The aquaculture sector in the Netherlands can be divided into two sub-sectors: shellfish culture and finfish culture. The shellfish sub-sector is the older and economically more significant of the two and consists of 50 companies growing blue mussels (Mytilus edulis) and 32 companies growing oysters (Ostrea edulis and Crassostrea gigas). Both branches apply mostly bottom culture, resulting in 50 000 to 60 000 tonnes of mussels, 3 000 tonnes of Pacific cupped oyster and 250 tonnes of flat oysters per year. The shellfish sector relies on natural oyster spat fall and the collection of mussel seed from natural populations. Mussel seed collection takes place in areas of great natural value where strict conditions and monitoring are applied. The annual amount of seed which may be harvested fluctuates considerably from year to year. Mussel production is supplemented by imported seeds. Shellfish culture takes place in the estuarine waters in the southwest Netherlands and in the shallow Wadden Sea in the North of the country. Approximately 275 persons earn an income from shellfish culture activities (employment in processing and trade is not included).
The culture of finfish for consumption purposes took off in the 1980s and there are currently approximately 90 companies growing fish for consumption in heated recirculation aquaculture systems (RAS), plus approximately five outdoor rainbow trout farms. The most popular species are European eel (Anguilla anguilla) (44 farms together growing 4 800 tonnes/year), African catfish (Clarias gariepinus) (4 000 tonnes/year from 33 farms) and tilapia (Oreochromis niloticus) (600 tonnes from five farms). In addition turbot (Scophthalmus maximus), sole (Solea solea), barramundi (Lates calcarifer), pike-perch (Stizostedion lucioperca) and whiteleg shrimp (Penaeus vannamei) are grown in indoor heated systems by a small number of pioneering farms. Approximately 155 people work on finfish farms.
Aquaculture plays only a minor role in the Dutch economy, but it is expected that the sector will develop from increased awareness of the benefits from increased consumption of fish and shellfish.
Aquaculture in the Netherlands possibly dates back to medieval times when monasteries kept common carp (Cyprinus carpio) in ponds. Mariculture began around 1870. Due to numerous conflicts among fishermen the open access fishing for blue mussel (Mytilus edulis) and flat oysters (Ostrea edulis) in the delta region of the southwest Netherlands was changed into a system whereby mussel and oyster fishers could rent exclusive access rights to plots in the sea (Ginkel, R. van, 1991). This plot system facilitated the start of bottom culture of blue mussel and flat oyster because only the person who rented the plot derived the benefits from efforts to enhance the harvest from the individual plots. In 1952 plots to grow mussels could also be leased in the shallow Wadden Sea in the north of the Netherlands, and this led to the development of a second region where blue mussel is cultured.
Around 1900 the government started a small number of salmonid hatcheries for stocking rivers and lakes. Around 1930 these small hatcheries (approx five, consisting of raceways and small flow-through ponds) were transferred to private owners who used the facilities to grow rainbow trout (Onchorhynchus mykiss). In the 1940s the government started to stock inland waters with glass eel (Anguilla anguilla) and pike (Esox lucius) fingerlings in order to support the inland fishermen. In 1952 this task was taken over by the semi-government Organisation for Inland Fisheries Improvement (OVB). In addition to glass eel and pike fingerlings, in the late 1950s the OVB also started to stock inland waters with common carp (Cyprius carpio). Some years later other species were also reproduced and stocked to support the growing number of anglers. In the 1970s the major target group of the fish stocking programme had gradually changed from professional inland fishermen to angling clubs and sports fishermen (Quack, J., 2003). The OVB was dissolved in 2006, but the stocking of inland water bodies continues, although on a far more limited scale than was the case in the 1970s – 1990s. In 1975 the Agricultural College of Wageningen (in 1986 renamed Wageningen University) began to conduct scientific research and academic education in fish culture. The initial focus of the research was on the reproduction and culture of African catfish (Clarias gariepinus) and on fish farming in recirculation systems. In around 1985 the knowledge and skills gained in these subjects led around 1985 to the start of farms with recirculation aquaculture systems (RAS) for African catfish and European eel by graduates from Wageningen University as well as others. It is believed that Dutch success with the culture of these species in recirculation systems can be partly attributed to the availability of a group of highly trained university graduates who were willing to pioneer commercial fish farming in these relatively complex systems. After an initial increase the number of catfish and eel farms has fluctuated over the years, but the total production of both eel and African catfish has witnessed gradual and steady growth. Since the 1990s the number of other fish species grown in RAS has gradually increased.
