STATE AND ASSESSMENT OF BULGARIAN FISH RESOURCES

MRS Nina K.STAVENA

Bulgaria is deficient in water sources but the number of water ponds is sufficient for the need of fish industry. Fishing means of living are developing intensively along the Black sea coast and the Danube, and along the valleys of the bigger rivers - Maritza, lskar, Vatcha, Mesta, Struma, Vit, Kamtchia, Chaia, Tunja etc. Many hydrotechnical equipments (big, medium and small dams) designed for energy and/or hydroamelioration were built up during the latest decades. There provide good conditions for natural and artificial fish breeding and for intensive fish industrial exploitation. There is a well developed set of specialised fish-farms in which triple-selectional work is performed and the main for the country fresh water fishes of commercial importance, carp and trout are bread and cultivated.

Estimation of fish resources of the country can be made about the Black sea the dams and the specialised fish-farms and also about the Danube and home rivers.

Dynamics of fish resources and their present state should be considered depending on tendency towards permanent determination of water quality and the diminishing of the water stock in the main water basins and catchment areas.

I. STATE AND ASSESSMENT OF FISH RESOURCES ALONG THE BULGARIAN BLACK SEA COAST

The specific hydrological and hydrochemical regime of the Black Sea is characterised by clear stratification with two main layers; superficial or productive one with oxygen present down to depth of 140- 16m and lower-from the depths cited above to the bottom (maximum depth-224m) with abundant hydrogen sulphide presence making the sea lifeless. It is a typical example of land - locked basin with intensive anthropogenic influence during the last 20–25 years. Pollution of the Black Sea with phosphates, nitrates pesticides, heavy metals, oil and oil products coming from the river flow (83 mn t suspension annually) and from coastal agglomerations, is well proved. As a result of pollution the processes of euthrophication are quickly developing, the phytoplankton blooms and accumulation of organics matter on the bottom sediment and in the pelagic takes place. The negative phenomena mentioned above and the abundant ctenophore Mnemiopsis (introduced from the Northwest Atlantic by ballast ship water in the 1980s) directly and indirectly influence the state of the fish resources and their dynamics.

The volumes of commercial catches give to a great extent an idea about the dynamics of fish populations. In Bulgarian Black Sea waters their volumes changed during the period 1959–1992 between 2.900 (1990) and 19.800 (1981) t (Tabl1). Undoubtedly those figures do not reflect correlatively the fluctuations in the resources abundance as the catches are also directly dependant on the market as well as on the development of the fishing gear, resp. on the trend of development of the fishing sector. A significant effect on the Bulgarian sea fishery had the implementation of trawl gears including the volume of the catches, pelagic trawls which have increased quickly, in the early 1970s, the volume of the catches. Selling few fishing trawlers to foreign companies or decommission have had an opposite effect. In general the fleet was reduced from 20 units in 1988 to 11 units in 1992. Sprat (Sprattus sprattus) is the most abundant commercial fish. It is of boreal origin, with local migration perpendicularly to the coast and has a comparatively short life-cycle of 4–5 years. Most important are the first two age groups which usually include 90–92% of the total population abundance. As sprat spawns in the open sea in October-March eggs and larvae are less negatively influenced by Mnemiopsis which forms a very low biomass within the same period. Sprat is mainly caught by trawls almost all the year round as well as by trap nets - in April – June. Then, after the end of spawning, the species enters the coastal waters for feeding. The mean size of the sprat is 9–10cm (in length) and 5g (in weight) (Table. 2). In the last 15 years a tendency appeared towards decline in the mean length. Sprat gives to 95% of the Bulgarian Black Sea catches.

The total biomass of the sprat undergoes annual fluctuations depending on the new generations and the size of the recruitment. The biomass is assessed by trawl hydroacoustic survey and the analytical methods, mainly by virtual population analysis (VPA). As a result of instrument assessment in 1982 the sprat biomass in the West part of the Black Sea was assessed at the range of 170–200 thousand t.

Assessment along the Bnlgarian Black Sea coast was as follows (thousand t):

1984 – 24
1985 – 69
1986 – 77
1987 – 21
1988 – 74
1990 – 27

The above figures, especially those for 1984 and 1987, are being considered as underestimated.

