Sustainable Freshwater Fishery in PondsReport

Tímea Kovács, Frank Duursma, Friso Ockhuizen

2nd of July 2014, Leeuwarden

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TABLE OF CONTENTS

I. INTRODUCTION....................................................................................................................3

II. TECHNOLOGY.......................................................................................................................4

II.1. Definitions............................................................................................................................4

II.2. Examples for extensive/sustainable fishing practices in Europe..............................................5

II.2.1. The Dombes, France.................................................................................................................5

II.2.2. Hungary....................................................................................................................................7

II.3. Pond design..............................................................................................................................9

II.3. Pond operation.........................................................................................................................9

III. ECOLOGY...........................................................................................................................11

III.1. Probably the best fish Species for sustainable fish farming.....................................................11

III.2. Countries of interest...............................................................................................................11

III.2.1. The Biharugra Fishponds Hungary.........................................................................................11

III.2.2. Ciocanesti fishponds Romenia...............................................................................................13

III.2.3. Dombes region, France..........................................................................................................15

III.3. Ecosystem services...................................................................................................................16

III.4. PES............................................................................................................................................16

III.5. Duck weed................................................................................................................................18

IV. ECONOMY..........................................................................................................................21

V. ENVIRONMENT..................................................................................................................24

V.1. Water fluctuation......................................................................................................................24

V.2. Water temperature and seasonal variation..............................................................................25

V.3. Soil composition........................................................................................................................26

VI. DISCUSSION.......................................................................................................................28

VII. CONCLUSION.....................................................................................................................29

VIII. REFERENCES.......................................................................................................................30

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I. INTRODUCTION

There are several polders in the province of Friesland. These areas are generated by landscape management. Dikes were built and water-flow is forced into artificial canals. Nowadays water is pumped out of the area in order to have more land for agriculture. These measurements had remarkable changes in soil composition, groundwater-level and in biodiversity. The present state of land use is not sustainable in these areas, since the agricultural production is not anymore adapts to the natural cycles but it is maintained artificially.

Alternative ways have to be found to provide proteins for the increasing human population, since the depletion of salt-and fresh water fish and decreasing biodiversity. Sea level rise at certain areas of Friesland (Feanwalden Butefjild gebied) would result more wetlands which can prevent the further lowering of the land what happened in the last decades. These changes incorporate that this area would be not useful for the same kind of agriculture as it is practiced recently. This offers an opportunity to look at the possibilities of alternative ways of food production and find additional sources of income for the farmers.

Farming of fresh water fish is very common in other countries. Could this be an alternative solution – at least locally –when it could be set up in a sustainable way? In this report we answer this question by looking at the technical, ecological, economical and environmental aspects of fish production in ponds. There are many ways of fish breeding techniques – we are focusing on the extensive sustainable fish breeding systems.

Better Wetter is an initiative which promotes sustainable use of the land. Our report is related to this project, since our goal is to find a sustainable solution how to change the present state of agricultural land toward a more natural system in a feasible way. We describe fish pond systems in European countries and investigate the possibility to use these systems in Friesland.

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II. TECHNOLOGY

II.1. DefinitionsSome phrases are often used in this report – these are defined as follows:

Ponds:

We are talking about floodplain areas whose are closer in terms of the definition to ponds. A lake as a water body in which wind-induced turbulence is mixing the water column, whereas in a pond a more gentle temperature-induced mixing is the rule (Brönmark and Hansson2005).

Extensive fish farming:

Extensive fish farming is defined (Horvath 2002) as a fish breeding technique where stocking density is generally low, there is hardly any or even no supplementary feeding and natural production results in some several hundred kg/ha/year. A simple form of it is illustrated in Figure 1 where the fingerlings are stocked into the pond and harvested after the growing season.

Figure 1: Extensive fish farming cycle with fingerlings stocking.

Sustainable fish farming:

A conventional idea of a sustainable fish harvesting when the fish population does not decline over time because of fishing practices. The fish population’s dynamics is taken into consideration to avoid overfishing. Some practices to reach this goal are: individual fishing quotas, prevent illegal fishing, setting up protected areas, educating stakeholders and the wider public.

Overfishing results a loss of significant potential yield – stock structure erodes to the point where it loses its diversity and resilience to the environmental fluctuations. Changes will also occur in the trophic balance: populations of species which are fed on fish will decline e.g. migratory and water

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birds. The opposite of this situation is sustainable fishing when biodiversity is enhanced – both of fishes and birds and another species.

II.2. Examples for extensive/sustainable fishing practices in Europe

In this report we are focusing on Europe since the characteristic of species and the environmental conditions are similar in the continent.

II.2.1. The Dombes, France

All information in chapter II.2.1. comes from Wezel 2013 (including the figures). The Dombes region is characterized by about 1100 shallow ponds with about 12,000 ha, located in an agricultural area with pastures, cropped fields and forests. Pond size varies from less than 1 ha up to more than 100 ha.

History of the ponds:

These landscapes have been created during the Middle Ages and are presently still used with different intensity for the production of fish. The farmers needed to drain the dominating clayey soils to be able to crop cereals. Because it was difficult to evacuate the water to smaller rivers or creeks, they stocked the drainage water in the lowest area of the depression, or in most cases they constructed dykes in preferred areas.

