Aquatic Living Resources最新文献

{"title":"Experimental estimation of ladder dredge efficiency for capture of European flat oysters over mixed sediment","authors":"Pauline Kamermans,&nbsp;Tom C. Cameron ,&nbsp;Russell Smart ,&nbsp;Alice Lown ,&nbsp;Alex Baker ,&nbsp;Rebecca Korda","doi":"10.1051/alr/2023021","DOIUrl":"10.1051/alr/2023021","url":null,"abstract":"<div><div>Fishing gear-based landings or survey methods are often used to make assessments of species stock abundance. In order to convert catch into abundance values, estimates or assumptions are made on the catch efficiency of the gear-based method. This is the case in areas where flat oysters, <em>Ostrea edulis</em>, are surveyed for fisheries and conservation objectives in a range of projects across Europe. Flat oyster dredge efficiency assumptions vary widely from 5–30% in published studies and uncertainty in what is an appropriate efficiency estimate has led some survey teams to switch to Catch-per-unit-effort (CPUE), where CPUE is also of concern should catch efficiency change with shellfish density, ground type or some other unmeasured variable such as shellfish distribution. We undertook an experimental approach to estimate dredge efficiency in a standard ladder dredge used to harvest and survey adult flat oysters in the UK and Ireland. The dredge efficiency trials assessed how efficiency was influenced by oyster density (between 1 and 2.2 oysters m²), distribution (clumped vs uniform) and ground types across a gradient of more hard to more soft surface sediments. Dredge efficiency was significantly affected by oyster distribution, but also density and ground hardness as well as their interactions. While a median value between 7 and 10% seems an appropriate universal ladder dredge efficiency to adopt, ground type and distribution had such an effect that local conditions may effect this considerably. Catch efficiency was negatively density-dependent, this makes CPUE methods challenging where oyster densities are likely to vary. Practitioners, regulators and researchers conducting surveys can improve CPUE approaches through standard techniques and knowledge of how catch efficiency varies as we have presented here.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57825003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pilot studies for stock enhancement of purple sea urchins (Paracentrotus lividus, Lamarck, 1816): usefulness of refuges and calcein marking for the monitoring of juveniles released into the natural environment","authors":"Pierre Boudry,&nbsp;Maria João Correia ,&nbsp;Patrícia Mega Lopes ,&nbsp;Pedro M. Santos ,&nbsp;David Jacinto ,&nbsp;David Mateus ,&nbsp;Francesco Maresca ,&nbsp;Bernardo Ruivo Quintella ,&nbsp;Teresa Cruz ,&nbsp;Sílvia Lourenço ,&nbsp;Ana Pombo ,&nbsp;José Lino Costa","doi":"10.1051/alr/2023009","DOIUrl":"10.1051/alr/2023009","url":null,"abstract":"<div><div>In the framework of stock enhancement, field experiments were conducted between March and July 2021 in rocky shores of Central Portugal to test the usefulness of refuges and calcein marking for juvenile sea urchins releases. Individuals with 10–20 mm in test diameter were captured in nature and tagged through immersion in a calcein bath with a concentration of 150 mg L⁻¹, during 48 hr. Artificial shelters were used to provide refuge and an acclimatization structure for the released sea urchins, and <em>in situ</em> monitoring was carried out by counting the marked specimens over three months. Results point out to the importance of using shelters to provide protection to sea urchins, and validated the efficiency of the calcein tagging protocol for <em>in situ</em> monitoring. Sea urchins' test diameter growth during the experiment was estimated to be 0.470 mm month⁻¹ (SD = 0.181).</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57825115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using a novel biologging approach to assess how different handling practices influence the post-release behaviour of Northern Pike across a wide range of body sizes","authors":"Verena Trenkel,&nbsp;Luc LaRochelle ,&nbsp;Declan Burton ,&nbsp;Jamie C. Madden ,&nbsp;Sascha Clark Danylchuk ,&nbsp;Steven J. Cooke ,&nbsp;Andy J Danylchuk","doi":"10.1051/alr/2023019","DOIUrl":"10.1051/alr/2023019","url":null,"abstract":"<div><div>There is a growing body of research focused on how angled fish respond to catch-and-release (C&amp;R). However, most of those studies do not span a wide range of body sizes for the targeted species. Physical injury and physiological responses to C&amp;R can be size-dependent, and methods used for landing fish of different sizes vary. As such, studying the response to C&amp;R across a range of fish sizes may help inform best practices that improve outcomes for released fish. Northern Pike (<em>Esox lucius</em>) widely ranges in body size. Anglers may land them by hand, cradle, or net, and they are often released voluntarily or to comply with regulations. We angled 25 Northern Pike (total length 620–1030 mm) from one population and recorded fight, handling, and unhooking times across landing methods (i.e., hand, cradle, net). Prior to release, a pop-off