Training course in fish stock assessment and fisheries management National Institute of Oceanography and Fisheries Fish Population Dynamics Lab 10-14 November, 2013ns
Sustainability and overfishing Recruitment overfishing A situation in which the rate of fishing is (or has been) such that annual recruitment to the exploitable stock has become significantly reduced. The situation is characterized by a greatly reduced spawning stock, a decreasing proportion of older fish in the catch, and generally very low recruitment year after year. If prolonged, recruitment overfishing can lead to stock collapse, particularly under unfavourable environmental conditions. Restrepo V. (1999): Figure ref: http://www.oceansatlas.com/
Sustainability and overfishing Growth overfishing occurs when too many small fish are being harvested, usually because of excessive effort and poor selectivity (e.g. too small mesh sizes) and the fish are not given the time to grow to the size at which the maximum yield-per-recruit would be obtained from the stock. A reduction of fishing mortality on juveniles, or their outright protection, would lead to an increase in yield from the fishery. Ecosystem overfishing Occurs when the species composition and dominance is significantly modified by fishing (e.g. with reductions of large, long-lived, demersal predators and increases of small, short-lived species at lower trophic levels).
Control measures • FAO Code of Conduct for Responsible Fisheries specifies “...States... should adopt appropriate control measures, based on the best scientific evidence available, which are designed to maintain or restore stocks • Control measures are management measures designed to regulate fishing mortality AND biomass • Can and should include measures to protect habitat and marine biodiversity • Management Plans therefore need to consider other species in addition to target species
Control measures • We have already considered these and they include: • Input controls to control fishing mortality • Output controls to directly control biomass • Closed areas to protect habitat • Closed seasons • etc
Examples of Management Plan Objectives • Biological • Economic • Social, cultural etc
Length : 2000 Km Mean Width: 28Km Depth : 491 m Egyptian sector : about 1080 km Mean catch: 30,000 ton Red Sea
It provide about 64% of harvested fish in Egyptian |Red Sea (1980-2009). The Gulf of Suez extends about 250 km from Suez in the north to Shadwan Island in the south. Its width varies between 20 and 40 km Its mean depth is 45 m GulfofSuez
EGYPTIAN MEDITERRANEAN FISHERIES • The Egyptian Mediterranean coast is about 1200 km extending from El-Salloum in the West to El-Arish in the East. • The mean annual fish production from this vast area did not exceed 55 thousand ton (GAFRD; 1984 - 2009). • The main fishing gears operated in this region were trawling, purse-seining and lining specially long and hand lining. • The fishing grounds along the Egyptian Mediterranean coast are divided into four regions namely • About 67% of Mediterranean production comes from eastern sector
Challenges in marine fisheries • Over-exploitation due to the high fishing pressure • Illegal size nets and destructive fishing methods • Illegal harvesting of fish fry • Increasing of tourism and industrial expansion which cause damages in coastal ecosystem and pollution • Lack of information on fishery status in terms of biological, ecological, social and economic policy • Lake of awareness about the importance of fisheries regulations
Recommendations • Reduce the fishing effort by at least 40% • Make a reliable stock assessment and risk analysis studies for all of our fisheries • Make EIA for all projects built along the Mediterranean coast • Encourage the investment in small factories for fish processing, fish meal and net-making • Prohibit the harvesting of fish fry • Regulation of mesh sizes, controlling gear types used and prohibition the destructive ones.
Identify and protect the nursery and spawning grounds through the implementation of MPA • Train women and youth to use some of fish parts, bivalves and gastropod in decoration and souvenirs to find an income resources and improve their livelihood • Introduce the by-catch reduction devices • Improve the collection of national statistics on catch and fishing effort • Revise the current fisheries law and improve it.
Degradation, fillingup and drought Main Challenges
Pollution Spread of aquatic plants in many places in the lakes. Over-fishing, illegal fishing practices and illegal harvesting of fish fry The blockage of Boughazes Eutrophication
By-catch • The low awareness of fishermen about environmental issues and the importance of fisheries regulation measures.
Recommendations • Studying the dynamics, reproductive cycle and stock assessment of the commercial fishes as this is an important step in establishing guidelines for fishery-regulation measures. • Stocking the lakes with sufficient and suitable fish fry species. • Controlling and optimizing the water quality of the lakes. • Regulation of mesh sizes, controlling gear types used and prohibition the destructive ones.
Developing suitable fishing gear for shallow lakes as well as detecting the economic factors affecting the fishery. • Monitoring salinities at various seasons and localities • Continuous clearance of the openings for exchange of water masses between the lakes and the open sea. • Revision of fisheries laws and improving the system for collecting and compiling fisheries statistics • Examining the water inflow of the agricultural drainage canals and different drains into the lakes regularly to control polluted water inflow into the lake. • Construction marine hatcheries to cover the excessive demand on fish fry and juveniles for aquaculture.