Densen, W.L.T., van

Lammens, E.H.R.R.

Steinmetz, B.

Van Densen, W.L.T.

NARCIS 

Management problems with the differential allocation of fishing rights to sport and commercial fishermen in the Frisian lakes, The Netherlands

Densen, van, W.L.T.

Management problems with the differential allocation of fishing rights to sport and commercial fishermen in the Frisian lakes, The Netherlands.

Wageningen Yield 

In: W.L. T. van Densen, B. Steinmetz & RH Hughes (Eds). 1990. Management of freshwater fisheries. Proceedings of a 
symposium organized by the European Inland Fisheries Advisory Commission, Göteborg, Sweden, 31 May-3 June 1988. 
Pudoc. Wageningen, pp.365-371. 
Management problems with the differential allocation of 
fishing rights to sport and commercial fishermen in the 
Frisian lakes, The Netherlands 
B. Steinmetz \ E.H.R.R. Lammens2 & W.L.T. van Densen 3 
1
 Department of Fisheries, Ministry of Agriculture and Fisheries, The Hague, The 
Netherlands 
2
 Limnological Institute, Oosterzee, The Netherlands 
Department of Fish Culture and Fisheries, Agricultural University, Wageningen, 
The Netherlands 
Abstract 
The Frisian lakes in the north of The Netherlands, with surface areas up to 2000 ha each, cover a total area of 
16 000 ha. They are all shallow eutrophic lakes, interconnected, and having a retention time of 3-6 months. The 
fish stocks in the lakes are dominated by pikeperch (Stizostedion lucioperca), bream (Abramis brama), perch (Perca 
fluviatUis), roach (Rutilus rutilus), ruffe (Gymnocephalus cemua), smelt (Osmerus eperlanus) and eel (Anguilla 
anguiUa). Since 1977 the fishing rights for eel have been allocated to commercial fishermen while those for all 
other species are allocated to sport fishermen. The discontinuation of the gill-net fishery for pikeperch and perch 
has caused a shift in the population structure of pikeperch and bream to older individuals. Although the fish stocks 
should be managed as a unit, the administrative organization and the rules applied were not strict enough to ensure 
this. 
1. Introduction 
The growing number of anglers in The Netherlands in the 1950s and 1960s provoked 
changes in the Fishery Act, and led to the political decision in 1972, that sport fishermen 
should be accorded priority in the acquisition of fishing rights, but that at the same time 
the interests of commercial fishermen should be considered. It was decided to re-allocate 
the fishing rights over inland waters. Commercial fishermen can now acquire the fishing 
rights for eel (Anguilla anguilla), and the organizations of sport fishermen can acquire 
the fishing rights for all other freshwater fish species. The major fish species in the latter 
category (coarse fish) are bream (Abramis brama), white bream (Blicca bjoerkna), 
pikeperch (Stizostedion lucioperca), roach (Rutilus rutilus), perch (Perca fluviatUis), pike 
(Esox lucius), rudd (Scardinius erythrophthalmus) and carp (Cyprinus carpio). 
In The Netherlands the allocation of fishing rights to fishermen is a normal procedure 
and covers some 120 000 ha of inland waters. The major exception is Lake IJssel 
(180 000 ha). The most important rights acquired by individuals or organization are: 
. To fish, within the restrictions of the National Fishery Act (closed seasons, minimum 
sizes etc.). 
365 
Steinmetz, B., Lammens, E.H.R.R & Densen, W.L.T. van 
. To stock, within the prescription of the National Fishery Act. 
Co-ordination of management has been stimulated by way of governmental extension to 
fishery managers. In some state-owned waters the organization that rents the fishing right 
is obliged to set up a management committee with representatives of both sport and 
commercial fishermen who become responsible for a management plan that must be 
approved by the State. The implementation of the re-allocation of fishing rights has been 
stimulated by the Ministry of Agriculture and Fisheries by means of a financial compen-
sation to those commercial fishermen who have voluntarily discontinued their fishery for 
