In the three countries visited by the mission, coastal aquaculture is in its infancy and there are no commercial operations. Some progress has been made in experimental work. Bulgarian scientists have conducted studies in mussel culture, which should lead to rapid development of a viable industry in that sector. Likewise, Romanian biologists have made good progress in research on mullet culture, although there are still many questions unanswered. Bulgaria and Romania both have well developed freshwater aquaculture industries, which tend to have a spill-over effect once development is attempted in the coastal regions. For example, it has been noted that in Bulgaria trout produced in freshwater hatcheries are being cultured in marine water, and in Romania a hatchery is being built for sturgeon. All the three countries have carried out studies and completed surveys of areas suitable for culture of different species.
Fish culture is a relatively new field of activity in the country, with the emphasis having been given to the production of common carp, and other cyprinid species, as well as rainbow trout. More than a decade ago experiments were initiated for the culture of introduced Chinese carps (grass carp, silver carp and bighead), and some encouraging results were achieved in the polyculture of carps with intensive feeding. Trout production is increasing rapidly: by the end of 1979 the expected production would be 1 000 t, twice as much as in 1978. However, due to a lack of suitable feeds, expansion has not kept pace with demand. There are now 400 ha of concrete ponds, and 14 hatcheries have been established to meet the demand for fry/fingerlings. There are 6 ha of floating net cages in a freshwater lake, and the area is expected to increase to 9 ha by the end of 1979. Considerable progress has been achieved in the production of the single cell algae Chlorella sp., with the major part of production destined for export. Small quantities are being utilized, on an experimental scale, in the preparation of pelleted feed (1–2 percent Chlorella) for trout and carp.
The country's water resources have, and are being, developed by State fish enterprises, cooperative fish farms and the sport fish organization. The State enterprises exploit the majority of the man-made lakes and the coastal lakes along the Black Sea, while the cooperative fish farms utilize the water resources available in the cooperative agricultural farms. Fish produced by the cooperative fish farms is purchased for distribution by the State, and the farms receive technical assistance (e.g., prevention and control of diseases, feeding, etc.) from the State Fisheries Board.
Credits for new ventures can be obtained from the State Bank if the submitted projects are approved by the Ministry concerned. A project is considered viable if it can be shown to become profitable within a period of ten years. Coastal aquaculture has not yet developed in the country, and plans for expansion of aquaculture activities in brackish/marine waters are being only considered now. The government is trying to create the necessary infrastructure for the establishment of mariculture. It is proposed to combine the development of a scientific base with commercial operations and the government is willing to accept the risk involved. Trials have been initiated for rearing trout in net cages in marine waters, and for mussel farming on suspended ropes. The latter has yielded particularly encouraging results. In the past, some attention was paid to seaweed culture, but the results of the initial laboratory-scale experiments have not been applied for commercial farming. At present the harvested wild weeds are utilized for manufacturing alginates.
Bulgaria has a shortage of workers and consequently the development policy is oriented to producing food and not creating employment. The government is most interested in establishing intensive, high-yielding aquaculture systems.
The Ministry of Agriculture, which has the overall responsibility for fisheries administration in Bulgaria, has a State Economic Board of Fisheries (Ríbno Stopanstvo) to assist in policy formulation. There are three institutes and several enterprises under the jurisdiction of the State Economic Board of Fisheries.
Fisheries Institute, Burgas
Responsible for investigations in the field of fishing gear; fish processing, mechanization and automation; and for the organization of production. A new sector is a group on marine aquaculture formed in 1979. There are laboratories for fishing gear, chemistry, fish processing technology and development of new varieties of fish products. A new experimental station for aquaculture will be established in Pomorie.
Institute of Fisheries Resources, Varna
Responsible for the areas of hydrobiology, icthyology and fishery statistics. It is also conducting research on mussel culture. The Institute has an experimental vessel of 60 gross tons, as well as an aquarium.
Freshwater Fish Culture Institute, Plovdiv
This is the main freshwater fish culture research centre with divisions for hydro-chemistry, hydrobiology, pathology, fish culture, nutrition and feed. There are 50 ha of experimental ponds.
Management of fisheries is under the direction of the Vice-Director General of the State Economic Board, Dr. V. Popov.
Financing for regular programmes of the Institutes is through subsidies from the Ministry. Subsidies are granted from the State Committee on Science, Technology and Development (State Committee on Science) for especially important programmes.