biologging package was temporarily affixed to each fish to monitor locomotor activity, depth, and water temperature during a 12-h period post-release to understand how the interaction of landing method and body size influenced post-release behaviour and short-term fate. Fight and handling time increased with increasing body size. Northern Pike landed with a cradle or net had shorter fight times but longer handling times, compared to fish landed by hand. Post-release locomotor activity was greater for larger fish and those landed with a net. Fish &lt;775mm and landed by hand had greater locomotor activity than fish landed with a net or cradle, while fish &gt;775mm landed by hand had reduced locomotor activity compared to fish landed with a net. There was no post-release mortality observed. Collectively, anglers should use a net for Northern Pike &gt;775 mm to avoid long fight times and reduce post-release exhaustion, but also attempt to reduce the extent of handling associated with fish landed by net.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Population dynamics of the European native oyster in a Marine Conservation Zone exposed to unregulated harvesting","authors":"Tom C. Cameron,&nbsp;David Smyth ,&nbsp;Rachel Millar ,&nbsp;Annika Clements ,&nbsp;Heidi McIvenny ,&nbsp;Maria Hayden-Hughes","doi":"10.1051/alr/2022023","DOIUrl":"10.1051/alr/2022023","url":null,"abstract":"<div><div>The implementation of closed zones as fishery management tools have been shown to be successful in the augmentation of habitat restricted species. A concerted restoration effort is currently being focused on the European native oyster throughout its natural range. This has been accompanied by an increase in oyster prices. In 2018 a native oyster for restoration purposes cost 80 pence sterling by 2021 the price had increased to £3.50. It is likely that these price increases have led to harvesting pressure on established wild populations. A number of recovering <em>Ostrea edulis</em> assemblages in Strangford Lough Northern Ireland are located within a closed zone which has been in operation since 2008. This research investigated the effectiveness of this restricted area in regards to protecting <em>O. edulis</em> assemblages. The study revealed that within policed regions of the restricted area the population increased from an estimated 1000 oysters in 2004 to &gt;88,000 in 2021. Furthermore, the age structure and population dynamics differed considerably from non-policed areas which still experienced harvesting. The research supports the use of closed zone legislation as a conservation tool with developing <em>O. edulis</em> populations. As newly restored populations become established, rising market prices will place these under increased harvesting pressure. The use of closed zones may offer a means of protecting these emergent populations.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fifty years of research to counter the decline of the European flat oyster (Ostrea edulis): a review of French achievements and prospects for the restoration of remaining beds and revival of aquaculture production","authors":"Pauline Kamermans,&nbsp;Stéphane Pouvreau ,&nbsp;Sylvie Lapègue ,&nbsp;Isabelle Arzul ,&nbsp;Pierre Boudry","doi":"10.1051/alr/2023006","DOIUrl":"10.1051/alr/2023006","url":null,"abstract":"<div><div>In the fifty years since the introduction of the Pacific oyster <em>Crassostrea gigas</em> and the first reports of the parasites <em>Marteilia refringens</em> and <em>Bonamia ostreae</em> in European waters, numerous research projects dedicated to the native European flat oyster <em>Ostrea edulis</em> have been conducted, notably in France. Most of these projects have been dedicated to developing controlled reproduction and hatchery technology for seed production, examining pathological aspects to understand and control diseases, and using genetics to develop resistant lines. While the long-term objective of most studies has been to revive the aquaculture production of <em>O. edulis</em>, a smaller number have addressed the ecology of local remnant beds and reefs in France. This article provides an overview of the major outcomes of all these projects, focusing on results obtained in France and prospects for future work there, taking into account the rising interest in increasing aquaculture production and ecological motivation to restore declining populations as part of the framework of the Native Oyster Restoration Alliance (NORA) and in line with UN Decade for Ecosystem Restoration.