Fish Stocks Research Articles

Projected habitat preferences of commercial fish under different scenarios of climate change

The challenges of commercial species with the threats of climate change make it necessary to predict the changes in the distributional shifts and habitat preferences of the species under possible future scenarios. We aim to demonstrate how future climatic changes will affect the habitat suitability of three species of commercial fish using the predictive technique MaxEnt. The dataset used to extract geographical records included OBIS (54%), GBIF (1%), and literature (45%). The output of the model indicated accurate projections of MaxEnt (AUC above 0.9). Temperature was the main descriptor responsible for the main effects on the distribution of commercial fish. With increasing RCP from 2.5 to 8.5, the species would prefer saltier, higher temperatures and deeper waters in the future. We observed different percentages of suitable habitats between species during RCPs showing distinct sensitivity of each fish in facing climate changes. Negative effects from climate change on the distribution patterns of commercial fish were predicted to lead to varying degrees of reduction and changes of suitable habitats and movement of species towards higher latitudes. The finding emphasizes to implement adaptive management measures to preserve the stocks of these commercial fish considering that the intensification of the effects of climate change on subtropical areas and overexploited species is predicted.

Accounting for spatio-temporal and sampling dependence in survey and CPUE biomass indices: simulation and Bayesian modeling framework

Abstract Estimating changes in the biomass of a fish stock is crucial for successful management. However, fishery assessment may be affected by the quality of the inputs used in stock assessment models. Survey biomass indices derived from fishery-independent and catch per unit effort (CPUE) biomass indices derived from fishery-dependent data are key inputs for model calibration. These indices have biases that could compromise the accuracy of the stock assessment models results. Therefore, there are plenty proposed methods to standardize survey or CPUE biomass data. From simpler models like generalized linear models (GLMs) to more complex models that take into account spatio-temporal correlation, like geostatistical models, and sampling dependence, like marked point processes. But many of them do not consider the underlying spatio-temporal or sampling dependence of these data. Hence, the goal of the study is to present a spatio-temporal simulation and Bayesian modeling framework to assess the impact of applying models that do not consider spatio-temporal and sampling dependence. Results indicate that geostatistical models and marked point processes achieve the lowest measures of error. Hence, to capture the underlying spatio-temporal process of the survey and CPUE biomass indices and data sampling preferentiality, it is essential to apply models that consider the spatio-temporal and sampling dependence.

PROTECTION OF BIODIVERSITY IN BERGUSHAD AND HAKARY RIVERS

The water resources formed in the territory of the liberated Karabakh region have special importance in the sustainable water supply of the republic. By using these water resources effectively and comprehensively, it is possible to reliably supply water to the population located in the territory of the liberated Karabakh and East Zangezur economic regions. It is necessary to efficiently use the water resources of these rivers, which are very loaded in autumn and spring. It is possible to fully meet the electricity demand of the population living in these economic regions by building hydraulic engineering devices for various purposes on these rivers and create large fishing farms by using the water resources that will be collected in the reservoir basins. In the article, the issues related to the management of the water resources of the Barghushad and Hekari Rivers, which have great hydropower and biological potential. Only the hydropower potential of the Okhchu River, which is located in the area and extremely polluted by Armenia, can be used. The water of the Okhchu River, which is extremely toxic and polluted with heavy metals, poses a serious threat to the fish stock of the Khudafar reservoir built on the Araz River.

Understanding How Parasites from Farmed Fish May Influence Wild Fish Declines Using Epidemiological Modelling

Beside various fields of its applications, in this study epidemiological modelling was used to understand how parasites from farmed fish may cause wild fish declines. Two separate strategic models were constructed addressing the transmission of micro-parasites and macro-parasites between farmed and wild fish: A SIR (Susceptible-Infective-Removed) model for micro-parasite infections and a compartmental density-dependent model for macro-parasite infestations. The results indicated that parasites originated in wild fish populations, after infecting farmed fish can cause epizootics. Subsequently, these parasites can be transmitted from farmed to wild fish and might have negative impact on the dynamics of wild fish populations. Sensitivity analysis of the basic model parameters in both models showed that model parameters, which are influenced by abiotic factors and allow passive manipulation, such as pathogen specific transmission rate (β), pathogen specific transmission rate between infected farmed and susceptible wild fish (δ), the rate of production of infective stages by an adult parasite (λ) and transmission rate between host and parasite infective stages (β) are more sensitive compared to model parameters which encompass chemical control and fallowing. This emphasizes the importance of the preventive medicine rather than intervention procedures in aquaculture aiming at eradicating epizootics caused by parasites and protecting wild fish stocks.

