Fish farming in Denmark: environmental impact of regulative legislation

1995 ◽  
Vol 31 (10) ◽  
pp. 73-84 ◽  
Author(s):  
T. M. Iversen
Keyword(s):  
Organic Matter ◽  
Environmental Impact ◽  
Freshwater Fish ◽  
Aquatic Environment ◽  
Action Plan ◽  
Fish Farming ◽  
Fish Farms ◽  
Nitrogen And Phosphorus ◽  
Local Impact ◽  
The Impact

The main environmental problems associated with fish farming in Denmark are attributable to the dam, the “dead reach” and nutrient and organic matter discharge. The environmental regulation of fish farming in Denmark started with the Environmental Protection Act of 1974, the Statutory Order of 1985 forbidding wet feed, and the Action Plan on the Aquatic Environment of 1987. In the case of freshwater fish farms, the latter was implemented through the measures stipulated in the 1989 Statutory Order on Fish Farms. The impact of Danish legislative measures to reduce and regulate the environmental effects of freshwater fish farms can be summarized as follows: - the number of fish farms has been reduced from about 800 in 1974 to about 500 at present; - production has tripled since 1974 and has been stable since 1989; - a change from wet to dry feed has reduced the environmental impact of the farms; - the national goals of the Action Plan on the Aquatic Environment of 1987 for reducing fish farm discharges of organic matter, nitrogen and phosphorus have been fulfilled. The main remaining problems are that: - the local impact of fish farms on downstream stream quality is still much too high in about 15% of cases; - the problem of the passage of migrating invertebrates and fish is still unsolved at some farms; - the problems posed by “dead reaches” are still unsolved. It is concluded that sustainable fish farming is possible in Denmark, but with the present technology production will have to be significantly reduced.

Environmental impact of nutrients from nordic fish farming

1995 ◽  
Vol 31 (10) ◽  
pp. 61-71 ◽  
Author(s):  
M. Enell
Keyword(s):  
Major Part ◽  
Fish Farming ◽  
Fish Farms ◽  
Feed Composition ◽  
The North ◽  
Comprehensive Development ◽  
The Baltic ◽  
Inland Water Bodies ◽  
The Impact ◽  
Feed Coefficient

During the last 20 years there has been an interesting development of the Nordic fish farming, with regard to the feeding and farming technology and to the increase in production quantities. During the period 1974-1994 the production increased from 15,800 to about 250,000 tonnes/year. In 1974 the major part of the production was in Denmark, and in 1994 the major part was in Norway. The nutrient impact of fish farming on surrounding sea areas is mainly a function of the feed coefficient, the feed composition and metabolic processes in the fish. The comprehensive development of the feed composition and the feeding technology has resulted in reduced load of unmetabolized nutrients from fish farms, calculated per tonne fish produced. In 1974 the mean Nordic feed coefficient was 2.08 and in 1994 the coefficient was 1.25. Feed coefficients of 1.0-1.1 are now reported for Danish and Norwegian freshwater and marine fish farms. The nitrogen (N) and phosphorus (P) content of the feed has decreased, in addition the quality of the nutrient substances in the feed has changed, especially for N. The N content has decreased from 7.8 to 6.8% during the period 1974-1994 and the content of P has decreased from 1.7 to 0.7% during the same period. This development of the feed coefficient and the feed composition has resulted in a present load from a typical Nordic fish farm of 55 kg N and 4.8 kg P/t fish produced. The figures for 1974 were 132 kg N and 31 kg P/t fish produced. The Nordic fish farming production in 1994 resulted in a load of about 13,750 t N and about 1,200 t P on the actual recipients. The load from the Swedish, Finnish and Danish fish farming operations, with the Baltic Sea and the Skagerrak as the recipients, is negligible in comparison with other pollution sources. The quantities of N and P from the fish farming are equal to 0.5% of the atmospheric deposition on the sea surface and 3% of the atmospheric P load. Norwegian, Icelandic and the Faroe Islands fish farming operations are using the North Sea and the Norwegian Sea as the recipients. However, the nutrient load from single fish farms in certain coastal and inland water bodies can be significant and must be considered in the impact assessment together with other sources.