coarse fish. In Friesland, a province in the north of The Netherlands, with 16 000 ha of 
inland waters, the Frisian Organization of Commercial Fishermen and the Frisian 
Association of Angling Clubs agreed on the re-allocation of fishing rights in 1975. This 
agreement was reached in 1977. The Ministry contributed 2 300 000 Dfl and the Frisian 
Association of Angling Clubs 700 000 Dfl. The main points of the agreement are: 
• The installation of a management advisory committee which is to co-ordinate the 
management of eel and coarse fish, and which would draft a management plan. 
. The contracting parties agree to take no management measures which may harm the 
interest of the other party. 
• The parties are obliged to manage the fish stock according to the views of the 
management advisory committee. 
. In case of serious disputes an independent committee with representatives oftheState 
as the owner of the fishing rights, the Province of Friesland and the Association of 
Dutch Municipalities must be instituted. The judgements of this committee are to be 
absolute. 
In 1977 the Ministry of Agriculture and Fisheries started annual trawl surveys to gain 
insight into the dynamics of the fish stocks in the lakes, and to provide the management 
advisory committee with information on the stocks. Until 1977, coarse fish were exploited 
by commercial fishermen with gill-nets (101 mm stretched mesh) and seines (Goldspink 
& Banks 1975), and there was an intensive fishery for the two valuable species, perch 
and pikeperch, which today, are also sought by anglers. It was anticipated that the sudden 
end to commercial exploitation would lead to an increase in the density of pikeperch and 
perch stocks, but how the stocks would develop in the long-term could not be foreseen, 
nor the degree of stability that would be reached. 
This contribution discusses critically, the fisheries management of the Frisian Lakes 
since 1977. A stricter organization of the management process than that hitherto em-
ployed, with an adequate supply of fisheries-dependent research data, is suggested. 
2. Management objectives and measures 
Until 1988 the management advisory committee did not succeed in drafting a manage-
ment plan with management objectives. From the beginning the discussions were frus-
trated by the strongly conflicting views of the commercial and sport fishermen regarding 
the future management of the fisheries. The commercial fishermen stated that the (now) 
increasing stock of bream had detrimental effects on the fyke net catches of eel, both 
directly and indirectly. Directly, because of too large a by-catch of low-valued bream in 
the fyke nets set to catch eel. Indirectly, because of the competition for benthic food 
organisms between bream and eel. Therefore the commercial fishermen advocated a 
366 
Management problems with the differential allocation of fishing rights in the Frisian lakes 
periodic removal of a large part of the bream stock by seining in winter. The sport 
fishermen strongly opposed this because they feared a gradual re-introduction of the 
commercial fishery for pikeperch and perch. The Association of Angling Clubs stated 
that their catches were satisfactory and that, if the development of the bream stock had 
an adverse effect on the catches of eel, this had to be proven by scientific research. 
Specific research into this question was carried out in 1982-1984 (see section 3). 
Figure 1. The location of the Frisian lake district. The arrows indicate the major water flow from the 
freshwater Lake IJssel through the lakes region into the Wadden Sea. 
There are no catch statistics available, neither from commercial fishermen, nor from 
sport fishermen. One reason why there are no landing statistics concerning the catches 
of the c. 40 full-time and 40 part-time commercial fishermen, is the dispersed nature of 
the fishery in Friesland. There are some 20 lakes (Figure 1) of which the largest is about 
2000 ha (ijeukemeer) and there are only 3 fishermen per lake at maximum. There is no 
central place for wholesale trading. Recording of catch-effort data would thus only be 
