Synopsis

 

Volume 1

Medits '98 Technical report

 

 

 

 

Co-ordination of the Medits programme (1998)

General presentation of the Medits '98 activity                                  

Technical report – Medits 98 survey                                                   

Work plan for 1999                                                                               

Tables

Table 1. List of the vessels used                                                      

Table 2. General calendar                                                                

Table 3. Boarding tables                                                                 

Table 4. Sampling scheme                                                             

Table 5. Stratification scheme                                                         

Table 6. Computer files                                                                  

 

Figure 1. Stratification scheme                                                          

 

Appendix

Appendix 1. List of papers                                                              

Appendix 2. Meeting reports                                                           

App. 2.1. Medits steering committe (Pisa, 18/03/1998)                       

App. 2.2. Medits co-ordination committee (Rome, 3-4/07/1998)       

App. 2.3. Medits meeting (Kavala, 18-20/11/1998)                         

App. 2.4. Meeting (Rabat and Casablanca, 1-2/12/1998)                

 

Appendix 3. Geometry of the trawl                                                      

 

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The Medits programme is conducted owing to the financial support from the European Commission (DG XIV) and the following partners, the IEO for Spain, the IFREMER and the Territorial Collectivity of Corsica for France, the Italian Minister of forest, agricultural and food resources (DG fisheries and aquaculture) for Italy as well as Slovenian, Croatian and Albanian areas, the NCMR for Greece.

 

 

 

 

 

Co-ordination of the Medits programme (1998)

Co-ordination Committee

Jacques Bertrand (General co-ordinator, IFREMER)

Luis GIL DE SOLA (IEO)

Arnauld SOUPLET (IFREMER)

Giulio RELINI (SIBM)

Costas PAPACONSTANTINOU (NCMR)

Steering Committee

The members of the Co-ordination Committee

Gianni ARDIZZONE : Ligurian Sea, North and Central Tyrrhenian Sea

Dino LEVI : South Tyrrhenian Sea and Sicilian Channel

Angelo CAU : Sardinia

Giovanni MARANO : West Ionian Sea and part of South Adriatic Sea

Corrado PICCINETTI : North, Central and part of South of Adriatic Sea

Stanko CERVEK : Northeast Adriatic Sea (Slovenia)

Stjepan Jukic-Peladic : Central-East Adriatic Sea (Croatia)

Kastriot OSMANI : Southeast Adriatic Sea (Albania)

Argyris KALLIANIOTIS : North Aegean Sea

George Tserpes : South Aegean Sea

Chrissi-Yianna Politou : Argosaronic Gulf and East Ionian Sea

Permanent guests

Loris Fiorentini & Pierre-Yves Dremière (Technologists)

Angelo Tursi (Co-ordinator of the Medland project)

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As for the previous years, the Italian teams were organized in eleven research teams:

 

1) IZUG Genova, Prof. G. Relini Istituto Zoologia - Università di Genova Via Balbi, 5 - 16126 Genova Tel. 010 - 202600 2099465 Fax : 010 - 2099323	7) DBAE Cagliari, Prof. A. Cau Dipartimento Biologia Animale ed Ecologia Università di Cagliari Viale Poetto, 1 - 09100 Cagliari Tel. 070 - 370263 Fax : 070 - 380285
2) ARPAT Livorno, Dr R. Auteri (ex CRIP) Agenzia Regionale Protezione Ambientale della Toscana - GEA Via dell'Ambrogiana 2 - 57127 Livorno Tel. e Fax : 0586 - 804181	8) LBMP Fano, Prof. C. Piccinetti Laboratorio di Biologia Marine e Pesca Università di Bolobna Viale Adriatico, 1/N - 61032 Fano (PS) Tel. 0721 - 802689 802736 Fax : 0721 -n 801654
3) CIBM Livorno, Dr S. De Ranieri Centro Interunivesitario di Biologia Marina Piazzale Mascagni, 1 - 57100 Livorno Tel. 0586 - 805504	9) LBMB Bari, Prof. G. Marano Laboratorio di Biologia Marina Molo Pizzoli (porto) - 70123 Bari Tel. 080 - 5211200 Fax : 080 - 5213486
4) DBAU Roma, Dr G.D. Ardizzone Dipartimento Biologia Animale e dell"Uomo Università di Roma Via dell'Università 32 - 00184 Roma Tel. & Fax : 06 - 49914773	10) DIZO Bari, Prof. A. Tursi (ex IZAC) Dipartimento di Zoologia Universita' di Bari Via Orabona, 4 - 70125 Bari Tel. & Fax : +39 - 080 - 5443350
5) COISPA Bari, Dott. ssa M.T. Spedicato COISPA Tecnologia Ricerca Soc Coop. a. r. l. Contrada Padovano - Cas. Post. 62 70042 Mola di Bari Tel. 080 - 8732077 Tel. & Fax : 080 - 8733440	11) IRMA Mazara del Vallo, Dr D. Levi (ex ITTP) Istituto di ricerche sulle Risorse marine e l'Ambiente - C.N.R. Via L. Vaccara, 61 - 91026 Mazara del Vallo (TP) Tel. 0923 - 948390 Fax : 0923 - 906634
6) ITM Messina, Dr S. Greco Istituto Talassografico C.N.R. Spianata S. Ranieri, 86 - 98122 Messina Tel. 090 - 669003 Fax : 090 - 669007