Horse mackerel (Trachurus mediterrancus ponticus)
A Mediterranean species hibernates in the Southwest part of the Black Sea and the Bosphorus prestrait area. In spring (May) it migrates for feeding and reproduction towards the Northwest part of the Black Sea; the autumn migration towards wintering areas takes place in September – October. The life-span is appr. 10–12 years though in the catches the first four age classes dominate. The average length depends on the volume of the recruitment and the dominating generations in the age composition generally range 11–15cm. It is caught by trawls and traps nets. The Bulgarian catches range from 35t (1968) to 2200t (1974) and include only a small part of the stock. A larger part of the catches is fished by Turkey (up to 65000t) (1979) and Russia (up to 2200t in 1972). The Romanian catches reach maximum of 2.200t. The assessments for utilisation of the species come close to the values of the optimum allowable yield corresponding to the total biomass of 100–400000t. Due to the seasonal character of the fishery (May – June and September – October) and peculiarities of the spring - autumn's migration, Bulgaria utilises appr. 1–2% of that stock. During the last 5 years the catches sharply decreased because of the negative influence of Mnemiopsis mccradyyi (t):

1988 – 1677
1989 – 1101
1990 – 164
1991 – 55 (estimated)
1992 – 55 (estimated)

Anchovy (Engraulis encrasicholus)
A warm water, high abundant species, life-cycle 4–5 years and mean length -11–13cm. It hibenates along the Anatolian coast and in spring (May) migrates towards the north regions of the Black Sea. A relative small portion of the stock comes to Bulgarian coast even in years of high stock. Stock assessments are usually given separately for the two halves of the Black Sea and are determined by the values obtained form experimental fishing with pelagic trawl (thousand t):

During the last 5–6 years the anchovy stock sharply decreased and almost lost its commercial significance. The causes are the negative influence of Mnemiopsis and the overfishing from the Turkish fishery during wintering.

Turbot (Scophthalmus maeticus)
A carnivorous demersal species, comparatively long life-cycle - 12–14 years, average length 55– 58cm, average weight appr. 3–7 kg. It performs hibernating migrations perpendicular to the coast, down to 80–90m depth (November) and reproductive migrations to depth 10–40m (May). The Bulgarian annual catches in the periods given below are as follows (t):

1925–1944 - 39
1935–1954 - 110
1955–1977 - 294
1978–1980 - 93

The total biomass of the stock (VPA) ranges between 430 (1977) and 1710 (1962)t. The recruitment of the stock begins to decline if the commercial stock fall below 300t. Such decrease was registered in the late 1980s and it was the reason for the 5-years fishing moratorium which had been put into effect by Bulgaria, Russia and Romania. The first two years of the moratorium (1989–1990) indicated stock recovery, but an invasion of Turkish fishing vessels within Bulgarian waters caused heavy damages to be hardly overcome. Determinations from biomass trawl survey in January 1992 indicated commercial biomass of 100t.

Black Sea Shad (Also pontica pontica)
A bathypelagic anadromous fish, 7-years life cycle, average size 24–26cm, average weight appr. 220g. Living in the Black Sea it enters the Danube for spawning (April – May). 3–4 age groups are dominating. The Bulgarian annual catches from the Black Sea are at the range of 6–440 and are determined both by abundance fluctuations and hydrometeorological conditions in April – May. The biomass of the species ranges between 1.8–11.000t (VPA). The main share of the catches is caught by Romania and Russia in the Danube mouth. In the last 5 years the stock declined, affected by the river pollution and hydroconstructive activity.

Pontic whiting (Odontogadus merlangus euxinus)
A boreal demersal species, life-cycle 6–8 years, mean length appr. 16cm, mean weight 258–30g. It is important medium link between bottom fauna and larger predators. Partially exploited by fishery as there are no traditions in its marketing. In the last 10 years the catches reach 10–12000t caught mainly by Russia and to a certain degree by Romania. In the 1980s the assessment of the stock for the whole basin is appr. 30–35000t; 3–400t on the Bulgarian shelf.

Picked dogfish(Squalus acanthias)
Length up to 150cm, weight 3–7kg, life-cycle up to 20 years, Annually up to 25–28 little dogfish are born. The catches are taken primarily by trawl and bottom longlines. There is no basis for a real assessment of the stock though the catches in recents years increase influenced by the market demand : 3–4000t for the basin as a whole and appr. 100–200 t for the Bulgarian shelf.