Most aquaculture firms are small, family owned companies in which the owner and his family do a large part (or all) of the actual work. Only the bigger fish farms and the five or six shellfish processing companies which are also active in shellfish culture hire extra employees on a permanent basis. Smaller family-owned farms may hire additional personnel seasonally or part-time on days when extra hands are needed (such as during harvest or grading of fish). Good quality statistics on seasonal or part-time employment in aquaculture are not available. It is estimated that 269 people are employed in the shellfish culture production on approximately 82 farms or companies. Most employees in shellfish producing companies learn the trade on the job while working in the shellfish company. Most finfish farmers learned about aquaculture either as a minor subject in agricultural trade school or by attending special short courses (trade school level). University graduates with a degree in biology, fish culture or animal husbandry form a minor but significant part of eel and catfish farmers. Women form a small minority among finfish farm owners and personnel. There are even fewer women in the shellfish sub-sector. (Aquaculture education is discussed in more detail later in the paragraph “Applied research, education and training.”)
Shellfish. All oyster farms apply bottom culture and are located in the Eastern Scheldt (1 550 ha of plots) and the salt Grevelingen Lake (500 ha of plots). Both water bodies are located in the Province of Zeeland (Southwest Netherlands). In the Eastern Scheldt there are also 2 000 ha of mussel plots. Mussel growers also have 3 500 ha of plots in the shallow Wadden Sea in the northern Netherlands. Approximately seven mussel companies apply rope culture to grow mussels (Meer, M.B. van der 2006). The mussels and oysters are never fed, but feed on plankton which occurs naturally in the water. Mussel growers regularly lift the mussels on board their vessel to remove excess starfish (the most important natural enemy of mussels), after which the mussels are returned to the plot.
Finfish. Fish farms are spread over the whole country and can be found in all provinces with a slight concentration in the southern provinces. Farms with marine species common sole (Solea solea) and turbot (Scophthalmus maximus) are located in the Southwest and West of the country near the sea (source of salt water). On the majority of farms the fish are kept indoors in heated water in fibreglass, plastic or concrete basins. There are approximately five small rainbow trout farms where fish are kept outdoors in concrete basins or earthen ponds. For most of these farms a put-and-take sports fishery for trout in ponds located near the farm is the major source of income. There are approximately four farms growing the coldwater ornamental species gold fish (Carassius auratus auratus), ide (Leuciscus idus), sturgeon (Acipenser spp.) both indoors in basins and in outdoor ponds. All finfish are fed with complete high-quality commercial feeds (pellets).
Shellfish. Blue mussel (Mytilus edulis ) is economically the most important aquaculture species. Total production in 2005–2006 was 58 000 tonnes with a total farm-gate value of €55.5 million in 2005 (LEI, 2006). It is an endemic species. The fishermen gradually developed bottom culture of blue mussel after the system of renting individual plots in shallow coastal waters was introduced. Juvenile mussels are collected mainly by means of dredging natural mussel beds found in shallow coastal waters and transferred to plots. The total production figure includes juvenile and adult blue mussels imported from Ireland. Flat oyster (Ostrea edulis ) is an endemic species. It was the only oyster species cultured until the severe winter of 1962-63 severely reduced the stock. Total production in 2005 was 76 tonnes at a farm gate value of €382 000. The Pacific cupped oyster (Crassostrea gigas ) is an exotic species which was introduced for farming purposes in 1964. Contrary to predictions by biologists the species reproduces successfully in the shallow west European waters and is at present expanding its range from the southwest coastal waters into the shallow Wadden Sea in the north of the Netherlands. In 2005 total production of Pacific cupped oyster was 3 347 tonnes at a farm gate value of €3.3 million. Most oyster growing companies raise both flat oysters and Pacific cupped oysters.
