Freshwater Fishes of Iran
Introduction - Fisheries
Freshwater fisheries are increasing in Iran and with this exploitation there is a commensurate need for an understanding of the whole ichthyofauna. Coad and Abdoli (1996) and Coad (1998; 1999) review the biodiversity of Iranian freshwater fishes. Reviews of fisheries, including aquaculture, can be found in the magazine Abzeeyan, e.g. Anonymous (1992c) and Madbaygi (1992), at the Food and Agriculture Organization of the United Nations website (www.fao.org), at www.agri-jahad.org, the Iranian ministry concerned with fisheries, at the Caspian Environment Programme (CEP), Baku, Azerbaijan at www.caspianenvironment.org and in various articles such as Matinfar and Nikouyan (1995), Nash (1997a, 1997b), Mehrabi (2002), Saeedi (2002) and Alam (no date). Additional information is found under each species account, in particular for sturgeons (Acipenseridae), the most valuable fishery.
Fisheries data from various sources (and sometimes the same source) are not always compatible or comparable. The data should be treated as indicative of trends and relative fishing pressure between species. Some years may have been inadequately reported, data is incomplete, sources for figures are disparate, poaching levels have varied, and low numbers may not reflect actual catches.
Early accounts of fisheries along the Caspian shore of Iran are given by Nedoshivin and Il'in (1927; 1929). The freshwater fish catch increased from 6954 tonnes/year in 1974-1976 to 24,613 tonnes/year in 1984-1986, a 254% increase and five times the world average (Gleick, 1993). Inland fisheries finfish production was 30,924 tonnes in 1986 and in 1992 Iran had an inland capture fishery of 40,000 t, as did Turkmenistan; Kazakhstan had 80,000 t, Uzbekistan 27,439 t, Azerbaijan 36,371 t, Iraq 4400 t, and Armenia 4500 t (Food and Agriculture Organization, Rome, Inland Water Resources and Aquaculture Service, Fishery Resources Division, 1995a). The Caspian Sea fisheries grew from 25,987 t to 98,000 t in the decade 1990-2000 (www.agri-jahad.org, downloaded 3 November 2003). Saheli (1999) gives figures that show total aquatic production was dominated by Persian Gulf and Sea of Oman fisheries in 1995 at 63%, the Caspian Sea occupied 15% and inland waters 15%, the remainder being from international waters. Petr and Marmulla (2002) give an average catch of 30,000 t for 1995-1999 in inland waters. Kilka was the most important factor for increased catches in the Caspian and aquaculture in inland fisheries. The catch in 1998 was 75,000 t for inland waters (IRNA, 15 June 1999) - catch records vary between sources but give a general idea of the importance of freshwater fisheries. The value of all fish production in Iran rose to 1046 billion rials in 1996 from 171 billion rials in 1989 (Tehran Times, 27 July 1998). Freshwater landings increased from 22,177 t in 1985 to 115,000 t in 1994 (Food and Agriculture Organization, Fisheries Department, 1996). Cold and warm water fish production was 67,000 t in 2001 with per capita annual consumption at 5.2 kg. Production was expected to rise to 220,000 t in 2000-2005 (IRNA, 11 November 2001). Per capita yields for inland capture fisheries in kilogrammes after Food and Agriculture Organization, Rome, Inland Water Resources and Aquaculture Service, Fishery Resources Division (1995a) was as follows and shows marked increases over these years:-
These values compare with neighbouring countries as follows for the
same period:- Iraq (range 0.182-0.672), Turkey (0.666-0.903),
Afghanistan (0.079-0.102) and Pakistan (0.773-0.874). Per capita supply of
cultured fish was 1.3 kg in 2003 while capture fisheries yielded 5.1 kg (Food
and Agriculture Organization, Fisheries Department, 2006). This same publication
gives fish consumption in kilogrammes per capita as follows:-
Catches in the Caspian Sea for 1991 and 1992 were 3036 t and 2692 t of sturgeons respectively, 13,817 and 21,527 t of kilka (herrings of the genus Clupeonella, family Clupeidae), and 18,571 and 16,873 t of bony fishes. The herring catch reached 51,000 t in 1994 from none 10 years previously (Food and Agriculture Organization, Fisheries Department, 1996). The FAO also records that the silver carp catch went from none in 1989 to 24,720 t in 1994. In inland waters the catches of warm water fish were 19,947 t and 21,462 t, of cold water fish 579 t and 775 t (both presumably from fish farming) and from "natural resources" 24,905 t and 20,183 t. These catches (totals 80,855 t and 83,512 t) are less than the totals for the marine catches in the Persian Gulf and Sea of Oman at 277,000 t and 271,000 t but are still significant (Abzeeyan, Tehran, 5(9):III, 1995).