scholarly journals Longitudinal evaluation of the impact of traditional rainbow trout farming on receiving water quality in Ireland

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5281 ◽  
Author(s):  
Alexandre Tahar ◽  
Alan M. Kennedy ◽  
Richard D. Fitzgerald ◽  
Eoghan Clifford ◽  
Neil Rowan
Keyword(s):  
Water Quality ◽  
Rainbow Trout ◽  
Fish Farming ◽  
Independent Data ◽  
Fish Farms ◽  
Cumulative Impact ◽  
Four Seasons ◽  
River Quality ◽  
Flow Through ◽  
The Impact

In the context of future aquaculture intensification, a longitudinal ten-year evaluation of the current traditional rainbow trout production in Ireland was performed. Publically available and independent data obtained from local authorities were gathered and analysed. Inlet and outlet concentrations of parameters such as BOD5, ammonium, nitrite, dissolved oxygen and pH for four consecutive flow-through fish farms covering the four seasons over a ten-year period (2005–2015) were analysed. The objectives of the study were (i) to characterize the impact of each fish farm on water quality in function of their respective production and identify any seasonal variability, (ii) to quantify the cumulative impact of the four farms on the river quality and to check if the self-purification capacity of the river was enough to allow the river to reach back its background levels for the analysed parameters, (iii) to build a baseline study for Ireland in order to extrapolate as a dataset for expected climate change and production intensification. For most of the parameter analysed, no significant impact of the fish farming activity on water quality/river quality was observed. These results, the first ones generated in Ireland so far, will have to be completed by a survey on biodiversity and ecotoxicology and compared after production intensification and the likely future introduction of water treatment systems on the different sites.

scholarly journals The effect of feed residues on the quality of aquatic environment in circulating aquaculture systems of african catfish (Clarias gariepinus (Burchell, 1822))

2021 ◽  
pp. 72-86
Author(s):  
Yu. Krot ◽  
◽  
D. Medovnyk ◽  
Yu. Krasiuk ◽  
D. Kudriavtseva ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Aquatic Environment ◽  
Inorganic Nitrogen ◽  
Clarias Gariepinus ◽  
African Catfish ◽  
Nitrogen And Phosphorus ◽  
Food Load ◽  
Extruded Feed

Purpose. To study the peculiarities of relationships between the aquatic environment and the extruded feed residues in the circulating aquaculture systems intended for growing Clarias gariepinus, and changes in the concentrations of inorganic nitrogen compounds and phosphorus phosphates. Methodology. The object of study is the quality of the aquatic environment when modeling the food load in accordance with feeding standards of different age groups of Cl. gariepinus. Water quality in experimental tanks was determined by analytical methods. Findings. It was found that the intake of extruded feed residues into the aquatic environment leads to a deterioration in its quality due to an increase in the concentration of compounds of inorganic nitrogen and phosphorus of phosphates, which negatively affects the vital activity of Cl. gariepinus. Nitrification processes are activated under conditions of sufficient dissolved oxygen content in the environment. The overload of the aquatic environment with organic matter promotes the bacterial transformation processes of nitrogen and phosphorus compounds, which are characterized by the predominance of the ammonification process and the suppression of oxidative processes. Upon completion of the mineralization of the excess organic matter, the appearance of a sufficient amount of dissolved oxygen activates ammonium oxidation and intensifies nitrification process. The leading factors in the ammonification and nitrification processes in an environment saturated with organic matter include the dissolved oxygen content, which regulates the activity ratio of anaerobic amonifying and aerobic nitrifying microflora. Optimum aeration in Cl. gariepinus cultivation systems is determined not only by the direct physiological needs of fish, but also by the need to maintain a sufficient content of dissolved oxygen to ensure nitrification processes. Originality. The study investigated the effect of the food load on the quality of aquatic environment in the circulating aquaculture systems for Cl. gariepinus rearing. Practical value. The study results can be used to optimize Cl. gariepinus growing methods in circulating aquaculture systems with adjustable parameters at high stocking densities. Key words: African catfish, quality of the aquatic environment, food load, inorganic nitrogen compounds, phosphorus phosphate content, circulating adjustable systems.