All the fishery Institutes have arrangements for collaborative work with other allied Institutes throughout the country, especially with the Centre of Biology of the Bulgarian Academy of Sciences in the fields of water pollution and primary production, and the Centre on Cibernetics of the Bulgarian Academy of Sciences for underwater electronics.
The State Economic Board of Fisheries also has jurisdiction over the Freshwater Fish Culture and Marine Aquaculture Enterprise. This enterprise operates hatcheries for freshwater fish and will carry out commercial marine aquaculture.
The Ship Repair Works Enterprise would be able to provide support for design and construction of aquaculture facilities.
At present there are no production systems in coastal waters. The coastline is exposed to northerly and northeasterly winds, and although there are a number of small bays which are protected - some of these have been developed for touristic purposes - by and large the coastline is rocky with steep rises from the sea level. In view of the limited number of suitable sites, there is a need for the development of systems and types of construction which can withstand strong wave action.
The number of coastal lagoons and lakes is also comparatively small. Those located in the proximity of Burgas and Varne, which in the past were productive, have now ceased to be, as a result of industrial development. Production from such lake/lagoon systems consisted, or consists, principally of various mullet species (Mugil cephalus, M. auratus and M. saliens) which, due to the high water temperatures occurring during the summer months, attain good growth rates. However, because of the shallowness of these lagoons, mullet do not survive during the cold winter months.
Mullet fry appear to be quite abundant along the coastline. There are two peaks of abundance, a minor one in the spring, and a major one in the autumn. Distribution or stocking of mullet fry takes place when the lake/lagoon systems are closed to the Black Sea. Mullet fry which survive the low water temperatures during the winter months exhibit good growth rates. Mullet fry of M. auratus and M. saliens stocked at 0.5 g by the end of summer attain weights between 150 and 200 g, while M. cephalus grows to 500–700 g in the same period.
In view of the difficulties confronting the oceanic fleet and the increasing domestic and seasonal tourist demand for fishery products, the government plans to increase production through the promotion of aquaculture activities and expansion of the Black Sea fleet. According to the plans prepared, it is expected that by 1985–90 the freshwater fisheries would yield 30 000 t, as against 10 000 t at present; the Black Sea fishery would produce 20 000 t instead of 12 000 t, and mariculture 10 000 t, the present production being insignificant.
To achieve the production rate proposed for aquaculture, emphasis has been given to expanding the culture of freshwater species (carps and rainbow trout), and the development of coastal aquaculture (e.g., fish culture in coastal lagoons, mussel farming, and cage culture of rainbow trout in marine waters). While no major difficulties are foreseen in the expansion in the freshwater culture sector, a number of constraints have been identified with regard to the implementation of the coastal aquaculture development programme, specifically the projects concerning trout and mussel. Consequently, priority has been given for the utilization of the 500 ha Pomorisko coastal lagoon near Pomorie, about 25 km northeast of Burgas, initially for mullet farming and at a later stage for seabass (Dicentrarchus labrax) and several species of flatfish: turbot, flounder (Platichthys flesus luscus), and sole (Solea sp.). Plans for the establishment of a hatchery and other ancillary facilities near Pomorie have been made, but construction has not yet commenced. The expected production from mullet farming in the lake would be in the order of 150 to 250 t.
Simultaneously, efforts have been made in the identification of suitable sites along the coastline for the cage culture of trout, rearing of seabass and mullet in ponds, and mussel farming, either located southeast of Burgas or northeast of Varna. Most of the identified sites were visited by the mission, and its observations are given in section 4.1.4.
Further development plans envisage the introduction and culture of penaeid shrimps, in view of the interest expressed by foreign experts in growing them in Bulgarian coastal lagoons; the development of oyster culture; and the feasibility of ocean ranching of salmon in some rivers, with salmon fry obtained from the USSR. The possibility of transplanting a mullet species (Mugil soyenni) in the Black Sea because of its resistance to low temperatures, has been considered, with the USSR providing technical assistance to this programme.
Cernomorec - This site, on a low, rocky promontory with fairly flat ground at an elevation of 10 to 15 m, has been identified for the construction of a small facility to serve as a nursery for juvenile rainbow trout, prior to their transfer and rearing in net cages under the lee of an offshore island north of Sozopol. As the site is at some height from sea level, pumping costs would be considerable. In addition, costs for construction of concrete tanks on the rocky ground would be substantial.