In 1996, the total Caspian Sea catch was 58,000 t while the southern, marine fisheries reached 265,000 t. The gross value of all catches (1995) including marine fish and shrimps was U.S.$45 million while fish imports were at $65 million. Caviar made up nearly 60% of exports in 1994 and nearly half of imports are fish meal. The industry had 111,800 primary employees in 1995, including about 8000 fish farmers. Most fish (70%) is eaten fresh, 15% is frozen and canned, with some smoked or salted and the remainder is made into fish meal (Food and Agriculture Organization, Fishery Country Profile, 1997, at www.fao.org/waicent/faoinfo/fishery/fcp/irane.htm). In 1998, the annual fish catch was listed as 65,000 t with the aim of raising the catch to 110,000 t by the end of the 1995-1999 economic development plan. It was estimated that 150,000 t could be obtained from 500,000 ha of ponds and dam reservoirs (IRNA, 23 October 1998).
TACIS (2002) demonstrates the growth in catches in the Caspian Sea basin of
Iran as follows. The kilka catch was 2000 tonnes per year in 1932-1959, 63,300
t/y in 1996-1998, mullets 390 t/y growing to 4560 t/y, and total catch 7440 t/y
to 81,360 t/y. Nezami et al. (2000) gives the following figures for fish
harvested from Caspian coastal provinces in Iran:-
|Rutilus frisii||174,869 kg||191,680 kg|
|Rutilus rutilus||20,124 kg||18.025 kg|
|Mugilidae||43,016 kg||229,487 kg|
|Cyprinus carpio||229,734 kg||260,890 kg|
|Other||2712 kg||10,529 kg|
|Total||470,455 kg||710,611 kg|
This province demonstrates a great variation in mullet catch between years.
|Other bony fishes||374|
|All bony fishes||2813|
Unauthorised fishing in Gorgan Bay in the southeastern Caspian was estimated at 167,681 kg in 2000-2001 (Kamran, 2006). Mullets (Liza aurata and L. saliens) comprised 35.7% of the catch.
The biomass of fishes in the Iranian Caspian is estimated at 556,530 t,
12.7% of the total for the sea, with a fish density of 50.6 tonnes/nautical mile
(the lowest values of any Caspian state)(Ivanov and Katunin, 2001). The Caspian
Environment Programme (1998) gives the following tables for bony fish production
in the Iranian Caspian Sea (tonnes) in recent years:-
Abdolmalaki and Psuty (2007) give figures over a wide range of years for Iranian coastal catches in the southern Caspian Sea as follows:-
|Catch and frequency||1927-1936||1937-1946||1947-1956||1957-1966||1967-1976||1977-1986||1987-1996||1997-2003|
|Total recorded catch (t)||8959||7224||4986||3262||5547||5384||16,903||16,201|
|Sander lucioperca (%)||29.7||1.7||1.0||0.2||0.4||0.1||0.1||0.2|
|Sturgeon meat + caviar (%)||13.4||8.8||16.3||50.9||40.9||34.2||9.4||5.0|
|Cyrpinus carpio (%)||9.8||8.5||1.8||2.5||2.6||1.1||6.3||6.1|
|Rutilus frisii kutum (%)||12.2||43.0||24.9||25.8||17.8||19.8||53.2||45.4|
|Rutilus rutilus (%)||20.7||25.5||18.8||0.7||0.8||2.3||5.8||6.1|
|Alosa spp. (%)||1.9||6.2||14.7||2.9||0.3||0.2||3.2||3.9|
|Liza aurata and L. saliens (%)||0||1.8||20.9||15.8||36.1||42.2||19.7||28.9|
|Other species (%)||12.3||4.5||1.6||1.2||1.1||0.2||2.5||4.4|
The Statistical Center of Iran (www.iranworld.com/Indicators/isc-t023.asp, downloaded 4 April 2005) gives kilka catches for 1997 as 60,400 t, for 1998 as 85,000 t and for 19919.79 as 95,000 t.