Exploring tradeoffs in southeast United States marine fisheries management using management strategy evaluation

Recreational fishing is the fastest growing sector in industrialized nations and can have substantial impacts on marine fish populations and ecosystems. Commercial objectives are typically characterized by maximizing yield and fishery stability whereas recreational anglers generally prefer sustained access to fishing and the availability of larger fish. Achieving these objectives while balancing tradeoffs between recreational and commercial fishing is essential to effective recreational and mixed-use fisheries management. Balancing multiple sector objectives is of particular concern in the southeast United States (US), where recreational fishing is the dominant source of mortality for marine fish stocks. We developed and applied a size-structured management strategy evaluation (MSE) tool, individually, to two stocks in southeast US Atlantic waters, black sea bass (Centropristis striata), a sedentary reef fish in overfished condition, and cobia (Rachycentron canadum), a migratory coastal pelagic fish, to evaluate the performance and tradeoffs of mixed management procedures against a variety of objectives. Several recreational and commercial objectives were aligned: fishers sought to conserve the stock and maximize catch, which simplified the evaluation of tradeoffs. We tested management procedures over alternate states of recruitment for black sea bass, and natural mortality for cobia. Management procedures that allowed harvest for black sea bass resulted in or risked an overfished status if the current weak recruitment regime continues, but could rebuild with no fishing regardless of recruitment state. Although results were sensitive to uncertainty in recruitment, no management procedures could achieve historic landings for either sector, and only management procedures that reduced effort consistently resulted in a reduced number of dead discards. No management procedures resulted in an overfished status for cobia. Management procedures for cobia generally achieved objectives and were robust to uncertainty in natural mortality. In both case studies, tradeoffs occurred between maximizing catch and season length and maintaining a stronger size structure in the population. This study resulted in a flexible MSE tool with strong potential utility for scoping management procedures that explicitly consider recreational fishing objectives.

The impact of ocean warming on selected commercial fisheries in New Zealand

AbstractWarming oceans affect the growth, reproduction and location of fish species. Using a bioeconomic framework, we estimate the relationship between sea surface temperature (SST) and the catch of de facto open‐access commercial fisheries of flatfish, trevally and jack mackerel in New Zealand. Assuming either a logarithmic or quadratic relationship between the SST and the carrying capacity of the fish stock, we consider three fishing methods (bottom trawl, set net and midwater trawl) and two measures of effort (count and duration). We show that ocean warming results in an increase in catch for all species if we assume a logarithmic relationship, with the highest marginal product of SST () for jack mackerel caught using midwater trawl. The highest marginal revenue product (computed by the MPSST, current price and fished area) is found for flatfish caught by set net. However, when assuming a quadratic relationship, there is a threshold above which catch starts to decrease, with the maximum catch of species ranging between 10 and 12.2°C. These results also vary spatially, with higher values of MPSST observed in areas closer to the South Pole. Our findings are relevant for any review of fisheries management systems in response to ocean warming.

Dynamic marine spatial planning for conservation and fisheries benefits

AbstractThe increasing global demand for marine resources raises concerns about sustainable resource management and biodiversity conservation. Spatial closures, such as marine protected areas, can be valuable tools for maintaining and restoring exploited populations. When these spatial closures adopt a dynamic nature being adapted to the changing environment, they can effectively account for factors such as shifting species distributions, which enhances their potential to achieve ecological and socio‐economic objectives. Here, we adapted a decision‐support tool (the software Marxan), typically used for selecting static and permanent areas, to produce management recommendations that integrate permanent and temporal closures to fisheries. Our aim was to compare the outputs of a static network of permanent no‐take reserves with four other dynamic scenarios, including permanent and temporal closures that account for seasonal variations in the populations of species. All scenarios prioritized sites for the conservation of one of the most valuable European fishing stocks, the Norway lobster (Nephrops norvegicus). Additionally, we considered 12 other commercially exploited species captured by the Norway lobster fishery. The assessed outputs included retained biomass, area extent, closure type (permanent and seasonal) and opportunity costs within each scenario. We observed that all dynamic scenarios required fewer management areas permanently closed than the static scenario. This resulted in a lower opportunity cost for fisheries but also a higher capacity for biodiversity conservation. Therefore, complementing permanent with temporal closures could enhance biodiversity conservation and fisheries management. The novel dynamic planning method presented here could be applicable to other species, ecosystems and socio‐economic contexts.