Pond management:

Extensive fish farming and grain farming are alternate on the same unit of land. Ponds are emptied every year for fish harvesting, and then refilled. After 3–4 years, the ponds are left to dry up to be cultivated mainly with oats, maize or sorghum for 1 year.

The water that fills the ponds during the wet phase comes either from a pond situated at a higher elevation or from a system of ditches which collect rainwater from the catchment. A dense network of parallel or slightly diverging ditches is responsible for filling, but also for emptying the ponds during the dry phase. Thus, a high degree of connectivity among most ponds is found.

Yields:

Table 1 sums up the potential yields by using different fishing practices.

Fishing practice Yield (kg/ha) FeedExtensive 100-1000 -

Semi-intensive 1000-2000 neededIntensive 2000-6000 needed

Table 1: Fish yields with different management of ponds.

In aquaculture, management practices such as supplementary feeding or fertilisation of water are considered to improve fish yield in water bodies. The use of fertilisation or manuring raises the

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natural productivity of phytoplankton, the use of fish polyculture improves the exploitation of the different trophic levels of the food web.

When very high nutrient status in ponds are reached, and want to be reduced, the most promising practice seems the application of the traditional practices of an emptying year with cropping, each third to fifth year.

There are annual and non-annual pond management practices: Annual = supplementary feeding, fertilization of pond water with manure. Non-annual = fertilization of pond ground during a year when a pond is emptied, liming of

pond ground during a year when a pond is emptied.

In the case of the Dombes, annual practices are managed by the fish farmer and the non-annual ones generally by a different person, a farmer who uses the pond ground for cropping, which demands a certain cooperation and communication. Fish yield by this practices are indicated in Table 2.

Table 2: The effect of annual and non-annual management on fish yield

Figure 2 shows the gross yield of 51 ponds in relation to annual pond management practices (supplementary feeding, fertilization).

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Figure 2: Average gross fish yield by use of different annual management practices (vertical lines indicate the standard deviation, the horizontal line shows the mean fish yield)

To compare properly this information we have to know the nutrient content of the water with and without applying fertilization and feeding. Significant effect of pond management practices on water parameters was only found for available NO3

—N – it was higher when fertilization or supplementary feeding was applied but the article doesn’t give an exact value for it, however the following is mentioned:

“In water, total phosphorous and chlorophyll-a concentrations were very high (median value 29–609mg m−3 and 3–474 g m−3, respectively), characterizing almost all ponds as hyper-eutrophic according to the OECD trophic status characterization developed for lakes and rivers…. Total nitrogen concentration (median annual value 1.3–6.7 g m−3) was significantly correlated with total phosphorus and chlorophyll-a (r = 0.76 and r = 0.77, respectively). Concentrations of nitrate (NO3

−–N), ammonium (NH4+–N) and phosphate

(PO43−–P) indicated large variations between the ponds.”

II.2.2. Hungary

History of the floodplain area fishery:

The traditional Hungarian fishery practice took the advantages of the floodplain areas of the two biggest rivers in the country: the Danube/Duna and Tisza. It was unpredictable that at which area the natural point bars will overflow and flood the surrounding land. Narrow canals were dig out to control this process and defined areas let to be flooded (see Picture 1). The openings of the canals were at the lowest point of the floodplain area: the water lever was rising constantly during the flood (see Picture 2), and after that it was flowing back (partially) to the river bed. These floodplain areas didn’t become marshes, since the flooding periods were last only for some weeks. The soil was fertilized during flood – the forests, orchard and pasturelands were rejuvenated and provided a breeding spot for fish (elotisza.hu). The backwaters were functioning also as fishponds – but constant ones.

The people were not living out from the fields but from animal husbandry, pasturelands, orchards and fishing – all of these connected to the floodplain areas. The materials for handicraft and house building came also from this area: reed, sedge, withy, clay and pise/adobe.

It demanded an attentive work to maintain this system and to adapt to the constantly changing natural conditions.

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Picture 1: The controlled floodplain areas with the use of canals (tankonyvtar.hu)

Picture 2: Filling up the floodplain from the lowest point – water level before and during flooding (own illustration)

This sustainable system was maintained until the 19 th century when these rivers were regulated to avoid the yearly floods. This meant that the field which were used for extensive animal husbandry and fishing, become useable for agriculture. As a consequence the biodiversity, soil composition and the culture/tradition was changed. Nowadays the remaining of the natural system of the river can be found in nature conservation areas, however the traditional fishing is not practiced anymore.

Fishing technique:

The fish doesn’t breed in the fast flowing river bed but in the warmer shallow still water. The floodplain areas were functioning during the flood as ponds where the fish could breed. When the flooding period was over they migrate back to the river. The fishermen were taking advantages of their habit: fishing tools and traps were placed to catch fish when their migrated back to the river. The target was the big fish – the smaller one was flow back to the river to ensure the population’s growth.

Picture 3 shows a barrier which was placed at the opening of the canals. By using these obstacles, the fish-migration’s way was controlled: only a small gap left open where the fishermen could easily catch the fish. Picture 4 illustrates a trap: the fish can go inside this trap but can’t find the way out. This tool was also suitable to store the fish inside the ponds/rivers.