 

These teams have managed a collaboration with the NIB (Slovenia), the IOR (Croatia) and the MAF Albania) to enlarge the programme in the Adriatic Sea.

In Spain, collaborations were arranged with the ICM from Barcelona and the University of Alicante (Department of Statistics).

In Greece, As during the last few years, three institutes expressly collaborated within the programme in 1998: the NCMR (Athens), the IMBC (Iraklion) and the NAGREF-FRI (Kavala).

Furthermore, the collaborations have been extended owing to the scientists who contributed in the survey (cf. the boarding tables, table 3) and who took part in the meetings (cf. the reports of the meetings, appendix 2).

 

 

This report comprises the contributions produced within the four studies whose references are presented in the cover page and which are developed through the co-ordination of the IEO, the IFREMER, the SIBM and the NCMR. It presents the progress and the results obtained in 1998 inside the Medits programme. This report intends to make available as much as possible all the basic information obtained by the different partners during the Medits ‘98 yearly survey. It is made by two complementary documents: a technical report and a biological report. The present document (technical report) includes the presentation of the basic information regarding the management of the survey in the different areas, as well as the report of the meetings held during the year.

 

During 1998, the Medits programme has been conducted with the same general organization as the one adopted since 1996, including seven countries and the intensifying of the work in the Aegean Sea. In 1998, the activity of the group has been focused on the organization of the Medits ‘98 survey, and on the development of analyses of the data obtained during the first campaigns through a symposium in Pisa (March 1998, list of the contribution in appendix 1). During the same period, the group took benefit of the progress gained within the SELMED project (co-ordinator: L. Fiorentini) and the MDMS project (Co-ordinator: C.Y. Politou). Strong relationships have been maintained with the MEDLAND project (Co-ordinator: A. Tursi).

To favor the opening of the programme abroad, some participants of the Medits programme have taken part in the symposium dealing with ‘’Environmental peculiarities and biological resources distribution in the Mediterranean sea’’ (Co-ordinator: G. Relini), during the VII^th International congress of ecology (INTECOL) in Florence (19-25 July 1998). Finally, thanks to an Fao-Copemed’s initiative (Director R. Robles), an enlargement of the Medits programme in the Moroccan area has been prepared during the last part of the period (cf. appendix 2).

Four meetings have been held during the year, implying all the Medits participants or the Co-ordination and the Steering committees (cf. reports of these meetings in appendix 2).

 

The works done at sea for the Medits ‘98 survey have been conducted from 03/05/1998 till 28/07/1998, occupying 302 ship-days in operation. Tens vessels have been used for this survey (table 1). Six of them are the same as for the ‘97 survey. Two have been replaced (one for the areas IT-M4 and ALB, the other one for the areas IT-M5, SLO and HRV) and one has been replaced by two new ships (respectively in the areas GR-G2 and GR-G3). The general calendar of the survey is presented in the table 2.

The survey has covered exactly the same areas as for the last previous ones (fig. 1). It has been conducted in the different regions involving more than 150 scientists (table 3) applying the same common protocols as for the ‘97 survey (cf. « Manuel des protocoles de la campagne Medits 95 » and the addenda for the surveys 1996 and 1997). As far as possible, the sea temperature has been systematically recorded during the hauls.

A total of 1109 hauls have been done in the whole area (table 4 and 5).