Gobies(farm. Gobiidac)
The species of the family are not dominant in the catches. Annual changes of the latter are as follows:

These examples are related to substantial reduction of gobies populations in the coastal lakes. Until 1960 the catches in the Bourgas lake were at the range of 30–115t per year. Similar was the case of Varna Lake influenced by pollution and salinity increase after the second canal between the sea and the lake built up.

In the sea dominant species are Neogobius melanostomus and Mesogobuis batracnocephalus (local names strongil and lihnus) caught by commercial and recreational fishery. Aprr, 80% of the sea catches (up to 30–40 t annually) include strongil, a species having a long reproductive cycle and multiple spawning. Since 1990 a prohibition for spring fishing of gobeis (45 days during their reproductive season) has been put into force. Assessment of the stocks (21 species in Bulgarian waters) has not been made. Recently, due to eutrophication and then oxygen deficiency gobies stocks have been continuously diminishing.

Except the species described, important for the fishery are also mullets (Mugilidae), blue fish (Pomatomus saltatrix), silverside smelt (Atherina mochon pontica) and other fish of secondary importance. Bonito (Sarda sarda) and mackerel (Scomber scombrus), almost significance in the early 1970s, today are rarely caught.

The generalised data demonstrate that since 1985 sprat has been the most important species for the Bulgarian fishery: up to 95% in the commercial catches. The Bulgarian catches include also horse mackerel, Black Sea shad about 2.5–3.0%) and other species. As a basis for comparison data for the species composition in the commercial fishery during the period 1931–1971 (period of “clean sea” are given below/%/ :

The differences are considerable and illustrate substantial changes in the composition of catches caused mainly by the eutrophication of the Black Sea.

Except the national legislation, fishery is regulated by the International Commission for the Application of the Agreement for Fishery in the Black Sea where Bulgaria, Romania and the Black Sea countries of the USSR participated. Every two years the Commission holds its meeting.

There are no quota limitations but regulations for minimum allowable fish size for fishing of each commercial species, for by-catching of catch commercial species, for by-catching at non-standard length, minimum mesh size etc. For the period 1 January 1989 – 31 December 1993 a moratorium over fishing of turbot has been established. After the political changes in the East European countries, the function of the Commission has been disturbed and it reflects mostly on the exchange of fishery and scientific information. At present Bulgaria is trying to re-establish the previous relations in order that a new text of the Convention to be elaborated. Turkey has been continuously invited and is expected to join the Commission.

Bulgaria takes measures to restrict the harmful effect of certain fishing activities on the fish resources and marine ecosystems in general. For the first time in 1991 a prohibition was put into force related to the use of bottom trawls. In the previous years the latter caused irreversible damages not only to the fish stock but to the whole bottom ecocoenosis. In 1992 all types of trawl fishery were forbidden in the 3-mile costal zone along the north part of the Bulgarian coast and in the 1-mile zone south from Cape Emine. Authorities are expected to put into force other regulations for fishery, protection of fish resources and carrying out activities to compensate the decrease in fish stocks and stimulate development of mariculture. In general, the main issue for the protection and recovery of the Black Sea fishery resources remains protection of the marine environment from further pollution and taking measures to improve the ecological state of the whole watershed basin.

STATE OF MARICULTURE AS LIVING RESOURCES

Along the Bulgarian Black Sea coast mariculture is still on their premature stage of development. The Institute of Fish Resources, Varna, and the Fisheries Institute, Bourgas, elaborated and implemented (R & D) biotechnologies (2 options, with and without net sleeves) for cultivation and processing at sea and ashore of mussels (Mytilus galloprovincialis). Two mussel farms were built: by Sozopol (of JRP-25; annual production 200–300t live weight) and by Nessebar (of Black Sea Fishing Co. Ltd; annual capacity (also not reached) 300–400 t). Both farms are being exploited much less than their actual potential.

In the 1970s the Fisheries Institute, Bourgas, experimented cage cultivation of steelhead trout Salmo gairdneri and kisutch Oncorhynchus kisutch by Sozopol.

In the Experimental Station, Pomorie the Fisheries Institute carried out R ?& D for hibernating (in a green house) and fattening (in the Pomorie Lagoon; Spring-autumn) of mullet fry (1+), catching of 1-year fish in autumn (annual harvest 10–20 c, dominant species Mugil saliens and M. cephalus).

Also in the Experimental Station, Pomorie, trials were held to propagate Black Sea shrimps (Palaemon adspersus) and Black Sea flounder )Platychtys flesus). Phyto-and zooplankton were used for their nutrition.
In 1992, due to deficiency in state investments, research in Pomorie Station was ceased.