The relationship between sediment and water quality, and riverine sediment loads in the wave-dominated estuaries of south-west Western Australia

2004 ◽  
Vol 55 (6) ◽  
pp. 581 ◽  
Author(s):  
L. C. Radke ◽  
I. P. Prosser ◽  
M. Robb ◽  
B. Brooke ◽  
D. Fredericks ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Soil Erosion ◽  
Organic Carbon ◽  
Water Column ◽  
Nitrogen And Phosphorus ◽  
Weathering Index ◽  
Sediment Loads ◽  
The Impact ◽  
Column Total

We examine surface sediment and water column total nutrient and chlorophyll a concentrations for 12 estuaries with average water depths <4 m, and calculated sediment loads ranging from 0.2 to 10.8 kg m−2 year−1. Sediment total nitrogen, phosphorus and organic carbon concentrations vary inversely with sediment loads due to: (i) the influx of more mineral-rich sediment into the estuaries; and (ii) increasing sediment sulfidation. Sediment total organic carbon (TOC) : total sulfur (TS) and TS : Fe(II) ratios correlated to sediment loads because enhanced sedimentation increases burial, hence the importance of sulfate reduction in organic matter degradation. Curvilinear relationships were found between a weathering index and organic matter δ13C in sediment, and sediment load. The rising phase of the curve (increasing weathering, lighter isotopic values) at low to intermediate loads relates to soil erosion, whereas regolith or bedrock erosion probably explains the declining phase of the curve (decreasing weathering, heavier isotopic values) at higher sediment loads. The pattern of change for water column total nutrients (nitrogen and phosphorus) with sediment loads is similar to that of the weathering index. Most water quality problems occur in association with soil erosion, and at sediment loads that are intermediate for the estuaries studied. Limited evidence is presented that flushing can moderate the impact of sediment loads upon the estuaries.

scholarly journals On the Environmental Impact of Freshwater Fish Farms in Greece and in Iceland

2017 ◽  
Vol 13 (1) ◽  
pp. 1-7 ◽  
Author(s):  
T Mavraganis ◽  
H Thorarensen ◽  
M Tsoumani ◽  
C Nathanailides
Keyword(s):  
Environmental Impact ◽  
Freshwater Fish ◽  
Fish Farms

scholarly journals Survey of the environmental impacts of pond fish farming

2006 ◽  
pp. 19-24
Author(s):  
Dénes Gál ◽  
Éva Kerepeczki ◽  
Pál Szabó ◽  
Ferenc Pekár
Keyword(s):  
Organic Matter ◽  
Environmental Impacts ◽  
Fish Farming ◽  
Nutrient Loads ◽  
Nutrient Amounts ◽  
The Impact ◽  
Nitrogen Phosphorus ◽  
Inputs And Outputs

The aim of this study was to survey the nitrogen, phosphorus and organic matter loads and the discharge of fishponds. The inputs and outputs of nutrient amounts of fishponds and their sources are described. The impact of a fishpond on the nutrient loads of receiver waters was determined. The investigations of this study were to determine and evaluate the nitrogen, phosphorus and organic matter budget of fishponds representing different technologies and areas.

scholarly journals Strategy for trout feeding with Aller aqua feeds

2018 ◽  
Vol 20 (84) ◽  
Author(s):  
I. Y. Bobel ◽  
J. I. Pivtorak
Keyword(s):  
Growth Rate ◽  
Mouth Opening ◽  
Fish Farming ◽  
Maximum Growth ◽  
The Body ◽  
Feeding Strategies ◽  
Natural Food ◽  
Young Fish ◽  
Nitrogen And Phosphorus ◽  
The Impact