The bony fish catches in the Iranian Caspian Sea waters for 1999-2000 were given by D. Ghaninejad (5th International Symposium on Sturgeon, Iranian Fisheries Research Organizatio, 9-13 May 2005, Ramsar). Beach seine cooperatives took 11,170 t and the total catch, allowing for poaching, was estimated at 16,860 t. The total kutum (Rutilus frisii) catch was 1400 t and this species had an estimated biomass in Iranian waters of about 22,000 t. The catch of Liza aurata was estimated at 3559 t with about 22% undersized and the biomass estimated at 11,100 t. Cyprinus carpio biomass was very low and was estimated at 4200 t. The Rutilus rutilus catch was estimated at 1340 t for 2000-2001, mostly poached with gill nets, and Sander lucioperca at 18 t for the same period, mostly undersized and immature. The total catch of Abramis brama was estimated to be 17 t, again undersized and immature.
Catches in the Caspian Sea showed no differences between 7 regions based on catch-per-unit-effort (cpue) (Mirzajani and Ghaninezhad, 2006). Catches varied from 88 to 459 kg/cpue for 1991-92 and 31-418 kg/cpue for 1994-95. In 2000-01, the Anzali region had the highest values, significantly different from the Astara-Hashtpar and east of Gilan province regions.
Beach seines are known as pareh in Farsi. Beach seine cooperatives increased from 68 in 1989 to 151 in 2004 while the numbers of fishers doubled from 6000 to 12,000. About 85-100 people are members of each beach seine cooperative. The beach seines are 1000 m long, with a cod-end 10-15 m wide and 100 m long and with a mesh size legally fixed at 30 mm (smaller meshes are used too). They are hauled in by tractors. Although there are minimum sizes for fish retention, e.g. 34 cm fork length for Sander lucioperca, fisheres do retain smaller ones for home consumption or even marketing (Abdolmalaki and Psuty, 2007). Some further details on Sander lucioperca catches are given in the Species Accounts.
