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بسم الله الرحمن الرحيم

بسم الله الرحمن الرحيم. Management of Mediterranean fisheries. Dr. Waheed M Emam Prof. of Marine Biology. INTRODUCTION . goal of fisheries management is to conserve the stock of different fish species for future generations.

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بسم الله الرحمن الرحيم

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  1. بسم الله الرحمن الرحيم

  2. Management of Mediterranean fisheries Dr. Waheed M Emam Prof. of Marine Biology

  3. INTRODUCTION • goal of fisheries management is to conserve the stock of different fish species for future generations. • pollution, coastal development and other human activities have lead to the degradation and destruction of spawning and the natural habitats of many fish species.

  4. INTRODUCTION • The reduction of spawning stocks below a threshold by fishing is called recruitment over-fishing. • It prevents many population from recovering to previous levels of abundance. • Intensive fishing with poorly selective gears may alter the habitat, and affect biodiversity, community structure, species composition and abundance of both target and other species within the food web.

  5. INTRODUCTION • The great majority of fishery production occurs within 200 miles of land which roughly corresponds in many areas to the limits of the Exclusive Economic Zone (EEZ). • Marine fishery resources are highly susceptible to the impacts of human activities.

  6. INTRODUCTION • The effective fishery management required: 1- an assessment of fish stock 2- a better understanding of the ecological susceptibility of a resource to forces leading to environmental change. 3- to know the kinds of responses likely to occur in a population of a species, hence in its ecosystem as a whole, for example, redistribution (to avoid an adverse environmental condition); changes in growth rate, mortality rate, fecundity and recruitment.

  7. INTRODUCTION • The basic purpose of fish stock assessment is to provide advice on the optimum exploitation of aquatic living resources such as fish and shrimp. • The optimum exploitation level (E0.5) achieves in the long run the maximum sustainable yield (MSY)in weight from the fishery. • The major economic gains from harvesting the marine resources must come from ensuring that harvesting capacity does not exceed the capacity of the resource to sustain this harvest while reproducing itself.

  8. INTRODUCTION • The Mediterranean system is formed of basins includes semi-enclosed seas ranging from: - Atlantic water masses in the Western Mediterranean to slightly hypersaline warm-temperate water masses in the Eastern Mediterranean (Levantine basin), hyposaline waters in the Black Sea. * The Mediterranean sea includes a large number of habitats with diverse stocks and species. * It is highly affected by various activities of populations living in its coastal states.

  9. INTRODUCTION • The present study aims to give more information about the strategy plan that can be applied for the management of Mediterranean fisheries including the Egyptian fisheries.

  10. CONTENTS 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA 1.1.Geographical setting 1.2. Water circulation 1.3. Water Balance 1.4. Chemical Characteristics 1.5. Primary Productivity 1.6. Zooplankton 1.7. Benthic Fauna 1.8. Pollutants

  11. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.1.Geographical setting SA= 2.5 million km2. Av Depth= 1.5 km TV= 3.75 km3., West Basin=0.85 km2 Lmax= 3800 km. Wma= 900 km Gibriltar strait: 1.5 km wide, 290 m deep, Sicily Strait: 150 km wide, 800 m deep

  12. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.1.Geographical setting

  13. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.1.Geographical setting • The Mediterranean Sea lies between Europe, Asia and Africa. • It covers without the Black Sea about 2.5 million km2. • Its average depth is about 1.5 Km. • Its water volume is 3.7 million km3. • Its maximum length from Gibraltar to Syria is about 3,800 km. • Its maximum distance in the north-south direction from France to Algeria is about 900 km.

  14. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.1.Geographical setting • The Mediterranean Sea is connected with: 1- the Atlantic by the Strait of Gibraltar (1.5 km wide and 290 m deep), 2- with Marmara Sea by the Dardanelles (between 450 m and 7.4 km wide and 55 m deep), 3- with the Red Sea by the Suez Canal (120 m wide and 1200 m deep).  

  15. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.1.Geographical setting • The Mediterranean sea has two major basins, western and Eastern that are separated by the Strait of Sicily (150 km wide and about 800 m deep). • The surface area of the western Mediterranean is about 0.85 million km2. • western Mediterraneanbasin includes the Alboran Sea, the Algerian Basin, the Algero-Provencal basin, the Balearic Basin, Ligurian Sea, Gulf of Lion, and the north and west Tyrrhenian Basins.

  16. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.1.Geographical setting • The Eastern Mediterranean (about 1.65 million km2) includes the Adriatic Sea, the Ionian Sea, the Aegean Sea and the Levantine  basin. • The eastern continental shelf is very narrow, not more than 8 km wide, except off the Nile Delta where 200 m depth contour lies 60 km offshore.

  17. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.1.Geographical setting • The major Mediterranean rivers (Ebro, Rhone, Po and Nile). • These rivers account for over 50 million tons annually of sediment injected into the system.