Due to the fact that the cost of forage for trout is up to 60% of all costs for its cultivation, the problem of rational use and saving has a special place. In the planned production the selection of the appropriate feed and feeding strategies are very important. Two extremely important coefficients of the indicator should be taken into consideration: coefficient of growth rate and fodder coefficient. The maximum growth rate is not correlates with the best fodder coefficient. All Allerg aqua production feeds are made in the form of ellipsoid granules. According to Aller aqua, the ellipsoid shape of the granules can significantly improve feed and, consequently, reduce its loss. When immersed in water, granular feeds at the expense of the ellipsoid form carry chaotic movements that attract fish to their capture. In addition, the granules of the ellipsoid form in the production process are better saturated with fat. Feeding trout it is necessary to take into account that the size of the granules for young fish in the length of 4–20 cm should be from 2.2 to 2.6% of the body length (according to Smith), which corresponds to the mouth opening size and the distance between the gill stamens in rainbow trout. The onset of feeding in time leads to the proper formation of the esophagus, which allows further intensive feeding. Provision of high quality fodder is one of the most important conditions for successful industrial fish farming. In conditions where the fish is devoid of natural food, the metabolism is controlled by humans and depends on the balance, quality and quantity of feed supplied to the fish. That is the reason of great opportunities for increasing the rate of growth of fish, with minimal expenses for mixed fodder, reducing the mortality of young fish, improving the quality of producers, and in general improving the efficiency of all fish farming processes. In order to determine with great accuracy the norms of feeding, it is necessary to carry out the control of weighing of fish. The size of the sample depends on the size of the pool and the amount of fish. The sampling should be from 50 to 100% of the general population in small containers and at least 1% in large pools. Fish is best fed often, in small portions. The smaller the fish, the more it needs to be fed. If necessary, it is needed to use special therapeutic granulated food or a mixture of therapeutic ingredients to add to the wet granules. Fish should be fed every day, since breaks lead to a decrease in its mass. It is necessary to create optimal conditions for cultivation and to carry out constant monitoring of water temperature and its fluctuations, oxygen content in water, pH, atmospheric pressure, etc. The impact of feed on the environment is also closely related to the value of the feed factor. The main products of fish metabolism that are isolated in aqueous medium, it is nitrogen and phosphorus. The Aller Aqua Feeding Program for trout includes the following: The amount of feed fed with trout depends on the temperature and size of the fish. These factors affect the amount of ration feeding.

scholarly journals Evaluation of the environmental impact of two types of food in intensive farming of rainbow trout fry (Onchoryncus mykiss. Walbaum, 1792).

2020 ◽  
Author(s):  
El Hassan abba ◽  
Oumaima Dahak ◽  
Tarik Ainane ◽  
Adnane El Yaacoubi
Keyword(s):  
Rainbow Trout ◽  
Environmental Impact ◽  
Experimental Period ◽  
Nitrogen And Phosphorus ◽  
Mass Balance Method ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Intensive Farming ◽  
Weight Growth ◽  
The Impact ◽  
Intensive Breeding

Abstract The environmental impact of two types of food distributed during the first phase of intensive breeding of rainbow trout (Oncorhynchus mykiss) fry at the station of the National Center for Hydrobiology and Pisciculture constitutes the main objective of this study. the method used for the evaluation of the impact of these two foods is the mass balance method based on the calculation of the quantities of nitrogen and phosphorus excreted according to the quantities of food ingested and the composition of the carcasses. The results obtained show that the weight growth of fry and the rate of nitrogen and phosphorus rejection during the experimental period are very different and vary depending on the type of food received.

Regulating the local environmental impact of intensive marine fish farming I. The concept of the MOM system (Modelling-Ongrowing fish farms-Monitoring)

Aquaculture ◽  
1997 ◽  
Vol 158 (1-2) ◽  
pp. 85-94 ◽  
Author(s):  
Arne Ervik ◽  
Pia Kupka Hansen ◽  
Jan Aure ◽  
Anders Stigebrandt ◽  
Per Johannessen ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Marine Fish ◽  
Fish Farming ◽  
System Modelling ◽  
Fish Farms ◽  
Marine Fish Farming

SOURCE APPORTIONMENT AND RETENTION OF NUTRIENTS AND ORGANIC MATTER IN THE MERKYS RIVER BASIN IN SOUTHERN LITHUANIA/SKIRTINGŲ ŠALTINIŲ POVEIKIS BIOGENINIŲ IR ORGANINIŲ MEDŽIAGŲ PERNAŠAI IR SULAIKYMUI MERKIO UPĖS BASEINE PIETŲ LIETUVOJE/ РАСПРЕДЕЛЕНИЕ И ЗАДЕРЖАНИЕ БИОГЕННЫХ И ОРГАНИЧЕСКИХ ВЕЩЕСТВ В БАССЕЙНЕ РЕКИ MEРКИС В ЮЖНОЙ ЧАСТИ ЛИТВЫ