Caviar and sturgeon catches from the Statistical Center of Iran (www.iranworld.com/Indicators/isc-t023.asp, downloaded 4 April 2005) were as follows (note that the Iranian years run from March to March, so the western years are an approximation here and in the above table) :-
|Year||Beluga caviar||Beluga meat||Asetra caviar||Asetra meat||Sevryuga caviar||Sevryuga meat|
The whole fisheries industry, including the Persian Gulf marine fin fisheries and shellfish, received an investment of 500 billion rials by government and 800 billion rials by the private sector, apparently for the period 1989-1993. Nine billion rials were allocated to aquaculture by the government in 1993, planned to rise to 23 billion rials in 1994, and to 210 billion rials in the next five-year economic development plan. In 1995, 200 billion rials were allocated to preparation and provision of infrastructure activities for fish farming (http://netiran.com/news/IranNews/html/9503131INEC.html). A national project to expand fish farming within a six-year period would raise annual production by 50,000 t, create 30,000 jobs, earn $50 million a year and increase consumption of fish to 10 kg per person (IRNA, 22 January 2000). Consumption of fish in Iran is estimated at 5 kg per capita, having risen from 1 kg in the decade prior to 1999 and is expected to rise to 6.5 kg in the next five-year economic plan (by the year 2000) and to 10 kg by 2004 (later revised to 8.5 kg by 2005 (IRNA, 25 September 2000)). Per capita consumption of fish increased due to increased production but also a government policy of lower prices than for meat and poultry (IRNA, 6 March 1999; 31 May 1999). In 1993, 350,000 t of seafood products were produced comprising 30% of the country's protein requirements and a sevenfold increase over catches before the Islamic Revolution in 1979 (Abzeeyan, Tehran, 4(9):VI, 1993). The annual fisheries output was expected to reach 1 million tons by the year 2004 from a 1999 level of 400,000 tons (IRNA, 6 March 1999). Fish exports were expected to earn Iran $400 million and create 150,000 jobs by 2004. The 1999-2000 government budget allocated 300 billion rials to fisheries (IRNA, 6 March 1999). In 1998, Rana and Bartley (1998) report the average per capita fish consumption in Iran to be 4.5 kg, low compared to the world average of 13.5 kg. The Government's plan is to increase consumption to 6.5 kg by the year 2020 which would require an increase in fishery production from 382,000 t in 1995 to 670,000 t; these amounts conflicting with news reports.
The Caspian Sea at this time produced 60,000 t and other inland waters 59,000 t. These waters would have production increased to 420,000 t by 2020. Aquaculture has a high priority in this plan and expanded at 8.2% per year during 1990-1996, the value in 1996 being U.S.$306.6 million for a production of 30,000 t. However aquaculture production for 1988 was only exceeded in 1995 (www.fao.org/fi/publ/circular/c886.1/wasia3.asp).
Over 975 million fingerlings were released into the Caspian Sea and inland waters from hatcheries or given to fish farmers to be cultured in ponds during the first five-year plan, 1989-1993. During the next five-year economic plan, the catch was expected to increase to 2.6 million t from 1.309 million t and 1.9 billion fingerlings would be released (Abzeeyan, Tehran, 4(9):V, 1993). The "Iranian Fisheries Research and Training Organization" was expected to have a budget of 35 billion rials by the end of 1993, indicative of the importance attached to developing fisheries in Iran (Abzeeyan, Tehran, 4(5):IV, VII, 1993).
Prior to the Islamic Revolution in 1979, the Iranian fisheries were divided into two companies, known as Shilat in Farsi, a northern one centred on the Caspian Sea and a southern one centred on the Persian Gulf. The combined companies, known as the Iranian Fisheries Organization or Shilat, were under the Jihad-e Sazandegi Ministry, starting in 1987. Jihad-e Sazandegi translates as "Construction Crusade" and is indicative of the attempt to develop the fisheries to serve the growing population of Iran. The Organisation is now known as Jihad-e Agriculture as of the year 2000. The Iranian Fisheries Research and Training Organization officially commenced its activities in 1990 and is now known as the Iranian Fisheries Research Organization . It has departments of Research, Training, Scientific Information and Administration and Research Centres at Bandar Anzali and Sari in the north of Iran and at Bushehr, Bandar Abbas, Ahvaz, Bandar Lengeh and Chahbahar in the south. A general account of the fisheries and their organization in Iran is given at http://netiran.com/press/economy-domestic/html/000000XXDE0090.html which was available on the net on 14 April 1997 and a more recent version was at www.netiran.com/php/artp.php?id=1609, downloaded 19 July 2004.
