Ekonomska efikasnost filetiranog prinosa ribljih vrsta gajenih u Mediteranu

Filetirani prinos (FY%) i koeficijent konverzije hrane (FCR) gajenog brancina (Dicentrarchus labrax); orade (Sparus aurata); kalifornijske pastrmke (Oncorynchus mykiss) i hame (Argyrosomus regius) ispitani su kod riba gajenih na severo zapadu Grčke. Rezulati predstavljaju procenjenu količinu ribe koje je potrebna da se proizvede da bi se dobio kilogram filetirane ribe. Ova procena je zahtevana u svrhe operativnog menadžmentaza kompanija koje se bave preradom ribe. Najniži FY i FCR bio je kod hame, dok su više vrednosti zabeležene kod gajene kalifornijske pastrmke. Dobijeni rezultati ukazuju da se FCR, FY i tržišna cena moraju uzimati u obzir za procenu ekonomske efikasnosti gajene ribe. U stvari FY ne mora da utiče na ekonomsku efikasnost proizvodnje hame, vrste koja ima mnogo veću tržišnu vrednost u poređenju sa brancinom, oradom I kalifornijskom pastrmko

A combination of selected indices for assessing the environmental impact of marine fish farms using long term metadata analysis

Several biological indexes can be used to assess environmental impacts of aquaculture in the aquatic ecosystem. Some biological indices are used within environmental legislative and policy frameworks which aim to monitor the impact of marine aquaculture and regulate the operation of fish farms. In Scotland, the impact of fish farms is assessed according to benthic ecosystem status compared with modeled organic loading. The purpose of this paper is to evaluate the benefits of using an optimal combination of a minimal number of selected benthic and aquatic parameters which can provide accurate and reliable information about the benthic status around the fish farm sites in Scotland. The data analyzed in this paper were obtained from the Institute of Aquaculture (IoA), of University of Stirling, and were collected from various fish farm sites across Scotland over several years. Macrofaunal and physico-chemical parameters included in the analysis were: Median Particle Size Analysis (MPSA); total sediment Carbon (C% by dw); total sediment Nitrogen (N% by dw) and Redox Potential (Eh). In this analysis a number of diversity and trophic level based indices were also used - including the Shannon Index (H'), the Infaunal Trophic Index (ITI) and the Azti's Marine Biotic Index (AMBI) - to asses the biotic status of the sites. Univariate and multivariate analysis of the data indicated that a combination of Abundance (N), H' and AMBI as biological indexes for describing the status of the ecological level along with the carbon percentage and redox potential appeared to be the give the best representation of change. This combination is even more accurate over a series of sampling stations and time points, rather than for a single site only, offering a convenient method for assessing the risk of aquaculture pollution of biotopes bellow or adjacent to floating marine fish farm cages

Delovanje različitih uslova sredine na kvalitet mesa farmski gajenog brancina u severozapadnoj Grčkoj

The chemical composition and lipid quality of farmed sea bass from NW Greece was investigated. A difference in the proximate composition and filleting yield of farmed sea bass reared in different environmental conditions was observed in the present work. Fish reared in aquaculture lagoons exhibited higher moisture and low lipid compared to the fish farmed in marine floating cages. The results of the present work indicate that farmed fish exhibit variability in the flesh quality which can be attributed to differences in the rearing systems, aquaculture conditions with consequences for the nutritional benefits of consuming farmed fish. This research has been co-financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: ARCHIMEDES III. Investing in knowledge society through the European Social Fund.Ispitivan je hemijski sastav i kvalitet lipida farmski gajenog brancina iz područja Severozapadne Grčke. Uočene su razlike u hemijskom sastavu fileta brancina farmski gajenog u različitim uslovima sredine. Ribe gajene u lagunama imale su imale viši sadržaj vlage I niži sadržaj masti u poređenju sa ribama gajenim u morskim plutajućim kavezima. Rezultati su pokazali da postoje variranja u kvalitetu mesa gajene ribe koji se mogu pripisati razlikama u sistemima gajenja i uslovima akvakulture. Istraživanje je bilo kofinansirano od strane Evropske Unije (Evropski Socijalni Fond, European Social Fund – ESF) i Grških nacionalnih fondova kroz Operativni program “Obrazovanje i celoživotno učenje” ("Education and Lifelong Learning") nacionalnog strateškog referentnog okvira, National Strategic Reference Framework (NSRF) – programa za finansiranje istraživanja ARCHIMEDES III Investiranje u društvo unanja kroz Evropski Socijalni Fond

Ekološki, ekonomski i socijalni parametri rekreativnog ribolova na akumulaciji reke Aoos

