Title Page
Contents
Abstract 9
1. Introduction 11
2. Materials and Methods 14
2.1. Study Area 14
2.1.1. The Region of El Kala 15
2.1.2. The Gulf of Annaba 15
2.1.3. The Gulf of Skikda 16
2.1.4. The Bay of Jijel 17
2.2. Prospecting of Fishing Areas 18
2.3. Collection of Biological Samples 19
2.4. Analysis of Sample 20
2.4.1. Numerical and Weight Abundance 20
2.4.2. Density 21
2.4.3. Biomass 21
2.4.4. Dominance 21
2.4.5. Frequency 23
2.5. Assessment of Fishery Resources 24
2.5.1. The Swept Area 24
2.5.2. Estimation of the Biomass with the Swept Area Method 26
2.6. Implementation of a Geographic Information System (GIS) 26
2.6.1. Georeferencing 27
2.6.2. Digitizing 27
2.6.3. Triangulated Irregular Network (TIN) 27
2.6.4. Digital Bathymetric Contour Map 28
2.6.5. Spatial Interpolation 28
3. Results and Discussion 30
3.1. Abundance of Target Species per Stratum 30
3.2. The Average Weight and Numerical Dominance 38
3.3. Frequency 39
3.4. Average Density and Biomass 40
3.5. Swept Area and Total Biomass 43
3.6. Spatial and Bathymetric Distribution of the Dominant Species 45
References 55
Appendices 61
Table 1. Distribution of the fishing hauls carried out during the ALDEM campaign by... 19
Table 2. The average weight and numerical dominance of each species for the years 2012... 38
Table 3. Frequency of each species for the two years 2012 - 2013 39
Table 4. Average densities (Ind/㎢) obtained during various bottom trawl survey carried... 40
Table 5. Average biomasses (㎏/㎢) obtained during various bottom trawl survey carried... 41
Table 6. Average density (Ind/㎢) per floor bathymetry obtained during various bottom... 41
Table 7. Average biomass (㎏/㎢) per floor bathymetry obtained during various bottom... 42
Table 8. Comparison of the estimated total demersal stock biomass (tons) for the Algerian... 44
Figure 1. General view of the Eastern Sector of the Algerian Coast. 18
Figure 2. Swept area. 25
Figure 3. Flow chart of the complete method for data processing using AutoCAD and Arc... 30
Figure 4. Percentage of target species captured in Stratum A (10-50 m)... 33
Figure 5. Percentage of target species captured in Stratum B (50-100 m)... 34
Figure 6. Percentage of target species captured in Stratum C (100-200... 35
Figure 7. Percentage of target species captured in Stratum D (200-500... 36
Figure 8. Percentage of target species captured in Stratum E (500-800... 37
Figure 9. Annual evolution of the registered Algerian fishing fleet... 43
Figure 10. Spatial, temporal and bathymetric distribution of European hake M. merluccius (㎏/㎢) in the Algerian... 48
Figure 11. Spatial, temporal and bathymetric distribution of red mullet Mullus barbatus (㎏/㎢) in the Algerian... 50
Figure 12. Spatial, temporal and bathymetric distribution of deep-water rose shrimp P. longirostris (㎏/㎢) in the... 52