Search Results (4)

The Bay of Bengal (BoB) is a global hub for marine elasmobranchs, particularly sharks and rays. These apex predators maintain and structure the balanced marine ecosystem and food webs. Marine elasmobranchs in Bangladesh are under-researched and under-managed, and face threats such as habitat degradation, global warming, pollution, illegal fishing, and overexploitation. This study aimed to evaluate the stock status of marine elasmobranches in the Bay of Bengal (BoB), Bangladesh. This research used catch and effort (CE) data for a period of 21 years (2002–2022). Both the Monte Carlo CMSY and BSM models were applied to assess biomass, exploitation rates, and sustainable yields. The BSM estimated a maximum carrying capacity (k) of 134,000 mt, which is larger than the CMSY estimate of 119,000 mt. The estimated intrinsic annual growth (r) from CMSY was 0.282. The MSY values ranged from 5110 mt (BSM) to 8420 mt (CMSY), with BSM indicating overexploitation, as the 2022 catch (7017 mt) exceeded the BSM-derived MSY. Both models suggested depleted and overfishing stock conditions, with B/B_MSY ratios < 1.0 and F/F_MSY ratios > 1.0. Effective management is crucial to prevent overfishing and ensure sustainable practices. Elasmobranch catches must be kept below the BSM-estimated maximum sustainable yield (MSY) of 5110 metric tons with fishing pressure maintained at or below F/F_MSY = 1.0. It is vital to regulate illegal and unlicensed fishing activities. Because of the aggregation of CE data, the results should be interpreted cautiously and never serve as a substitute for species-level assessments. Full article

This research examined the biological reference points (BRPs) and stock status of the sardine fishery in the Bay of Bengal (BoB), Bangladesh, to determine the sustainability of this resource. The Monte Carlo method (CMSY), the Bayesian state-space Schaefer surplus production model (BSM), and the ASPIC (a Stock Production Model Incorporating Covariates) software suite, were used to analyze catch–effort data obtained from the Yearbook of Fisheries Statistics of Bangladesh. All models derived maximum sustainable yields (MSY) ranging from 37,900 to 41,280 t, which is quite near to the catch from the latest year (38,051 t in 2020), indicating the fully exploited status of sardines. The estimated B < B_MSY and F > F_MSY values from the BSM and Schaefer models indicate a poor biomass and an unsafe fishing status. For Schaefer and BSM, the calculated F/F_MSY values were 1.07 and 1.06, and the B/B_MSY values were 0.92 and 0.75, which also indicate the overexploited status of the sardine fishery in the BoB, Bangladesh. This information will aid in developing management strategies and conservation policies for the sustainability and rebuilding of this commercially important resource in the BoB on the Bangladesh coast. Full article

Fishery resources play an important role in the national economy and ecological diversity in China; it is of great significance to evaluate and rationally exploit the fishery resources. Most fisheries off the coast of China are data-limited, as the complex assessment models are not suitable for its resource assessment. Therefore, data-limited models for fishery resources assessment in China are among the current research hotspots. In this paper, two new data-limited assessment models (Bayesian state–space implementation of the Schaefer production model (BSM) and Monte Carlo MSY estimation model (CMSY)) were used to evaluate the fishery resources of Scomber japonicus and Muraenesox cinereus in the East China Sea. The results showed that the estimated value of MSY of S. japonicus was 220 × 10³ t to 240 × 10³ t, the estimated value of F/F_MSY was greater than one, and the estimated value of B/B_MSY was very close to one, indicating that the fishery in the East China Sea had been overfished. The estimated value of MSY for the M. cinereus fishery in the East China Sea ranged from 140 × 10³ t to 170 × 10³ t. The estimated value of F/F_MSY at the biological reference point was greater than one and the estimated value of B/B_MSY was less than one, indicating that the fishery had been overfished and resources had declined. Both models can be used for data-limited fisheries offshore of China. To better understand the impact of uncertainty on fishery resource assessment, more research should be carried out on these two data-limited assessment models. Full article

This research evaluated fisheries reference points and stock status to assess the sustainability of the croaker fishery (Sciaenidae) from the Bay of Bengal (BoB), Bangladesh. Sixteen years (2001–2016) of catch-effort data were analyzed using two surplus production models (Schaefer and Fox), the Monte Carlo method (CMSY) and the Bayesian state-space Schaefer surplus production model (BSM) method. This research applies a Stock–Production Model Incorporating Covariates (ASPIC) software package to run the Schaefer and Fox model. The maximum sustainable yield (MSY) produced by all models ranged from 33,900 to 35,900 metric tons (mt), which is very close to last year’s catch (33,768 mt in 2016). The estimated B > B_MSY and F < F_MSY indicated the safe biomass and fishing status. The calculated F/F_MSY was 0.89, 0.87, and 0.81, and B/B_MSY was 1.05, 1.07, and 1.14 for Fox, Schaefer, and BSM, respectively, indicating the fully exploited status of croaker stock in the BoB, Bangladesh. The representation of the Kobe phase plot suggested that the exploitation of croaker stock started from the yellow (unsustainable) quadrant in 2001 and gradually moved to the green (sustainable) quadrant in 2016 because of the reduction in fishing efforts and safe fishing pressure after 2012. Thus, this research suggests that the current fishing pressure needs to be maintained so that the yearly catch does not exceed the MSY limit of croaker. Additionally, specific management measures should implement to guarantee croaker and other fisheries from the BoB. Full article