Field Document 2
December 1992



Report prepared for the Project -
Anzali Lagoon Productivity and Fish Stocks Investigations


J. Holčik,
Institute of Zoology and Ecosozoology
Slovak Academy of Sciences
Czech and Slovak Federative Republic


J. Oláh
Fish Culture Research Institute

The designations employed and the presentation of the material in this document do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal or constitutional status of any country, territory or sea area, or concerning the delimitation of its frontiers or boundaries.


This document summarizes the results of all investigations carried out during the project (1989–91) identified on the title page. The conclusions and recommendations given in the report are those of the authors, based on their studies of fish stocks, fisheries and environment. Special attention was paid to the impact of the rising water level of the Caspian Sea upon the coastal lagoons and their fishery resources. Proposals for future management are included.


This document evaluates the impacts of watershed manipulations and of the Caspian Sea water level fluctuations upon the environment, fish species composition, fish stocks, and fisheries of the Anzali Lagoon, a coastal waterbody in northern Iran. This lagoon was important as a rich source of fish some 50–60 years ago when the catch was dominated by diadromous fish, mostly Rutilus frisii kutum. Investigations carried out during the IRA/88/001 project have shown that Anzali Lagoon now has a low fishery value. The catch is 50–75 times lower than before when the fisheries were at their peak. It is now dominated by Carassius auratus, an accidentally-introduced coarse fish. The low yield can be seen as reflecting extreme environmental changes which have occurred in the catchment and in the Anzali Lagoon over the past 5–6 decades as a result of the synergistic impact of the Caspian Sea level decline and increasing river bed erosion. Man induced changes such as the damming of the inflowing rivers, accidental introduction of exotic species, extraction of water for irrigation, eutrophication and to an extent also pollution are responsible. In addition, the absence of fishery management is a further constraint on the lagoon ecosystem. The rise in the level of the Caspian Sea observed since 1977 is gradually bringing about a slow improvement in the situation, and the Lagoon is now slowly returning to its former brackish-water status. However, to bring back the fishery to its former level, one needs to adopt and introduce remedial measures including hydraulic engineering, an antipollution strategy and implementation of fishery management.


The Food and Agriculture Organization is greatly indebted to the following organizations and individuals who assisted the authors in the implementation of the project by providing information, advice and facilities:

The Government of the Islamic Republic of Iran for the privilege of participating in studies on Anzali Lagoon which presented a most interesting ecological situation.

V. Haghpanah and H. Abdulhay, two successive directors of the IFRTO branch in Bandar Anzali, for their interest and mobilization of the institute staff. N. Hosseinpour, National Project Director, for his invaluable help, advice, and collaboration.

M. Karimpour and D. Haghighi, National Project Staff, for their valuable work in the field. A. Mohammed, hydrologist from the North Water and Power Organization in Rasht who provided hydrological data and organized the topographical survey on Anzali Lagoon.

B.A. Razavi, who supplied interesting and important information on the Caspian Sea fish and fisheries and, together with A. Mellatparast, S.H. Khodaparast and Mrs. T. Mohammedjanii, organized sampling in their laboratories.

N. Gorouhi, head of the FRC Experimental Hatchery and H. Yosefpour, head of the Shehidbehesti Warm Water Fish Hatchery, who were most helpful in providing samples of interesting fishes, information and data on the fisheries and hatcheries programme.

E. Olami, fishing gear expert of the FRC in Bandar Anzali, who kindly arranged manufacture of experimental fish traps.

M. Tahjah and M. Mahboub, indefatigable drivers and also to M. Iranpour, the boat pilot who was helpful with his knowledge of the lagoon conditions. Fishermen, Sayiad, Abbas and R.S. Ghanbari, who provided field fishing and invaluable information of the former fishery in the Anzali Lagoon.

A.A. Esteky and S.A.B. Nezami, then postgraduate students in Szarvas, Hungary for their sampling, analyses and in part also evaluation of various hydrochemical and hydrobiological data and also to H. Ahnelt, Institute of Zoology, University of Vienna for identification of gobies.

A. Malkovitsová, T. Besedová and J. Weisová from the Institute of Zoology and Ecosozoology, Bratislava, Czechoslovakia assisted with the preparation of the manuscript, typing, statistical calculations and drawing of figures. A.I. Glubokov, Vsesoyuznyi Institut Morskogo Rybnogo Khozyaistva i Okeanografii (VNIRO), Moscow, was most helpful in providing some old Russian literature.