At the end of the survey, all the data have been checked and validated by each of the teams, using the CHECKMED program (a specific program defined for the project). The data have been grouped in Ifremer-Sète to produce the common data bank. The data of each region have been sent back to each of the respective regional co-ordinators after a second validation. Furthermore, as for the previous ones, the corresponding computer files (table 6) will be deposit in five places (to the EC-DG XIV and each of the members of the Co-ordination committee) to ensure their protection. All these data will be managed by the tool defined within the MDMS project.

Owing to the progress done by the different teams to manage the rough data, the procedure of grouping and validation of the data was finished by the middle of October, that means a very few months after the end of the survey. A first global run to produce biomass/abundance estimators as well as length frequency distributions for the species included in the reference list has been made available to the Steering committee members early in November 1998, to help the preparation of the biological analysis at a global level.

We may underline that the checking of the data before their grouping at the general level and through the common analyses done during the general meeting in Kavala (November 1998) have confirmed the good qualification of the teams involved in the project to produce such data.

Technical reports written by the respective regional co-ordinators are presented below. They set out the conditions whereby the Medits ‘98 survey has been conducted in their region.

The Medits ES survey took place from the 2^nd of May to the 1^st of June. 94 hauls were carried out with the R/V “Cornide de Saavedra” from Strait of Gibraltar to Barcelona: 34 hauls in the Alboran Sea and Gulf of Vera, 27 in the Alicante area and 31 in the Catalan Sea. Two hauls were not valid. A total of 25 fishing days and 6 days of technical break were spent.

Scientific participants came from the laboratories of the IEO of Málaga, Murcia and Balearic Islands, of the ICM of Barcelona, of the Ecology Department of the University of Málaga and of the University of Alicante. The scientific team was composed of biologists, technicians and two physicists for the CTD working. A Moroccan biologist, D. Ali Srairi, of the INRH laboratory, boarded during two weeks.

It has not been possible to carry out all the stations planned in the sampling scheme due to three days of technical break: between Barcelona and cap of Creus (area 113), respectively zero and one haul have been done in the strata 200-500 m and 500-800.

Apart from that, the fishing activities was conduced without important difficulties. The geometry of the trawl has been monitored during the whole survey using a SCANMAR, and the temperature, salinity and oxygen concentration have been recorded with the CTD measurement system. In the haul 25 the gear suffered important damages but it could be repaired aboard the ship. No haul was new. As during the previous years, great catches of pelagic species were observed.

A total of 361 species were identified: 144 fishes, 80 crustaceans, 72 molluscs including 24 cephalopods and others 65 invertebrate species. A systematic inventory of waste products present in the caught has been made. Determination, numbering and weighting of each species, biological examination of the principal species, introduction of the data (characteristics of each haul, weight and number of the caught species, length and maturity index of the principal species) was made with the CAMP and DAME programs aboard the vessel. The checking of the data and the calculation of the abundance indices with the INDMED program were made in the laboratory.

The Medits FR survey took place from the 16th of May to the 19th of June aboard the « L’Europe » vessel. The first part of the survey (17/05 - 23/05) has been conducted on the eastern coast of  Corsica and the second part (28/06 - 19/06) in the Gulf of Lions. During the whole survey, the weather conditions were very good except for two or three windy days.

Observations on the behaviour of the gear

The geometry of the trawl has been monitored during the whole survey using a SCANMAR. As far as possible the rigging accorded with the latest version of the "Manuel des protocoles". In only one deep haul (around 800 m) it has been impossible to make the trawl put down on the bottom although we tried four times. P.-Y. Dremière suggested that, at depth greater than 500 m, we should use 200 m bridles.

Nevertheless and in general, the gear specifications, as indicated in the "Manuel des protocoles", lead to a good efficiency of the trawl. At each haul it is however important to wait that the trawl geometry be well stabilised before to decide the beginning of the haul, even if this waiting time can seem rather long.

Survey's progress

This year no damage to the gear occurred during the survey. As previously, the shallowest strata in Corsica (13101 and 13106, between 10 and 50 m) have been considered as not trawlable due to very large quantities of algae, sea urchins and eel grass (Posidonia sp.). Furthermore and as explained in the last year report, for practical purposes the trawlable parts of the north most strata in Corsica have been reduced and their northern limit have been set at 10 miles north of Bastia, but it does not affect the total surface of these strata for the analysis. Only one valid haul has been made in the stratum 500-800 m in the southern part.

In the Gulf of Lions, it has been possible to make only one haul in the stratum 200-500 m in the western part and in the stratum 500-800 m in the eastern part

During the '98 survey, 95 valid hauls have been made : 71 in the Gulf of Lions and 24 in Corsica.

