Temporal and spatial distribution of CPUE in three species of shrimps and its relationship with environmental factors along the west coast of Madagascar
In this paper,shrimp trawl fishery yield statistics from Representative Office in Madagascar of China National Fisheries Corp.during 2012-2019 were used to analyze the spatial and temporal distribution of CPUE of the main target catch species(Fenneropenaeus indicus,Metapenaeus monoceros and Penaeus semisulcatus)and its relationship with major environmental factors based on generalized additive model(GAM).The fishery production data was first standardized by CPUE,the resolution of environmental data was transformed to get the preprocessed data,and then R software was used to build GAM model.The results showed that the CPUE of F.indicus showed a decreasing trend month by month from March,while CPUE of M.monoceros and P.semisulcatus increased first and then decreased with month.This difference indicated that the reproduction and supplement of the three main shrimp species along the west coast of Madagascar might not be synchronized in time.As a dominant species,F.indicus might reproduce before the other two species.As for spatial distribution,CPUE of F.indicus and M.monoceros increased from south to north in latitude as well as from east to west in longitude.The higher CPUE of P.semisulcatus was found in the north and south section of the fishing ground.In the north-south direction,CPUE of the three shrimp species reflected the trend of high in the north and low in the south,indicating that there was a preference for the distribution of the three main shrimp species in this sea area,and they preferred higher SST in this sea area.Significant effect of depth on CPUE of M.monoceros(P＜0.05)was detected,CPUE showed an obvious increasing trend with water depth from shallow to deep.For environmental factors,significant positive correlation was found between runoff on CPUE for M.monoceros(P＜0.05)and P.semisulcatus(P＜0.05),CPUE of both shrimps increased with the increase of runoff.While significant effect of precipitation on CPUE of F.indicus(P＜0.05)and P.semisulcatus(P＜0.05)was detected,CPUE of both shrimps increased with precipitation.And CPUE of M.monoceros increased significantly with sea surface temperature(SST,P＜0.05),but significant effect of SST on CPUE for other shrimp species was not found.CPUE of M.monoceros(P＜0.05)and P.semisulcatus(P＜0.05)decreased significantly with the increase of sea surface height anomaly(SSHA).Significant effect of chlorophyll a concentration on CPUE of all shrimps was detected.(P＜0.05).There was a significant positive correlation between chlorophyll a concentration and CPUE of F.indicus and M.monoceros,while there was a significant negative correlation between chlorophyll a concentration and CPUE of P.semisulcatus.In conclusion,the abundance of main shrimp resource along the west coast of Madagascar has obvious temporal and spatial heterogeneity,and is susceptible to environmental factors,such as oceanographical factors,precipitation,runoff,and so on.The significance of this study is to provide a scientific basis for assessing the abundance of fishery resources,standardizing fishery management,maintaining fishery resources and ensuring the sustainable development of fishery in the area.
west coast of MadagascartrawlFenneropenaeus indicusMetapenaeus monocerosPenaeus semisulcatusCPUEenvironmental factors
万方数据
维普