Aquaculture is now of major significance. Demand for fishery products is expected to outstrip that available from fisheries (Salehi, 2003). Iran is a major producer of Chinese carps (Billard and Berni, 2004). For the year 1986-1987 aquaculture production was the largest in Southwest Asia and in 1992 at 42,420 t, it represented 50% of the production for West Asia and by value it was 62% (Food and Agriculture Organization, Rome, Inland Water Resources and Aquaculture Service, Fishery Resources Division, 1995b). Yearly cultured fish production climbed from 4753 t in 1985, to 15,000 t in 1986, 18,000 t in 1987, 33,684 t in 1988, 39,913 t in 1989, and to 45,134 t in 1990. In 1995, Iran had 32% of the main aquaculture production in West Asia (among Turkey, Israel, Iraq and Syria) although it had been 47% in 1984. The decline was due to a slower growth rate. The 1995 production was 29,000 t (Shehadeh, 1997). However other sources differ with a freshwater aquaculture production of 13,615 t for 1995 according to the Food and Agriculture Organization, Rome, Fisheries Department and Network of Aquaculture Centres in Asia-Pacific Bangkok (1997). This source summarises action plans and national objectives for aquaculture. The year 2005-2006 had 96,000 tons of warm and 32,000 tons of cold water production (Iran Daily, 10 May 2006).
The Food and Agriculture Organization, Rome, Inland Water Resources and Aquaculture Service, Fishery Resources Division (1995b) also gives different figures for a range of years:-
|$U.S. x 1000||36,988||62,217||94,650||164,201||251,500||299,000||446,876||208,298||424,534|
|% West Asia t||47.72||44.58||48.54||50.80||50.15||50.87||57.76||35.84||50.30|
|% West Asia $||33.23||44.54||51.26||63.47||63.40||66.32||71.23||49.33||62.04|
The Caspian Environment Programme (1998) gives annual production (in thousands) of the main cultured fish species in government and private hatcheries as follows:-
*Total from CEP (1998), not quite accurate; 1 = 2107.9; 2 = 137,586; 3 = 201,412.
Aquaculture production was expected to reach 110,000 t by 1999 (Abzeeyan, Tehran, 6(8):V, 1995) although reports in 2001 list a figure of 90,000 t. The production target for 2006 was 550,000 t, an increase of 1800% over 1995 (Shehadeh, 1997). These figures conflict with the ones in the table above*. The following table from www.agri-jahad.org, downloaded 15 November 2002 gives somewhat different figures for production of aquatic farms but it is not always clear whether the same values and methods of organising data are being used:-
|Number of Farms||3330||3647||3801||4524||-|
Hosseinzadeh (2003) gives the following figures in tonnes for total fisheries
production in Iran (note that southern waters are marine captures):-
|Year/Area||Caspian Sea||Southern Waters||Inland Waters||Total|
Hosseinzadeh (2003) also gives warmwater fish (major carps, see below)
production by province. Average production (tonnes/ha) increased as follows:
1989 (1 t/ha), 1990 (1.5), 1991 (1.5), 1992 (2.8), 1993 (3.0), 1994 (3.1), 1995
(3.3), 1996 (3.5), 1997 (3.4), 1998 (3.5) and 1999 (3.6). Coldwater fish
production (primarily rainbow trout, Oncorhynchus mykiss) was as follows in tonnes:-
|Bovir Ahmadi va Kohkiluyeh||6||9||9||53||45||39||24||52||43||124||239.2|
|Average (kg/cu m)||-||9.5||9.5||9.5||9.3||10.3||10.7||11.2||12||12||-|
The website www.iranseafoodexpo.ir/portion.asp, downloaded 9 February 2006, gives the following production of freshwater fishes, presumably in tonnes, with some obvious rounding of figures and conflicts with figures above:-
Carp culture is the most important fisheries subsector according to Salehi
(1999, 2004a). Chinese major carps are reared in hatcheries and, at about 8 days
of age, they are transferred to nursery ponds. At about 10 g in weight they are
transplanted into water bodies or grown out to market size (1 kg) in farm ponds
(Saheli, 1999). Salehi's 1999 thesis gives an economic, marketing and consumer
study of carp culture in Iran in the 1990s, concentrating on Cyprinus carpio.