done on the initiative of the fishermen themselves. On the basis of an economical study 
of the Frisian fishery, in the years 1966-1970, the annual yield of eel was estimated at 
8.6 kg/ha and that of pikeperch at 7.2 kg/ha (van Densen 1983). These figures were in 
the same order of magnitude for Tjeukemeer, the only lake for which detailed catch 
367 
Steinmetz, B., Lammens, E.H.R.R. & Densen, W.L.T. van 
statistics were analysed over the period 1964-1970. Catch rates were 6.6 kg eel/ha and 
3.7-10.4 kg pikeperch/ha (Goldspink & Banks 1975). 
Sport fishing is popular among the inhabitants of the province of Friesland. The number 
of licenses issued per unit number of inhabitants is roughly twice as high in Friesland as 
the national average (van Densen 1983). Some 50 000 licences were issued in the 
province in 1986, of which 24 000 were issued to people in angling clubs. About 40% of 
the people angling in Friesland come from elsewhere (de Groot & van Haasteren 1979). 
In The Netherlands, anglers fish some 25 times a year. The conservative estimate of 
angling pressure in Friesland is 1300 000/rod days/yr (80 rod days/ha/yr). 
In addition to national regulations, the management measures taken by the commercial 
fishermen in Friesland are: 
• Stocking of glass eel and young eel. 
• Limitation of fishing effort to prevent the over-exploitation of the eel stocks. 
Their effort is limited by the maximum number of 50-60 fyke nets/fisherman allowed. 
These have to be littoral fyke nets of 150-300 meshes, set at fixed sites. Summer, open 
water, fyke nets, longlines and eel boxes, as used in Lake IJssel (van Densen et al. 1990) 
are forbidden. 
The Association of Angling Clubs in Friesland has changed the minimum allowable 
size of pike to 50 cm (national 45 cm) and has set catch limits of 10 pikeperch/day and 1 
pike/day. The catch limit has been set to prevent, among other things, the sale of valuable 
pikeperch to fish traders. 
3. Research 
Catch-effort data are lacking. Since the discontinuation of the gill-net fishery, in 1977, 
a monitoring programme for fish other than eel has been performed by the Fisheries 
Department. Every autumn about five 10 minute trawl hauls per lake are taken in 7 
selected lakes. The total weight and the LF-distributions per species are recorded. By 
comparing these catches with the more frequent and detailed sampling carried out in the 
Frisian lakes (especially Tjeukemeer) by the Dutch Limnological Institute, the value of 
the annual monitoring programme can be established (van Densen & Klein Breteler 
1985). The mean length of 0-group fish can be recorded unbiased. However, the estimate 
of their relative abundance (numbers/10 minute trawl haul) is influenced by the changing 
patterns of distribution of the younger age groups at the end of the summer, especially 
those of young bream and roach. For this reason the monitoring programme must not 
be executed later than in September. 
On the basis of the research by the Limnological Institute (Ministry of Education) into 
the dynamics offish populations and food organisms, future monitoring programmes can 
be considerably improved by investing marginal extra time. The condition of the fish is 
easily recorded and proves to be a sensitive indicator f or the well-being of the populations 
of pikeperch and bream (Lammens 1982, van Densen & Vijverberg 1982). The impact 
of planktivorous fish on the large Daphnia hyalina was so great that the mean size of D. 
hyalina could be used as an indicator of the biomass of 0-group fish, and of the availability 
of the zooplankton for the facultatively planktivorous older bream (Lammens 1982, 
Vijverberg & van Densen 1984, van Densen 1985). The zooplankton, and certainly the 
abundance and mean size of the key organism D. hyalina, is easily monitored. A lumped 
368 
Management problems with the differential allocation of fishing rights in the Frisian lakes 
zooplankton sample (0.125 mm gauze) for the whole of the lake gives a reliable average 
