The Relation Between Marine Environment Factor And The CPUE Of Main Shrimp And Prawn In Inshore West Of Madagascar

This thesis utilizes the collected catch data, which was collected from May to July in 2012 by arms rack bottom trawl shrimp fisheries in Madagascar catch yield, to analyze the fish production, composition ratio, time fluctuation, and the spatial distribution characteristics of fishing grounds. Combining with the operating depth, surface water temperature, salinity, chlorophyll and other environmental factors data to study the relations between formation of shrimp fishery and each factor, and analyze and discuss discuss conditions and fluctuation rules about the formation of fishing ground fishery.The result shows, when the total production is 50.55 t,total CPUE is 30.21 kg/h. Penaeus indicus 、 Metapenaeus monoceros 、 other species such as Penaeus semisulcatu Penaeus semisulcatus, Penaeus monodon and Penaeus japonicas respectively is 40%, 43%, 17% of the total capture. Their corresponding fishing amount were 21.44 t, 16.22 t, 12.89 t per month.Monthly CPUE were 41.70 kg/h, 30.49 kg/h, 20.56 kg/h. Penaeus indicus、 Metapenaeus monoceros Penaeus monodon,Penaeus japonicas the weight of each is in the range of the 4.6 g ~ 75 g. In G4(19 ~ 26 g/only), the most production is 13.70 t. The weight of the Penaeus semisulcatus is in the range of the 25 g ~ 370 g.When it is in grade R2(100 g ~ 200 g), the largest production, is 1.25 t. At the same time catch some species of fish, mainly including Trichiurus lepturus, Anguilliformes, Ariussinensis Lacepede, Dentex tumifrons, etc.The monthly production of Penaeus indicus were 13.04 t, 4.18 t, 3.44 t, its corresponding CPUE value were 25.36 kg/h, 7.86 kg/h, 5.49 kg/h. The larger value of production appears in C4, C9, C10, C11 fishing area, the maximum value appears in C11 fishing area, it is 6.19 t, the maximum of CPUE also appears in C11 fishing area, it is 24.62 kg/h. In fishing area C1 、C2, C8 ~ C12,the CPUE value are all over 12.57 kg/h. the maximum value of production appears in the scope of 10 m to 15 m the depth,it is 8.99 t. The CPUE value increases gradually with the increase of water depth. The CPUE value has little differences. In 9.21 kg/h ~ 14.34 kg/h. The peak of CPUE appears within 27.5 ℃ to 28.0 ℃, it is 34.62 kg/h. When it is in the scope of 0 mg/m ~ 3 mg/m the chlorophyll-a,the CPUE all have larger values, but its value decreases gradually with the increase of chlorophyll- a. In the area of 34.4 ~ 34.4 the salinity, the value of CPUE were all large, its peak is in the area of 34.6 ~ 34.6,it is 23.75 kg/h. Overall, the CPUE decreases gradually with the increase of the sea surface salinity.The monthly production of Metapenaeus monoceros were 6.94 t, 8.42 t, 8.42 t and its corresponding CPUE value were 13.49 kg/h, 15.82 kg/h, 1.53 kg/h. In fishing area of C3 and C4, C10, C11, the yields are all over 3.27 t, a maximum of CPUE appears in C12 fishing area, it is 19.07 kg/h. The CPUE value increase gradually with the increase of the depth of water. In operating scope of depth of 15 m ~ 25 m, The CPUE value is 15.14 kg/h. The maximum CPUE value appears in sea surface temperature is 26.5 ℃ ~ 27 ℃ range, it is 33.37 kg/h. CPUE value gradually lose, 1 mg/m after ~ 2 mg/m radius after maximum, 14.78 kg/h. In sea surface salinity of 34.4 ~ 34.6 within the scope of CPUE peak, 19.47 kg/h.The monthly fishing yields of other species(Penaeus semisulcatus 、 Penaeus monodon、Penaeus japonicus) were 1.47 t, 3.67 t, 2.85 t and its corresponding CPUE value were 2.86 kg/h, 6.81 kg/h, 4.54 kg/h. The larger value of shows in C4 and C11 fishing area, they are 2.44 t, 2.09 t respectively. The production is concentrated in 10 m to 15 m. The CPUE peak appears in the operation depth of 20 m ~ 25 m,it is 6.52 kg/h. The CPUE value increase with the rise of temperature.In 4.00 kg/h ~ 5.85 kg/h the chlorophyll- a, the CPUE value has no much difference.The production is mainly concentrated in the salinity range of 34.8 ~ 35.4As a whole, the average value of CPUE decrease gradually with the increase of chlorophyll and salinity,increase with the rise of temperature,what’s more,With increase of operating depth,the CPUE gradually increased.The accomplishment of this study can be used for the sustainable development of fishing companies and utilize the local shrimp and prawn resources.At the same time,the result can reduce ecological damage to the seabed, provide scientific data to support the the company to be more efficient, to make production reasonably in order to boost profits, establish a good corporate image, enhance competitiveness of our fishing enterprises in the international market. The research for fisheries in this area also fill the gaps in Chinese offshore fishing on the west coast of Madagascar shrimp fishery.