Sozopol - The actual site, under the lee of the small island, in which trials for the culture of trout in floating net cages have been conducted in the past, was seen only from a distance. It would appear that the protected area from north-northeasterly winds is small and could not support a significant number of culture units.
Gagarin - A small experimental mussel culture unit has been set up on the northern side of the small bay, which is partially protected from northerly winds. The available area for culture purposes appears to be about 1 ha. The water edge is barren, indicating substantial wave action at times, generated from easterly or southerly winds. On the southern side of the bay, there exists a camping site which might lead to interference by visiting tourists.
Alepou - A 200 ha swamp area, with a poor connection to the Black Sea, has been selected for aquaculture development. The area appears suitable for aquaculture purposes: it can be either divided into ponds or used as a lagoon fishery if filled with seawater through pumping and provided a control gate in the outlet canal. Although the area was partially filled with fresh water in late September, it appears that there is only a limited supply of fresh water run off.
Primorsko - An extensive area of marsh and drained low land near the estuary of the River Djarolska has been identified as suitable for pond culture of mullet or other fresh-brackishwater species. The river at this location is brackish. The plan envisages the digging of freshwater wells so the site would have a supply of both fresh and brackish water.
Kiten - The possibility of utilizing the estuarine area of the River Karachay, located about 1 km south of Kiten, has been considered in view of the occurrence of eels and the abundance of mullets, and the extensive marsh and lowlands up-river. It was observed that while the river water appeared to have a dense growth of phytoplankton, the communication with the sea is restricted due to formation of a sand bar.
All the above mentioned coastal sites are located between Burgas and Micurin, on the southeast coast of Bulgaria.
Cape Kaliakra - The high cliffs of Cape Kaliakra, about 90 km northeast of Varna, protect an extensive water area from northern and easterly winds, but it is exposed to southerly wave action. This site has been identified as a suitable area for mussel culture, and trials on longlines are already in progress. The shoreline, as well as the rocks above water level, have abundant submerged algal growth, indicating the absence of frequent wave action. The water has a good colour indicating high productivity, and fouling in the area is heavy. The sea bottom, at a depth of 10 m, is flat and muddy. The existing mussel culture installation is monitored by a fishermen's cooperative, and is supported in this activity by the Fisheries Institute of Varna, which initiated the studies and is responsible for the entire project. The cooperative operates a fish weir and stake nets in the vicinity, and is greatly interested in aquaculture development. In addition to the shore facility, supplied with electricity, the cooperative owns a number of boats for its fishing activities. A good road system connects the site with nearby towns.
The protected area is quite extensive and if a satisfactory system for growing and harvesting is developed, a large mussel industry could become established in the area. The mission also recommends that floating net cages be installed in this area for experimental culture of trout.
Pomorisko lagoon - The shallow 500 ha lagoon, located about 25 km northeast of Burgas, is connected with the sea by a long narrow channel at its southern end, the floor of which is above sea level. The lagoon is filled primarily through filtration at its northern end where the majority of the salt works are located. At the southern end, in the vicinity of Pomorie, numerous salt pans have been abandoned, but some are still in production. As there is no entry of fresh water into the lagoon, salinity in several portions may reach 85 ppt.
In the past, the lagoon yielded large quantities of fish, but the current production is only about 100 t per year, consisting chiefly of mullet. The production can possibly be doubled if young mullet, collected in the channel leading to the lagoon, were over-wintered and released in spring. Some of the abandoned salt pans could be adapted for fish culture if the required improvements are made.
The Government plans to fully utilize this important site for aquaculture development and a marine station is proposed to be established near Pomorie. Over-wintering of mullet fry will be done, utilizing the supply (15–20 1/sec) of heated water from a salt processing plant. It is expected that the existing problem regarding the installation of the water intake pipe will be solved, and the greenhouse facility for over-wintering will be operational towards the end of 1980. An experimental production centre will be established for flatfish, trout and, eventually, mullet. Most of the hatchery produced flatfish will be used for growing in marine farms and the rest will be released in the sea. The expected annual production of flatfish is in the order of 1.5 million.
A site near Pomorie, covering an area of 1.5 ha, has been made available by the Government to the State Fisheries Board for the construction of the marine facility. Initially it will be staffed by 5 professionals and the required technical support personnel. The centre could be further expanded if the neighbouring countries would be interested in cooperative work.