Private companies are interested in commercial mussel culture development. Mussels (Mutilus galloprovincialis) are still the main species of interest to emerging farmers. In this respect bi-and polyculture with algae or fish are also tempting for R & D. Worth attention are also the combination traditional fishing (trap nets, recreational fishing)- mussel culture as well as establishment and exploitation of artificial reefs.

Private companies are also interested to cultivate commercially salmonid species such as Salmo salar, S. gairdneri and O. kisutch. Though numerous problems such as financing, legal aspects (e.g. permission for sea concessions), environmental effects of the introduced species, risks of the introductions etc. are still under discussion and remain to be solved in practice.

Turbot (Scopththalmus maeoticus) is also of utmost interest as a potential candidate for cultivation related to its high marketing demand and damaged stocks.

In 1991 Bulgaria jointed MEDRAP II (Mediterranean Regional Aquaculture Project) (UNDP/FAO). Main activities of the project are constitution of networks for information, training, research, aquaculture and environment. The Fisheries Institute, Bourgas is the National Coordinator to MEDRAP. For the effective participation of Bulgaria in MEDRAP II a number of organizational-technical and financial problems have to be solved.

Though the promising results achieved and expanding private mariculture initiatives aqua/mariculture development in Bulgaria is primarily influenced by the general social-economic development of the country in the context of the integrated coastal activities. Mariculture ;is a means for recovery and augmentation of the fishery resources and a field for employment of the coastal population, with better utilization of the fish processing capacities available and underexploited today.

The mariculture facilities of Bulgaria established until now could be a stable, promising prerequisite for development of mariculture along the coast. The capacities and facilities of IRP-25 (exFisheries Institute) include the following:

MUSSEL CULTURE FARM, SOZOPOL

IRP-25 Co. Ltd, Bourgas, Bularia; ex Fisheries Institute)

A marine farm for suspended mussel culture (Mytilus galloprovincialis), 2 miles from the shore, in the vicinity of town Sozopol (5000 inhabitants, by an island. “Long-line” systems for 5000 collectors (5 m long). Production cycle 9–10 months. Harvesting season February – May.

Ashore - farm buildings, a quay, laboratory rooms, utility buildings, water supply, electrification, beating installations. Personnel-4 people (2 biologists). 3 exploitation boats.

Production transported to Bourgas (35 km northward) for processing (cannings and freezing; IQF). Shells used for chicken fodder.

MARICULTURE EXPERIMENTATION STATION, POMORIE

(IRP-25 Co.Ltd., Bourgas, Bulgaria; ex Fisheries Institute)

Ashore 0.6 ha working area. Canal connecting the sea and the lagoon. The lagoon - 250 ha, depth 0.8–1.2 m.
Earth ponds depth - 0.8–1.0m; 2 ha.
Open tanks: 45 pcs, 30–50 cubic m, depth 0.8–1.8 m (mountable)
Covered: nursing tanks 67 pcs, 1.5–3.0 cubic m -round and rectangular; incubating department; equipment for food; phyto-and zooplankton.
Laboratories: chemical, ichthiological, hydrobiological, ichthiopathological (not completely equipped).
Supplementary installation - water supply from the sea, lagoon and drilling. Salinity 15–30‰.
Water temperatures max 26–27 C (outdoor), min O-(-1) C (outdoor, indoor 8–10 C.
Water purification installations.
Pomorie - 30000 inhabitants, 20 km northward from Bourgas.
Bourgas - district center, 250000 inhabitants.

II. DAMS, SPECIALISED FISH FARMS AND THE DANUBE

Bulgaria as a comparatively scarce water resources area. Though regarding its territory the fresh water potential is considerable. Its cadastral area is appr. 700 mln sqm, 300 mln sq m - the area of the artificial water basins with good conditions for commercial fish exploitation with natural and artificial breeding for industrial and recreational fishery. The area of the specialised fish farms is appr. 37 mln sq m with pond for artificial breeding and raising of fresh water fish. There are good conditions for semiintensive fish farming in some dams - for artificial propagation of valuable fish species, raising, fattening and catching. In larger part of the dams proper fish species are placed, the latter being of interest for the commercial fishery and for the specialised fish farms. They are still state companies or Co. Ltd. With state property. Privatisation in fish culture sector is still pending decision. Larger is the share of the dams with no suitable conditions for commercial fishery with technical and technological gear applied. Those dams are used for recreational fishery and their fish resources and naturally reproduced. Only some of them are artificially bred from time to time.