On possibility of using Danish seine to assess the stocks of commercial fish species

In modern conditions of less number of research expeditions, more information is collected by fishing vessels, where Danish seine is used as a fishing gear. Biostatistical data obtained by bottom trawl and Danish seine were compared in the joint survey in the Ussuri Bay (Japan Sea) and showed good comparability. Availability of the Danish seine using for assessment of fish stocks in this area is concluded.

Sustainable fish production in Egypt: towards strategic management for capture-based aquaculture

AbstractThis study assessed the sustainability of capture-based aquaculture (CBA) practices in Egypt, identified challenges, and proposed solutions to enhance sustainability. It relied on published data and studies, revealing that these practices are globally widespread for cultivating a diverse range of marine and freshwater species based on wild seed collection. The assessment showed that these practices in Egypt cultivate a variety of fish species. In 2021, they contributed to approximately 34% of the total aquaculture production, amounting to an estimated value of USD 1.476 billion, representing about 57% of the total value of the aquaculture sector. Additionally, these practices provided around 106,022 full-time jobs. Official fishery statistics have not indicated any negative impact of CBA on fish stocks over the past 30 years. Measures aimed at enhancing the sustainability of these practices included granting licenses for the collection of wild seeds for specific species under specific regulations. Facilitating licensing procedures for hatcheries, providing incentives, and promoting farmers’ preferences for hatchery seed were also part of these measures. Furthermore, these actions include facilitating access to financing under favorable conditions, selective breeding, training hatchery workers in best management practices, implementing biosecurity measures, and establishing an accurate statistical system. The implementation of the proposed plan to transition from capture-based aquaculture to hatchery-based aquaculture will contribute to achieving sustainability for both aquaculture and fisheries.

Life-history of masked water snakes (Homalopsis buccata) in Java: implications for the sustainability of harvesting

Context Masked water snakes (Homalopsis buccata, Homalopsidae) thrive in the muddy edges of agricultural ponds and canals in densely populated areas of West Java, Indonesia, and are harvested by local farmers to protect fish stocks and to provide meat, skins, and medicines for commercial use. Aims Here, we aimed to quantify sexual dimorphism and reproductive biology of H. buccata, so as to deepen our knowledge of the species’ inherent ability to withstand commercial harvests. Methods We examined carcasses of 4286 snakes at six processing sites to quantify biological attributes (e.g. sexual dimorphism in body size and shape, seasonality of reproduction, fecundity, reproductive frequency), with emphasis on traits that affect the ability of snake populations to withstand this intensive harvesting. Key results The snakes we examined were primarily adults (<1% juvenile), with approximately equal numbers of males and females except in January (when females comprised >90% of specimens). Females grow larger than males, and they are more heavy-bodied but shorter-tailed than are males of the same snout–vent length. Reproduction is seasonal in both sexes, with testis volumes decreasing to a minimum over the period August to November (late dry season) when most adult-size females were gravid. Litter sizes ranged from 1 to 37 (mean 12), increasing with maternal body size, with ~75% of females reproducing each year. Conclusions On the basis of these results, we infer that the life history of H. buccata (viviparity, high fecundity, frequent reproduction, rapid maturation) renders it inherently resilient to harvesting, especially because that offtake is based on males as well as females. Because a lack of sustainability is evident only in hindsight, regular monitoring of the trade could assure that any problems are detected rapidly. Implications To further buffer these populations from the impact of harvest, hunting could be restricted during January (a time when gravid females are disproportionately vulnerable) and the largest snakes (females, with high fecundity and reproductive frequency) could be excluded from harvests.

Sistem Sosial dan Ekologi Pantai Batu Pinagut

The interaction of social-ecological systems in coastal villages often causes problems, ranging from decreasing ecological quality to social conflict. This research aims to determine the description of the social interaction system in the coastal area and to determine the description of the ecological system in the coastal area of Kuala Kaidipang Village, North Bolaang Mongondow Regency. The data used is secondary data obtained by direct observation. The research results show that the separation between social and ecosystem management causes a decline in small-scale fisheries production on the coast due to a decline in fish stocks. The decline in fish stocks is caused by overfishing, habitat degradation and pollution. Open access further exacerbates the problem of overfishing. Managers and stakeholders face difficulties in designing and implementing effective management solutions. As for social interaction, it can be seen from 2 aspects, namely close relations between residents, interaction with the natural environment and coastal activities. Meanwhile, the ecological system includes coastal ecological systems including marine biodiversity, mangrove ecosystems, human activities and sustainability.