The mission considered the proposed scheme for the construction of the centre justifiable, and agreed that some of the novel design concepts could prove useful to other countries.
Research related to coastal aquaculture consists of two main activities: (i) culture of mussels, and (ii) culture of rainbow trout in sea water.
(i) Culture of mussels
As cultivated mussels grow more rapidly than those occurring on natural banks, and in addition they are generally free from pearl-like calcareous concretions which render them unsuitable for sale to consumers, the Fisheries Institute at Varna commenced studies in 1971 to develop suitable techniques for the culture of mussels along the Black Sea coastline. Initially the studies were conducted in the Varna Bay and in the Cape Kaliakra area, to provide the basic data on spatfall intensity and growth rates. Underwater and surface structures were utilized, and while useful information on settlement and growth rates were obtained, the gear used did not resist the strong wave action. Far better results were obtained with longlines, and it was also demonstrated that the Cape Kaliakra area was the most suitable one for pilot and commercial culture of mussels.
The studies conducted showed that mussels can attain the commercial size of 50–55 mm in a period of 12–14 months. Better growth rates were observed from spat settled during the spring months than in the autumn, suggesting early spring as the most suitable period for placing the collectors.
As fouling with epibionts, particularly with ascidians, can be quite heavy, particularly during autumn, collectors and ropes are taken ashore to dry, usually for a period of 2–3 days, depending on weather conditions.
The present system consists of collectors and ‘growing’ ropes suspended from longlines supported by styrofoam blocks covered with netting. The collectors, made from old trawl ropes, are 8 m in length. During the mission's visit (end of September 1979), the number of collectors/growing ropes was 600. During this period the collectors are removed, cut into two equal lengths and rehung.
The present production through the longline culture is rather small, but future plans have a target production of 500 to 600 t per year, sufficient for the production of 100 t of canned mussels.
(ii) Culture of rainbow trout in sea-water
Studies on the possibility of rearing trout in fixed nets (pens) in shallow water were initiated in 1971. As the installations were severely damaged during winter storms, it has been decided to rear trout in floating net cages, and the first trials are expected to commence in 1980.
Generally, trout of 10–20 g are placed in the pens during March, when the seawater temperature is between 8° and 10°C, and harvest takes place in June, when the temperature has risen to 17–20°C. During this period, fish attain weights of 100 to 250 g, the average weight being 150 g. Because of the availability of sprat throughout the year, cooked sprat is utilized as feed. The quantity of sprat required to produce 1 kg of trout varies between 5 and 6 kg, costing 1 to 1.20 Leva. The market price of seawater-grown trout is 3 Leva. Trials utilizing trout pellets showed a lower conversion ratio, 2 or 2.5:1, but the cost of trout pellets was higher than that of sprat.
Any expansion in the production of seawater-grown trout would require the improvement of the culture system. It is proposed to construct concrete tanks on low-lying shore areas, and fill them with pumped seawater. Trout fry will be grown to a size of 30 g in the tanks before being transferred to floating net cages. If growing trout in floating net cages would prove impractical or uneconomical, trout would be grown in larger concrete or earthen ponds. In that case, the ponds will be utilized for trout rearing during the autumn and winter and for mullet during spring and summer.
Because of the difficulties encountered in the culture of trout in floating cages on the rather exposed coastline, the Fisheries State Board has acquired the services of a Japanese consultant to develop suitable gear which can withstand unfavourable weather conditions. One of the main reasons for this project is the need to utilize excess quantities of sprat landed by the Black Sea fleet as feed for trout.
There have been discussions with the USSR concerning bilateral cooperation. The USSR is expected to supply salmon fry for ocean ranching experiments.
There is a bilateral cooperation agreement with Japan in the field of fisheries which covers also aquaculture. An expert from Tokai University was in Bulgaria for six months to assist in planning new facilities, including the design of floating fish cages.
The tourist industry is the main competitor for use of coastal waters and shore land. Tourism is well organized and can probably show more benefits than aquaculture. Still, aquaculture products are needed to feed the populace and if available locally, the tourist industry would benefit. It would be useful if zoning regulations can be introduced to ensure that adequate areas are preserved for the development of coastal aquaculture.