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Picture 3: Barrier at the opening of the canal (elotisza.hu) Picture 4: Trap to catch and store fish in the canal (elotisza.hu)

II.3. Pond design

During the planning/construction work of the fish ponds the overall goal is to develop a system that is capable of filling and draining using the natural gravitational forces of moving water. When the design is planned, it is taken into consideration what will be the function of the pond: fingerlings, marketable fish production etc.

Usually fish ponds apply a minimum water depth of 1m – and 1,5m is considered to be ideal.

The slope of a pond is always less than 1% and usually closer to 0.1%, especially when the pond size is getting larger.

Proper soil compaction and sufficient clay content are very important to maintaining the slope of the dike during the actual operations in the years ahead.

The inlet and outlet structures are sometimes referred to as monks – these control the amount of water coming in and going out of the pond (fishfarming.com).

II.3. Pond operation

Full operation – part operation:

A full operation farm produces all fish age groups from fry, fingerlings to marketable size fish.A part operation farm confines its operation to certain phases of production cycle only (Horvath 2002).

Phases of full operation production:

1. Hatchery propagation: starts with the procurement of eggs – ends with “feeding fry”.2. Early fry rearing: starts with the stocking of feeding fry – ends with 1-month-old “advanced-

fry”.3. Fingerlings rearing: starts with the stocking of 1-month-old fish – ends with the harvesting of

fingerlings.4. Ongrowing (fattening) period: from the stocking of fingerlings until the end of the second

season.5. Production of marketable size fish: from the stocking of 2-summer-old fish until the end of the

third season (except in the case of a two-year growing cycle).

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In the case of Friesland it has to be decided if the polders will be utilized as natural floodplain areas/wetlands or will function as fish ponds. Both systems can be described as extensive fish breeding, while the floodplain area/wetland fishery could be described rather “sustainable” than the fish pond system since it require less energy input &management and adapts to the seasonal water level variations and do not “fight” against it. The floodplain area version provides fish yield, enhance the biodiversity (plants, water birds etc.) and improve the soil fertility in a natural way. The fields which would apply this traditional technique can be utilized for extensive agriculture or nature conservation/recreation area with the benefit of providing fish as well.

Before choosing a technique it has to be investigated which one is geographically suitable for the Feanwalden Butefjild area (see Picture 5-6):

Ponds: excess water is stored in the landscape depressions Floodplain/wetland: excess water is coming from the lowest point and filling up the area

from below to the “top”

Picture 5: Ponds are filled up from “above” (own

illustration)

Picture 6: Floodplain area is filled up from “below” (own illustration)

Water quality requirements also have to be taken into consideration. It is regulated in EU by the Water Framework Directive (WFD). It describes the required quality of surface waters as lakes and rivers. For the fish ponds there is no WFD regulation. It is important when during the fish breeding fertilization or feeding is applied: since the WFD regulations is not possible to apply such a technique in open surface water bodies only in closed fish ponds.

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III. ECOLOGY

III.1. Probably the best fish Species for sustainable fish farming

The fish species that came forward the most from the papers read about extensive and intensive fish farming was the grass carp (Ctenopharyngodon idella).This fish was introduced in 1973 in the Netherlands for weed control. In China the carp is already been bred for food for centuries. The grass carp can grow up to be 1.6 meters long and weigh up to be 37 kilo's in weight. (Conover, G., R. Simmonds, and M. Whalen, 2007). It lives mostly in lakes, ponds and backwaters of rivers and canals. It prefers large scale and standing water bodies in which he feeds on the vegetation. Not only does it grow quickly but has a low requirement for dietary protein. By feeding them with aquatic weeds, terrestrial grasses and by-products from grain processing and vegetable oil extraction there can be a low cost for feeding. (Beto Borges, 2006)

FROM: http://www.fao.org/fishery/culturedspecies/Ctenopharyngodon_idella/en

III.2. Countries of interest

III.2.1. The Biharugra Fishponds Hungary

This area of the Biharugra consists of 16,000 ha of which 2,000 hectares are used as fishpond and are one of the most valuable bird habitats in Hungary. The area is situated between Körösnagyharsány and Mezõgyán in the eastern part of the country and comprise a low-lying flood-plain and a large system of fish-ponds and is surrounded by extensive saline grasslands and arable fields. The Fishponds are regarded as important wetland habitats in Hungary as they support significant proportions of threatened breeding water birds and large concentrations of migratory waterfowl. Therefore the area and the ponds are managed for conservation.

There is a conflict between conservation and fish-farming in Central and Eastern Europe already for a very long time which has led to cost increase and shift in markets. These economic pressures forced the fish-farmers to look for alternative uses of their fishponds. Many of these alternatives that replace the old way of fish farming do not support biodiversity and can be less supportive of biodiversity values.

By applying practical, nature-friendly solutions for the local fish farming industry at Biharugra in association with Birdlife Hungary, the Bihar Public Foundation and Agropoint Ltd – with WOW support - created a viable way for fishpond management that promotes cooperation between the

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private sector and conservationists. Management like cutting reed, mowing grass after the breeding season and the constructionof breeding platforms to attract birds which attracts tourists. This showed that the fish farming industry can profit from adopting nature-friendly management techniques. This has not only benefited wildlife conservation, but also opened the doors for eco-tourism opportunities, which in turn serves the interests of the local community around Biharugra. For the breeding terns and gulls two breeding platform were made in 2009. 140 Common Terns laid eggs on these platforms. A new record for the gathering of the Ferruginous Duck reached more than 3300 individuals during autumn. This is a new regional record. Breeding numbers show a slight increase over the last years.