Finfish and crustaceans. European eel (Anguilla anguilla ) is economically the second most imported species produced on 44 farms. Total production in 2005 was 4 800 tonnes at a farm gate value of €38.4 million (LEI, 2006). It is an endemic species that cannot yet be reproduced in hatcheries. At present eel culture is actually the ongrowing of juveniles (glass eels) caught from wild stocks. Because of the very serious decrease in the number of glass eels entering Dutch rivers since the early 1980s, the capture of glass eels in Dutch waters has been prohibited and the eel farmers depend on glass eels caught from French and British estuaries. African catfish (Clarias gariepinus) is an exotic species originally imported from Central Africa in 1975. Over the past two decades the species has by means of selection been improved and adapted for farming in very intensive systems. African catfish which escape from farms do not survive the Dutch winters. In 2004 total production was 4 000 tonnes at a total farm gate value of €4.8 million (LEI, 2006). Tilapia (Oreochromis niloticus ) is an exotic species which originates from Africa and is now grown on five indoor RAS farms in the Netherlands. Total production in 2006 was 600 tonnes at a farm gate value of €2.4 million (NeVeVi, 2006). Barramundi (Lates calcarifer ) is an exotic species at present grown on one new farm. Fingerlings are imported from an Australian hatchery. Production is in its start up phase and there are as yet no production figures. Pike-perch (Sander lucioperca) is a fish species originally from Central Europe, but it entered Dutch inland waters a century ago and is now considered endemic. Pike-perch has been reproduced in carp ponds in 1960s – 1990s and fingerlings were stocked in inland waters. The indoor culture of pike-perch in RAS systems for consumption purposes started five years ago on a pilot scale. The fingerlings are produced by one Dutch farm from brood stock originating from Dutch and Central European farms. Turbot (Psetta maxima ) and common sole (Solea solea) are endemic species grown in indoor marine farms using water recirculation systems. Most of the farms are rather new and starting up their production. Turbot fingerlings are imported from France. In 2006 total production was 100 tonnes at a value of €700 000. The production of common sole (Solea solea) is starting up and currently carried out on one farm in the Netherlands. There is a small production of Rainbow trout (Oncorhynchus mykiss ). The production of whiteleg shrimp (Penaeus vannamei ) is under development in the Netherlands.
Oyster culture. The oyster farmers are found in the southwestern part of the Netherlands (province of Zeeland). They depend on oyster spat that settles naturally on the oyster plots. The plots are prepared by cleaning them and by spreading mussel shells, which is a substrate suitable for the settlement of the oyster spat. Due to the presence of the Bonamia parasite in other waters, the flat oyster is grown exclusively in the salt Grevelingen Lake. It takes 4-5 years to grow flat oysters to market size (70-100 g). The Pacific cupped oyster, which is resistant to the Bonamia parasite, is also grown on plots in other coastal waters of southwest Netherlands. The Pacific oysters are grown from spat to market size in 3 years and fetch a lower price than the flat oysters. During the culture period the oysters are lifted two to three times on board in order to sort out those of poorer quality. At the storage and culture plots the water quality and presence of phytoplankton species that are harmful for human health are monitored frequently by Wageningen IMARES, the Institute for Marine Resources and Ecosystems Studies.
Finfish. Except for rainbow trout all freshwater finfish grown for consumption in the Netherlands are grown in-doors in heated recirculation systems (23 – 26o C). In such installations the water circulates continuously between fish basins and a filter system. The water flowing from the fish tanks passes through a filter system that removes solid and dissolved waste compounds. Then oxygen is added and the water is pumped back to the fish tanks. In recirculation systems fish are kept in high densities with efficient water and energy use and with minimum and controlled discharge of wastewater to the sewage system. Fish are fed with high-quality feed pellets. The solid waste particles (sludge) are in most cases collected on the fish farm and often applied as fertilizer on grass land or agricultural fields. The marine finfish species (turbot, sole) are also kept in recirculation systems. For many of the farmers growing African catfish, the income derived from fish culture supplements the income from other agricultural activities or other employment. Rainbow trout is an exotic species kept in outdoor ponds and basins. Fingerlings are mostly obtained from neighbouring countries and grown out in ponds and flow-through basins. Only a small part of the fingerlings is produced in the Netherlands. A part of the production (total 300 – 400 tonnes/year) is used in a put-and-take sports fishery in recreational fishing ponds which are part of the trout farm.
Crustaceans. In 2007 the first Dutch farm with whiteleg shrimp (Penaeus vannamei) began production. The shrimp are kept in a green house in which the water and air are heated using the warm cooling water from a nearby electric power plant. Post-larvae are imported. Production capacity is expected to be 30 tonnes/year.