A State Fishing Enterprise operates in the Danube delta. It conducts commercial fishing operations in the sea and 75 000 ha of lagoons in the delta. There are also 12 000 ha of water stocked and managed for fishery production, most of which are in freshwater areas, but there are also a few brackishwater ones. The production units are simply large lagoons or lakes with weirs constructed across their inlet/outlets to control water level and movement of fish. Some are stocked with fry produced in hatcheries. Production from the managed units is substantial, about 2 000 t annually. The Enterprise also produces 4 000 t from the sea and 2 200 t from natural waters in the delta.
Freshwater aquaculture is well established in Romania, especially carp culture. There are State operated hatcheries which provide fry for the use of enterprises and individual farmers. Most of the ponds have a natural productivity of 300–500 kg/ha annually, but with supplementary feeding, yields exceed 1 000 kg/ha and some attain 2 000 kg/ha.
There are trout hatcheries which produce fingerlings for stocking rivers for sport fishing. The main constraint to the commercial production of trout relates to feed manufacture. It is difficult to obtain some of the ingredients needed and the machinery for processing feed.
Mariculture research is conducted by the Romanian Institute for Marine Research in Constanta. The Institute is in the process of constructing a new office and laboratory complex which will be completed in early 1980. It will have wet rooms and outside tanks for conducting aquaculture experiments. Other laboratories at the Institute lend support to aquaculture work: hydrochemistry for water analysis; pollution control for water quality evaluation; fishery resources for equipment fabrication; and ecology for life history studies. Currently 15 scientific staff are working exclusively on aquaculture research.
The Institute has conducted aquaculture research in the following areas:
Reproduction of grey mullet, flounder, mussels, clams and shrimp (Palaemon sp.).
Culture: intensive polyculture of mullet, flounder and sturgeon; accelerated growth on Mugil sp. fry by using radioactive cobalt; mussel; clams; shrimp (Palaemon sp.).
Over-wintering grey mullet.
Acclimatization of freshwater species to brackish water: common carp, pike-perch and trout.
Introduction of exotic species: Oysters, Crassostrea gigas, C. angulata, C. virginica and Ostrea edulis; penaeid shrimp, Penaeus duorarum.
Besides continuing the ongoing efforts, future work will include development of promising types of aquaculture from laboratory to pilot scale and then to industrial scale. Acquisition of basic information and skills in fields such as physiology, genetics and nutrition, are also included.
Research on freshwater aquaculture is carried out by the Research and Fish Culture Projects Institute at Tulcea. This Institute also supports the commercial aquaculture industry by supplying improved broodstock and fry.
From Constanta south, the coast is open with steep shores, and is subject to high wind waves during storms. The protected areas all have sandy beaches which are developed for tourism. There seems to be little scope for development of aquaculture along this section of the coast.
North of Constanta the coast is comprised principally by the Danube delta. The land is low lying, with extensive lagoons and marsh land. Lake Sinoe alone has 15 000 ha of water, all of which is suitable for aquaculture. There are also an estimated 5 000 ha of salt marsh which could be developed for aquaculture.
In 1975 an algal bloom of Exuviaella cordata, known as “red tide”, caused mass mortalities of many organisms along the Romanian coast. Fishes in the rocky areas were almost totally killed. Clams suffered losses of more than 60 percent and numerous mussels were found dead on the beach.
The mission was told that the red tides occurring in Romanian waters do not produce toxins. Mortalities occur due to degradation of the algal bloom and the consequent low levels of dissolved oxygen. Any aquaculture operation must, therefore, take into account the potentially disastrous effects of a red tide bloom.
Aquaculture is being emphasized in the Government's efforts to produce more high quality fish because the country has large areas which are suitable for culture and the environmental conditions appear good. The overall plan calls for production from inland waters to be trebled because of the need for more fish and fishery products. Production gains will be achieved primarily through intensification. The primary objective of developing aquaculture is to produce food, rather than employment.
The main development activities will be concentrated at a new laboratory and production facility which will be constructed at Lake Istria. There will be nursery ponds, growing ponds and ponds for over-wintering fry. Lake Istria itself will be divided into two 250 ha production units. This facility will be a focus for development of aquaculture in nearby coastal areas.
