Sierra Leone - State of the Marine Environment 2015

5.4. Tuna and Billfish

5.9. Small pelagics – inner shelf (0–50)

The tuna species, which include Thunnus albacares (yellowfin tuna), Katsuwonus pelamis (skipjack) and Euthynnus alletterates (little tuna) are associated with upwelling zones. Tuna stocks are in good condition and improving according to results of the present assessment. 5.5. Inner shelf (0–50m) demersal fish assemblages The shelf demersal stocks include mainly the sciaenial fauna. Members of the sciaenial assemblage live above the thermocline on shallow muddy bottoms. Some 60–80 species have been identified with the dominant ones being Pseudotolithus elongatus , Drepane africana , Cynoglossus goreensis , Arius lasticutus and Dasyatis margarita . These stocks are under pressure from artisanal fishermen and from commercial trawlers (Fig. 5.2). They are in poor condition and in a state of decline according to results of stock assessments and the present assessment. 5.6. Outer shelf (50–200) demersal and benthopelagic fish assemblages According to the assessment and results of stock assessment surveys (2005, 2010) these assemblages are in good condition and stable. 5.7. Slope-demersal fish assemblages (>200m) According to the results of stock assessment surveys; (2005, 2010) these assemblages are in good condition. 5.8. Meso-pelagic fish assemblages

These fisheries are in a poor and declining condition. 5.10. Small pelagics – outer shelf (50–200) Stocks of small pelagics are in good but declining condition. 5.11. Inner shelf Shell Fish (Invertebrates, Squid, Crustaceans etc.) The two species of Cuttle fish, Sepia officinalis and Sepia berthelotii are found in the north and south of the EEZ on coarse ground at depths of 17–18m. There are four squid species; Thysanoteuthis rhombus and Toderopsis eblanae are demersal below 1000 meter depth. Molluscs such as bivalves are commercially important shell fish resources for the coastal communities. Mangrove oyster ( Crassostrea tulipa ) can be found on the roots of mangrove trees in coastal swamps and estuaries where they are harvested for subsistence as well as for commercial purposes. Other bivalves exploited include clams such as Senilia senilis , Anadara senegalensis , cockles and periwinkles ( Tympanotonus spp.). The Inner shelf shell fish populations are assessed to be in good condition. 5.12. Outer shelf and inner slope invertebrate species The invertebrate species of the outer shelf and inner slope also consist of the shrimps, cuttlefish and squid. These stocks are being exploited by commercial trawlers. They are in good condition according to results of the present assessment.

These assemblages are in good and stable condition.

Figure 5.2: Fish landings Sierra Leone (Sea Around Us project 2011)

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