Knowledge can be enhanced during the implementation of some activities of the conservation practices. Knowledge and competencies can be enhanced in these projects. Knowledge in subjects such as fishpond management and artificial breeding islands - personal contacts – during the project, management team building, but also other persons from different stakeholders could strengthen their relations or meet with new persons. These contacts can prove very useful in the future in conservation work.

Picture 7: Migrating Birds (theguardian.com)

One of the biggest assets ecology wise are the great variety of bird communities prospering in the conservation areas with nature-friendly management techniques . The area supports over 100,000 waterbirds, including 9 species in the Bird species of principal importance under the AEWA agreement which are listed below.

AEWA species list made for the Convention on the Conservation of Migratory Species of Wild Animals breeding/migrating:

(Ixobrychus minutus minutus,) The little bittern

( Platalea leucorodia leucorodia) Erasian spoon bil

(Anser erythropus ) Lesser white fronted goose

(Anser anser anser, ) Grey leg geese

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(Anas platyrhynchos platyrhynchos,) Wil duck

(Aythya nyroca, ) ferruginous duck,

(Limosa limosa limosa,) The black-tailed godwit

(Phalacrocorax pygmaeus,) Pygmy cormorant

Globally threatened waterbird species occur regularly.

(Phalacrocorax pygmeus,) Pygmy cormorant

(Anser erythropus, ) Lesser white fronted goose

(Branta ruficollis ) Red-breasted Goose

(Aythya nyroca) Ferruginous duck

Picture 8: Ferruginous duck (sundancevillas.co.uk)

There is an increase in numbers of Common Terns from 40-100 to possibly as many as 200 pairs by the 3rd year of the project. Ferruginous Ducks appear as a breeding species on the ponds and their number will reach 15 pairs.

“The Biharugra Fishponds are a positive way showing how the private sector can thrive in partnership with nature conservation. Sustainable fish farming practices are becoming more accepted by fishpond farmers throughout Hungary and hopefully will spread even further across the industry.” - Simay Gábor, Project Manager. (Wings Over Wetlands.org)

III.2.2. Ciocanesti fishponds Romenia

The fish ponds of Ciocanesti cover is a Natura 2000 and potential Ramsar site ( Ramsar-conventie 'Convention on Wetlands of International Importance Especially as Waterfowl Habitat'). it covers an area of 255 ha. They are an important place for migration of 20.000 birds. Also are the

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fishponds a feeding place for the two endangered species Pygmy cormorant and ferruginous duck. Another asset is the carbon storage potential of these wetlands which has an estimated value of 9400 Europer year as shown in picture 8. Picture 7 gives a clear overview of Carbon sequestration (reed, soil vegetation and trees) and Carbon retention (trees) (Alberto Arroyo Schnell 8th October 2013)

Picture 9: Carbon sequestration/retention (blog.floorcoveringinstitute.com)

One of the most significant ecosystems within the Park is the flooded forests along the Danube and the inland marshes. These aquatic habitats are of great important for bird and fish species. In this way it is of high relevance to local fisheries communities that make use of this system downstream of the Danube. It also act as carbon sink, if maintained in the right way the Kyushu swamp of the size of 150 ha accumulates 600 tons of carbon per annum, which is worth 6000 EUR. The management of vegetation can be made in to a green energy source and can be seen as a another asset. It can be used as generating income for local people and also for nature conservation. In this way maintaining, and even increasing the biodiversity around the fish ponds, while at the same time continuing commercial fish production. (panda.org)

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The Danube PES project, Ciocanesti pilot

Table 3: PES For Ciocanesti (ceeweb.org)

Support for the provision of ecosystem services from these areas is currently available from national payments for extensive fish farming practices (aqua-environmental measures co-financed by the European Fisheries Fund).

III.2.3. Dombes region, France

After reading reports that were available about the Dombes region and the way of fish farming in that region. Although the way of extensive fish farming is mangent still feeding the fish takes place and in that way having a high nutrient level in the water. This does not support the way of practice described by the client of extensive and nature friendly way of fish farming wishful in Friesland. That’s why the focus on ecology was on other countries. As the way of harvesting fish and in that way the presents of its possible assets(described below and in the chapter technics) don’t support the water management whished in the Friese boezem.

In average every third year the ponds emptied completely leaving them without water the following year and 66% is limed and plowed and then turned in to a field 90% of which is then cropped for one year and of which 50% in harvested and the rest is there to attract game animals for hunting or to remain as organic fertilizer for the soil and the fish for the next year when the pond is filled with water again.( Robbin. 1999)

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III.3. Ecosystem services

Wetlands not only supply water, but they cleanse it too. When water enters a wetland, it filters out impurities before allowing the water to leave. The wetland vegetation, such as reeds, plays a large role in this filtering system as it uses its roots and stems to trap and gather sediments comprised of both chemicals and nutrients. As the importance of Ecosystems and smart water use becomes more evident the WWF helps governments, companies to raise awareness of freshwater issues and the importance of our water footprint. WWF is also piloting industry round tables and seminars on water stewardship and the way to Payment for ecosystem services. (WWF.org) The picture below gifs a clear overview of PES.

