAS BEEN UNDERTAKEN WITH THE SUPPORT OF COPEMED Advice, Technical Support and Establishment of Cooperation Networks to Facilitate Coordination to Support Fisheries Management in the Western and Central Mediterranean C O N T E N T S Page 1. Introduction 1 2. The definition for an “Operational Unit” 1 3. Literature and database review 2 4. Data on fishing activities in various Management Units 3 4.1 Mazara del Vallo (Istituto di Ricerche sulle Risorse Marine e l’Ambiente 3 4.1.1 General information 3 4.1.2 Identification of Operational Units 3 4.2 Fuengirola (Centro Oceanografico de Malaga) 5 4.2.1 General information 9 4.2.2 Identification of Operational Units 9 5. Conclusion 9 References 10 Tables 12 Table I: Stock concentrations of different species in various areas of the Mediterranean (area 37) 13 Table II – VIII: Preliminary identification of operational units and associated areas within management units of the Mediterranean (area 37) 15 Appendix 34 GFCM - Scientific Advisory Committee Sub-Committee on Statistics and Information Operational Units : a preliminary study 1. Introduction During the first session of the Scientific Advisory Committee (SAC), 27 provisional management units for small pelagic and shelf demersal species where broadly defined (App. 1). Whilst making every effort in keeping the existing GFCM statistical divisions (App. 2), the creation of the proposed management units was based on a number of criteria including, inter alia, continental shelf geography (App. 3), species distribution patterns (App. 4) and oceanographic features (App. 5 and 6). National management units for coastal resources established within limits of national jurisdiction were not considered and it was suggested that islands would constitute distinct management units. It was envisaged that this arbitrary partitioning would be revised following further in-depth studies which needed to be carried out by the different Sub-Committees of the SAC in the future. In this respect, at the 24th session, the GFCM Steering Committee agreed that a number of working groups would be set up to examine the geographic coordinates of the proposed management units. Under the general guidance of the Chairman of the SAC and supervision of the Co- ordinator of the Sub-Committee on Statistics and Information (SCSI), this preliminary study on “Operational Units” within the “Geographical Management Units” of the Western and Central Mediterranean regions was carried out. By using existing literature and data available at the FAO headquarters together with information from Fisheries Institutions and Research Centres in the countries concerned, the study focussed on the identification of Operational Units. 2. The definition for an “Operational Unit” During a preliminary meeting1 held at FAO headquarters (December 1999) a number of possible definitions for an “Operational Unit” were discussed. The members at this meeting eventually agreed upon a definition, which seemed to be compatible with all disciplines concerned with fisheries management: “An Operational Unit is composed of the same category of fishing vessels, operating in the same Management Unit, practising the same type of fishing operation and targeting the same group of species” An Operational Units would be a set of localised ones connected to different ports within the Management Unit. 1 S. Coppola, P. Oliver, I. De Leiva, R. Franchesa, M. Camilleri In trying to find a universal definition for an “Operational Unit”, the major bottleneck was confronted when dealing with artisanal fisheries. From an economic point of view artisanal fisheries are considered to be one operational unit even if different types of fishing gear are used. In order to overcome this problem, the words "practising the same type of fishing operation" were used instead of "using the same type of fishing gear". Thus, artisanal fisheries could be considered to be one type of fishing operation. This definition was reviewed at a follow-up meeting2 held in Barcelona (January 2000) where it was finally suggested that the definition for an “Operational Unit” should read as follows: “For the sake of managing fishing effort within a Management Unit, an Operational Unit is the group of fishing vessels practising the same type of fishing operation, targeting the same species or group of species and presenting similar economic structure. The grouping of fishing vessels should not be understand as fixed over time, but be function of the management objectives to be reached”• The second definition needs a few grammatical amendments, nevertheless, within the framework of this study a third definition is being proposed: “An Operational Unit is a category of fishing vessels operating in the same Management Unit, practising the same type of fishing operation and targeting the same species or group of species”Ž 