Fish Stocks Research Articles

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.

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.

Decadal changes in biomass and distribution of key fisheries species on Newfoundland's Grand Banks.

Canadian fisheries management has embraced the precautionary approach and the incorporation of ecosystem information into decision-making processes. Accurate estimation of fish stock biomass is crucial for ensuring sustainable exploitation of marine resources. Spatio-temporal models can provide improved indices of biomass as they capture spatial and temporal correlations in data and can account for environmental factors influencing biomass distributions. In this study, we developed a spatio-temporal generalized additive model (st-GAM) to investigate the relationships between bottom temperature, depth, and the biomass of three key fished species on The Grand Banks: snow crab (Chionoecetes opilio), yellowtail flounder (Limanda ferruginea), and Atlantic cod (Gadus morhua). Our findings revealed changes in the centre of gravity of Atlantic cod that could be related to a northern shift of the species within the Grand Banks or to a faster recovery of the 2J3KL stock. Atlantic cod also displayed hyperaggregation behaviour with the species showing a continuous distribution over the Grand Banks when biomass is high. These findings suggest a joint stock assessment between the 2J3KL and 3NO stocks would be advisable. However, barriers may need to be addressed to achieve collaboration between the two distinct regulatory bodies (i.e., DFO and NAFO) in charge of managing the stocks. Snow crab and yellowtail flounder centres of gravity have remained relatively constant over time. We also estimated novel indices of biomass, informed by environmental factors. Our study represents a step towards ecosystem-based fisheries management for the highly dynamic Grand Banks.

Recent Declining Trends in Pelagic Fish Catches in the Indian Ocean off Sri Lanka: Is Gill Oxygen Limitation Theory (GOLT) a Possible Explanation?

Recent trends in the pelagic fish landings of multi-day fishing fleets operated from Sri Lanka indicated significant declines in many fish species. Therefore, the present preliminary analysis investigates the perceptions of fishers on recent declining trends of pelagic fish landings from offshore areas of the Indian Ocean and further investigates whether the most common pelagic species landed in Sri Lanka conform to the gill oxygen limitation theory (GOLT) and to speculate GOLT as a possible explanation to such trends. According to the perceptions of 457 skippers of fishing vessels interviewed, such declines were possibly attributed to shifting of the areas of occurrence of pelagic fish species, making them less vulnerable to multi-day fishing vessels. As climate change and deoxygenation are major stressors affecting fish stocks, there is a challenging need for disentangling the impacts of these stressors from the effects of overfishing. The 18 most common pelagic fish species harvested from the Indian Ocean confirmed to the predictions from the GOLT, suggesting that shifting of these stocks could be due to deoxygenation which may have been triggered by increased sea surface and sub-surface temperatures. Therefore, fishery-independent surveys are needed to investigate the shifting of areas of occurrence of pelagic fishes in the Indian Ocean to understand their areas of occurrence the further investigate the relevance of GOLT for defining regional fisheries management plans.

Simulated reproductive allocation to fisheries-induced evolution among small yellow croaker populations in the Yellow and Bohai Seas

Fishery-induced evolution (FIE) affects the body size and reproduction of offspring, resulting in feedback regulation of fish survival and stock recruitment. Small yellow croaker (Larimichthys polyactis) is a species of high ecological and commercial importance in the Yellow and Bohai Seas, with large fluctuations in abundance linked to overfishing and environmental changes in recent decades. To better understand the maturation size and age, threshold reproduction cost, and energy trade-offs of small yellow croaker under environmental changes (e.g. conditions) and human impacts (e.g. fishing) in the Yellow and Bohai Seas, we utilised a two-pool uncertain growth model containing the growth threshold of reproductive energy and reproductive energy cost. The results showed that for growth, maturation age, and reproduction under the baseline scenario based on field survey data from the 1950 s, when resources for small yellow croaker were underexploited, the average age was 5–6 years old and the average body length was approximately 220 mm. As the model parameters for fishing pressure and condition mortality increased, small yellow croaker tended to mature earlier, had a smaller body size, and allocated more energy to reproduction, resulting in higher population fecundity but shorter lifespan. Higher reproductive costs led to a greater proportion of reproductive energy being allocated during the spawning period, resulting in an older age of sexual maturity, shorter lifespan for spawning populations, and poor physical conditions, resulting in higher post-reproductive mortality and a limited capacity for stock recruitment. The key life-history traits of small yellow croaker, including maturity age, mean age of the population, age-specific body weight, and spawn production at different age stages, can change under different conditions. The model represents the main life history strategies and energy allocation characteristics of small yellow croaker. The simulated age and body size were within the observed range and the predicted fecundity aligned with the observed values. This study provides a prediction tool for protecting the spawning and recruitment of small yellow croaker and establishes a biological reference for sustainable management of small yellow croaker populations in the Yellow and Bohai Seas in the future.