The dams with fishing activities have various hydrographic, hydrochemical, hydmbiological and fish farming peculiarities. They vary in space area and volume and occupy different climatic zones. The forms of their fish exploitation differ respectively, too.

The share of the dams of more than 5 mln sq m is the largest and they are classified as large dams-61.3% of the total dam area of the country. The average ones are those with area of 2–5 mln sq m and their share is 9.5% small ones with an area less than 2 mln sq m -28.2% of the total dam area. Dams proper for intensive fishery activity cover 37% of the total dam area in the country. The remaining part of the dam potential is used for energy production, water supply, irrigation farming hydromelioration, commercial and recreational fishery and other activities, too. In 1989 taken as a basis related to complete and detailed information, as well as favourable prerequisites for commercial fishery available, 12455 t of fish was caught. The Danube catches added 360 t. Most important species in the catches are: carp - 8011 t (64.36%), phytophages (mainly Hypophthalmichthys molitrix (VAl)- 2815t (66,60%), trout - 1099 t (8,82%) and other species - 530 t (4,26%).

In the Danube catches, the following species dominate: carps (Hypophthalmichtys molitrix), pick perch, Carassius carasssius (L.) Abramis brama L., Scardinius erythrophthalmus, Danube barbel, chub and other species. Catches of sheatfish and sturgeaons decline. In the 1940s the Danube catches were several times bigger, also in the 1950s and in some years-over 1500 t. Several factors contribute to the sharp decline of the fish stock and catches: industrial and sewage pollution of the river, destruction of the swamps along the Danube (the latter having been a source of good catches and areas for natural fish reproduction (recruitment) of the fish stock of the river. A large part of the natural fish spawning areas were destroyed. The commercial constructive activities along the coast, Taking away sand and other material from the river bottom, disturb the natural migration routes, (especially the hydrotechnical devices along the river). Sturgeons (fam. Acipenseridae) migrating from the Black Sea for breeding in the Danube were heavily damaged. Also the Black Sea shad (Alosa pontica pontica) called karagyoz.

As a result of the socio-economic and political changes in the country after 1989 and the disturbances in agriculture, the production of fish for human consumption, fry and fingerlings has sharply decreases. Last year the fish production was 6–8000 t. A precise estimation cannot be given as the system for collections statistical information is disturbed. On the other hand, production expenditures quickly increase (prices of fodder, electricity, water, pharmaceuticals etc), and fish on the market has less demand. There are certain factors such as the forms of property, and management of the fish ponds in restoration of private land ownership and transfer to market economy which raise difficulties in the processes of privatization of the branch.

There is a serious decrease in production of fry and fingerlings of basic commercial fish species related to: high labour operations, risk factors (e.g. water supply problem), quality demands, the heavy losses caused by the fish-eating bird phalacrocorax carbo (L.1758) with its much abundant population.

The state of the fish-water fish in the country and its potential (available fresh waters suitable for propagation and cultivation) are illustrated in the tables as follows: table 3 - fish ponds available in the fish farms of the Bulgarian region; Table 4 - dams water potential (breeding, cultivation, catches); Table 5 - fish production and consumption per species and regions in 1989.

The present situation in the country does not create favorable prerequisites for building up new fish farms. Fish productions would considerably increase of better utilisation of fish ponds and dam waters is established. Plans for development of existing water potential demonstrate the following:

1. The existing 37 mln sq m pond farms (average production 0.15–0.17 kg/m) could produce 5.5–6.000 t and better management could give more than 0.20 kg/m.

2. Small and average dams (total area appr. 115 mln sq m; average production 0.075–0.085 kg/m) could give total fish production 8.5–10.000 t.

3. Larger dams with an area 190 mln sq m can give average production 0.0065–0.0085 kg/m and 1250–1700 t could produced.

Along this line in, optimum conditions, the fresh water potential of the country could produce 15000–18000 t. Such quantities could satisfy consumers demand for fresh water fish and a share of it could be exported to the European market. The Bulgarian trout production is well appreciated in some European countries and can compete with its quality the fish quality the fish quality in mainly other countries. The demand for carp is less; it is exported mainly to Greece where wild carp is under demand.