The graph below shows total aquaculture production in Netherlands according to FAO statistics:
Shellfish. All mussels are sold by shipload at one special mussel auction which is located in Yerseke (Province of Zeeland, Southwest Netherlands). Payment per unit of weight is based on the percentage of meat, average size, the amount of debris in a load as well as several other quality parameters. Sixty – seventy percent of the mussels are exported to Belgium and France. The remainder are sold and consumed in the Netherlands. Most mussels are sold fresh in bags or in vacuum plastic packages containing 2 to 2.5 kg. A part is cooked and sold in jars. Oysters never pass through a fish auction but are sold directly to retailers, restaurants, etc. or indirectly through wholesalers. Some wholesalers also have a share in the producing companies. Oysters are a luxury product that is sold fresh. The majority of Dutch oysters are exported to Belgium and France.
Finfish. farmers sell nearly all African catfish to three or four processing companies which produce fresh or smoked fillets as well as a small quantity of value-added (ready-to-cook) products. Catfish is a species not well known by Dutch consumers and 60–70 percent of the fillets are exported to Germany, Belgium and France.
Smoked eel is a much-appreciated traditional Dutch product and nearly all the eel grown on farms is smoked and sold as whole smoked fish or as smoked fillets on the Dutch market (open markets, specialized fish shops and supermarkets). A small part of the production (especially the fish > 500 g) is sold fresh for the German and Belgian markets. The total production of eel from Dutch farms is now five times the total amount of eel caught in Dutch waters.
Tilapia is processed and sold as fillets on the Dutch and French market. Pike-perch, barramundi, turbot and sole are sold to wholesalers, restaurants and retailers and are mostly for the Dutch and Belgian market.
Aquaculture plays only a minor role in the Dutch economy as a whole. However, the culture, processing and trade of shellfish are significant contributors to employment and economic activity, especially in the southwestern part of the country (Province of Zeeland). Aquaculture is considered a viable future alternative or supplementary income generating activity for some of the farmers and some of the fishers. The latter are facing economic difficulties due to catch limitations as a result of decreasing catch quotas as well as increasing operating costs (high fuel prices). Compared with the consumption of fish from capture fisheries or with imported aquaculture products (especially Atlantic salmon, pangasius sp., tilapia and trout); Dutch aquaculture products still make up a minor part on the Dutch diet, also because most of the mussel and catfish production is exported. On the markets the products from Dutch fish farmers are relatively expensive compared to many imported products due to high investment costs (building, recirculation systems) and high operating costs (i.e. high cost of labour, land, feed, heating, and investment related to compliance to strict environmental regulations) of Dutch producers.
Aquaculture is under the responsibility of the Fisheries Directorate which is part of the Ministry of Agriculture, Nature and Food Safety. On the basis of the policy and regulations of the European Union the Directorate issues regulations, sets broad policy guidelines and stimulates innovation with subsidies. The Directorate establishes committees that identify bottlenecks in the production and generate and spread innovative solutions and ideas. For finfish culture three main issues have been (i) the development of the culture of new species; (ii) animal welfare and (iii) regulation of the use of medicines in fish farming. For the shellfish sector the need for innovations that would make the sector less dependent on (or fully independent of) the collection of juvenile mussels from the wild stocks was identified as most important in the medium term. The Dutch aquaculture sector is generally well organized. The mussel farmers and oyster growers each have their own producers’ organization. Some of the fish farmers are organized in the Netherlands Fishfarmers Association “NeVeVi.” The shellfish producers’ organizations and NeVeVi are represented in the Fish Product Board which acts as the fish sector’s main representative body with respect to national government. The Board stimulates and supports the fish sector in making its own rules and regulations within the limits and standards set by the national government and by the European Commission. NeVeVi has written a Code of Practice for fish farmers that is subscribed by its members. The Code refers to minimum and wise use of chemicals and medicines, responsible behaviour with regards you among other things fish transport, the prevention of fish diseases, and minimizing environmental pollution.
