Qala local council voices concerns over proposed site for North Aquaculture Zone
The Qala local council has voiced ‘grave concerns’ over the preferred location at sea being marked for the North Aquaculture Zone (NAZ), and calls for an alternative site to be used so as to safeguard the quality of bathing waters along the south coast of Gozo.
Similarly to the designation of the South Aquaculture Zone, which is located roughly 6km off the south-east of Malta, the NAZ would group in a single polygon, measuring 4.5 square kilometres, all the blue-fin tuna rearing facilities currently located in waters off the north of the archipelago, the council said in a statement.
“The main scope of such aquaculture zones is to relocate all aquaculture facilities from coastal waters to relatively offshore ones, thus mitigating the occurrence of effluents originating from the same facilities within bathing areas. Consequently, the concept of an NAZ, which has been actively pursued by the Department of Fisheries and Aquaculture since 2011, is a valid one since it is not feasible to aggregate all local tuna-rearing facilities within the South Aquaculture Zone. However, concerns and misgivings exist over the location currently being proposed for the siting of the NAZ, which is expected to house a total of 4,500 tons of bluefin tuna biomass, a marked increase over the current capacity (3,300 tonnes) held by the AJD facility further to the south-east.”
These concerns have led the Qala local council to engage the services of marine biologist Alan Deidun as a consultant, in order to critically evaluate the findings of the NAZ Environment Impact Assessment (EIA) study, the council said.
The current temporary location of the AJD tuna-rearing facilities, assigned by the ERA in 2017 over a public outcry fanned by a constant occurrence of fish oil slick, currently lies 5km away from LAhrax Peninsula and 4.9km from Qawra Point, the council said.
“More importantly, the dispersal of fish oil from tuna-rearing operations in the current location to the south coast of Gozo is not likely given the element of sheltering provided by the island of Comino and by the L-Ahrax peninsula itself. So much so that the occurrence of oily slick along the south coast of Gozo, putatively originating from tuna-rearing facilities, is minimal. The preferred polygon for the siting of the NAZ is the closest any aquaculture facility has been to the coast of Gozo, lying a mere 4.56km from Qala Point and, most importantly, lying in lee of the south coast of Gozo in case of strong north-easterly and easterly winds,” the council said.
One of the most evident socioeconomic and environmental impacts of bluefin tuna rearing facilities is the generation of a fish oil slick, the council added. “Citing the NAZ EIA document itself, 5% of the baitfish fed to the reared bluefin tuna will be lost as fish oil, totalling 264.7kg of fish oil per cage per day, with a total of 34 cages expected to be housed within the NAZ. Whilst the aquaculture operators strive to recover the same fish oil, through the use of booms and by a stand-by contractor outside the cages and by means of a skimmer inside the cages themselves, the EIA document acknowledges that the fish oil recovery process is not 100% efficient.”
The council said that as part of the EIA exercise, “a hydrodynamic study was commissioned so as to anticipate the dispersal of the same fish oil under two different scenarios – one characterised by strong North-West winds and one characterised by strong North-East winds. This study concluded that: a total of 10m3 of fish oils per day are expected to be released by the tuna penning operations arising from the total 5,500kg of baitfish fed to each cage on a daily basis; the fish oil slick (consisting of fish oils, melting ice, body fluids, and fish mucus) is expected to be generated twice a day, in synch with tuna feeding operations, in the morning and in the afternoon; and that under ‘Scenario 2’ conditions (wind blowing predominantly from the East, a scenario which arises on approximately 28% of all days, considering both NE and E wind directions), the fish oil plume disperses westwards, reaching the south Gozo coast in just 17 hours if there is no containment.”
The council came up with two recommendations.
The first is maintaining the status quo (i.e. going for the ‘zero option’ and not relocating the current tuna penning operations located 5km from l-Ahrax peninsula and 4.9km from Qawra Point, “given that the socio-economic benefits to result from such a relocation are outweighed by the anticipated deterioration in water quality along the south coast of Gozo as confirmed by the results of the commissioned hydrodynamic study.”
The second is opting for an alternative location/site to the south-east of the proposed NAZ, located slightly to the north of the current AJD tuna-rearing facilities.
“The implementation of this option has the following advantages: It does not impinge on the ‘il-Bahar Madwar Ghawdex’ SPA, as the proposed NAZ location will; It will represent a lower probability of the anticipated fish oil slick reaching the south Gozitan coastline due to sheltering by the eastern coastline of the island of Comino for most (but not all) of the easterly wind directions; and It will represent more congenial operational water depths for the tuna penning industry given that water depths within the proposed new site are shallower than those within the proposed NAZ.”