Improving Fish Quality and Yield: An Automated Monitoring System for Intensive Aquaculture

The growing interest in the fish farming industry is driven by the depletion of natural fish stocks in the market. However, intensive aquaculture systems, which involve raising fish in artificial tanks and cages, can lead to challenges such as low-quality fish and increased mortality rates, depending on the species being cultivated. To address these issues and maximize yield, this paper proposes a fish quality monitoring system with automatic correction. The system focuses on monitoring and maintaining critical water quality parameters essential for fish growth, including temperature, water level, and pH level. The system comprises an Arduino connected to sensors and a web-based application for data collection and monitoring. Correction devices such as an aquarium heater, a valve, and a water pump are integrated into the system to maintain these parameters at optimal levels for fish development. To assess the system's efficiency and reliability, two fish monitoring setups were compared: one using the proposed controlled system and the other using a traditional setup. Results indicate that the controlled system increased efficiency, reduced stress on fish farmers, decreased fish mortality rates, and improved product quality compared to the traditional setup.

Lower fishing effort would benefit fish stocks and fisheries profitability in the Gulf of Lion in the Mediterranean Sea

The increasing pressure on marine resources due to the high demand for fish and fishery products from an increasing population can lead to the overexploitation of fish stocks worldwide. In addition, climate change has already impacted fish populations pushing them towards states never seen before with a risk of irreversible changes. Evaluating the socioeconomic consequences of climate and anthropogenic impacts is challenging due to the large variety of interactions between social, ecological, and economic systems that make future effects difficult to predict. In this study, we develop climate-socioeconomic scenarios for the Gulf of Lion’s most important commercial fisheries using the MEFISTO bioeconomic model. Here, the biomass, catches and profit changes for the main commercial species (anchovy, sardine, hake and red mullet) and three fleets (demersal trawlers, gillnets, purse seiners) are modeled. We project the potential future storylines of fisheries under four different climate-driven and socio-political scenarios considering changes along three components: (i) climate change affecting fish stocks’ productivity through physiological processes, (ii) economic changes impacting fish price and fishing costs and (iii) technological management (fishing effort). Under alternative assumptions of productivity, market and management changes, our results indicate that fishing mortality reductions would mitigate the impacts of climate change and economic volatility over the GoL fisheries. An improvement in the overfished fisheries' management seems to be the main driver of change by 2050, over the direct impact of climate change. The market volatility (fluctuations in fish and fuel prices) will also be key for the future viability of Mediterranean fisheries.

Trade-offs between spatial temporal closures and effort reduction measures to ensure fisheries sustainability

Overexploitation has led to large scale declines in many fish stocks around the world with the 2030 United Nations agenda calling for more spatial management tools to achieve sustainability targets. However, without spatially explicit consideration of fisheries dynamics, assessment of management measures combining spatial temporal closures and effort reduction measures remain limited. This is particularly true when balancing population biomass recovery goals and their socioeconomic consequences. Using ISIS-Fish, the first spatially explicit bioeconomic model describing hake (Merluccius merluccius) fisheries in the Gulf of Lion, Mediterranean Sea, we investigated the consequences of individual spatial temporal closures and spatial closure network effects with all-at-one and gradual effort reduction measures. Their effectiveness in restoring the collapsed population and economic objectives were quantified to identify measures best suited for rebuilding population biomass, increasing catch weight, and maintaining revenue levels. While severe effort reduction was more effective in achieving population recovery goals than spatial temporal closures, these scenarios did not lead to an increase in catches until after five years. In contrast, spatial temporal closures failed to reach population recovery goals at any point during the simulation period, but impacted revenues the least. Simulated effort redistribution also led to greater depletion of juvenile hake, a pattern common elsewhere in the world. The present study illustrates how robust spatially explicit models may be used to evaluate the impacts of complex alternative management scenarios and to identify tradeoffs between biomass recovery, fishery viability, and the management equitability (and acceptability) between fishing fleets.