The Fisheries Act (1963, as amended) (Visserijwet ) contains the basic framework for the regulation of marine and inland fisheries. Although the act does not specifically regulate aquaculture, it allows the Minister to further regulate the farming or processing of and trade in fish for purposes of prevention or eradication of fish diseases. The Regulation on Aquaculture (1993, as amended) (Regeling Aquicultuur ), issued under the act, contains detailed requirements on the farming and processing of and trade in aquaculture animals and products. Also relevant to the sector is the Animal Health and Welfare Act (1992) (Gezondheids- en welzijnswet voor Dieren ). The Decree on the indication of animals that may be kept for production purposes (1998) (Besluit aanwijzing voor productie te houden dieren), issued under this act, lists the fish and shellfish that may be kept for production purposes in the Netherlands. Whereas shellfish is cultured in an extensive way, i.e. without addition of feed, chemicals or veterinary drugs, regulation of these issues is at present not considered a priority area in the Netherlands. Regulatory issues mainly focus on resource allocation between fisheries and nature conservation and on the quality control of shellfish.
Overall responsibility for the development and management of the fisheries sector, including aquaculture, rests with the Ministry of Agriculture, Nature and Food Quality (Landbouw, Natuur en Voedselkwaliteit or LNV). Within the Ministry of LNV, the Fisheries Directorate is responsible for policy issues and the translation of EU regulations into national legislation. The recently created Food and Consumer Product Safety Authority (Voedsel en Warenautoriteit or VWA), being an independent agency in the Ministry of LNV, is responsible for, inter alia , the inspection and supervision of aquaculture products, animal health and animal welfare. Research is carried out by a number of institutions, including the Netherlands Institute for Fisheries Investigations (Rijksinstituut voor Visserijonderzoek or RIVO ), which is part of LNV. The Fisheries Directorate, in conjunction with the industry, steers the management and research task of RIVO. In 2003, the Ministry established the Innovation Platform Aquaculture. Different parties, such as the government, science and research institutions and the sector itself, contribute to this Platform where new initiatives and improvements are discussed leading to a sustainable development of the sector.
The Dutch fishing industry is well-organized and based on a system of co-management. Fisher folk, fish and shellfish farmers, fish processors, whole-salers and retailers all have their own interest organization. Together they are united in the Fish Product Board (Produktschap Vis), which is a statutory organization responsible for promoting and managing the interests of the fisheries sector, including aquaculture. The Board is headed by an executive committee. The members of this body are not elected. Instead, they are nominated by business associations and trade unions in the fisheries sector. The chairman of the Board is appointed by the Crown. The Board’s work is co-ordinated by various committees. The Board gathers information, informs the public, gives advice to the Government, and can adopt decrees, which are binding for the entire sector, on a wide range of issues. Since the Board exercises a great deal of influence as an administrative body under public law, it is subject to close supervision, not only by the Ministry, but also by the Social and Economic Council of the Netherlands (Sociaal Economische Raad or SER). In 2001, the Board published a Policy Note on Aquaculture (Beleidsnota Viskweek ), which contains the Board’s view on the development of the Dutch aquaculture sector.
For more information on aquaculture legislation in Netherlands please click on the following link:
National Aquaculture Legislation Overview - Netherlands
According to its policy priorities the national government finances research projects. In addition, fish and shellfish producers’ organizations and private corporations also commission research, for example on spat collection devices and shellfish hatcheries. Fish feed producing companies involve private farmers in the testing of new products. The major research institutes are IMARES (Institute for Marine Resources and Ecosystems Studies) and the Aquaculture & Fisheries Department of Wageningen University. The latter offers BSc, MSc and PhD degrees in Aquaculture. Sustainability is a major issue influencing the research agenda of the University. Aquaculture is taught at one agricultural trade school (“Wellant College”, Houten, Province of Utrecht). At agricultural cllege level aquaculture is one subject on the course “Aquatic Eco-technology” at the “Hogeschool Zeeland,” and the “Christian Agrarian College” in Dronten (Verdegem et al., 2007). In addition, courses on finfish culture at trade school level are offered to students and as short courses for (future) fish farmers by the “Wellant College” in Houten. No special shellfish culture courses are offered at trade school level, but some of the fisheries trade schools do discuss this subject briefly during lessons on fisheries technology.
