Management of mediterranean fisheries [recovered]

Dr. Waheed M Emam
Prof. of Marine Biology
www.emam.byethost13.com

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.

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.

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.

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.

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.

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.

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.

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

SA= 2.5 million km2. Av Depth= 1.5 km TV= 3.75 million km3.,
West Basin=0.85 million km2 Lmax= 3800 km. Wma= 900 km
Gibriltar strait: 1.5 km wide, 290 m deep, Sicily Strait: 150 km wide, 800 m deep

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.

The Mediterranean Sea is connected with:
1- the Atlantic by the Strait of Gibraltar (1.5 km wide
and 290 m deep),
2- Marmara Sea by the Dardanelles (between 450 m
and 7.4 km wide and 55 m deep),
3- the Red Sea by the Suez Canal (120 m wide and
1200 m deep).

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 Mediterranean basin 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.


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.

The major Mediterranean rivers (Ebro, Rhone, Po and
Nile).
These rivers account for over 50 million tons annually
of sediment injected into the system.

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 Marsa
Matrouh 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.

1.3. Water Balance
The total input water to the Mediterranean Sea is about
1801500 m3s-1. This comes through :
1- the inflow of Atlantic water from the Strait of Gibraltar
(l675 000 m3s-1),
2- the Dardanelles from the Black Sea and Sea of Mormara
( 87 600 m3s-1),
3- the rivers run off (7 300 m3s-1),
4- precipitation (31 600 m3s-1).

1.3. Water Balance
• On the negative side of the balance there is outflow of water
to:
• 1- the Atlantic (1 660 000 m3s-1 ),
• 2- the Black Sea (26 100 m3s-1 )
• By evaporation (115 400 m3s-1).

Mediterranean sea does not has 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 ug L-1.
The eastern Mediterranean has a smaller range of
phosphate content than the western.

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.

1.6. 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.

1.7. 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 %).

1.8. Pollution
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 %).

CONTENTS
2- MEDITERRANEAN FISHERIES
2.1. Fishing gears
2.1.1. 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

2.1. 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.

2.1. Fishing gears
2.1.1. 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.

2.1. Fishing gears
2.1.2. 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.

2.1. Fishing gears
2.1.3. 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.

2.1. Fishing gears
2.1.4. 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.

2.1. Fishing gears
2.1.5. 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.

2.1. Fishing gears
2.1.6. 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.

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.

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.

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).

2.3. 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

a. 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.

b. Overfishing
The main reasons for overfishing are:
The continuous use of trawling in the area between Abu
Qir and Damietta.
The use of efficient nylon nets in restricted area.
The haphazard use of purse seine, particularly at day
time.
The currently used Italian trawling nets with narrow mesh
size in the cod end.
The use of beach seine in certain areas, despite its
illegal use.

c. Pollution
 Continuous drainage of industrial and other wastes into
the
Mediterranean
coast at Max and Abou Qir had affected mainly the fish
larvae and also the abundance of adult fish.
 Some species such as grey mullets have been greatly
influenced.
 The pollution through the lake sea connections hindered
the entrance of fry into the lake and adult fish from the
lakes to the sea for spawning.

The annual catch during the period from 1962-1968 was
subjected to continuous decrease from 38000 tons to about
12000s (with annual average of 23000 tons). This significant
decrease was mainly caused by the decrease in sardine catch
which amounted from 18000 tons to 1000 tons during this period.
Meanwhile, the shrimp catch was decreased from 7000 tons to
3000. About 60 % of the landed catch in this period was caught by
the trawling net.
 An average annual catch of about 8000 tons was landed during
the period from 1969-1977. The trawling catch constituted about
66 % of the total annual catch. The noted decrease was due to the
actual drop in the pelagic fisheries, mainly sardine.

The annual average catch greatly increased during the period
from 1978-1986 and reached 15000 tons. Meanwhile, the trawling
catch decreased to about 46 %. The sudden increase in the
average catch was relevant to the use of purse seine nets on large
scale, attracting the pelagic fish which flourished in the more
transparent water in the period of no flood.
The period from 1987-1991 was characterized by significant
increase in the Mediterranean production to about 40179 tons.
The annual catch was also increased to reach 89943 tons during
1999. This was followed by sharp reduction in fish catch to about
54872 and 59520 tons during 2000 and 2001 respectively. The
total annual production of shrimps, sardines and sea bream
represented about 33 % of the total annual fish catch.