К изучению биологии судака (Sander lucioperca) в изменившихся экологических условиях северной части Аграханского залива Каспийского моря

The northern part of the Agrakhan Bay, which used to play a peculiar role of a receiving reservoir for migratory and semi-migratory fish migrating to spawn and wintering, and served as a kind of nursery for the development of larvae of their young, rolling here from spawning-growing reservoirs and the lower reaches of the Terek, in recent years, as a result of a critical decrease in river flow and a drop in the level of the Caspian. It has ceased to perform its main functions to increase fish stocks in the Terek-Caspian fisheries area. Among semi-migratory fish, the walleye is of particularly important fishery importance, as the largest and most valuable representative of the Percidae family in commercial and food relations. It was found that the structure of the walleye population in the northern part of the Agrakhan Bay in the last 2018-2021 turned out to be the most susceptible to unaccounted withdrawal, and its number is in a depressed state. It was revealed that the current level of reproduction of walleye in the bay turned out to be relatively lower as a result of intensive overgrowth and weak water availability. Histological examination of the gonads showed that the ovaries of walleye in the IV stage of maturity are for five months, from the end of October to April. It is established that the growth rate at different stages of development depends on environmental factors (hydro-hydrochemical and temperature regime of reservoirs, regime, salt balance, etc.) as well as their food supply.

Optimal harvest for predator–prey fishery models with variable price and marine protected area

In this paper, we propose a predator–prey fishery model with prey harvesting, variable price and marine protected area. We assume the price changes faster than other processes such as population growth and predation, and get a slow fast Ordinary Differential Equation (ODE) system. A simplified three-dimensional model is obtained by using approximate aggregation methods. The results show that there are two main scenarios, one is the depletion of fish stocks due to overfishing by fishermen, which is called a “catastrophic” equilibrium; and the other is a stable and sustainable fishery equilibrium. In order to avoid the extinction of fish, we consider establishing marine protected area (MPA) near fishing areas where fishermen only catch the prey. The results of the study provide the conditions for the establishment of MPA, allowing us to avoid the extinction of prey populations and establish sustainable fisheries. As another possibility, we consider increasing taxes to discourage overfishing by fishermen. In addition, when the tax revenue increases, the optimal harvest strategy is obtained. The optimal policy ensures the sustainable development of fisheries and maximizes the interests of fishermen.

Evidence of economic benefits from marine protected areas

Marine protected areas (MPAs) have been used for biodiversity conservation for decades. However, critics argue that evidence of their economic benefits is weak, particularly with regard to fisheries. This continued opposition to MPAs for fisheries slows progress towards conservation targets and undermines the economic and ecological sustainability of the oceans. This paper provides 48 examples of fishery-related and 31 of tourism-related economic benefits in 25 and 24 countries, respectively. There was no evidence of net costs of MPAs to fisheries anywhere. Fishery benefits included increased fish stocks, catch volumes, catch per unit effort, fecundity and larval export, and larger fish and lobsters. Well-designed and enforced MPAs provide sustainable benefits for fishing communities and even sub-optimally designed MPAs can provide economic advantages. MPAs represent one of the best strategies for maintaining the sustainable exploitation of marine resources.

APPLICATION OF BIOTECHNOLOGY IN AQUACULTURE

Biotechnology plays a major role in fish production through various techniques such as selective breeding , genetic engineering to enhance the growth rate and disease resistance in aquaculture . Fish culture business is fastest-growing sector of agricultural fields. The consumer demand for fish products continues to rise at an alarming rate. At the same time, wild fish stocks are declining at a fast pace due to over-fishing – a major concern. Every year, aquaculture contributes more than 18 million tons of fish and shellfish to the world's food supply. The increased public demands for fish, coupled with the dwindling natural marine habitats, have led scientists to study ways in which biotechnology can help boost fish and shellfish production. application of biotechnology allows researchers to identify and combine traits in fish and shellfish to enhance the productivity and quality . This article delves into the various ways in which biotechnology is applied to aquaculture and what the future holds for fish farming. The field of aquaculture has been revolutionized by the introduction of biotechnology. With the help of advanced genetic research, scientists have been able to enhance the growth of fish production.

Modelización bionómica de poblaciones de peces hiperestables. La pesquería de curvina golfina, Cynoscion othonopterus, como estudio de caso

Catch and fishing effort data are generally available, hence surplus production models are commonly used to conduct assessments. However, hyperstability resulting from spawning aggregations (SA) pose challenges to determine status and inform management of many fisheries resources. Using data from 1991 to 2019, we develop a method to study hyperstable fished stocks relaxing the assumption of constant catchability, hence direct dependence of catch-per-unit-effort and biomass. Information criterion was used to choose the best model including a Cobb-Douglas function for gulf corvina (Cynoscion othonopterus), a sciaenid fish endemic to the gulf of California managed through annual quotas. Bionomic stock-reduction models were fit using catch, effort, published natural mortality, virgin biomass, and economic structure. Models were solved using maximum likelihood and the best model chosen with Akaike information criterion. Current fishing effort is beyond bionomic optimum. This deserves a precautionary approach to protect this endemic species and sustain the fishery.