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

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, stock assessments have not yet been conducted. In the present study, the length-based Bayesian estimation method was applied for the first time to assess 20 single-species fishery stocks in the region. Catches of eight fish species from the Class Actinopterygii and 12 shrimp species 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 eight species were overexploited with an estimated B/B MSY (i.e., the current exploited biomass relative to the biomass producing the maximum sustainable yield) < 0.8 (range from 0.26 to 0.71). Three overexploited fish species (Gray's grenadier anchovy Coilia grayii, the big head croaker Collichthys lucidus, and the Trevavas croaker Johnius trewavasae) are commercially important food species in the region. All four overexploited shrimp species (the shrimp Parapenaeopsis cultrirostris, the Japanese snapping shrimp Alpehus japonicus, and the Caridean shrimps Palaemon annandalei and Palaemon carinicouda) are small-sized and have low commercial value. The threelined tongue sole Cynoglossus abbreviates, a commercially important species, was classified as fully exploited (0.8 ≤ B/B MSY ≤ 1.2). Osbeck's grenadier anchovy Coilia mystus and the Japanese mantis shrimp Oratosquilla oratoria, both commercially important food species in the region, had non-fully exploited statuses (B/B MSY > 1.2). The results revealed that some commercially important food fishes are overexploited in the region and that 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.

Assessments of 16 Exploited Fish Stocks in Chinese Waters Using the CMSY and BSM Methods

“…These decisions, if vigorously implemented, may help the stock to recover, in spite of the pollution and degradation of its habitat (Yang et al, 2012). Note, finally that the stock of C. mystus in the Min River Estuary was found to be in good shape (Zhang et al, 2020), thus suggesting a strong influence of local conditions.…”

“…Thus, there are still deficiencies regarding China's fish stock assessments: the range of species covered by assessments is narrow, evaluation methods are limited and the results are not usually expressed as B/B MSY , i.e., the ratio of stock biomass to the biomass that can produce the maximum sustainable yield (MSY) or other management-relevant indicators. Until recently, very few stock assessments were conducted that allowed for estimating the potential for stock rebuilding (Villasante et al, 2013), although this dire situation is now being overcome (see Zhai and Pauly, 2019;Ji et al, 2019;Liang et al, 2020a,b;Wang et al, 2020;Zhang et al, 2020).…”

Stock Status Assessments of Five Small Pelagic Species in the Atlantic and Pacific Oceans Using the Length-Based Bayesian Estimation (LBB) Method

“…This approach assumes constant recruitment, growth and mortality, and can provide the best available information if the LF data is representative of the exploited stock, including data-limited fisheries. The LBB method has recently been applied in the East Asian waters to assess some data-limited stocks (Liang et al, 2020;Wang et al, 2020;Zhang et al, 2020). Thus, even in most non-targeted species which are mostly data-limited, the LBB approach may be applied by fishery managers for precautionary management of these species.…”

Transcriptome Sequencing of the Endangered Species Elongate Loach (Leptobotia elongata) From the Yangtze River: De novo Transcriptome Assembly, Annotation, Identification and Validation of EST-SSR Markers

“…At present, elongate loach is an endangered fish species endemic to Yangtze River in China (Yuan et al, 2010). Like elongate loach, populations of many fish species in the Yangtze River are getting smaller (Zhang et al, 2020). That's why Chinese government has planned to carry out a ten-year forbidden fishing in the Yangtze River, which will be fully implemented since January 1, 2021 (Huang, 2020).…”