2.3.3. Fishing Gears
a.) The Italian trawling net is the main gear and produces 45 % of the
total fish catch during the period 1987-1990.
b.) The purse seine net (Shanchaulla) is the second main gear and
produces about10 % of the total fish catch during the same period. The
fishing season of purse seine extends for 9 months (from March
-November). The maximum catch of purse seine could be taken in June
and July. The main catch of this gear is sardine (78 %).
c.) The beach seine is considered producers to about 20.5 % of the total
fish catch during 1987-1990.
d.) The long line produces about 3.4 % of the total annual fish catch
during 1987-1990.
e.) The gill and trammel nets frequently operate in the coastal zones and
produces about 3 % of the total fish catch during 1987-1990.
f.) Other types of gears and about 17 % of the total fish catch is produced
by using them.

a.) The Eastern area, extends 180 km from Port Said to Rafah , with total
area of about 2 143000 feddan, with rocky bottom except infront of EI-Arish.
b.) The Middle area, extends 300 km from Port Said to Alexandria and has
3090000 feddan total area. The bottom is muddy or silty muddy, suitable for
trawling where 80 % of fishing effort takes place. It includes five landing sites
(Port Said, Demietta, Borullous, Rosetta and Abou Qir). Demietta landing
site is the most important one and contributed by about 28 % of the Egyptian
Mediterranean landings.
c.) The Western area, from Alexandria to EI-Salloum (450 km), with 1
610000 feddan total area. Rocky bottom, not favourable mostly for trawling.
Fishing Boats used trammel net, gill nets and long line. In summer, large
boats are used in trawling on suitable grounds in Marsa Matrouh.

3- SPECIAL PROBLEMS IN FISHERY RESOURCES IN THE
MEITERRANEAN SEA
The General Fisheries Council for the Mediterranean (GFCM)
Definitions:
1- shared stocks : stocks of fish that migrate across the Exclusive
Economic Zone (EEZ) boundary of adjacent or opposite coastal
states.
2- Straddling stocks : stocks which occur in both within EEZ and
in an area beyond and adjacent to EEZ.
3- Highly migratory: stocks include marine species whose
life cycle includes lengthy migration, usually through EEZ of two or
more countries as well as into international waters (this term is
used to denote tuna and tuna-like species, marlins and swordfish).

MEITERRANEAN SEA
Problems of Shared and Straddling species:
1- Reasons :
•Interference of EEZs of 2 or more countries.
•Lack of co-ordination between management authorities
responsible for exploitation of shares species.
•Lack of information on shared and straddling stocks

MEITERRANEAN SEA
Problems of Shared and Straddling species:
2-Proposed action to overcome these problems:
•Issuing of limited licenses to fish
•closed fishery zones and/or seasons, (including marine parks or
reserves) .
•The collection of license fees for use of the resources, and
realistic penalties for misuse of the resources
•Strict monitoring and control of the disposal of organic waste and
nutrients into the shallow shelf-sea environment
•Promotion of studies aimed at improving fishing gear, gear
selectivity
•The establishment of a code of conduct for responsible fishing
with regular consultation between the industry and government.

MEITERRANEAN SEA
Discarding:
Wastage fish= (discarded fish )
1- Reasons :
•Target species may be discarded because they are too small or below minimum
landing size (MLS)or damaged upon capture and also will either not be
acceptable to the market or will command an uneconomic price.
•Target species which are acceptable to the market and legal may still be
discarded in favour of better sized or quality individuals.
•Marketable non-target species which have a lower value than the target species
may be discarded to reduce the workload on the crew or to preserve storage
capacity required for higher priced target species.
•Non-target species will be discarded if there is no financial return to be
generated once they are landed e.g. starfish have no commercial market value.
• At the beginning of a lengthy trip discards may occur of species which do not
keep well, such as shark.

