Population genomic structure of small pelagic fish species of the genus Encrasicholina and Sardinella: implications to fisheries management in Tanzania

Population genomic structure of small pelagic fish species of the genus Encrasicholina and Sardinella: implications to fisheries management in Tanzania

The identification of small pelagic fish species based solely on morphological characteristics presents a challenge due to high variability and taxonomic difficulties, especially among species from the genera Encrasicholina and Sardinella. To date there are contradictory findings about species of genus Encrasicholina and Sardinella based on morphological identification. Additionally, the unique hydrographic conditions of the Tanzanian coastal region, influenced by channels such as Pemba, Mafia, and Zanzibar, may affect species composition, distribution, and genetic diversity. The existing study indicates the possibility of larva retention in these channels. Managing these resources without genetic insight could lead to ineffective conservation strategies and potential population collapse.

This study aims to investigate the genetic population structure of selected marine small pelagic fish species of the genus Encrasicholina and Sardinella found in Tanzania. Specifically, the study seeks to detect biomass composition of small pelagic fish species, determine the molecular phylogeny of species of the genus Encrasicholina and Sardinella, Analyse population genetic structural variation of Sardinella gibbosa across different water channels in Tanzanian marine waters and examine local adaptability signatures of Sardinella gibbosa along the coastal waters of Tanzania.

The study employs eDNA metabarcoding and DNA barcoding technique to detect small pelagic fish species found in Tanzanian waters and establish their phylogenetic relationships. The research also focus on determining genetic structures using Restriction Site-Associated DNA sequencing (RADseq), a next-generation sequencing method that facilitates the discovery of thousands of Single Nucleotide Polymorphisms (SNPs) in large sample sizes. 

This research is expected to provide crucial insights into the genetic structure of small pelagic fish populations in Tanzania. Moreover, the study will enhance scientific knowledge on the molecular basis and evolutionary relationships of small pelagic fish species in Tanzanian waters. The research is anticipated to result in three scholarly publications in reputable scientific journals, contributing significantly to the global discourse on fisheries management.