Figure 3: Ecosystem services en PES (blog.ecoagriculture.org)

III.4. PES

The way PES has its existents and is valuated is shortly described below:

Biodiversity PES: Market Drivers

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Scientific evidence of biodiversity importance in ensuring reliable access to natural resources

Concern emerging in key financial services institutions

Permitting challenges, lawsuits, and regulatory concerns emerging around biodiversity

Biodiversity PES included:

Establish biological corridors

Create and strengthen protected areas

Replant degraded areas with native species

Remove invasive alien species

Minimize need for fertilizers and pesticides

Conserve outside of project areas

Manage biodiversity to:

maintain quality agricultural products

ensure pest control, pollination, genetic resources, habitats

preserve cultural spiritual or aesthetic valued areas

Water PES: Market Drivers

Scientific evidence growing about water quantity and quality issues .Concern rises over future water availability. Regional and national political pressure to take action on water issues. Interest in new mechanisms for protecting water quality and quantity

Payments for Watershed services (quality & quantity) Paying land owners Purchasing land Nutrient trading -Nitrogen, phosphorus, sediments How? Restoring, creating, or enhancing wetlands Maintaining forest cover Reforesting Adopting ‘best’ land use management practices Why? Reduce pollution in local water supplies Filtration and regulation of water flow Controlling for floods Minimizing soil loss and sedimentation

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( Beto Borges,2006 )

III.5. Duck weed

Another asset could be duck weed. Still in a developing stage but looking ferry promising. In the Netherlands there are at least 7 different species of duckweed, belonging to 3 genera and 1 family. Lemna sp,Spirodela sp and Wolffia sp. Wolfia spearea is eaten in Thailand and other countries by people ant cattle already for centuries. Duckweed is easily crown on static waterboddys . It multiplies very quickly and shown in the quick scan in table 2 the value and energy that has to go in versus the value and energy out looks very promising. It is possible by rising nutrient levels and creating optimum conditions to increase the volume of duck weed. As it is possible for Duckweed to contain more protein cultivated on ha/yr as soy and soy being the number one protein crop in the world. In table 1 a overview of the main protein rich crops that are cultivated are shown. Farming duckweed good be very promising. It can be used for food consumption for human, cattle or fish feed. Soy is one of the most important sources of protein in the world. On average the world produces approximately 241 million tons soy/year. ( Cees Gauw 2014)

Table 4: Protein crops (CBS,2014)

Other protein rich crops that are harvested in the Netherland and there demand of acres for cultivation is shown in the picture above.

• Specific content production

– Focus in the Netherlands is protein production

– Others seem to focus more on starch

– Vitamins and colorants also seem very interesting.

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It’s possible to use duckweed for biogas/combustion In the USA a lot of energy is focused on bio-ethanol production from duckweed .With the competition with regard to food versus feed or energy It doesn’t compete for space with conventional crops. ( Cees Gauw 2014)

1760-5280 m3 biogas/ha/yr (with a harvest of 10-30 ton/ha/yr)

A substantial demand for proteins in the Netherlands.

– Approximately 1.800.000 ton soy/yr1

– For human use approximately 135.300 ton soy/yr is used1

– Together 708000 ha/yr is needed

– The prices of protein concentrates in 2011:2

– Soy flower (40%) € 0,80

– Soy-concentrare (70%) € 2,00

– Soy-isolate (>90%) € 3,00

– Potato protein (cattle feed) € 0,80

– Potato protein (food) >> € 3,00

– Soybean € 0,41

– Soy meal € 0,30

– Maize € 0,12

(Cees Gauw 2014)

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Table 5: QuickScan sustainability soy vs. duckweed(Cees Gauw,2014)

As protein is one of the head ingredients in many food products it becomes more common to see duckweed protein being used in daily used food products like Cheese, bread ,milk and more products as shown in the picture 10 below.

Picture 10: Duckweed ussed in food Products, ( Van hall 2014)

Picture 11: Open pond system for Duckweed cultivation( Cees Gauw 2014)

As duckweed is cultivated in closed and open pond systems. On the figure above in pictuere 11 a open system is shown. The possibilities of duckweed cultivated in a sustainable freshwater fish pond could be considered of one of the options.(Cees Gauw , Lecturer Agronomy, Friday 09 May)

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IV. ECONOMY

Concerning the economical feasibility it has to be defined the use and the size of the affected area.

How to use the land?

1. Using the land as natural floodplain area: The land is temporally flooded: the fish is breeding during these periods - after the breeding, fish can be harvested. During the dry periods the land is suitable for extensive animal husbandry as pasture land or as orchard.

2. Using the land as wetland:The land is permanently flooded with seasonal variations on water level.

3. Using the land to establish closed fish ponds:The land is used as fishpond or agricultural land in yearly variations. Polders are naturally occurring in Friesland, these can be utilized as fish ponds. This system requires more maintenance, regulation of fish feed and allows the use of fertilizers.

Land as natural floodplain area:

The main income source is the created natural area, which can be used for recreation, bird watching, hunting, fishing etc. An additional income is the seasonal fish yield. The farmers whose contribute are compensated by Payment for Ecosystem Services practice.

Payments for Ecosystem Services

This program includes conversion of a certain area in order to benefit from the services what it can provide. In the case if landowners use these land for e.g. agriculture they will receive a reward (subsidies or market payments) in exchange for the services what their land provides. The services are classified as Environmental goods, Regulating Services, Supporting Services and Cultural Services.