MEITERRANEAN SEA
Discarding:
2- Proposed actions to reduce it:
•International, regional and national agencies have adopted a
number of measures to prevent discarding:
•Minimum landing size (MLS) below which fish may not be landed
for sale.
•Technical measures like regulation of mesh size in areas with
high discards.
•Closed areas to reduce discards by restricting fishing in areas
where catches of juvenile fish may be high.
•Identification of critical areas such as nursery zones where
discarding of juveniles occurs.

4- Potentials and Constraints for Sustainable Mediterranean Fisheries
Development:
The development of the Mediterranean has a number of dramatic changes in
its ecological bodies that are attributable not only effects of fishing, but also,
and perhaps independently, to the effects of the discharge of organic
wastes from human activities, toxic or nitrifying or otherwise into its marine
environment.
Two types of effects occur due to the human activities in Mediterranean Sea:
1- Top-down effects:
This due to the removal or reduction of apical predators (notably seals and
small cetaceans and in the numbers of large predatory fish such as bluefin
tuna).
This can lead to increase abundance of prey species of fish and other
organisms with low economic values.

4- Potentials and Constraints for Sustainable Mediterranean Fisheries
Development:
2- Bottom-up effects:
•These are due to Increased discharges of organic materials and nutrients
which lead to increased phytoplankton blooms of species different from
those found in un-enriched waters.
•These blooms can affect marine vegetation by reducing light penetration,
and in decomposition, lead to seasonal and eventually permanent anoxia of
bottom and shelf waters. and can cause a decline in benthos, crustacean and
molluscan shellfish, and in the demersal fish.
•In the pelagic food web, zooplankton species often a typical of the un-
enriched environment, increase in abundance. Initially, they support growth
of populations of small pelagic fish, but also of other pelagic predators of no
commercial value such as medusae (jellyfish and ctenophores).

5 Proposed actions to achieve sustainable Mediterranean Fisheries:
•Exploitation of the unexploited mesopelagic resources which include
mesopelagic fish, small crustaceans and cephalopods.
•Reducing the large proportions of edible by-catch that lost in fishery
operations.
•limited licensing of vessels.
•Coastal Mediterranean States should cooperate through meetings of a
regional management body attended by involving decision-makers
representing those States.
•strict control of discharge of toxic wastes, nutrients, silt and soil run-offs
and airborne pollution entering the sea .
•adjacent countries fishing a common stock, should co-operate to harmonize
their management regimes.
• preparing common data bases on the environment, resources and socio-
economic activities within and around the Mediterranean Sea countries.
•finding solutions to the problems of transit through straits and estuaries of
migratory fish species .

5 Proposed actions to achieve sustainable Egyptian Mediterranean
Fisheries :
• Assessment of the impact of the currently used fishing gear on stock of fish
and implementation of new gear with appropriate mesh size.
•Complete prevention of the beach seine.
•Management of fishing effort according to the type of gears to obtain the
maximum sustainable yield through:
Limitation of number and size of fishing vessels.
Prevention of fishing with all fishing gears during the period from April-
May (spawning season of most fish species).
Legislation of fishing gear and fishing activity.
Developing long-range fisheries of Egyptian marine waters by joint
venture agreements with Arabian and African countries to absorb excess
fishing effort.
Supporting financial structure of Egyptian fishery cooperative and union
of fishermen and offering subsides and other forms of incentives to
fishermen in closed season or areas and improving their living settlements.

6. Stock Assessment methods applying for Mediterranean Fisheries :
• Acoustic Technique
•Fishing Surveys
•Tagging Techniques
•Eggs and Larval surveys
•Stomach content analysis
•Catch and Effort statistics

• Acoustic Technique:
Advantages:
-Can be used to assess exploitable stocks which have not yet been fished.
-Provide the capability to survey a resource rapidly.
-Recommended to be used with pelagic stocks
Disadvantages:
-Do not provide species composition or other biological information
-Not suitable for most demersal stocks
-Has high costs
-Need well trained people

• Fishing surveys:
Advantages:
- provide species composition or other biological information needed
-Can be used to assess exploitable stocks which have not yet been fished.
-Provide the capability to survey a resource but not rapidly.
-Recommended to be used with demersal stocks
Disadvantages:
-Need similar fishing vessels working with the same fishing gears at the
same time.
-Has high costs

Management of mediterranean fisheries [recovered]

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