To satisfy the needs of fresh water farming production 40–60mln pcs of fry and fingerlings are necessary. Those quantities could be obtained in the hatcheries and ponds of the country, also in the selected fish of the farms.
In some of the large dams fish cultivation in net cages could be carried out with a lot of machinery applied.

The quality of the pellet fodder remains one of the important issues of the fresh water fish production. The country does not produce fodder of the quality required, and the high prices of the imported food is also a barrier for the expansion of the commercial farming activities.

III. HOME RIVERS

The fish resources of the home rivers in Bulgaria are of interest to the recreational fishery. In some of them, the large ones recreational fishery. In some of them, the larger ones such as Maritza, Tundja, Iskar and Kamchia commercial fishery was held in the last century up to the Second World war. Fishing gave food to the coastal population, and now the fish resources are of no commercial significance anymore.

Trout takes the most important place in the fishery from the home rivers (Salmo trutta morpha fario, Salmo irideus Gbb). It occupies the “trout zone” of the rivers over 800 m above the sea level; over 28% average slope of the river bed. The determinations given below are obtained as a result of ichthiological survey in 26 rivers (Table 6).
The ichthiologic material is collected according to the methods described by Mahon et al. (1979), Penezak (1981), Penezak et al (1981, 1982, 1984), Lebon -Cervia and Penezak (1984), Zalewski, (1983). The abundance is determined in accordance with the methods of Zipin (1956 1958), Seber and Le Cren (1967), Seber and Whole (1970).
The biomass estimation is achieved with the application of the Mahon's et al formula (1978).

The bottoms of the investigated rivers usually are covered with gravel and stones, their depth is appr. 10–40 cm and in the pools it reaches 60–80 cm. The river is covered with coniferous and mixed forest and decidious bushes. In general there are no water plants.

The oxygen content in the water usually increase 8 mg/I, pH - 6.8–7.4, total hardness - 1.53–6.30 German degrees, oxidation - 1.8–2.5 mg/1. The mean annual temperature of the water is 4-8–2.5 mg/1. The mean annual temperature of the water is 4–8 C. With few exceptions trout is the sole species living in the rivers of that zone. In some of the rivers under investigation individual specimen from the mountain barbel (Barbus meridionalis petenyi Henkel), leshanka (Phoxinus phoxinus L.), glavoch (Cottus gobio L). could be caught though their abundance is very low and does not influence the trout population. There is no industrial and sewage pollution in the trout zone or it is very negligible. The state of the stock depends primarily on the recreational fishery. The populations investigated in most of the rivers are natural and reproduce themselves. The influence of the artificial breeding is very small and it is felt mainly in some parts of the rivers. In many river sectors where the conditions for natural reproduction, conservation and recovery of the populations are good, threshold and pools are built up.

The data of Table 6 illustrate that the abundance and biomass of the trout in the rivers permitted for recreational fishery are appr. 2 times less than in the prohibited ones. An indirect conclusion can be made about the potential of the fishery rivers that it is at least 2 times bigger and for their compete exploitation one cannot rely only on the natural reproduction. They have to be artificially cultivated to allow increase in the population abundance up to the optimum.

Except trout, many other native species live in the home rivers. Dominant are chub, mountain barbel, Maritza barbel, Krim barbel.

The abundance and the biomass of the ichthiofauna from the Bulgarian home rivers, 3 main fishing areas, are given in Table 7.

The share (%) of the valuable species in the home rivers, 3 fishing areas, are given in Table 8.

The abundance and the biomass of the dominant valuable species living in those fishing areas are illustrated in Table 9.
The abundance and the biomass of the fish population in some of the main Bulgarian rivers cited in Table 10 and Table 11 reflect the abundance and the biomass of the dominant fish species in the same rivers. (Note: in Table 9 and Table 11 the abundance is given in individuals/ha in the numerator, and in the denominator - biomass is given in kg/ha).

It has to be stressed that the river Zlatna Panega is heavily polluted along the whole stream. River Struma is contaminated in different parts of the stream; along 60km there is no fish. River Vit, in the sector after Pleven, has 70km without fish. Such is river Sredetzka in the sector after the town of Grudovo (Sredetz).