Other observations

For all hauls, the MICREL ichtyometre has been used, together with the DAME program written by G. Delmas. The bugs detected in this program were partly corrected in advance of the survey by G. Delmas (although he is now retired !) and myself. The data files have been checked and when necessary corrected immediately after the survey.

In addition to the normal biological observations, a systematic inventory of waste products present in the codend (glass, plastic, metal, etc.) has been made. This inventory showed the importance of waste concentration near the biggest harbours (Marseilles, Bastia) and on the ferries routes between Corsica and the mainland.

In the M1 region the 1998 Medits survey was carried out from May 20 to 18 July using the professional trawler "Francesco Padre". A total of 155 hauls were carried out among which 153 were valid. A total of 38 fishing days, 1 day of bad weather brake and 10 days of technical break were spent.

No particular technical problems were met during the survey. As far as possible, all stations have been made at the same positions as in the previous years.

Scientific participants came from the laboratories of the Consorzio Interuniversitario di Biologia Marina di Livorno, from the Centro Regionale Idrobiologia e Pesca di Livorno, the University of Genova and the University of Rome.

A Minilog instrument has been used to collect data on surface and bottom water temperature. A new file (tdit98m1.txt) was created.

The data were input on computer on board using the DAME program and checked using the CHECKMED2 routines. Abundance indices and length frequencies have been calculated using the INDMED4 program.

The species of the reference list which were most abundant in weight were, in order: Merluccius merluccius, Mullus barbatus, Eledone cirrhosa, Trachurus trachurus, Trachurus mediterraneus Phycis blennoides and Nephrops norvegicus.

An increase in the catches of Micromesistius poutassou, Mullus barbatus, Pagellus bogaraveo, Illex coindetii, Aristaeomorpha foliacea, Nephrops norvegicus, Parapenaeus longirostris and a decrease of Raja clavata and Eutrigla gurnardus  was evident during the 1998 survey.

Using the commercial trawler ”Nuovo Splendore”, 123 out of the 124 scheduled hauls were made. The presence of nets has prevented from doing one haul in the stratum 13316. Moreover the absence of trawlable grounds in the neighbourhood did not permit its substitution.

The survey took place in seas surrounding Sardinia from 25^th May to 3^rd July 1998. During this period 30 days were spent for fishing and 11 days were spent for technical breaks.

Unfortunately, scanmar equipment was not available, but the duration of hauls was recorded following the recommendations of the Medits protocol.

No technical problems were encountered, although often in the shallower waters large quantities of sea urchins, eel grass (Posidonia oceanica) and algae were encountered and the duration of hauls was slightly decreased. Not many waste products were fished.

During some hauls, especially near the coast where the substrata was irregular and hard, gear was damaged to a certain extent. When damage was not serious some parts of the net were changed; in other cases the reserve net was utilised.

Sometimes the course of the hauls was modified due to the presence of nets.

Finally, weighting, measuring and maturity evaluation were performed on board, recorded and checked on the computer in the laboratory.

The 1998 Medits (MED’98) survey in the M3 region was carried out from 21^st May to 28^th June using the professional stern trawler “Sant’Anna”. The first sub-zone covered was the northern side of the M3 study area (M3a), i.e., the grounds of Central and Southern Tyrrhenian Sea facing Campania (Volturno river) and Calabria (Cape Suvero) Regions, respectively. This sub-zone has been surveyed, from 21^st May to 5^th June, by the scientific staff of the “COISPA – Tecnologia and Ricerca” of Bari. The second sub-zone covered was the central part of M3 study area (M3b), i.e., the grounds of Southern Tyrrhenian Sea facing Calabria (Cape Suvero) and the Northern coasts of Sicily (Cape S. Vito). This sub-zone has been surveyed, from 6^th June to 12^th June, by the scientific staff of the “Istituto Talassografico – CNR” of Messina. The third M3 sub-zone, the area known as the Strait of Sicily (M3c), has been surveyed, from 13^th June to 28^th  June, by the scientific staff of the “Istituto di Ricerche sulle Risorse Marine e l’Ambiente, IRMA-CNR” (formerly ITPP-CNR) of Mazara. The MED’98 ended on June 28^th.

