Figure 56. Geographic references for the central Mediterranean area 



of Sicily also became extinct after its 

 two most productive ones, including 

 the first order trap of Marzamcni, 

 took little or nothmg m 1969. Less 

 important return traps on the south- 

 em coast of Sicily had failed in the 

 1950s. One at a new location off Cape 

 Granitola, at the southwestern comer 

 of Sicily, fished successfully through 

 1966. After poor seasons in 1967- 

 1969, it was set for the last time in 

 1972 with no success (R. Sara, per- 

 sonal communication) Its failure 

 marked the end of the Sicilian retum 

 fishery. The last traps in the Palermo 

 (northwestem Sicily) district were 

 also abandoned after the 1972 sea- 

 son (R. Sara, personal communica- 

 tion). This left two or three traps be- 

 ing set each yeai" in the Trapani dis- 

 trict at the westem tip of the island. 



and two in the Acgadcs Islands west 

 of there, as the on!\' sui"vivors of the 

 once flourishinjz Sicilian trap fish- 

 ery In Sardinia, the first order trap 

 of Saline (compartment of Sassan, at 

 the northwestern tip of the island) 

 took very poor catches (1-366 fish 

 per year) in 1967-1972. and evidently 

 has not been set since. The three first 

 order traps of the Carlofortc group 

 (department of Caglian, southwest- 

 cm Sardinia) averaged about 1,000 

 fish each per year through 1971, but 

 took only 1,174 tuna in all in 1972 

 In 1973, only two were set, and they 

 caught only 295 fish The first order 

 trap (5,000 fish per year) of 

 Favignana m the Aegades Islands is 

 the only one in Italy which has even 

 come close to a second order perfor- 



mance (2,000 fish per vear) (Pavesi 

 1889) since 1970 (Tabic II) 



Pollution and the disturbing ef- 

 fects of increased coastal traffic and 

 other fi.sheries (trawling and fishing 

 with lights) are regarded as contrib- 

 uting factors, along with reduced 

 numbers of fi.sh, in the decline of the 

 Italian tuna trap fishenes (Sara 1969, 

 1973, de Cri.stofaro 1970, Cesareo 

 1973) This fits in with the progres- 

 sive decline of the fisheries from 

 Calabria and eastern Sicily to west- 

 em Sicily, while the traps in Sar- 

 dinia, perhaps less subject to these 

 effects until recently, continued to 

 produce good catches The produc- 

 tion of the Sardinian traps, however, 

 has also collapsed since 1972 (Table 

 11) Sara (personal communication) 

 advised us that the 1974 catch of the 

 three southwestem Sardinian traps 

 was only 300 tuna He noted that the 

 entire coast had been contaminated 

 with the wastes of an aluminum plant 



The sizes of fish taken varied 

 with the location of the traps, or with 

 the water temperature at the traps 

 during the fishing season (Sella 

 1 929a) as well as fi-om year to year. 

 Sella (1929a, 1932a) considered the 

 traps off westem Sicily and those off 

 southwestern Sardinia as "cold" traps 

 (surface temperature 18 0-19 0°C, 

 salinity 37.37-37.65 o/oo) and pro- 

 ducers of large fish, and those off 

 Calabria and Tripolitania as hot" 

 traps (surface temperature 20.8- 

 21.8°C, salinity 37.48-37.66 o/oo) 

 and producers of medium sized and 

 small fish The relationships between 

 occurrences of tuna in traps and en- 

 vironmental conditions are discussed 

 in detail in section VI 



The numbers and weights of the 

 bluefin tuna taken by traps in each 

 compartment of Italy in each of the 

 years 1951-1957 were presented by 

 de Cristofaro (1970) The mean 

 weights of the fish taken in each 

 compartment in each year were cal- 

 culated from these data The maxi- 

 mum, minimum and average of these 

 mean weights over this period, for 

 each compartment which contained 

 important tuna traps, are shown in 

 Tabic 14 



fhcse data support Sella's 

 ( 1 929a) findings in regard to westem 

 Sicih and Calabria, but the traps off 



55 