picture of zooplankton density and composition (de Nie, Bromley & Vijverberg 1978, de 
Nie & Vijverberg 1985). Wind induced water circulation in the shallow lake prevents the 
clumping of the zooplankton. The analysis of the lumped sample will take about 4 hours 
per lake, including data processing. 
The major food organisms for fish in the Frisian lakes are zooplankton and chirono-
mids. Sampling of chironomids is most time-consuming. Because of their heterogeneous 
spatial distribution at least 15-20 samples have to be taken over several transects in each 
lake (Beattie 1982). The samples have to be separated from the bottom sediments (peat, 
sand, clay) by laborious sieving. The incorporation of this type of observations into a 
monitoring programme must be done selectively. 
Specific research was done by the Fisheries Department and The Netherlands Institute 
for Fishery Investigations to study the effect of a cropping programme for bream in part 
(3000 ha) of the lake district during 3 consecutive winters (1981/1982 - 1983/1984). 
Parameters recorded were the condition of the bream, the fat content of the eels and the 
abundance of the zoobenthos. Because all lakes are interconnected 10 000 bream and 
570 pikeperch were tagged to study their migrations in the area concerned. The cropping 
by winter seining was done by the commercial fishermen. Only 50% of the target for 
cropping (100 kg/ha/year) was realized. The evaluation of this large-scale research 
programme has not yet been completed, but it can already be concluded that this type 
of research would have been better started on a much smaller scale. 
The Limnological Institute was able to follow the development of the fish stocks in 
Tjeukemeer after the re-allocation of the fishing rights in 1977. There was a shift in the 
bream and pikeperch populations to the larger size classes which were formerly caught 
by the intensive gill-net fishery of the commercial fishermen (Lammens 1986, Lammens 
1987, Goldspink & Banks 1975). An indirect effect of the re-allocation was the decrease 
of the roach and the perch populations, which almost disappeared from the open water 
area as a result of the increased prédation pressure by large pikeperch. The latter can 
prey upon almost all length classes of these species. Within the zooplankton, only the 
large Daphnia hyalina showed a significant increase after 1977 and made the growth of 
the bream population possible. Only in years with very successful recruitment of smelt 
(Osmerus eperlanus) and perch, did Daphnia hyalina stocks collapse and cause deterior-
ation in the condition of bream (van Densen & Vijverberg 1982, Lammens, de Nie, 
Vijverberg & van Densen 1985). 
4. Conclusions 
The re-allocation of fishing rights in the Frisian lakes in 1977 brought about a situation 
in the management of the fish stocks which was difficult to handle. The administrative 
organization was not strict enough, nor were the rules obligatory. Therefore the manage-
ment of the eel stocks and the stocks of other freshwater fish as a total unit could not be 
ensured. The latter aspect is necessary because of the strong interaction between both 
categories of fish (Lammens et al. 1985). 
Other constraints on the management of the fish stocks result from the physical 
character of the lake district. There are many small lakes, which form a typical Dutch 
polder (reservoir) system, together with the surrounding pasture land. All lakes are 
369 
Steinmetz, B., Lammens, E.H.R.R. & Densen, W.L.T. van 
interconnected, water has a short retention time (3-6 months) and the system as a whole 
is open to the immigration of large numbers of larval and juvenile fish from the nearby 
Lake IJssel (van Densen & Vijverberg 1982). 
The dispersed character of the lakes hampers the introduction of an official system for 
recording commercial eel catches. This is even more difficult for the catches of sport 
fishermen. They fish chiefly for recreational purposes and put the major part of their 
catch (bream, roach) back into the lake. There is a specific group of anglers, both from 
