"Barbara NW" platformu Kuzey Adriyatik Denizi'nde k?y?dan 56 km uzakta ve 68,5 m derinli?e yerle?tirilmi?tir. Bu platform konu?land?r?ld?ktan sonra üç y?l boyunca (2000-2002) monitör arac?l??? ile farkl? bal?k türlerinde zamansal ve horizontal da??l?m? ara?t?r?lm??t?r. Bal?klar, platforma ortalama 1,8 km mesafede hem dipte av ekipman? ile hem de aç?k denize yerle?tirilen tuzak a??yla örneklenmi?tir. Her bir operasyonda av, platformun suyun içinde kalan k?sm?ndan elde edilmi?tir. Her 34 m'lik geni?likte ekipmandan yatay olarak 204 m yukar?ya kadar alt? katman tan?mlanm??t?r. Platform kurulumun ard?ndan bir sene içerisinde toplama etkisini göstermi?tir. Av oranlar? ekipmandan uzakl?k artt?kça önemli dü?ü? göstermi?tir. Yap?dan 34 m içerideki kaydedilen de?er 140 m'den daha büyük mesafelerden ve kontrol bölgesinden elde edilenlerden önemli derecede daha yüksektir. Resif özellik gösteren alanda ya?ayan bentik bal?klar, k?smen resif ya?ayan pelajik ve nekton bentik türler ekipmana yak?n olan katmanlarda üstünlük gösterirken, sert substratlara ilgisi/affinitesi olmayan organizmalar daha uzak katmanlarda ve kontrol bölgesinde bask?n gelmi?lerdir
The "Barbara NW" platform, located in the northern Adriatic Sea 56 km offshore and at 68.5 m depth, was monitored for investigating the temporal and the horizontally spatial extent to which the gas platform attracted different fish species during the three years after its deployment (2000-2002). Fish were sampled with a trammel net both at the rig and at an opensea control site placed at a distance of about 1.8 km, on the same type of seabed. At each survey, the catch obtained around the platform was subdivided based on the distance from the jacket (submerged part of the platform). Six strata, each 34 m wide, were identified up to 204 m horizontally from the rig. The platform showed its aggregation effect within the first year after installation. Catch rates significantly declined at increasing distances from the rig. The value recorded inside a 34 m radius from the structure was significantly higher than those obtained at distances greater than 140 m and at the control site. Reef-dwelling benthic fish, partially reef-dwelling pelagic and nekto-benthic species dominated inside the stratum closest to the rig, whilst the organisms which had no affinity towards hard substrates prevailed in the farther strata and at control site.
Temporal and spatial variation of the fish assemblage around a gas platform in the Northern Adriatic Sea, Italy
Giuseppe Scarcella;Fabio Grati;Gianna Fabi
2011
Abstract
The "Barbara NW" platform, located in the northern Adriatic Sea 56 km offshore and at 68.5 m depth, was monitored for investigating the temporal and the horizontally spatial extent to which the gas platform attracted different fish species during the three years after its deployment (2000-2002). Fish were sampled with a trammel net both at the rig and at an opensea control site placed at a distance of about 1.8 km, on the same type of seabed. At each survey, the catch obtained around the platform was subdivided based on the distance from the jacket (submerged part of the platform). Six strata, each 34 m wide, were identified up to 204 m horizontally from the rig. The platform showed its aggregation effect within the first year after installation. Catch rates significantly declined at increasing distances from the rig. The value recorded inside a 34 m radius from the structure was significantly higher than those obtained at distances greater than 140 m and at the control site. Reef-dwelling benthic fish, partially reef-dwelling pelagic and nekto-benthic species dominated inside the stratum closest to the rig, whilst the organisms which had no affinity towards hard substrates prevailed in the farther strata and at control site.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