By applying this practice in Friesland the land owners whose give up their current agricultural practice will be rewarded for the services (enhanced biodiversity and watershed services) which these converted lands can provide.

An example for the floodplain area is mentioned before in chapter II.2.2. form Hungary. Another example is from the Netherlands from Arnhem where Europe’s largest city park is situated in 300ha (dutchwatersector.com). The measures are done in cooperation with Rooms for the River flood prevention program. Here, adaption to the seasonal flooding is carried out in a creative way – showing that such a landscape conversion is possible also in urban areas, creating a recreation area for the citizens.

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“The area will now be transformed in a large floodable city park including new cycle paths, various fishing spots, a bird watch facility, a hand ferry and car parks. The currently present semi-wild Konik horses and Galloway cows will remain to move free around in the new park. The present beaver colony will remain in a special preservation area.”

- from dutchwatersector.com

Wetlands:

The main income source is tourism (bird watching, hiking, water tour/canoeing etc.), PES and additionally fish yields. An example is mentioned before in the Ecology chapter (Biharugra fishponds from Hungary), another example is situated at the lower Danube in Romania which is a former floodplain area but nowadays used as nature conservation area with fish ponds (wwf.panda.org). This area benefits both from the Ecosystem Services (biodiversity conservation) and from the fish yields. The value of this area is indicated below (wwf.panda.org):

Fish production: 3200 Euro/ha Biodiversity maintenance (hunting penalties): 11 000 EuroCarbon sequestration (reed, soil vegetation and trees): 5850 Euro/yearCarbon retention (trees): 3550 Euro

Fish ponds:

The main income source is the fish production. In this case fertilizing of pond’s water is allowed, which means higher fish yields. As it is mentioned in the former chapter, in Nederland the most suitable fish for farming is the grass carp. Currently, retail prices are usually USD 0.7-1.0/kg which can be considered as a low price commodity (FAO).

In the article of Wezel 2013 the following is stated about the French fishpond-system:

“…fish production is only one economic activity among others for these fish farmers. In the present study region, some fish farmers even consider to abandon fish production as they do not see the benefits of fish farming anymore because yields are not sufficiently high or market opportunities are very variable or because of the high predation level by cormorants on fish which could reverse all the management efforts carried out by the fish farmer.”

So, based on this article we would not recommend counting on the fish yields from extensive ponds as a main income source for the farmers.

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What is the size of the land?

If we calculate the benefit/profit of the above mentioned fish breeding areas, the size of the convertible land has to be known. It is possibly also depend on how the local farmers think about the idea – if they are willing to change their recent agricultural practice. If they together willing to make a change, than we can think about to create a floodplain area/wetland. In the case when only some of the farmers are interested in the idea, it’s still possible to create small fishponds on their own land.

Feasibility?

Finally we have to mention that not only the cost and the net profit of the landscape conversation have to be taken into account, but also think about the savings which are gained when we don’t “fight” against the water at the given area: savings on the water pumping, and the cost which was spent on agriculture (fertilizers, energy cost of harvesting) are also saved. The benefit of the extensive fish breeding/agricultural lands is that they don’t require external input (=no cost on feed, fertilizers etc.) to produce yield, but they provide profit year by year.

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V. ENVIRONMENT

The aspects of technology, ecology and economy are researched by the comparing of fishponds found in the countries Hungary and Rumania. These two countries contain extensive sustainable fish breeding systems that work in a natural way, needed is to see is what the environmental aspects are and which special environmental requirements are needed to set up these fish ponds in Friesland. The definitions (Encyclo,2014) of the selected environmental aspects are:

Water fluctuation: is the variation of the water level reached by the surface of the water body

Water temperature: is the degree of hotness or coldness of a water body in a environment.

Seasonal variations: is a component of a time series which is defined as the repetitive and predictable movement around the trend line in one year or less. It is detected by measuring the quantity of interest for small time intervals, such as days, weeks, months or quarters.

Soil composition: is an important aspect of nutrient management. While soil minerals and organic matter hold and store nutrients, soil water is what readily provides nutrients for plant uptake

V.1. Water fluctuation

In chapter II.2.2 the technique of floodplains in Hungary are already explained, the report shows that this way is effective. In the ponds where the grass carp will be bred, water management is required to maintain food sources, reproduction, vegetation and water level. Picture 12 shows a water management system that is being used for fish breeding ponds(A. Kamstra en J.W. van der Heul, 1995).

Picture 12: Water transfer system for fish pond (A. Kamstra en J.W. van der Heul, 1995)

The way this system works for floodplains is: the river (rivier) will supply the fish pond (teeltbassin) with fresh water from a higher level, this water will go into the pond with a stream. With this first step the water level can be raised to a level that is needed with water from rivers that are on a higher level. With a floodgate the water level can be dropped in the fishpond to a water level that is needed

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for restoring vegetation or transporting fish eggs to a lower part. A second pond (bezinkvijver) can be implemented for biological waste, by transporting water through this pond waste can sink and used for other projects or as a nutrient. As last the water can be transported somewhere else with the lower level river, in Friesland these will lead to the sluices in Harlingen and Dokkumer Nieuwe Zijlen that end up in the Waddenzee (Ecomare). This kind of water management is used for the floodplains in Hungary.