An overall of 141 hauls were performed in the M3 area; in particular, 57, 28 and 56 hauls were realised in the first (M3a), second (M3b) and third (M3c) sub-zone, respectively. In all hauls, but those realised in the M3c sub-zone, a miniature data logger (MINILOG-TD), that records both temperature and depth, was mounted on the head rope of the gear. Water temperature has been registered in all the hauls of M3a and M3b; unfortunately, the device was lost during the 1^st haul carried in the M3c sub-zone, as a consequence of the breakage of the gear. As regards its maintenance, some damaged parts were substituted both before and during the survey.

A SCANMAR equipment was not available, but haul duration was recorded according to average effective time on bottom as from previous trials with SCANMAR by IRPEM-CNR technicians.

Both haul registration and processing of biological parameters were accurately performed according to the Medits protocol. As in the previous years, the gear operative validity was confirmed at depth above 200 m whereas some doubts still remain for the deeper waters where relatively scarce catches of crustaceans were observed.

The Medits-IT & ALB 1998 survey was carried out from 05/05 to 13/07 (70 days, including Medits net setting – by IRPEM technicians -, stand-by and transferring).

The survey lasted 24 days in Ionian areas from Cape Passero to Cape of Otranto (2 Medits net setting days, 1 transferring day, 3 days of stand-by and 18 full working days), 25 days for south-western Adriatic areas from Cape of Otranto to Vieste (3 transferring days, 3 days of stand-by and 19 full working days) and 21 days for south-eastern Adriatic areas from S. Johan to Saranda (7 transferring days, 2 days of stand-by and 12 full working days).

During the survey 186 hauls were carried out (74 in the Ionian areas; 72 in the south-western Adriatic areas; 40 in the south-eastern Adriatic areas); the new vessel “Pasquale e Cristina” was utilised this year by Medits-It M4 Unit in the whole research area.

During this survey, a larger number of days was used than in 1997(2 days more), due to the bad weather in the last June and the beginning of July; also this year the entry and standing of the vessel in Albanian harbours was very difficult (bureaucracy) and for this reason the trawler was forced to continuous transfers from Italy to Albania and vice versa.

During the 1998 survey two damages occurred: the first one was at the net, lost and fortunately found again during one haul in the Italian South Adriatic area; the second damage occurred at a powerblock during the sampling in the Albanian South Adriatic area.

The Medits - M5 survey in the northern and central Adriatic Sea took place from June 9 to July 4. The survey started in the central Adriatic, then continued in the western part of the Adriatic, in the North Adriatic and ended in the Slovenian and Croatian territorial waters.

The vessel ‘’Igor’’, a commercial trawler, was used for the entire survey and a total of 138 valid hauls were made. 86 stations were carried out in the international and Italian territorial waters, 2 in the Slovenian waters and 50 stations were located in the Croatian territorial waters. The position of the hauls was the same as for the previous survey, except for few stations (4) changed to prevent damages.

No Scanmar equipment was available and the haul duration was recorded following the recommendations of the Medits protocol. During the whole cruise the same net was used.

Scientists from three concerned laboratory (Split, Ljubljana and Fano) took part to the survey ; generally, 4 scientists worked in same time on board.

Haul registrations and first biological processing were performed on board ; the more detailed biological analysis and data entry in computer were made in the laboratory according to the Medits protocol.

The Medits G1 survey for 1998 was carried out from 15^th June to 23^rd July in the northern Aegean Sea (North of 38N). The commercial trawler «Kapetan  Paraschos» was used for the sampling operation, as it was done in the previous two years. The research cruise lasted 39 days, 2 of which were spent on trials, 31 days on fishing and 6 days on stop due to bad weather conditions.

During the research cruise 64 hauls were carried out successfully. One haul (the 51st) was characterized invalid as the doors were pinned in the muddy bottom and the haul stopped too early. A new haul (65th) was realized during this survey in the western part of Lesvos island. The presence of hauled gill nets and long lines near the coasts and in the open sea induced us to change slightly the co-ordinates of some hauls remaining however in the same isobath. The progressive experience of the trawl particularities and the field characteristics through the years permitted better shouting and towed conditions and affected the quantities fished.

Four French students took part in the research cruise. Mrs. B. Jorez and Mrs. E. Vienot from E.S.I.T.P.A (Ecole Superieure d’Ingenieurs et de Techniciens pour l’Agriculture) participated for 4 days while Mr. C. Ponsonnet and Mr. J.M. Cochet from E.N.S.A.(Ecole Nationale Superieure Agronomique) participated for 15 and 12 days respectively.

Weight and length measurements as well as maturity of the sampled fish were carried out on board. The maturity stage of Centrophorus granulosus, Raja asterias, Raja clavata, Mustelus mustelus, Scyliorhinus canicula and Squalus acanthias was not estimated.