Friesland and from elsewhere, who fish more selectively for pikeperch for consumption. 
Poachers are expected to take a considerable part of the pikeperch stock. 
The openness of the lake district for immigrating larvae and juveniles causes fast and 
unpredictable shifts in the ratio of predator to prey species. These strong variations have 
been superimposed on the main trend since 1977, Le. the ageing of the populations of 
pikeperch and bream. It is difficult for the fisheries managers to distinguish both dynamic 
aspects. 
The monitoring programme can be up-graded by investing just a little extra time. 
However, the set-up of a catch and effort registration system for both commercial and 
sport fishermen seems even more urgent. Such a system has not been imposed by the 
government and, preferably, it should be developed on a voluntary basis. The efforts of 
fisheries administrators and extension officers must be directed to the development of 
such a system, before intensive specific research is done. The combination of catch 
statistics and an efficient and up-graded monitoring programme is a pre-requisite for the 
future management of the fisheries, including the essential evaluation of management 
objectives which has still to be formulated. 
References 
Beattie, D.M., 1982. Distribution and production of the larval chironomids populations in 
Tjeukemeer. Hydrobiologia. 95:287-306. 
Densen, W.L.T. van, 1983. Fish ecological studies in Tjeukemeer and fishery management. 
Hydrobiol. Bull. 17:59-65. 
Densen, W.L.T. van, 1985. Feeding behaviour of major 0+ fish species in a shallow, eutrophic 
lake (Tjeukemeer, The Netherlands). Z. f. angew. Ichthyol. 1:49-70. 
Densen, W.L.T. van, 1990. Structure for the decision-making process in inland fisheries manage-
ment. In: Densen, W.L.T. van, Steinmetz, B. & Hughes, R.H. (Eds). Management of fresh-
water fisheries, Pudoc, Wageningen, The Netherlands, pp. 301-312. 
Densen, W.L.T. van & Klein Breteler, P.H.M., 1985. De stand aan 0+ vis in het Friese 
merengebied. Visserij. 38:306-313. 
Densen, W.L.T. van & Vijverberg, J., 1982. The relations between 0+ fish density, zooplankton 
size and the vulnerability of pikeperch, Stizostedion lucioperca, to angling in the Frisian lakes. 
Hydrobiologia. 95:321-336. 
Goldspink, CR. & Banks, J.W., 1975. A description of the Tjeukemeer fishery together with a 
note upon the yield statistics between 1964 and 1970. J. Fish Biol. 7:687-708. 
Groot A.T. de & Haasteren, L.M. van, 1979. Samenvatting provinciale informatienota's sportvis-
serij. Direktie van de Visserijen. Ministerie van Landbouw en Visserij. Den Haag. 40 pp. 
Lammens, E.H.R.R., 1986. Interactions between fishes and the structure of fish communities in 
Dutch shallow, eutrophic lakes. PhD thesis. Agricultural University Wageningen. 100 pp. 
370 
Management problems with the differential allocation of fishing rights in the Frisian lakes 
Lammens, E.H.R.R., 1987. The change in the fish stock in Tjeukemeer after the re-allocation of 
fishing rights in 1977. Onze Zoetwatervisserij 1987.3: A1-A7. (in Dutch). 
Lammens, E.H.R.R., Nie, H.W. de, Vijverberg, J. & Densen, W.L.T. van, 1985. Resource 
partitioning and niche shifts of bream {Abramis brama) and eel (Anguitta anguilla) mediated 
by prédation of smelt (Osmerus eperlanus) on Daphnia hyalina. Can. J. Fish. Aquat. Sei. 42: 
1342-1351. 
Nie, H.W. de, Bromley, HJ. & Vijverberg, J., 1978. Distribution patterns of zooplankton in 
Tjeukemeer, The Netherlands. J. Plankt. Res. 2:317-334. 
Nie, H.W. de & Vijverberg, J., 1985. The accuracy of population density estimates of copepods 
and cladocerans, using data from Tjeukemeer (The Netherlands) as an example. Hydrobiol-
ogia. 124:3-11. 
Vijverberg, J. & Densen, W.L.T. van, 1984. The role of the fish in the foodweb of Tjeukemeer. 
Verh. Int. Ver. Limnol. 22:891-896. 
371 


Management problems with the differential allocation of fishing rights to sport and commercial fishermen in the Frisian lakes, The Netherlands.

Abstract

Similar works

Full text

Available Versions

NARCIS

NARCIS

Wageningen Yield