A station for reproduction of sturgeon will be constructed near Rusca in 1980. Operations will be based on Russian technology. It is planned to release 3.5 million fry in the St. George's arm of the Danube annually. The fry will be released at an age of 45 days, with an average weight of 3 g. The release point is 100 km from the sea and it is expected that the migration to the sea will take three months. The adult fish will be caught in the commercial fishery when they return to the estuary. It is estimated that returns will be one percent. Huso huso may grow to a size of 50 kg in 18 to 20 years and Acipenser stellatus 15 to 20 kg in 15 years.
The Romanian Institute of Marine Research at Constanta has certain cooperative arrangements with an American company for the culture of penaeid shrimp in intensive systems. A small number of Penaeus duorarum has already been imported into Romania, and a Romanian biologist has been sent to the United States for training. The Institute intends to conduct research preparatory to industrial production and an amount of 5 million Lei is being sought to construct special facilities for shrimp culture.
The only aquaculture activity for production of marine species at present is in lagoons. Various species, including seabass, sea bream, sole, mullet and eel (Anguila anguila), enter the coastal lagoons in the spring and are retained there by a weir across the entrance channel. After growing throughout the summer, the fish are captured at the weir as they attempt to return to the sea when temperature decreases in the autumn. All the catch is marketed, including some undersized fish.
There are only two freshwater aquaculture facilities in the Black Sea coastal region. In the area of Bafra a 30 ha farm has commenced growing common carp in combination with grey mullet in fresh water. In addition to fish, it is planned to produce caviar from fish roe. There are two freshwater trout farms under construction near Sürmane; one belongs to a cooperative, and the other is private. The planned completion date is February 1980. Twelve other applications to establish trout farms were being processed at the time of the mission's visit.
The Government is placing considerable emphasis on developing aquaculture along the Black Sea coast as, traditionally, most of the fish produced in Turkey have come from the Black Sea. It is planned that Samsun will be the centre for development because of its central location and existing infrastructure, such as processing plants, etc.
The principal species considered as suitable for aquaculture are discussed below.
Grey Mullet (Mugil cephalus)
Grey mullet occur in fair numbers along the coast, especially in the vicinity of Samsun. Mullet is a valued species as it brings 50–60 L.T./kg to the fishermen and sells for about 100 L.T. in the market. Mullet roe is very valuable, because of its high market price (4 000 L.T./kg in 1979). Fishermen process the caviar themselves.
The delta area of the Red River, east of Bafra, has 25 lakes, of which five are large. The total water surface area of the lakes is 4 000 ha. The largest, Lake Bafra, has an average depth of 2 m, with deeper portions of 5 m. The estuarine lakes are connected with the sea by only a few openings and these frequently close during storms by the accumulation of sand. There are extensive areas of low-lying marshland which are currently unproductive.
The lakes are State owned and at present are leased for exploitation for three year periods. The fee is set by the Government and there is no bidding. The current lessee has an agreement with a fishery cooperative, which does the actual fishing. The fishermen of the cooperative, work on a share basis and supply their own gear.
An average of 400 t of fish is produced from the area annually: 60 percent consist of common carp; 25 percent pike-perch, and 15 percent grey mullet. Small numbers of crayfish are also taken.
Large grey mullet occur in appreciable numbers from March to June, while fingerlings are abundant in autumn.
Due to the abundance of plankton, the water in Lake Bafra is deep green, but according to fishermen, no fish kills have been associated with green water. Red tides have not been reported from the lakes or other coastal areas near Samsun. Carp and pike-perch sometimes suffer mortalities when the salinity rises abruptly with incoming sea water. Another cause of mortalities is the stranding of fish in small pools when water recedes after floods caused by run-off from adjacent land.
The climate in this area is mild; it never freezes and snows only rarely. The average monthly seawater temperatures at Samsun are as follows:
| January | 14°C |
| February | 14.5°C |
| March | 15°C |
| April | 16°C |
| May | 17°C |
| June | 21°C |
| July | 23°C |
| August | 22°C |
| September | 19°C |
| October | 18°C |
| November | 15°C |
| December | 14 or 15°C |
Salinity in the lakes varies greatly. It is fresh on the landward side, but near the connections to the sea it varies from 30 ppt in winter, to 50 ppt in summer.
As the delta area is frequented by numerous migratory birds, over 200 species have been recorded, the governor of Samsun has proposed that the area be designated as a National Park. If this materializes, the Water Products Directorate will have a major responsibility for management of the lakes. Improvements to increase the catch of mullet are planned, and a biologist has recently been assigned to Lake Bafra. Improvements planned include the opening of additional connections to the sea, and construction of dikes and canals to divert the inflow of rainfall runoff. There are no plans to construct weirs at the entrances for fish trapping.
