1. Introduction

The surimi industry, a significant part of the global seafood processing sector, heavily relies on the availability and sustainability of demersal fish stocks^[1][2] [1,2]. Hence, the demersal fish stock assessment is a cornerstone of sustainable fisheries management^[3] [3]. These fish live and feed on or near the bottom of seas or lakes, making their assessment crucial for maintaining the balance of marine ecosystems and ensuring the industry's long-term viability^[4] [4]. This detailed exploration delves into the importance, methodologies, challenges, and future directions of demersal fish stock assessment, highlighting its significance in sustainability in the surimi industry^[5] [5].

Understanding the dynamics of demersal fish populations is essential for several reasons^[6] [6]. First and foremost, it provides critical insights into these species' population dynamics, which are vital for formulating effective management and conservation strategies^[1] [1]. Accurate stock assessments also help prevent overexploitation, ensuring that fish populations remain sustainable^[7] [7]. This is particularly important for the surimi industry, which relies on a steady supply of high-quality fish to produce its products^[1] [1].

Overexploitation of demersal fish stocks, which describes excessive and unsustainable fish harvesting, can have severe ecological and economic consequences^[8] [8]. Depletion of critical species can disrupt marine food webs, negatively impacting other aquatic life and biodiversity^[4] [4]. Economically, a decline in fish stocks threatens the livelihoods of those dependent on the fishing industry, including fishers, processors, and related businesses^[9] [9]. Ensuring sustainable practices is an environmental concern and a socioeconomic necessity^[10] [10].

Several methodologies are employed to assess demersal fish stocks, each with advantages and limitations. One of those is the length-based spawning potential ratio (LBSPR), which is a prominent method for assessing fish stocks, especially in data-poor conditions, which refer to situations where there is a lack of comprehensive and reliable data on fish populations^[10] [10]. The LBSPR method estimates a fish population's reproductive potential by analyzing individuals' length distribution^[11] [11]. This approach is beneficial for data-limited fisheries where traditional stock assessment methods may not be feasible^[11] [11]. LBSPR provides insights into the spawning potential of the population, helping determine whether the stock is being fished sustainably^[12] [12].

Several case studies show where LBSPR has been successfully applied. For instance, studies conducted in Palau's Northern Reefs and the Sunda Strait in Indonesia show the effectiveness of LBSPR in assessing the stock status of key demersal species^[2][13] [2,13]. These assessments have guided management interventions to prevent overfishing and ensure sustainable harvesting [6]. Such practical applications underscore the method's value and potential to support sustainable fisheries management^[14] [14].

In addition, LBSPR needs to advance the sampling technologies to develop more accurate analyses^[15] [15]. Advanced sampling technologies, such as electronic catch assessment surveys, enhance the accuracy and reliability of stock assessments by providing detailed and systematic data^[16]. [16] These technologies, which include underwater cameras and sonar systems, facilitate more precise monitoring and managing of fish stocks, contributing to better-informed decision-making^[17] [17].

Despite the advancements in stock assessment methodologies, several challenges persist. One of the main challenges is obtaining reliable and high-quality data^[18] [18]. Accurate stock assessments require consistent and precise data collection, which can be challenging to achieve in remote or resource-limited areas^[19] [19]. Data limitations can lead to uncertainties in stock assessments, potentially compromising management decisions^[20] [20].

Additionally, variability in fish growth rates and environmental factors can affect the accuracy of length-based assessments like LBSPR^[21] [21]. Environmental changes, such as temperature fluctuations and habitat degradation, can influence fish behavior, growth, and reproduction, complicating the assessment process^[22] [22]. While LBSPR has shown promise, its adoption in the sector remains limited. More empirical studies and interdisciplinary research are needed to bridge the knowledge and methodological gaps in fish stock assessment^[23] [23]. Collaborative efforts among scientists, industry stakeholders, and policymakers are crucial to advancing these methodologies and ensuring their broader application^[23] [23].

2. Findings

To tackle these challenges and improve the sustainability of demersal fish stocks, there are several recommendations for future research and practice. Data collection quality and scope are crucial for accurate stock assessments^[24] [24]. In addition, historical sampling data to provide insights into changes over time and identify critical periods for conservation efforts should be incorporated^[25] [25]. Historical data can reveal trends and patterns not immediately apparent from short-term observations, informing long-term management strategies^[26] [26]. Interdisciplinary research combining ecological, economic, and social perspectives is essential for developing holistic management strategies [9]. Collaboration among researchers, fisheries managers, and industry stakeholders can foster a better understanding of the complexities of fish population dynamics and the impacts of fishing practices^[27] [27].

For example, studies in the Persian Gulf and Sea of Oman have highlighted the importance of stricter fishing regulations and adjustments in gear usage to allow juvenile fish to reach maturity^[28] [28]. Such interdisciplinary approaches can help balance conservation goals with socioeconomic considerations, promoting sustainable fisheries and supporting ecological and human communities^[29] [29]. The emphasis on the importance of multidisciplinary research should make the audience feel the need for collaboration and shared knowledge in the demersal fish stock assessment field^[30] [30].

Effective management practices, such as catch limits, size restrictions, and seasonal closures, are vital for maintaining fish populations at sustainable levels^[27] [27]. Hence, the tailored management strategies that account for the unique ecological characteristics of different fisheries can significantly contribute to the sustainability of fish stocks^[31] [31]. From this perspective, it can provide a more comprehensive understanding of global fish stock dynamics and support the development of region-specific management strategies [23].

Case studies from diverse regions, such as Liberia's coastal waters and Indonesia's blue-swimming crab fisheries, illustrate the importance of context-specific approaches to fisheries management^[9][21] [9,21]. Regional variations in environmental conditions, fishing practices, and socioeconomic contexts necessitate tailored strategies that address local challenges and opportunities^[14] [14].

Therefore, to achieve long-term sustainability, it is essential to address data collection and analysis challenges, promote interdisciplinary research, implement tailored management practices, and expand the geographic scope of the study. By embracing these recommendations, the surimi industry can contribute to the broader goals of marine conservation and sustainable resource management, ensuring the health and viability of demersal fish stocks for future generations. Focusing on these critical areas allows the surimi industry to navigate the challenges of fish stock assessment and promote sustainable practices that benefit both the environment and the economy.

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