He maps fish culture facilities and hatcheries, gives production of carps by
species and by provinces, and also gives an overview of Caspian fisheries apart
from carps. However carp culture is more generally used in the sense of the Chinese major carps (Cyprinus carpio,
Hypophthalmichthys molitrix, Ctenopharyngodon idella and
Hypophthalmichthys nobilis, often reared in polyculture. C. idella
commands the highest price followed by H. molitrix with C. carpio
the cheapest. Polyculture stocking in natural and artificial water bodies is
usually 28-32% Cyprinus carpio, 40-50% Hypophthalmichthys molitrix,
5-10% H. nobilis and the rest Ctenopharyngodon idella. Average
yields varied from 43 kg/ha in 1993, to 40 kg/ha in 1994 to 49 kg/ha in 1995.
Higher yields are cited by Salehi (2004a) at 1540 kg/ha in 2001 but this may be
for growth in summer months and special condition. Total carp production was
54,000 t in 2001 (but see below after FAO, also from Salehi). Salehi's data
differ from those of Hosseinzadeh (2003) above. The following figures are in
|Species/Year||1991||1993||1995||1997||1999||2000||% growth 1990-2000|
Production by major fish-culturing provinces from Salehi (2004a) for carps is
|Province/Year||1991||1993||1995||1997||1999||2001||% share in 1995||% share in 2001|
|Mazandaran and Golestan||1958||3813||8975||10,060||9518||15,700||36||60.9|
|Sistan and Baluchestan||4353||3000||4600||4200||11,307||0||19||0|
New aquaculture developments are reported regularly, e.g. see Abzeeyan, Tehran, 7(4):IV-VI, 1996; Aavakh-Kismi, 1996). The share of aquaculture compared with total fisheries production more than doubled between 1980 and 1987, from 5.5% to 12% due to high private sector investment while the monetary value climbed from 10.9% to 22.2%. Aquaculture is concentrated in Gilan, Mazandaran, Khuzestan and Markazi or Tehran provinces where 96% of the total number of existing establishments are found and 87% of total production (Ahmadi, 1993). Various other areas of the country are taking on fish culture plans, e.g. Anonymous (1991b; www.irna.com/newshtm/eng/08151227.htm, IRNA, 29 July 2000) - Lorestan Province; Anonymous (1992b) - Chahar Mahall va Bakhtiari Province; Anonymous (1996) - Kermanshahan Province; Islamic Republic News Agency (19 October 1997) - Ilam Province). In 1992 there were over 8047 ha of ponds and 503,500 ha of natural and semi-natural reservoirs. Consumption of aquaculture products was 800 g and over 10,400 people were employed in private sector aquaculture (Emadi, 1993a). The number of warm-water fish farms in 1996 was 3736 with an area of 7989 ha and the number of cold-water fish farms was 79 with an area of 164,984 ha (Iranian Fisheries Research and Training Organization Newsletter, 17:4-5, 1997). Lorestan Province produced 772 t of farmed fish in 1997 with 1000 t predicted for 1998 and a long-term goal of 21,000 t worth 156 billion rials and 10,000 jobs. In 1997, 50 fish farms were under construction along with 125 pools for fish culture purposes and 10 billion rials were invested (Tehran Times, 22 September 1998). Yazd Province produced 36 t of trout from ponds, 16 t of this from saline water, in 1997. In Dehshir and Marvast, 250 t were to be cultured with 200 t in salt water. For 1999, 500 t were forecast for this province (Tehran Times, 17 September 1998). The Azadegan Fish Farm south of Ahvaz was scheduled to produce 70,000 t of cold and warm water fishes annually from 342 pools of 15 or 40 ha, employing 4250 people directly and 13,000 indirectly, and with a gross revenue of 305 billion rials annually (IRNA, 11 November 1998). In the Iranian year ending 20 March 2002, warmwater fish culture produced 3843 t and coldwater culture 12,169 t (www.irna.com, downloaded 6 November 2002). Confusingly, the warmwater fish production in the year ending 20 March 2003 was expected to be 30,000 t according to IRNA (17 December 2002), and compare tables above.