3. Literature and database review Within the context of the proposed definition for an “Operational Unit”, information related to “stock concentrations” (Table I), species distribution and population dynamics for a number of species was gathered together with data on associated fisheries. The key sources used were the POPDYN database, ASFA, FAO (GFCM) documents, the Atlas of Italian Demersal Fishery Resources (GRUND) (Ardizzone and Corsi, 1997) and the Atlas of the Fisheries of the Western and Central Mediterranean (Charbonnier and Garcia, 1985). In order to be compatible with the studies which were being carried out by the Sub-Committee on Stock Assessment (SCSA), the species chosen in this study were the same as the ones focused on by the working group of the SCSA (see Appendix 7 for species information). Tables with the relevant information were drawn up by species and preliminary identification of Operational Units and / or areas hosting particular Operational Units was carried out (Tables II -VIII)3. 2 President of SAC, 2 SAC Vice-Presidents, 3 SAC Sub-Committee Coordinators, Chairman of SAC demersal species Working Group, 3 FAO experts backstopping SAC, COPEMED director, 3 experts preparing documents for SAC Sub-Committees 3Double horizontal lines separate the information by country. Single horizontal lines provisionally group the information by areas hosting particular operational units for that species. N.B. The Eastern Adriatic countries have been grouped with Italy on the Western Adriatic. 2 4. Data on fishing activities in various Management Units Following the literature and database review, it was decided that visits should be made, in the first instance, to Fisheries Institutions / Laboratories in the Management Units of the Alboran Sea and Southern and Eastern Sicily (and Malta). It was agreed that these visits would serve to obtain more detailed qualitative (and possibly quantitative) data on fishing activities in these areas which would be essential for the eventual identification of Operational Units. 4.1 Mazara del Vallo (Istituto di Ricerche sulle Risorse Marine e l’Ambiente) 4.1.1 General information The fishing grounds in the Sicilian Channel (including Tunisian waters and Libyan waters) for various species or groups of species are well known and named. The number of boats operating in different areas of this region is also known, however, the fishing effort for particular species in each fishing ground is highly variable since the abundance fluctuates in short spaces of time and there is a shift in activity from one to another. 4.1.2 Identification of Operational Units In the light of the discussions held on the concept of Operational Units and the data available for this region, it was concluded that there are four different scenarios which should be considered: a) In many cases there is not enough evidence to consider a fishing ground as being the area occupied by the population of a particular species. Furthermore, due to the lack of data, the fishing grounds and / or species abundance concentrations cannot be aggregated into distinct areas hosting a number of operational units. Hence, an operational unit in such a situation, would only be a function of the group of the vessel, type of fishing operation and species / group of species i.e. without defining a particular area within the management unit. b) A few population dynamics studies have identified species “sub-stocks” in certain management units. Thus, if discrete fractions of a species or group of species live and are exploited in separate areas, they may be associated with different Operational Units. Examples: (i) Parapenaeus longirostris in the Central Mediterranean (Fig. 1) Three different sub-stocks belonging to the same population in three distinct fishing grounds. Identification was based on length and maturity data. (Levi D., Andreoli M.G., Giusto R.M., 1994). Areas hosting Operational Units: 1 area in management unit 1.3k 2 areas in management unit 2.2f 3 Figure 1. The three fishing grounds for Parapenaeus longirostris in the Sicilian Channel (Levi et al. 1995) 4 (ii) Aristeus antennatus in the Ionian Sea (Fig. 2) Populations in the three different fishing areas in the NW Ionian Sea have different length-frequency distributions, sex ratio, mating and size at first maturity. (G. D’Onghia, A. Tursi, P. Maiorano and M. Panza, 1998). Areas hosting Operational Units: 3 areas in management unit 2.2c c) The same approach as described in (b) could be applied more confidently when dealing with genetically defined stocks within a region. Example: Two stocks of Engraulis encrasicolus in Adriatic waters (Fig. 3a and 3b) Allozyme electrophoresis and morphometric analyses confirmed the genetic separation of two putative stocks; one located in the north-western Adriatic and the other in the central-southern region (D.G.