Rome, 1992

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2.1   Implementing strategy
2.2   Technical training
2.3   Status of the Anzali Lagoon

2.3.1   Environment
2.3.2   Pollution
2.3.3   Azolla invasion
2.3.4   Fish fauna
2.3.5   Fisheries

2.4   Summary of conclusions


3.1   Hydraulic engineering measures
3.2   Antipollution strategy
3.3   Fishery management
3.4   Other recommendations



1   Anzali Lagoon and its watershed
2   Sediment load and siltation
3   Chemical environment
4   Industrial load
5   Pesticide load
6   Groundwater nitrogen load
7   Atmospheric nitrogen load
8   River load of organic carbon
9   Nitrogen fixation by Anabaena and Azolla blooms
10   A brief history of ichthyological investigations in Anzali Lagoon
11   Vanishing fish species
12   Fish species not recorded before


1   Anzali Lagoon, location

2   Anzali Lagoon watershed

3   Open water area in the Anzali Lagoon:
A - 259.1 km2 (around 1930); B - 96.8 km2 (1956); C - 54.2 km2 (1966); D - 58.3 km2 (1989)

4   Anzali Lagoon 1989. Hatched area = cultivated and abandoned land; stippled area = aquatic plants; depth in cm

5   Caspian Sea level in 1977–91
Based on water gauge records in the Bandar Anzali port

6   Caspian Sea level in 1900–91. Black rectangles represent open water areas in Anzali Lagoon
Based on Abdullaev et al. (1963), and the present study

7   Schematic drawing of the Anzali Lagoon (western basin, all outlets and two main inlets) showing the mean salinity values (the average is calculated from surface and bottom salinity data in parts per thousand; 1990 = numerator, 1991 = denominator

8   Anzali Lagon chlorophyll a and bacteria concentrations (1991)

9   Concentrations of dissolved oxygen (morning values in summer (A), NO2-N (B) and NH3-N (C) in Anzali Lagoon

10   Relationship between the Caspian Sea level and fish catches from Anzali region (1932–1962). Data from Baku gauge (x) and Vladykov (1964) (y)
y = 72651.89 - 2516.16 x, r = 0.80, d.f. = 27,P 0.001


1   Land use in the Anzali Lagoon watershed

2   Precipitation, evaporation, runoff and discharge of the Anzali Lagoon watershed

3   Monthly average concentration of total suspended solids in rivers entering Anzali Lagoon

4   A suspended sediment transport to Anzali Lagoon

5   Dissolved oxygen concentrations in Anzali Lagoon

6   Redox (mV) condition in Anzali Lagoon

7   pH status in Anzali Lagoon

8   Nitrite concentrations in Anzali Lagoon

9   Number of workers in agriculture and industry in Anzali Lagoon watershed

10   Number of factories and amount of investment in industries in Anzali Lagoon watershed

11   Size of factories based on number of workers in Anzali Laghoon watershed

12   Heavy metal concentrations in various types of sewage effluents

13   Heavy metal concentrations in the Pirbazar River

14   Pesticide application on Anzali Lagoon watershed

15   NH4-N concentrations in the hyporheic region of 11 rivers discharging into Anzali Lagoon

16   NO3-N concentrations in the hyporheic region of 11 rivers discharging into Anzali Lagoon

17   NH4-N and NO3-N content in the rain water in Bandar Anzali

18   Organic C released by livestock in Anzali Lagoon watershed

19   Organic C released by human populations in Anzali Lagoon watershed

20   Monthly averages of all river and outlet organic carbon concentrations, river discharge and organic carbon released into the sea

21   List of fish species known for Anzali lagoon and its watershed 1785-71

22   List of fish species recorded in Anzali lagoon 1989–91

23   Anzali Lagoon total annual catch of fish in 1990

24   Average annual catch of fish in Anzali Lagoon 1932–64

25   Fish catch statistics of bony fishes in Anzali area 1933–62

26   Standard length of Carassius auratus in Anzali Lagoon

27   Linear growth of Carassius auratus in various waterbodies outside lran

28   Linear growth of Cyprinus carpio from various localities of of the southern Caspian Sea

29   Catch of Rutilus frisii kutum in the lranian waters of the Caspian Sea in 1987–91

30   Number of Rutilus frisii kutum fingerlings released into lranian waters of the Caspian Sea watershed

31   Differences in length in the young-of-the-year juveniles of Rutilus frisii kutum caught in Sowsar roga on 14.4.91

32   Age composition by percent of Rutilus frisii kutum

33   Age/length key for Rutilus frisii kutum in Anzali Lagoon in 1991

34   Growth in length of Rutilus frisii kutum males in Anzali Lagoon

35   Growth in length of Rutilus frisii kutum females in Anzali Lagoon

36   Parameters of the von Bertalanffy equation characterizing linear growth of Rutilus frisii kutum from various localities

37   Growth characteristics of Rutilus frisii kutum in Anzali Lagoon in 1970 and 1990

38   Growth in length of Chalcalburnus chalcoides from Anzali Lagoon in 1991

39   Parameters of the von Bertalanffy equation characterizing linear growth of Chalcalburbus chalcoides from various localities in the Caspian Sea basin

40   Growth in length of Vimba vimba from Anzali Lagoon in 1991

41   Parameters of the von Bertalanffy equation characterizing linear growth of Vimba vimba from various localities in the Caspian Sea basin

42   Length composition, total mortality rate (A), survival rate (S) and instantaneous rate of total mortality (2) of Astacus leptodactulus in Anzali Lagoon in 1990