2008 ◽  
Vol 16 (4) ◽  
pp. 195-204 ◽  
Author(s):  
Arvydas Povilaitis
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
River Basin ◽  
Water Quality Monitoring ◽  
Point Sources ◽  
Anthropogenic Sources ◽  
Simultaneous Estimation ◽  
Successful Implementation ◽  
Nitrogen And Phosphorus ◽  
The Impact

The assessment of the type of human activity in a basin area that may cause an impact on the status of a water body is needed for successful implementation of the EU Water Framework Directive. Lack of necessary information often makes it difficult to perform the task. Therefore, the statistical MESAW model based on export coefficients approach has been used in this study for evaluation of the impact of different sources of nutrients and organic matter on the water quality in the Merkys River in southern Lithuania. The model was tested on the basis of data from 5 water quality monitoring sites with corresponding subbasin data on land use, point sources and atmospheric deposition. Nonlinear regression was used for simultaneous estimation of the export coefficients and retention. The results revealed that the impact of anthropogenic sources accounted for 73% of COD, 56% of BOD, 90% of Ntot and 78% of Ptot loads measured in the Merkys River. Forest and wetlands contribute from 9.5 to 44% to the corresponding load. The retention in the Merkys River, Basin was found to be high for nitrogen and phosphorus and low for organic matter. Santrauka Įgyvendinant vandensaugos uždavinius turi būti įvertintas konkretaus upės baseino vandens taršos lygis ir numatytos priemonės, padėsiančios pasiekti gerą būklę. Kiekvienos upės baseinas yra sudėtinga ekosistema, kurioje susipina gamtiniai ir antropogeniniai veiksniai. Jie veikia kompleksiškai, todėl analizuojant vandens terpėje migruojančias medžiagas sunku įvertinti kiekvieno jų įtaką. Gamtinių ir antropogeninių veiksnių poveikiui biogeninių ir organinių medžiagų srautams bei jų sulaikymui Merkio upės baseine įvertinti buvo pritaikytas statistinis MESAW modelis. Jis pagrįstas emisijos koeficientų nustatymu įvertinant baseino žemėnaudą, taškinius taršos šaltinius ir atmosferines iškritas. Taikant netiesinės regresijos metodus nustatytas skirtingų veiksnių poveikis upės vandens kokybei. Rezultatai parodė, kad antropogeninių šaltinių poveikis sudaro 73 % ir 56 % (pagal ChDSCr ir BDS7 ) bendro pernešamo organinių medžiagų kiekio Merkio upėje. Žmogaus veikla lemia 90 % pernešamo metinio bendrojo azoto ir 78 % bendrojo fosforo kiekio. Miško poveikis biogeninių ir organinių medžiagų srautams sudaro nuo 9,5 % iki 44 %. Bendrojo azoto ir bendrojo fosforo sulaikymas upės baseine siekia 79 % ir 64 %. Organinių junginių sulaikymas mažas – 9,7 % pagal BDS7 ir 42,3 % pagal ChDSCr. Резюме При решении задач по водоохране должна быть учтена степень загрязненности воды каждого конкретного бассейна реки и намечены меры по улучшению его состояния. Бассейн каждой реки является сложной экосистемой, на которую комплексное воздействие оказывают разные природные и антропогенные факторы, определить влияние каждого из которых довольно трудно. Для оценки воздействия природных и антропогенных факторов на потоки биогенных и органических веществ и их задержание в бассейне реки Меркис была применена статистическая модель MESAW, основанная на определении коэффициентов эмиссии. Результаты показали, что воздействие антропогенных источников составляет 73% общeго объемa химического потребления кислородa (XпK), 56% биохимического потребления кислородa (бпK), 90% общeго количества азота и 78% общeго количества фосфора, измеренных в реке. Воздействие лесов и болот на поток биогенных и органических веществ составляет от 9,5% до 44% общeго объемa веществ. Было устaнoвлeнo, что в бассейне реки Meркис задерживается много азота (79%) и фосфора (64%) и мало органического вещества (9.7–42.3%).

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