Biodiversity of commercially important finfish species caught by mid-water and bottom trawls from two different coasts of Arabian Sea: Threats and conservation strategies.

H. Ul-Hassan,K. Gabol,S. Mahboob,M. Waqar,N.A. Khan,A.M. Chatta,S. Rizwan,M.F.A. Abdel-Aziz,K. A. Al-Ghanim,M. N. Riaz,Saeed Saeed,Z. Masood,F. Al-Misned

doi:10.1590/1519-6984.249211

Abstract

This study was conducted to estimate the diversity and the occurrence of commercially important finfish species collected by twenty fish sampling site of Sindh and Baluchistan coasts of the Arabian Sea in Pakistan from January to December 2019. Additionally, physicochemical characteristics of seawater were analyzed from these selected sites and found to be within suitable ranges required for fish growth and survive. A total of 81287 fish individuals were collected and identified as 49 species belonging to 26 families in our study. The most diversified family was Sparidae (13 species) followed by Carangidae and Lutjanidae (4 species), Mullidae, Serranidae, Ariidae (3 species), and Sciaenidae (2 species). The remaining 20 families were represented by only one species. The values of Shannon diversity index calculated for the four selected habitats revealed that high fish diversity was reported at Sonmiani Coast (H'=1.81), while less at Ormara Coast (H'=0.23). Likewise, Evenness index (E) was high at Sonmiani Coast (E=0.50) and less fish diversity was reported at Ormara Coast (E=0.06). Reducing risks to threatened marine species in coastal habitats also requires conservation actions at multiple scales. Thus, it was concluded that our study could be valuable in providing the more information's regarding to the diversity of finfish species and their occurrence along the Pakistan Coast. Further, to better understand the effects, regular monitoring and conservation measures should be taken to mitigate the influence of anthropogenic activities and protect finfish diversity from further decline.

Highlights

Fish is one of the chief sources of high-quality protein to consume one billion people globally (Ahmad et al, 2020; Khalid et al, 2021; Hassan et al, 2021a)
All these water samples were kept in polyethylene bottles stored in ice boxes and their physio-chemical analyzed were done in the laboratory of Marine reference collection and resources center (MRCC) of the University of Karachi
Among 49 species, high fish catch and relative abundance (R=91.6%), were reported for Netuma thalassina followed by Arius arius, Arius maculatus, Otolithes argenteus, Formioniger, Pampus argenteus, Lutjanus argentimaculatus, Acanthopagrus arabicus, Cynoglossus arel, Chanos chanos, Epinephelus coioides, Sillago sihama, Lutjanus malabaricus, Acanthopagrus berda, Acanthopagrus catenula, Pomadasys kaakan(ni=124; R=0.15%), Muraenesox cinereus, Platycephalus fuscus, Caranx malabaricus, Lutjanus rivulatus, Rastrelliger kanagurta, Coryphaena hippurus, Lutjanus fulvus, Acanthopagrus bifasciatus

Summary

Introduction

Fish is one of the chief sources of high-quality protein to consume one billion people globally (Ahmad et al, 2020; Khalid et al, 2021; Hassan et al, 2021a). Fish as the second trophic level in a food chain, play a vital role in aquatic ecosystems. Vertebrate diversity is severely affected due to increased anthropogenic activities in aquatic ecosystem changes result in changes to the habitats of vertebrate species, parameters of water quality distinct biological and environmental variables (Hassan et al, 2020a). Microplastics is affecting certain factors including habitat conditions, overall health implications, improper gill functioning early life, reduced feeding intensity, immuno-suppression, compromised reproducibility, fish fatness, season, development pattern, degree of stomach completeness, gonad middle age, sexual category, size range, physical condition, and common fish form and maintenance techniques (Tesch, 1971; Froese, 2006; Jisr et al, 2018; Hassan et al, 2020b)

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Discussion

Conclusion