  18. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.2. Water circulation • The Atlantic water moves eastward as a surface along the North African coast from Gibraltar to strait of Sicily, where it enters the Ionian Sea basin of the eastern Mediterranean. It continuous eastward to reach the Levantine basin through the strait of Crete to the Egyptian coast where it finally entrapped in the large MarsaMatrouh anticyclone gyre . • The return of Mediterranean water is by way of Levantine intermediate water and Mediterranean deep water flowing from east to west and spilling over the sill of Gibraltar into the deep Atlantic. Such intermediate and deep water is produced by very pronounced evaporation processes which gradually transform surface water with salinity above 36 %o into denser water with salinity of 38.4 %o or more. • The estimated residence time for Mediterranean waters is 80 years.

  19. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.2. Water circulation

  20. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.2. Water circulation

  21. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.3. Water Balance • The total input water to the Mediterranean Sea is about1801 500 m3s-1. 1- through the inflow of Atlantic water from the Strait of Gibraltar (l675 000 m3s-1), 2- through the Dardanelles from the Black Sea and Sea of Mormara ( 87 600 m3s-1), 3- through the rivers run off (7 300 m3s-1), 4- through precipitation (31 600 m3s-1). * On the negative side of the balance there is outflow of water to the Atlantic (1 660 000 m3s-1 ), to the Black Sea (26 100 m3s-1 ) and by evaporation (115 400 m3s-1).

  22. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.4. Chemical Characteristics • Mediterranean sea does not have a chemistry of its own. Since residence time of the Mediterranean waters is about 80 years, most of the elements have plenty of time to tour the Mediterranean sea. • A fundamental characteristic of Mediterranean water is its impoverished nutrient concentration. • No deep nutrient rich Atlantic waters take part in the Mediterranean circulation. • the upper 150 m of the Atlantic water provide replacement for the Mediterranean Sea. • the only increase in the concentration of nutrients is due to river input and agricultural run off or pollution. • phosphate values in the Mediterranean vary from 0.l to 0.5 ugL-1. • The eastern Mediterranean has a smaller range of phosphate content than the western.

  23. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.5. Primary Productivity • The major productivity of the Mediterranean sea is low. • It ranged from (5-150 mg C/m3 /24 h). • the lowest values are in the south eastern basin (5-30 mg C/m3 /24h) . • The primary productivity in the central parts of the Mediterranean sea and in many of the coastal areas away from the influence of major rivers is rather low. • The principal nutrients, such as nitrogen and phosphorus, are often limiting. • Of the main source of the low nutrient content in the Mediterranean Sea is the surface Atlantic waters, which are low in nutrients. • The continental shelf of the southern Mediterranean is less productive than the shelf of the northern  Mediterranean where a number of rivers pour nutrients into the sea.

  24. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.6. Zooplankton • The general trends of zooplankton distribution (in which the Mediterranean areas are not affected by continental enrichment) show an increasing abundance toward the south-west end of the western basin.

  25. 1- CHARACTERISTICS OF THE MEDITERRANEAN SEA1.7. Benthic Fauna • The Mediterranean Sea is very rich in the variety of its benthic communities, although it is relatively poor in the quantity of organisms produced. • Its fauna is characterized by many endemic species and is considerably richer than the Atlantic coasts. • The percentage of endemic species is very high for the sessile or sedentary groups such as ascidians (50.4 %), sponges (42.4%), hydroids 27.1 %), echinoderms (24.3 %), decapod crustaceans (13.2 %) and demersal fishes (10.9 %).

  26. Thank you

  27. CONTENTS 2- MEDITERRANEAN FISHERIES 2.1. Fishing gears2.1.1. Purse seine 2.1.2. Trawls and dredges 2.1.3. Baited hooks and line gears 2.1.4. Gill nets 2.1.5. Trammel nets 2.1.6. Traps and pot 2.1. Fish Production

  28. 2- MEDITERRANEAN FISHERIES2.1. Fishing gears • Fishing gears used in the Mediterranean fisheries can be classified as active or static/fixed. - Active gears are those which involve motion and include trawls and dredges which are towed and purse seines which surround the school of fish. - Static gears are those which are anchored or fixed and depend on the movements of the fish to come into contact with the gear like longlines, gill nets, trammel nets, pots, and traps.

  29. 2- MEDITERRANEAN FISHERIES2.1. Fishing gears2.1.1. Purse seine • A purse seine is an active encircling gear, supported by floats, which is used to catch schooling fish in the upper part of the water column (pelagic species). • The depth and length of the net can be considerable, more than 100 m deep and 500m long in the case of large tuna purse seiners. • Once the net has been set around the school, the net is 'pursed', Closing the bottom as the net is hauled and trapping the fish.

