Fishery Stock Assessments in the Min River Estuary and Its Adjacent Waters in Southern China Using the Length-Based Bayesian Estimation (LBB) Method

Lan-Lan Zhang,Bin Kang,Qing Xu,Qing-Qiang Ren,Xiao-Bin Jiang,Min Liu

doi:10.3389/fmars.2020.00507

Abstract

The Min River Estuary and its adjacent waters, connecting to the East China Sea, is one of the most important fishing grounds in Fujian Province, southern China; however, the stock assessments have not yet been conducted. In the present study, the length-based Bayesian estimation (LBB) method was applied for the first time to assess 20 fishery single-species stocks in the region. Catches of 8 fishes from the Class Actinopterygii and 12 shrimps from the Class Malacostraca were obtained from two commercial demersal trawlers, operated in the Min River Estuary and its adjacent waters in February, May, August and November of 2017 and 2018, covering all four seasons. The results showed that 8 species were overexploited with the estimated B/BMSY (i.e., the current exploited biomass relative to the biomass producing the maximum sustainable yield) 1.2). The results revealed that some commercially important food fishes are overexploited in the region, and small-sized, non-commercial food species can also be overexploited. There is an urgent need for local and national fisheries authorities to focus on coastal fishery management.

Highlights

Stock assessments are essential for managing the fishery resources exploited
The results provided valuable information for understanding the current degree of fishery exploitation in the region
C. grayii was listed as Least Concern in 2012 (Vidthayanon, 2012)

Summary

Introduction

Stock assessments are essential for managing the fishery resources exploited. The age composition of fisheries catches provide, for many fisheries in, e.g., Europe and North America, the key parameters for stock assessments and evaluations (Fournier et al, 1998; Sparre and Venema, 1998; Mesnil, 2003; Benjamin and Kurup, 2012; Mäntyniemi et al, 2013; Francis et al, 2016; Zhu et al, 2016). Length-frequency data, which can be collected from catches, have been widely used in stock assessments in both fishes (e.g., Munro, 1983; Fournier et al, 1990; Dennis, 1991; Pauly, 1998; Al-Qishawe et al, 2014; Nadon et al, 2015; Rudd and Thorson, 2018) and crustaceans (e.g., Pauly et al, 1984; Dineshbabu et al, 2007; Haist et al, 2009; Afzaal et al, 2016). T0, which cannot be estimated from length-frequency data alone, is the (usually negative) age they would have had at a size of zero if they had always grown in the manner predicted by the equation (which they have not; see, e.g., Pauly, 1998).

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Results

Conclusion