On the probable distribution of stock-recruitment resilience of Pacific saury (Cololabis saira) in the Northwest Pacific Ocean

Abstract Determining how resilient a stock-recruitment relationship is to environmental variation is crucial for fisheries management. Steepness is a key factor characterizing the resilience of a fish stock and, hence, for establishing management reference points. This study estimates the distribution of steepness for Pacific saury using a simulation approach based on evolutionary ecology and reproductive biology, and how it changes in response to environmental change. The median estimated steepness is 0.82 (80% probable range 0.59, 0.93) based on the best available biological information, which suggests that Pacific saury can produce a relatively high proportion of unfished recruitment when depleted to 20% of unfished spawning biomass. Elasticity analysis indicates that steepness for Pacific saury is most sensitive to the survival rate of early life stages, mean body weight, growth, and length-at-maturity. Environmental change could substantially impact steepness, with unfavorable conditions related to survival rates, length-at-maturity, mean body weight, and growth potentially leading to a reduction in resilience. Understanding these impacts is crucial for the assessment and management of Pacific saury. Our numerical simulation approach provides an analytical tool applicable for calculating the steepness distribution in other small pelagic fish influenced by increases in sea surface temperature due to global warming.

Asymmetrical individual both left and right otoliths of Tuna Scombrini collected from the Java Sea

Otolith can be used as a natural marker of fish stock or anomalies between individuals within fish stock. This research aims to study the relationships between fish length and otolith length and confirm differences in otolith shape between species in the Scombrini tribe and Carangidae family (Decapterus ruselli). Sample used in our analysis were collected around July - September 2023 from three different location, Rastrelliger brachysoma (Lekok waters, Pasuruan), Scomber australasicus (Bali Strait waters) and Decapterus ruselli (Sendang Biru, South Malang). Total 96 specimens were identified based on morphological character as Rastrelliger brachysoma, Scomber australasicus and Decapterus ruselli. Each of following samples were cut horizontally at the frontal head to open the skull and remove sagitta otolith below the hindbrain using dissecting set, then cleaned and stored dry in microtube 1,5 ml separately for left and right to further documented using Celestron Digital Microscope Pro Gray USB 44308. Otolith morphometric data collected includes maximum length using TpsDig and weight using analytical balance. The relationship between Forked Length (FL) and otolith length, length-weight relationship of otolith was determined using simple linear regression on software Statistical Product and Service Solutions (SPSS). Paired sample t-test was applied to determine asymmetrical size of left and right otoliths. In this study, it was found that the shape of the otoliths between species has differences in the rostrum, antirostrum, ventral and dorsal parts. FL-otolith length relationship of S. australasicus, R. brachysoma and D. ruselli are Y=0,725+0,164X, r2= 0,519; Y=0,191+0,230X, r2= 0,911; Y=3,156+0,075X, r2=0,071 respectively. The LW sagitta relationship shows that there is a very strong relationship (P<0,05) between L and W of otoliths. The results of the Paired Sample T-test showed that there was no significant difference in the size of the left and right otoliths (Sig>0.05). Otolith shape is influenced by fish behaviour, diet and environment and it may be used as additional information to distinguish between tribe or even species. Otherwise, its asymmetric relationship and LW relationship may be potential new methods for stock discrimination and have other implications such as stock assessment, understanding natural asymmetry, and its potential applications in fisheries management and conservation.

Morphometrics and Truss-networking distances among three species of croaker (Johnius borneensis, Johnius argentatus and Johnius belangerii) from Bangladesh coast of the Bay of Bengal

Morphometric features are efficiently used for the differentiation of species and long-term management of fish populations. Truss analysis is a frequently used taxonomic method as well as a stock identification tool to dissimilitude the morphologically similar species. Using landmark-based truss networking techniques following 18 morphometric lengths, 10 meristic counts, and 23 truss-network distance, the morphological variation of three croaker species viz. Johnius borneensis, Johnius argentatus, and Johnius belangerii were examined from Bangladesh coast. Data were analyzed and visualized through univariate ANOVA, canonical discriminate function analysis (DFA), and principal component analysis (PCA). Results found that the first DFA was responsible for 80.6% &amp; 81.1%, whereas the second DFA was responsible for 19.4% &amp; 18.9% variations among three species for the morphometric and truss-distances, respectively. In addition, 14 out of 18 morphometric and 12 out of 23 truss-network measurements were significantly different (p &lt; 0.05) among means of three species. 1st PCA found 70.76% &amp; 64.49% explained variations and 2nd PCA displayed 12.8% &amp; 11.5% explained variations respectively for morphometric and truss distances. The findings of the study demonstrates that J. borneensis and J. belangerii are highly morphologically similar and J. argentatus is completely distinct which might be due to their physiological and genetic variations. The present study might be helpful in differentiating species and managing existing stocks of marine fish. Further studies regarding the molecular characterization of the Cytochrome c oxidase subunit I (COI) gene could confirm the genetic variations among these species. Bangladesh J. Zool. 51(3): 233-251, 2023

Interplay of management and environmental drivers shifts size structure of reef fish communities.