There are eight sites for lagoon or valli-type culture along the Marmara coast. Only one now has a permanent weir for controlling water and trapping fish - Big Drawer Lake. Fishing is carried out only during November. The canal connecting the lake and the sea is left open until 15 June, when the weirs are closed, and fishing commences in November. Salinity in the lake is low, varying from 0–8 ppt. The total income from the weir fishery is estimated at 1.5 million L.T. The major catch is mullet, 40 t, and eel, 5 t. The mullets are caught at a very small size; 25–40 cm in length.
Mussel (Mytilus galloprovincialis)
In view of the limited time available to the mission, it was not possible to carry out any examination of mussel stocks. Available information, however, was reviewed and discussions were held with biologists, fishery administrators and fishermen. Mason (1971) has reported on available biological information and observations on the Black Sea mussel stock. Baird (1973), has described the prospects for expanding the mussel fishery, and indicated the difficulties in developing a commercial fishery. Both reports, however, suggest that aquaculture might contribute to the expansion of mussel fisheries in the future and recommended a research programme.
Little research has been carried out since Mason and Baird reported on the mussel fishery. There was no evidence of a planned programme of research aimed at increasing knowledge on mussels or developing methods of cultivation.
Mussels occur widely along the Black Sea coast of Turkey. A number of beds at the western end (Kana Barun, Sile, Kefken) have been well surveyed. One bed (Kefken) is reported to be 12 km long and over 3/4 km wide, with average catch rates of 50 kg/10 min haul using a 1.5 m dredge. This catch rate has been repeated on other beds. During the present mission, beds were reported as far east as Fatsa. Fishermen indicated that they could take 10 t/day using a bottom trawl without any difficulty. These mussels are said to be largely free of calcareous accretions within the shell. Rapana thomesiana thomesiana is the most common gastropod predator, and causes substantial losses to the stocks. Predation by starfish is not considered a major problem, and apparently red tides do not occur in the area. The average size of mussels on these beds is 80 mm, with a size range of 0–110 mm, but in samples taken 90 percent are usually over 60 mm in length. Mussel beds occur between 30–60 m depth and maximum catches (66.2 kg/10 min) are taken at 45 m depth. Trawlers do not fish them, except at Fatsa, where some quantities are taken for meal production.
Growth studies have not been carried out on the Black Sea mussels, but it is reported that they attain a length of 6 cm in three years. In both areas, small mussels of different sizes occur, which suggests that there is some spat settlement over a wide area.
The condition index in the Bosporus area was studied by Artüz and Erdogan (1969) and it was found to be low from August to December. Improvement occurs in the spring, and exceeded 35 percent from March to July, with a peak in May. The minimum condition index of commercially caught mussels in Europe is 40 percent. No further studies on condition have been carried out, although it was reported that the condition index in the Black Sea reached only 27–30 percent.
Mussel landings in Turkey between 1964 and 1971 ranged from 14 to 706 t/year. Although the amount landed in 1978 could not be ascertained, it is likely to be less than 1 000 t, as the overall production of marine invertebrates was only 1 400 t.
Mussels are consumed only in large centres of population; they are unknown in inland areas. The largest markets are in Ismir, Ankara and Istanbul. There are no exports, and the difficulties in developing export markets would be substantial, unless a method of improving meat condition is found.
Sturgeons
Three species of sturgeon spend part of their life in the Turkish Black Sea waters: Acipenser gueldenstaedti colchicus, A. stellatus, and Huso huso. Two other species, A. ruthenus and A. nudiventris spend their entire life in fresh water.
Sturgeons are most abundant between the Red and Green Rivers. Stocks have declined drastically in past years, and the fishery has been closed; however, the most common species, H. huso, is frequently caught with anchovy in purse seines. The catching of strugeon will continue to be restricted in 1980.
There is danger that the stock might be subject to further reduction because of the construction of dams across rivers. One has been completed, and another is under construction on the Red River; and two dams have recently been constructed on the Green River. These dams are in areas where sturgeon usually spawn, and in addition to preventing entry of sturgeon to the spawning grounds, these spawning grounds themselves will be flooded.