U cilju prikupljanja podataka o rekreativnom ribolovu sprovedeno je anketiranje ribolovaca na akumulaciji reke Aoos u severozapadnoj Grčkoj. Upitnik je obuhvatio pitanja o demografiji, alatima koje koriste za pecanje, uslovima za ribolov, opremi, ciljnim vrstama, intenzitetu odlaska u ribolov, ribolovnom naporu, sezonama, podacima o ulovu. Prikazani rezultati ukazuju da rekreativni ribolov na tom području ima potencijal za razvoj turizma i poboljšanje socioekonomskog uticaja u čitavom regionu. Ribolovci imaju sve izraženiju svest o životoj sredini. Šaran je trenutno vrsta koja se najviše lovi i koja održava ovu aktivnost, a ukazuje da će ova vrsta moći opstati i na duže ukoliko dodje do promene klimatskih uslova i ukoliko protok bude smanjen kao posledica globalnog otopljavanja i kompeticije sa drugim korisnicima. Rukovodeći se rezultatima u ovom radu koji ukazuju na potencijal za razvoj ribolovnog turizma i povećanje ekološke vrednosti ovog područja, upravljači područjem bi trebalo da razmotre mogućnosti poribljavanja na području akumulacije koju formira brana na reci Aoos. Konačna preporuka za uspešno upravljanje ribolovom na području hidroelektrane treba da bude bazirana na kombinovanju parametara koji uključuju ekonomske, ekološke i ribarstvene podatke

Uticaj različitih termalnih uslova na hemijski sastav mesa kalifornijske pastrmke sa dve farme u severozapadnoj Grčkoj

Rainbow trout from two fish farms were reared under different thermal regimes, Farm Awas located by a river in a mountain region of Epirus and farm B was located in a lowland location at the coast of Preveza. Lower temperature prevailed in farm A (10-11 oC vs. 16-16,6 in farm B). Proximate composition analysis indicated that the different thermal conditions resulted in significant differences in the filleting yield and the proximate composition of rainbow trout axial musculature. The fish from the farm B exhibited higher growth rate and fillet lipid contents. This research has been co-financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: ARCHIMEDES III. Investing in knowledge society through the European Social Fund.Kalifornijske pastrmke su gajene u različitim termalnim režimima. Jedna farma (A) se nalazila pored reke u planinskom regionu Epira, a druga (B) se nalazila u nizijskom delu, na obalskom delu Preveza. Na farmi A su preovlađivale niže temperature (10-11 oC prema 16-16.6 na farmi B). Analiza hemijskog sastava ukazuje da su različiti temperaturni režimi doveli do značajnih razlika u kvalitetu fileta I cele aksijalne muskulature. Ruba sa farme B je imala veću stopu rasta I sadržaj lipida u filetima. Ovo istraživanje je ko finansirano od strane Evropske Unije (Evropski socijalni fond, European Social Fund – ESF) i Grčkih nacionalnih fondova kroz Operativni program «Obrazovanja i celoživotno učenje - Education and Lifelong Learning «Nacionalnog Strateškog referentnog okvira (NSRF) – Program finansiranja istraživanja ARCHIMEDES III – Investiranje u društvo znanja kroz Evropski socijalni fond

Korelacija između nivoa alkalne fosfataze i fosfata u otpadnoj vodi ribnjaka sa masom pastrmki

Otpadne vode iz pastrmskih ribnjaka se obično ispuštaju u nezagađene akvatične ekosisteme, s obzirom na to da su ribnjaci najčešće locirani na velikim visinama, gde nema drugog izvora antropogenog zagađenja. Cilj ove studije je da se istraži odnos između aktivnosti alkalne fosfataze (APH) izmerene u otpadnim vodama i mase riba u ribnjaku. Uzorci vode sa ribnjaka su prikupljani u proleće i leto i iz nje su određivani nivoi APH, fosfata (PO4-P) i količine bakterija (CFU). Ustanovljena je pozitivna korelacija između mase riba i nivoa APH i PO4-P u efluentu, dok sa druge strane, nije utvrđena korelacija između mase riba i CFU. Rezultati ove studije su pokazali da nivo APH može biti korišćen kao potencijalni indikator zagađenja vodenih ekosistema otpadnih voda iz pastrmskih ribnjaka

Pituitary Collection from Gibel Carp Carassius gibelio (Bloch 1782) in Lake Pamvotis (Greece): Prospects for Use in Carp Reproduction