In the area of Feanwalden Butefjild the surface water altitude is around -5 - 0 meters from the NAP (J.J. de Vries,2007). This means it has a high groundwater / surface water level. Visible in Figure 3 is that upper North the water altitude is lower from the NAP, this confirms the sluices in Harlingen and Dokkumer Nieuwe Zijlen that will lead the water at a lower level to the Waddenzee.

Figure 3: Water altitude in the Netherland accorded to the NAP (J.J. de Vries,2007).

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V.2. Water temperature and seasonal variation

The water temperature is an aspect that is linked to the seasonal variation in the Netherlands. Throughout the year the days get shorter, the temperatures drops or raises and vegetation will change, these changes will have an influence on the system. For the crass carp it is necessary to survive that the environment contains some priorities. It should need vegetations to feed on and temperatures to survive and reproduce.

The grass carp needs a temperature of 12 degrees to eat, Holland is sufficient enough for the grass carp to survive. The grasscarp is a species that reproduces itself best between temperatures of 20 and 25 degrees. (Conover, G., R. Simmonds, and M. Whalen, 2007). This means that the breeding season starts in July at a average temperature of 20 degrees visible in figure ..(Klimaatinfo). The female carps will lay their eggs at the moment when the water level rapidly declines to a lower level, these eggs will submerge to the bottom till they come out. In Table 6 the amount of sun and rain is visible as well, the change per season is clearly visible.

Table 6: Temperature, rainfall and sun hours per month in the Netherlands

The type and amount of vegetation will change by the seasons as well. The main source of food for the Grass carp is duckweed, this type of weed contains a high level of proteins explained in chapter III Duckweed. Duckweed grows all over the world in moderate and tropical temperature zones. It grows on quiet water with a temperature range between 6 and 33 degrees, this means duckweed will grow almost all year long.

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V.3. Soil composition

The soil in Feanwalden Butefjild exists out of peat (Jaime van Trikt & Hansjorg Ahrens). Peat soil exists out of multiple layers of dead plants, leafs, roots etc. and has of natural cause a high water level. This water level needs to be high otherwise the ground will sink in, this is not a problem with the fishpond because there always will be a high water level. In the peat soil there are a lot of cracks and air bubbles which contain methane gas. Peat is an acid type of soil because of the chemicals it contains. Peat contains the chemicals: Nitrogen, Sulphur, Phosphor and most important carbon. Usually plants have photosynthesis to process carbon dioxide from the atmosphere into carbon and oxygen, when plants are under the water surface it’s a different story. When plants are in the water the diffusion of carbon dioxide will be decreased by a factor of 100.000. In water the diffusion is slower than in the open air, as well as the concentration of carbon dioxide that is being less in the water, just 15 µmol CO2 per litre.( Fons Smolders en Sake van der Schaaf, 2007)

The chemicals that are mentioned above can be a source of nutrients for the vegetation that grows in and on the edge of the fishpond. Duckweed is an weed that could absorb nutrients quickly, because of this it has a function in water cleansing. (G. Holshof, I.E. Hoving, E.T.H.M. Peeters, 2009

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VI. DISCUSSION

In this report the parts of technology, ecology, economy and environment have been researched. The reason is to find if it’s possible to create extensive sustainable fish breeding systems in Feanwalden Butefjild, the information that has been found and implemented in this report shall give an overview of the possibilities. A research like this has not been done before, this report will be the foundation of information for possible future projects.

The information that is shown in this report is based on information that has been found by the research of reports and websites. A restriction for our information is, that the information we use comes from within Europe. The countries we implemented the most in this project are Hungary and Romania, the information we found about fishponds in these countries was clear and good to compare with this project. It is important that the information we used was related toextensive sustainable fish breeding systems and useable for Feanwalden Butefjild. For more specific results information is needed about the soil and water composition, there was a lack of information available to make a solid conclusion about this subject. Another error that could be improved in the future is the lack of up to date information, a lot of information is old and could use a update to be more accurate. What could be improved the next time is an extra meeting with Altenburg & Wymenga, in de second meeting there can be check if the project still goes in the good direction. At some point it wasn’t completely clear what the consultant wanted and our tutor, this could be avoided with an extra meeting halfway the project.