In the laboratory, data were recorded in the computer using the INDMED program and checked using the CHECKMED program. Abundance indices were calculated for target species and for some of the reference species. The species from the reference list, which were most abundant in weight this year were, in the following order: E. encrasicolus, M. merluccius, S. pilchardus, R. clavata, T. trachurus, L. budegassa, M. barbatus, P. longirostris, S. canicula and D. annularis. Comparatively, in ’97 survey the most abundant species in weight were: E. encrasicolus, S. pilchardus, M merluccius, A. sphyraena, L. budegassa, M. poutassou, E. cirrhosa, R. clavata, P. longirostris and T. mediterraneus.

Considering the number of individuals, the most abundant species were in order: E. encrasicolus, T. trachurus, P. longirostris, A. sphyraena, S. pilchardus, T. minutus capelanus, M. barbatus, D. annularis, S. flexuosa and M. merluccius. In comparison, the most abundant species in number of individuals, in the previous year survey were: E. encrasicolus, A. sphyraena, S. pilchardus, P. longirostris, T. mediterraneus, T. minutus capelanus, T. trachurus, M. poutassou and M. merluccius.

The most widely distributed species were, in order: M. merluccius (60 of 64 hauls), L. budegassa (53 of 64 hauls), I. coindetii (51 of 64 hauls), P. longirostris (41 hauls),  E. cirrhosa (37 hauls), P. blennoides (35 hauls), S. canicula (35 hauls), T. trachurus (34 hauls), R. clavata (33 hauls), A. sphyraena (32 hauls) and L. boscii (30 hauls).

In zone G2 (Argosaronikos and Ionian Sea), the sampling cruise started on 12/6/97 and ended on 10/7/97. A different vessel was used for the 1998 survey, because the trawler used during the previous surveys was withdrawn. The new vessel DEMETRIOS is also a commercial trawler. Before the beginning of the cruise, the assemblage of the fishing gear was inspected by the regional co-ordinator, in order to assure the observance of the Medits protocol. The functioning of the gear was tested in Saronikos Gulf.

A total of 53 hauls was effected (21 in Argosaronikos and 32 in the Ionian Sea). In the Ionian Sea, the number of hauls was increased in comparison with the previous years in order to obtain a more representative sampling of that region. The weather conditions were generally good with some exceptions mainly in the Ionian Sea. The functioning of the gear was generally good in Argosaronikos, however in some stations of the Ionian Sea, the doors stuck in the bottom. Another problem confronted in the Ionian Sea was the irregular and steep bottom in the deep, which made trawling difficult.

As in the previous years during the 1998 sampling period, a SCANMAR system was used to observe the following parameters: fishing depth, horizontal and vertical opening of the gear and clearance. This system was connected with a GPS, which recorded the hauling speed and the track of the hauls. However, the SCANMAR system was damaged after the sixth haul and it was out of operation.

The temperature during hauling and the hauling depth were also recorded using a MINILOG device. The MINILOG sensor was broken and lost in the sea during the 21st haul.

Finally, as in the previous years, the temperature and salinity profiles were recorded by means of a CTD. Data were obtained for only 27 stations, because of a battery problem.

The Medits G3 survey took place from the 15th of June to the 28th of July, in the southern Aegean and the Cretan seas. This year the survey in the G3 area was carried out with a new vessel hired by IMBC. The vessel named “Nautilos”, was a commercial trawler very similar to “Ioannis Rossos” which had been used the previous years. The functioning of the gear was tested in the Gulf of Iraklion on the 10th and 11th of June.

Bad weather conditions, caused by strong winds (meltemi) which commonly affect the Aegean Sea during the summer months, resulted in an extension of the survey duration for about 15 days. The rocky substrate and obstacles on the sea-bottom caused in three cases small damages in the gear which, however, were fixed on board.

The gear showed a generally homogenous performance and the trawling speed ranged from 2.8 to 3.1 knots. Trawling with the highest speed was realized mostly in the deeper hauls and (or) on muddy bottoms. The electronic observation  and recording of the track of the hauls was conducted by means of a GPS and a plotter. In this way, there was a complete representation of the haul (beginning, end, change of direction).

During the 1998 survey a total of 61 valid hauls were accomplished: 17 around the islands of the Cyclades complex, 28 in the area of the Dodecanesian and south-eastern Aegean islands and 16 in the Cretan Sea.