The following table from www.agri-jahad.org, downloaded 15 November 2002 shows production of fry of various species in thousands:-
|Perch (probably zander)||2414||3800||3615||4257||3931|
Kutum or whitefish (Rutilus frisii) is very popular in Iran and has local cultural significance, hence the effort expended. Carps presumably includes the common carp (Cyprinus carpio) and other major carps (Hypophthalmichthys spp., Ctenopharyngodon) farmed in numerous localities as is rainbow trout (Oncorhynchus mykiss) which probably accounts for most, if not all, of trouts above. The salmon is Salmo trutta, difficult to re-establish its Caspian Sea migratory stocks because of habitat changes.
Integrated rice-carp farming and trout farming during the post-harvest period is also being developed. In 1999 rice-field farming yielded 126 t of fish, as well as fertilising the fields and controlling the rice stem borer (Petr and Marmulla, 2002).
Drought conditions have severely affected fish farming in parts of Iran, e.g. the warm-water farming in Golestan and Mazandaran provinces which lost $6.5 million in 2006 because of low rainfall and the subsequent drought. Output shrank by 5000 tons in Mazandaran and 1000 tons in Golestan and projected growth of 15-20% was not attained. This report, from www.agriculturenews.net, downloaded 2 February 2007, noted that Mazandaran alone accounts for 30% of Iran's farm fish production.
Various studies have been carried out on aquaculture facilities or fish farms in Iran, aimed at improving the yield and combating problems. For example, Fathiazad et al. (2002) found clove oil to be a suitable substitute anaesthetic for MS-222 (which has side effects and 21-day withdrawal period) in juvenile Cyprinus carpio, Hypophthalmichthys molitrix and Ctenopharygodon idella; Abtahi et al. (2002) found the LC50 of clove essence was no different from MS-222 for cultivated Acipenser persicus, Oncorhynchus mykiss and Cyprinus carpio; Ebrahimzadeh et al. (2003) examined polyculture of female grass carp x male bighead carp with silver, bighead and common carp (final weight gain was not different between hybrids and grass carp, for example); Ghomi Marzdashti and Azari Takami (2004) studied effects of polyculture of silver, common, grass and bighead carp (only bighead showed increased growth, for example); Safari (2006) sampled bacteria on 51 farms and examined their use in improving chemical conditions; Esteki (2006) determined the best conditions for manuring fish farms; Rahmani and Ehsani (2006) studied ion exchange and air stripping methods for removing ammonium, which can kill fish in culture systems.
Parasites of fishes are common in aquaculture and wild-caught fishes; the species are detailed in each Species Account. Clostridium botulinum is present in coastal areas of northern Iran and is a potential food hazard if preservation is inadequate. Contamination rate was 10% in Sander lucioperca and 6.66% in Salmo trutta (Tavakoli and Razavilar, 2003; Tavakoli and Tabatabei, 2005), 2.2% of smoked carp, 1.1% of fresh carp, 1.1% of smoked kutum and 1.1% of osetr caviar (R. S. E. Khandaghi in 5th International Symposium on Sturgeon, Iranian Fisheries Research Organization, 9-13 May 2005, Ramsar).
Shariati and Nikfetrat (2005) survey the attitudes of fishermen to stock enhancement and conservation efforts in Gilan Province and found a significant positive attitude. Overfishing and illegal fishing were commonly cited as major problems. Emami and Hosseini (2004) also assessed the participation of fishery cooperatives from Sari in preserving fish resources. Marketing fish in Iran was discussed at www.shilat.com (downloaded 28 February 2007) and in Salehi (2006) including such items as product quality, availability, variety, safety, price control, shelf-life, size control, consumption behaviour, prices, among others.
Quliyev (2006) details fish farming in the neighbouring country of Azerbaijan with relevance to Iranian Caspian Sea basin species.
© Brian W. Coad (www.briancoad.com)