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VII. CONCLUSION

In the framework of Betterwetter we have been looking into the possibility of sustainability of fresh water fish farming in Friesland more specific in an area as the Veenwalden Butenfjeld. This is wanted because of soil degradation in the area. This process of soil degradation is a process already going on for decades for agricultural benefits of the land. To stop this process a higher water level in the area is wanted. The higher water level will compromise the way of agriculture used at the moment and solutions for this are needed, therefore this research. Is sustainable freshwater fish farming possible in Friesland with the focus on the Butenfjeld area. For this research we looked at possible sustainable fish farming in ponds in Europe. More specific we looked at fish harvesting techniques, Ecological assets, economy and environmental aspects of the fish pond areas. The conclusion of our research is shared with you in this chapter. As we look at the fish ponds in France you can say that the way of management techniques has not changed much over the years and consist of feeding fish for higher yield and harvesting by draining the pond. Afterword’s it is used for crop cultivation for a time and this circle is repeated. We could say that this way of fish farming is not really sustainable or wished for the Frieze Boezem because it does not enhance ecological sustainable assets. The way management techniques are used in the eastern European parts look more promising by combining fish farming with nature-friendly management techniques. This enhances bird populations and also eco-tourism. By smart use of bio mass for green energy and the use of PES for example carbon sequestration, more financial benefits are made to secure a good income for these regions. Due do this the community’s around these sustainable fish pond areas prosper to. Aspects within the environmental part were water fluctuation, temperature, seasonal variations and soil compositions have an influence on fish breeding. Conclusions one the environmental part are; the source for the wish to rise the fresh water level in the Feanwalde area is good and departure of water is also feasible with the techniques used at the moment of too much water in the area. Seasonal variation and temperature is good for Grass carp for breeding and reproduction. This is also the case for the seasonal fluctuation for the growth of duck weed. The Soil composition with multiple nutrient levels will be a good stimulation for vegetation and in that way beneficial for fish and for breading and migrating birds. The research also concluded that the benefit of finance by fish farming is low. So it is suggested to look for financial support by PES for starting up projects in the area and supporting for management of the area.

GoalHanding in a report that could be a foundation for the next step in the Better Wetter projects related to sustainable farming of fresh water fish. Now the project has come to a end we can say as a group, that we reached this goal. It is a first foundation, and there are parts that needs more specific data or information. Further all it still gives a view of how a extensive sustainable fish breeding system could look like at Veenwalden Butenfjeld compared to other countries in Europe.

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VIII. REFERENCES

Brönmark e.a. (2005): The Biology of Lakes and Ponds, p. 7.

Horvath e.a. (2002): Carp and Pond Fish Culture: Including Chinese Herbivorous Species, Pike, Tench, Zander, Wels Catfish, Goldfish, African Catfish and Sterlet, p. 12-13, 17

Wezel e.a (2013): Management effects on water quality, sediments and fish production in extensive fish ponds in the Dombes region, France, Limnologica 43. p.210–218

http://www.elotisza.hu/uploads/dokumentumtar/2-informacios-tabla-anyaga-cd-re.pdf

http://www.fishfarming.com/services/fish-farm-design-construction.html

http://www.fao.org/fishery/culturedspecies/Ctenopharyngodon_idella/en

http://www.dutchwatersector.com/news-events/news/9099-groundbreaking-ceremony-for-

europe-s-largest-floodplain-city-park-in-arnhem-the-netherlands.html

http://wwf.panda.org/what_we_do/where_we_work/black_sea_basin/danube_carpathian/

our_solutions/green_public_funds/pes/the_danube_pes_project/pilot_activities_/

ciocanesti_pilot_site/

D.C. Little and P. Edwards:I ntegrated livestock-fish farming systems, (2003) Magnus van der Meer, Agro Eco: Vis: een superbiologisch product? Conover, G., R. Simmonds, and M. Whalen :Management and control plan for bighead, black,

grass, and silver carps in the United States,(2007) (A. Kamstra en J.W. van der Heul:Afvalwater van Viskwekerijen, (1995) Simay Gábor: Description of Demonstration Project Simay Gábor: WOW Demonstration Project: Biharugra Fishponds, Hungary

http://www.tankonyvtar.hu/en/tartalom/tamop425/0027_TAL14/ch01s04.html Conover, G., R. Simmonds, and M. Whalen, 2007 Beto Borges, 2006 Wings Over Wetlands.org Alberto Arroyo Schnell 8th October 2013 WWF: Ciocanesti pilot site http://wwf.panda.org/ WWF.org http://blog.ecoagriculture.org/ http://www.fao.org/fishery/culturedspecies/Ctenopharyngodon_idella/en http://www.forest-trends.org/documents/files/doc_2720.pdf http://www.groundwatergovernance.org/fileadmin/user_upload/groundwatergovernance/

docs/Hague/Readings/Groundwater_De_Vries.pdf http://www.ecomare.nl/nl/ecomare-encyclopedie/gebieden/waddengebied/nederlands-

waddengebied/friese-wadkust/waterbeheer-in-friesland/

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http://www.geologievannederland.nl/ondergrond/bodems/veenbodem-veenlandschaphttp://edepot.wur.nl/239706

http://www.natuurkennis.nl/index.php?hoofdgroep=2&niveau=1&subgroep=19 http://www.klimaatinfo.nl/nederland/leeuwarden.htm http://edepot.wur.nl/142216 Cees Gauw 2014 Picture 7 Migrating Birds

http://www.theguardian.com/environment/2009/apr/15/migrating-birds-climate-change Picture 8 Ferruginous duck http://sundancevillas.co.uk/page.asp?page=birds Picture 9 Carbon sequestration/retention

http://blog.floorcoveringinstitute.com/2010/05/wood-floorings-role-as-sustainable.html Picture 8 PES For ciocanesti

http://www.ceeweb.org/wp-content/uploads/2013/11/CEEWEB_Academy_WWF-AAS_131008.pptx.pdf

Picture 9 Ecosystem services en PESBron,http://blog.ecoagriculture.org/ Table 4 Protein crops (CBS,2014) Table 5 QuickScan sustainanlity soy vs. duckweed(Cees Gauw,2014) Picture 10 Duckweed ussed in food Products, ( Van hall 2014) Picture 11 Open pond system for Duckweed cultivation( Cees Gauw 2014)