Gibel carp (Carassius gibelio Bloch, 1782) is regarded as a pest species in most aquatic ecosys- tems where it occurs and eradication methods have not been very promising. However, because of the close taxonomical proximity between gibel carp and cultured cyprinids, the pituitary of gibel carps could be exploited for hormonal induction of artificial propagation in aquaculture. Thirty-two mature female gibel carps were electrofished in Lake Pamvotis (northwest Greece) in March 2005 and their pituitaries were collected and processed. The carp luteinizing hormone (cLH) levels in 20 pituitaries were assayed and found to correlate with total body weight, total length, dry pituitary weight, and gonadosomatic index. The cLH levels were in the same range as cLH levels in pituitaries of common carp (Cyprinus carpio Linnaeus, 1758) used in Israeli hatcheries for artificial propagation. Hence, it may be possible to use gibel carp pituitaries for hormonal induction in cyprinids, with total weight of the gibel carp as a field criterion for select- ing pituitary donors

Antemortem and postmortem biochemistry, drip loss and lipid oxidation of European sea bass muscle tissue

AbstractSlaughtering methods of farmed fish can influence swimming activity and stress levels with consequences for the flesh quality properties of fish fillets. For example, muscle metabolic activity prior to death can affect the concentration of oxygen, ATP and the pH of muscle. Handling stress of fish prior to harvesting is characterized by increased swimming activity which leads to anaerobic metabolism while energy stores are depleted and white muscle pH drops leading to acceleration of autolytic reactions after death with consequences for the organoleptic parameters of fish fillets and the filleting yield of farmed fish. In addition to the food quality aspects of the slaughtering method, the potential suffering of fish being handled during common aquaculture procedures or during slaughtering prompted scientific research in the welfare of farmed fish during harvesting. The purpose of this work was to investigate the effect of handing stress on post- mortem muscle pH and rigor mortis. European sea bass were harvested using two different levels of handling stress. Muscle pH was monitored shortly after death and after ice storage. Drip loss, and thiobarbituric acid reactive substances (TBARS) were measured in ice stored fillets. Antemortem stress resulted in rapid drop of muscle pH and onset of rigor mortis. Drip loss, and thiobarbituric acid reactive substances (TBARS) increased in the stressed fish. The results indicate that reducing handling stress during harvesting can delay rigor mortis and improve the quality of European sea bass fillets

Occurrence of the Invasive Crab Species Callinectes sapidus Rathbun, 1896, in NW Greece

The present work aims to review and describe the current status of the invasive species Callinectes sapidus Rathbun, 1896, along the Ionian coastal zone of Greece and to assess its invasive potential. Blue crab has a long invasion history in the Mediterranean Sea, but the available data on the species occurrence in the Ionian sub-region are scarce and fragmented. The proximity of most of the estuaries and lagoons to local ports and to the shipping routes, as well as the swimming/dispersal ability of the adults of the species, indicate that range expansion will likely continue. The invasiveness risk of the species in the region was estimated with the use of a decision support tool (Marine Invertebrate Invasiveness Screening Kit, version 1.19). The observed impacts are discussed, along with urgent mitigation priorities. Measures to limit the expansion of this invasive species may include the effective management of ballast waters and the targeted increase of fishing pressure on C. sapidus populations. The importance of ballast water management is further highlighted by the existence of numerous ports with the capacity to serve ships with ballast tanks in close proximity to the recipient ecosystems. Moreover, the Ionian Sea, which connects the Adriatic Sea to the rest of the Mediterranean, is a significant shipping route for the local, regional, and international seaborne trade

Probiotics Have the Potential to Significantly Mitigate the Environmental Impact of Freshwater Fish Farms

Probiotics for freshwater fish farming can be administered as single or multiple mixtures. The expected benefits of probiotics include disease prophylaxis, improved growth, and feed conversion parameters, such as the feed conversion rate (FCR) and specific growth rate (SGR). In the current work, we review the impact of probiotics on freshwater finfish aquaculture. Data were gathered from articles published during the last decade that examined the effects of probiotics on fish growth, FCR, and water quality in freshwater fishponds/tanks. While the expected benefits of probiotics are significant, the reviewed data indicate a range in the level of effects, with an average reduction in ammonia of 50.7%, SGR increase of 17.1%, and FCR decrease of 10.7%. Despite the variability in the reported benefits, probiotics appear to offer a practical solution for sustainable freshwater aquaculture. Disease prophylaxis with probiotics can reduce the need for antibiotics and maintain gut health and feed conversion. Considering that fish feed and waste are two significant parameters of the aquaculture ecological footprint, it can be argued that probiotics can contribute to reducing the environmental impact of aquaculture. In this direction, it would be beneficial if more researchers incorporated water quality parameters in future aquaculture research and protocols to minimize aquaculture’s environmental impact