  30. 2- MEDITERRANEAN FISHERIES2.1. Fishing gears2.1.2. Trawls and dredges • Trawls and dredges are active gears towed by one or a pair of fishing vessels. • Various types of trawls are used to target demersal species from relatively shallow inshore waters to depths of more than 1000 m, • as well as schooling or pelagic species in the water column. • Size selectivity of fish is a function of the mesh size used in the cod-end of the trawls.

  31. 2- MEDITERRANEAN FISHERIES2.1. Fishing gears2.1.3. Baited hooks and line gears • Include handlines, electric reels for fishing in deep water and longlines. • In the case of handlines and electric reels, the terminal tackle consists of a lead weight and a spall number of hooks, usually not more than six. • Longlines consist of a mainline to which is attached branch lines at regular intervals supplied with hooks. • Types of longline: bottom, semi- pelagic, vertical and pelagic. Bottom longlines target demersal species such as sea bream and cod. • The semi-pelagic longline has floats which lift the mainline off the bottom, and is used for species such as hake. • Vertical longlines are often used for very deep water species, • pelagic or drifting longlines are mainly used to target large pelagic fish (tuna, shark and billfish) with hooks suspended in the water column.

  32. 2- MEDITERRANEAN FISHERIES2.1. Fishing gears2.1.4. Gill nets • Gill nets are single sheets of netting, usually monofilament, with a weighted footrope and a headrope with floats, which are usually fished anchored on the bottom to catch demersal and benthic fish.

  33. 2- MEDITERRANEAN FISHERIES2.1. Fishing gears2.1.5. Trammel nets • Trammel nets consists of three sheets of netting: an inner small mesh panel (e.g. 80 mm stretched mesh) between two large mesh outer panels (e.g. 140 mm stretched mesh). • While some fish may be gilled or wedged in the smaller mesh netting, larger fish will push the small mesh netting through the larger mesh, forming a pocket in which they are tangled. • Trammel nets are widely used for species of flatfishes, sea breams and cuttlefish.

  34. 2- MEDITERRANEAN FISHERIES2.1. Fishing gears2.1.6. Traps and pots • Traps and pots are passive capture gears . • Bait may or not used as an attractant. • Traps have one or more openings and chambers in which the catch remains until the gear is hauled. • These gears are generally thought to be highly selective.

  35. 2- MEDITERRANEAN FISHERIES2.2. Fish Production • The Mediterranean total annual fish production was 1.4 million tons in 1998. • It seems unlikely that any under-exploited stocks have not been left in the Mediterranean, although in certain years and seasons there may be a sudden increase in abundance of some small pelagic stocks, often as a result of some temporary environmental condition. • It is only in Morocco that a substantial industry has been built up using marine fish (from Mediterranean Sea and Atlantic Ocean) as the main resource for large scale industrial processing and export of fish products.

  36. 2- MEDITERRANEAN FISHERIES2.2. Fish Production • FAO fisheries statistics consider almost 200 species or group of species in their Mediterranean database. • According to Scientific Advisory Committee (SAC) of the General Fisheries Commission for the Mediterranean (GFCM) only eleven species account for 50 % of the total Mediterranean landings. They represent shared and highly migratory stocks in the Mediterranean Sea and have high economic values.

  37. 2- MEDITERRANEAN FISHERIES2.2. Fish Production • These species were: • Demersal species (5) • European hake(Merluccius merluccius)Red mullet(Mullus barbatus) Striped red mullet (Mullus surmuletus) Blue whiting(Micromesistius poutassou).Blue and red shrimp(Aristeus antennatus)Small pelagic species(3)Anchovy(Engraulis encrasicolus).Sardine(Sardina pilchardus).Sardinella(Sardinella aurita)Large pelagics (3)Blue tuna (Thunnus thynnus).Albacore(Thunnus alalunga).Swordfish(Xiphias gladiusi).

  38. 2- MEDITERRANEAN FISHERIES2.2. Fish Production

  39. 2- MEDITERRANEAN FISHERIES2.2. Fish Production

  40. Thank you

  41. 2- MEDITERRANEAN FISHERIES2.3. Fisheries of Egypt 2.3.1. Problems of Egyptian Fisheries a. Shortage of Nile flood b. Overfishing c. Pollution 2.3.2. Change in Egyptian Fisheries 2.3.3. Fishing Gears 2.3.4. Main Fishing Areas

  42. 2- MEDITERRANEAN FISHERIES2.3. Fisheries of Egypt 2.3.1. Problems of Egyptian Fisheries • Shortage of Nile flood • The Mediterranean Egyptian Fisheries was affected by the construction of the Aswan High Dam. • The extruded flood water into the Mediterranean decreased from 43.5 Xl012 m3 (before the dam) to 4.4 x 1012 m3. • The coast salinity increased by about 2.3 mg/l • The coast and transparency was increased from 10 m to 20 m. • The silicates and phosphates was extremely decreased and this causes great reduction in phytoplankton to become 100 times less. • The abundance and size of different aquatic populations, particularly sardine were decreased.

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