In order to protect the stocks, and if possible increase them, the Government is planning to construct a hatchery to raise fingerlings for stocking in the Green and Red Rivers. The proposed hatchery site is 12 km from the sea on the Red River. It is accessible by an all-weather road, and electricity is available. The land at the proposed site is flat, with gravel and sand. The river is extremely turbid with silt, and it will be necessary to clean the water prior to its use in the hatchery. The estimated cost of constructing the hatchery and operating it for five years was given as 41.2 million L.T., based on 1978 prices. The Water Products Directorate has requested 1.4 million L.T. to be made available so it can be initiated in 1980 as a research project.
Initially large fish for spawning purposes will be caught at sea. The plan calls for one million young fish to be released in the rivers annually. At release the fish will be 15 to 20 cm long, which takes an estimated three months growing period. The fish will be harvested when they return to their home rivers after spending about eight to ten years at sea. The fish will be caught by fishermen, either as private individuals or as members of cooperatives. The catch will be marked and fishermen will be required to report data on weight, length, etc. to the Directorate of Water Products.
It is estimated that, 3 percent of the fish released will be harvested. This would result in a total of 495 t of fish meat and 75 t of caviar annually. Calculated at 1978 prices of 100 L.T. per kg for meat and 4 000 L.T. per kg for caviar, the value of the meat would be 49.5 million L.T. and caviar 300 million L.T. (1979 prices: meat 200 L.T./kg; caviar 10 000 L.T./kg).
If sufficient fry are available, it is planned to conduct some culture of sturgeon for food fish in the lakes near the mouth of the Red River.
Seatrout (Salmo trutta labrax)
There is a natural stock of seatrout in the eastern Black Sea. Its distribution in Turkish waters is only from Ordu east to the Russian border. It is not taken by purse seiners beyond the three miles offshore zone.
The Storm River (Firtina Deresi), one of the main trout rivers in the country, was visited by the mission. It is fast flowing, with clear water and a rocky bottom. In the spring flood season the water level is high.
Trout are caught on each side of the river mouth as they enter the river on their spawning migration. The trout travel 8–10 km upstream to the headwaters of the river where some traps are used to catch them. In the sea, trout are caught incidentally by purse seiners when fishing for horse mackerel and bonito, but not by anchovy fishermen.
The trout attain a size of up to 50 cm in length and 12 to 15 kg in weight. They are all shipped to Istanbul, Ankara and Izmir, where the price is very high, ranging from 1 500 to 2 000 L.T./kg.
The fishery has been closed since 1977, because of apparent declining stocks, but in the absence of past records, there is no clear evidence of this.
The Directorate of Water Products would like to undertake ‘ocean ranching’ by constructing a hatchery on the Storm River, near Rize. Juvenile fish will be released in the rivers for eventual migration to the sea. They would be captured as they enter their home rivers to spawn. While little is known of the biology or habits of the seatrout, Turkey has experience in producing other species of trouts in hatcheries, which could be readily adapted for ocean ranching purposes.
The Fisheries Department has little research capability. The regional office in Samsun has only one biologist, who is conducting an ecological survey of the Lake Bafra. Although universities are not conducting research related to coastal aquaculture, it would appear they they are capable of doing so if funds were available.
The agency responsible for coastal aquaculture is the Department of Fisheries of the Ministry of Water Products. Staffing of the Fisheries Department is almost entirely with agricultural engineers. For example, the regional office in Samsun has a staff of 31, but only one is a biologist. There are no extension agents for aquaculture, although staff fit extension activities in amongst their other duties. The Fishery Department has regulatory and police functions and they operate patrol boats for law enforcement. There is no clear distinction between staff who are involved in extension activities and law enforcement.
By law, the permission of the Government is necessary for the practice of aquaculture.
The participation of cooperatives in fisheries, including aquaculture, is encouraged. Under a decree of 1972, fisheries cooperatives enjoy the right of exemption from import duties for equipment used in fishing. This exemption also covers aquaculture and supplies like fish nets, engines, and importation of fish seed and eggs. The Ministry of Cooperatives and Rural Affairs gives financial assistance to cooperatives in the form of grants. Credits are also supplied to cooperatives.
Turkey is not a member of the Black Sea Fisheries Commission. There is, however, a Turkish-Bulgarian Scientific and Technical Commission, whose function is to prepare annual Technical and Scientific Cooperative Agreements as from October 1979. It will also ratify annual programmes concerning the mutual exchange of scientists and experts.