Environmental issues. Most coastal areas of the Netherlands are considered to be valuable natural areas (feeding areas for a great number of birds, hauling areas for marine mammals, etc.) and are also intensively visited for recreation and by tourists. Mussel seed is collected by means of a metal net scraping the bottom. The amount to be harvested is based on an annual scientific stock assessment and a quota system. The seed collection is strictly controlled and regulated; for a great part of the Wadden Sea (the major source of mussel seed) the collection is prohibited. Nevertheless, mussel seed collection is still often contested in court by environmental organizations. These organizations fear that removing part of the seeds will affect the survival of some shellfish eating bird species, and that organisms living on the sea bottom will be affected for several years after the seed collection has taken place. Growing fish in recirculation systems is environmentally friendly due to the limited amount of fresh water used per kg of fish produced. Wastewater is either treated on the farm or discharged into sewage systems and cleaned before being discharged in open waters. Sludge is often applied as fertilizer on fields or grasslands.
Shellfish culture. Lack of seed has been (and still is) the major problem in the mussel sector for over a decade. The amount of spat fall fluctuates from year to year. Large parts of the Dutch coastal waters are closed for fishermen collecting mussel seed. To protect the feed source of mussel-eating birds a minimum amount of young mussels must be left in the sea, and mussel farmers are only allowed to collect a percentage of the seeds that are available above the amount which is reserved for shellfish eating birds. Seed collection is only possible during two short periods each year. With financial support from the government the sector has embarked on the development of spat collectors for placement in coastal waters. The offshore growing of shellfish (near abandoned oilrigs and wind mills) is also being investigated. Pilot shellfish hatcheries for blue mussel and cockles (Cerastoderma edule) have been built to test whether the amount of seed collected from the wild can be increased. Mussel farmers have resorted to importing blue mussel seed from Ireland, an action that is contested by environmental groups because of the exotic (non-indigenous) organisms that are introduced in Dutch waters together with the seed. A main problem for the oyster growers is the Bonamia parasite that can destroy a complete oyster crop. Its occurrence prevents the growing of the expensive flat oyster in most coastal waters. Research on this disease is on-going. The imported Pacific cupped oyster is resistant to the parasite. However, the wild stock of Pacific cupped oyster is spreading and the large amount of spat that grows into heavy clumps of misshapen oysters poses a problem to both mussel and oyster farmers.
Finfish. The eel farmers are confronted with low numbers of fingerlings (glass eels) that arrive each year with ocean currents in the European coastal waters and river mouths. Due to the scarcity of glass eel and the high demand from Chinese buyers the price of glass eel has reached very high levels, at times approaching €1 000/kg. The European Commission has discussed measures to protect European eel because its presence in EU inland and coastal waters is considered under threat. Measures issued by national European governments to protect the eel stocks may affect the availability and price of glass eels for fish farmers in the future. Research into induced spawning of European eel is on going, including in the Netherlands (at the University of Leiden), but is not expected to lead to the mass production of fingerlings in the short term. Dutch African catfish farmers are confronted with limited local demand for their product and weak organization of this sub-sector. As a consequence there is currently no concerted effort to promote the product to Dutch consumers. Dutch farmers are testing the culture of fish species which have not been kept in the Netherlands before such as pike-perch, barramundi, sole, whiteleg shrimp and sturgeon. The Dutch climate is often said to be too cold to grow warm water species and too warm to grow cold-water species such as salmon. Most fish is grown indoors in heated water, and Dutch fish farmers have therefore relatively high investment costs (building, water recirculation systems, high cost of land) and operating costs (high cost of labour, energy for heating and continuously running pumps, charges for waste water purification). In addition to competition from capture fisheries, Dutch finfish farmers also face competition from cheaper imported cultured fish products on the domestic and international market. The economic situation and prospects of Dutch fish farmers will depend on their entrepreneurial skills, technical expertise, innovative approach, and on the consumer appreciating a home-grown, well-controlled, traceable and safe product (i.e. free of medicines and residues) of high quality that is produced in an environmentally friendly way. In 2007 the development and testing of the growth of common sole in outdoor basins and ponds in the southwestern province of “Zeeland” began with support from national and provincial government. This culture could develop into a possible alternative for some of the farmers in those areas which are faced with low profits from traditional agricultural products. Dutch consumers are becoming increasingly aware of the health benefits of increased fish consumption, and the demand for fish products in the Netherlands is growing. It is expected that the Dutch fish and shellfish farmers will also benefit from this trend.
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