Countries are expanding marine protected area (MPA) networks to mitigate fisheries declines and support marine biodiversity. However, MPA impact evaluations typically assess total fish biomass. Here, we examine how fish biomass disaggregated by adult and juvenile life stages responds to environmental drivers, including sea surface temperature (SST) anomalies and human footprint, and multiple management types at 139 reef sites in the Mesoamerican Reef (MAR) region. We found that total fish biomass generally appears stable across the region from 2006 to 2018, with limited rebuilding of fish stocks in MPAs. However, the metric of total fish biomass masked changes in fish community structure, with lower adult than juvenile fish biomass at northern sites, and adult:juvenile ratios closer to 1:1 at southern sites. These shifts were associated with different responses of juvenile and adult fish to environmental drivers and management. Juvenile fish biomass increased at sites with high larval connectivity and coral cover, whereas adult fish biomass decreased at sites with greater human footprint and SST anomalies. Adult fish biomass decreased primarily in Honduran general use zones, which suggests insufficient protection for adult fish in the southern MAR. There was a north-south gradient in management and environmental drivers, with lower coverage of fully protected areas and higher SST anomalies and coastal development in the south that together may undermine the maintenance of adult fish biomass in the southern MAR. Accounting for the interplay between environmental drivers and management in the design of MPAs is critical for increasing fish biomass across life history stages.

Unintended use of a calculative practice: conflicting institutional logics in the Norwegian fishing industry

PurposeThis paper explores how conflicting institutional logics shape the behaviors of macro- and micro-level actors in their use of a calculative practice. Thereby, this paper explains how quantification can undermine the intended purpose of a governance system based on a single number.Design/methodology/approachThe study draws upon the literature on calculative practices and institutional logics to present the case of how a single number—specifically the conversion factor for Atlantic Cod, established by macro-level actors for the purposes of governance within the Norwegian fishing industry—is interpreted and used by micro-level actors in the industry. The study is based on documents, field observations and interviews with fishers, landing facilities, and control authorities.FindingsThe use of the conversion factor, while intended to protect fish stock and govern industry actions, does not always align with the institutional logics of micro-level actors. Especially during the winter season, these actors may seek to serve their interests, leading to potential system gaming. The reliance on a single number that overlooks seasonal nuances can motivate unintended behaviors, undermining the governance system’s intentions.Originality/valueIntegrating the literature on calculative practices with an institutional logics perspective, this study offers novel insights into the challenges of using quantification for the governance of complex industries. In particular, the paper reveals that when the logics of macro- and micro-level actors conflict in a single-number governance system, unintended outcomes arise due to a domination of the macro-level logics.

Stock assessment and reproductive biology of bluespotted seabream Pagrus caeruleostictus (family: Sparidae)

AbstractBluespotted seabream Pagrus caeruleostictus, a member of the family Sparidae, is one of the high‐priced seabream species in Ghana. Although the fish has been exploited in the Gulf of Guinea for over hundreds of years, there is scanty information on the state of the fish stock. Hence, we sought to investigate the exploitation status and aspects of the reproductive biology of the species by collecting monthly length and weight data for 18 months (February 2016 to July 2017). These data were fitted to growth and mortality models. The sexual maturity, fecundity and spawning seasons were also determined within the same period. The growth model of the fish revealed that the asymptotic length (L∞) and growth coefficient (K) values determined were 52.7 cm (total length) and 0.52 year−1, respectively. The mortality models also showed that the fishing mortality (F) of the fish was 2.20 year−1, whereas its natural mortality (M) was 0.83 year−1, with F/M &gt; 0.5 indicating that the fish is over‐exploited. The lengths at first sexual maturity (Lm) of the males and females were 36.2 and 28.0 cm, respectively. Pagrus caeruleostictus, which was found to be highly fecund, had two spawning periods in a year, occurring in September and March, both with unimodal ova diameter frequency distributions. Based on these findings, we recommend that catch limits and other appropriate management measures (e.g. temporal and spatial closures) should be prescribed for the seabream fishery in the Gulf of Guinea to ensure the sustainability of the fishery.