CONCLUSION

As a conclusion to this report it should be pointed out that there is no complete, well defined and precise evidence about the present state of the fish resources of the fresh water basins and along the Bulgarian Black Sea coast. It is due to lack of systematic research about the state and dynamics of ichthyofauna development as a resources. Much more systematic research is carried out by the Institute of Fish Resources, Varna (for the Black Sea), ex Fisheries Institute (now IRP-25 Co. Ltdon mariculture), Institute of Freshwater Fish Culture, Plovdiv (mainly regarding fresh water commercial culture including state fish farms), certain centres for applied research within the Council of Hunters and Fishermen (regarding water basins for recreational fishery, mainly rivers and dams).

Some scientific data are also available in the Institute of Zoology and the Institute of Oceanology (Bulgarian Academy of Sciences), the Biological Faculty of the University of Sofia though their research refers more to biological than resources (stock) aspects.

Main issue remains the lack of linkage and co-ordinating unit to harmonise the efforts of the numerous highly specialized and competent scientists, to stimulate and encourage their activities and generalise scientific results in the form of useful and applicable commercial conclusions and recommendations. Such necessity becomes more urgent as the state monopoly over fishing and fish culture caused heavy exploitation of the resources while the care for their protection, reproduction and recovery was not the same.

Though high values of pollution in most water basins of Bulgaria, the latter are source of large volumes of production having high nutritive, dietary and pharmaceutical value. The potential described above needs attention paid by the society and state to create favourable conditions for development, reproduction, recovery, augmentation and rational exploitation of the fisheries resources of Bulgaria.

As a result of the analysis made in the report it may be concluded that the state of Bulgarian fishery resources is critical (unsafe) and serious measures for improvement of their natural and artificial rearing, their conservation and surveillance have to be undertaken. In this sense some recommendation can be pointed, the accomplishment of which will contribute for the enforcement of the resource base as a whole and to improve the present state of fish resources as well.

1. Improvement of the laws and other legislative acts in the field of the fishery in order to retain the fish resources:

1.1. Elaboration of a new project for Fishery Law and to convey it to the Prime Ministry (Concil) and also to the Parliament till the end of 1994.

1.2. Improvement of the operating laws and other legislative acts for commercial utilisation, protection, reproduction and control of fish resources by statements of the Cabinet Council and the other responsible institutions to the end of 1993.

1.3. Prohibition of all types and kinds of trawling and dragging fishery gears, equipment and installations in the 3-mile coastal zone of the Black Sea to avoid the disturbance of the bottom benthic biocoenoces at the productive depths.

1.4. Prohibition by stages of all types fish-activities at separate sections or home rivers and at the same time taking measures for improvement the conditions for natural fish reproduction, artificial fish rearing, preservation (protection) and control.

1.5. Introduction of a system for giving licences to persons accomplishing commercial fishery in the Black Sea, the Danube and home water basins.

1.6. Preparation for introduction of quota limitation for commercial fishery and a control system on it.

1.7. Perfection of the International agreements for fishery in Danube and the Black sea through attracting the attention of Bulgarian and international non-governmental organisation. Re-examination of the Agreement for Fishery in the Black sea and involvement all the Black sea countries in it.

2. Other measures and actions connected with protection and reproduction of fish resources:

2.1. Stimulation of the development of maricultures along the Black sea coast by building up (creating) installations for mussels farms and fish farms for rearing of mussels, mullets, salmons and other species.

2.2. Stimulation of private fish-farming during the privatisation through creating private and cooperative fish farms, and effective fish industrial exploitation of dam water fund.

2.3. Making inventory and classification of the fresh water fund suitable for fish farm exploitation (for commercial and recreational fishery and fish-farming). Each water basin have to he divided into commercial and recreational fishery zones as well as into zones reproduction of fish with normative (legislative) regulation of the regime of their utilisation, management and conservancy.

2.4. Creation of a register for all permanent fishing objects along the Black sea coast and the Danube and regulation of the regime of their exploitation, law protection, law protection, conservancy and control.

2.5. Stimulation of tribal-selection activities (genetic breeding) in country fish farms, ensuring qualified fry and fingerlings for all fish producers.

2.6. Exploitation of all possibilities for acclimatisation of some new fish species, suitable for Bulgarian climate and determination of the corresponding water basins, aiming increment of fish production, variation of its assortment in the country and achieving a positive ecological effect.

2.7. Carrying out activities for limitation the harmful effect from the imported in the Black sea, ctenophore, from the genus Mnemiopsis, over the state of the Black sea resources.

2.8. Taking measures for re-establishment of fishery-statistic with a view to ensure a full and exact information for the state of the fish resources per species for their present commercial exploitation.