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applicability of the gape monitor to study flat oyster (Ostrea edulis) feeding behaviour","authors":"Tom C. Cameron,&nbsp;Linda Tonk ,&nbsp;Rob Witbaard ,&nbsp;Pim van Dalen ,&nbsp;Chiu H. Cheng ,&nbsp;Pauline Kamermans","doi":"10.1051/alr/2022021","DOIUrl":"10.1051/alr/2022021","url":null,"abstract":"<div><div>Innovative techniques are needed to assess oyster performance in flat oyster reef restoration projects. A valve gape monitor, a device that continuously measures opening and closing of live bivalves, can potentially be used as an effective method to determine survival and behaviour of the European flat oyster <em>Ostrea edulis</em>. The method has been successfully used in combination with a number of bivalve species to investigate valve gape activity in response to environmental factors. In this study, eight <em>O. edulis</em> were equipped with valve gape sensors in order to relate gape to environmental conditions such as food availability. Valve gape activity was monitored under controlled laboratory conditions, with and without food, in a concrete basin in the Oosterschelde and in the field (Voordelta, Dutch North Sea). Under controlled laboratory conditions, oysters clearly responded to changes in food availability. Starved oysters closed their valves significantly longer than oysters that received food, and the relative gape width in fed oysters was larger. In the concrete basin (Oosterschelde), a positive correlation between valve opening and Chlorophyll-<em>a</em> was found. Additionally, valve gape activity and tidal movement appeared to be linked. When exposed to a full tidal cycle (Voordelta), a negative correlation between valve opening and Chlorophyll-<em>a</em> was found. However, there was no correlation between valve gape and current velocity. In autumn, longer periods of inactivity were seen, but when valves opened, the valve gape was larger. These data indicate that valve gape can provide valuable information on behaviour (gape frequency and gape width), but also show that it is not necessarily a good proxy for feeding rate. Nevertheless, these results show that the gape monitor can be used to determine the natural behaviour of flat oysters under field conditions, and that gape opening provides information on behaviour and the stress response of bivalves to environmental conditions.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fishmeal replacement by mealworm (Tenebrio molitor) in diet of farmed Pacific white shrimp (Litopenaeus vannamei): effects on growth performance, serum biochemistry, and immune response","authors":"Pierre Boudry,&nbsp;Moslem Sharifinia ,&nbsp;Zahra Afshari Bahmanbeigloo ,&nbsp;Mehrzad Keshavarzifard ,&nbsp;Mohammad Hossein Khanjani ,&nbsp;Moslem Daliri ,&nbsp;Emad Koochaknejad ,&nbsp;Mohammad Sedigh Jasour","doi":"10.1051/alr/2023013","DOIUrl":"10.1051/alr/2023013","url":null,"abstract":"<div><div>Reducing the use of fishmeal (FM) in shrimp feed means significant savings in the amount of FM consumed globally and subsequently reducing production costs and environmental impacts. Insect meal (IM) is one of the protein sources to replace FM in aquafeeds. In this regard, this study was conducted with the aim of investigating the effect of replacing FM with mealworm (MW, <em>Tenebrio molitor</em>) on the growth performance, haemolymph biochemical responses, and innate immunity of <em>Litopenaeus vannamei</em>. Shrimps with a mean weight of 7.41 ± 0.13 gram were cultured in 300-liter fiberglass tanks (with a useful drainage volume of 200 liters) with a density of 20 shrimp per tank over a period of 60 days. Dietary treatments, including the control treatment (no mealworm; T0), 15% (T15), 30% (T30), 60% (T60), and 100% (T100) level of replacing FM with mealworm (MW), each with three replications, were investigated in the form of a randomized design. The results of this study showed a significant difference in body weight gain (BWG), feed efficiency (FE), feed conversion ratio (FCR), and hepatopancreas index (HPI) among the treatments (<em>P</em> &lt; 0.05). With the increase of the replacement of FM with MW up to 30%, BWG, FE, and HPI were significantly increased then reduced. The levels of cholesterol (Chol), triglycerides (Tg), and glucose (Glu) showed a decreasing trend with increasing replacement of FM with MW and revealed a significant difference with the control treatment at high levels of replacement (<em>P</em> &lt; 0.05). Besides, the results showed that replacing FM with MW had a significant effect on the activities of superoxidase dismutase (SOD), phenol oxidase (PO), lysozyme (LZM), acid phosphatase (ACP), alkaline phosphatase (ALP) and the total count of hemocytes (THC) in the practical diets compared to the control group (<em>P</em> &lt; 0.05). Overall, the findings suggest that MW is a promising alternative protein source for <em>L. vannamei</em>, as it enhances both growth performance and the immune system. The study recommends the use of MW in the diet of farmed species in the aquaculture industry, given its lack of adverse impacts on growth performance and its potential to reduce environmental consequences resulting from its production. The results also underscore the importance of exploring alternative protein sources to reduce dependence on FM and enhance sustainability in the aquaculture industry.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57825253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal structure of narrow-barred Spanish mackerel (Scomberomorus commerson) from the Red Sea and western Indian Ocean based on otolith micro-chemistry","authors":"Mohamed A. Sougueh ,&nbsp;Maylis Labonne ,&nbsp;Abdourahman Daher ,&nbsp;Ahmed Ali ,&nbsp;David M. Kaplan ,&nbsp;Catarina Vinagre","doi":"10.1051/alr/2023015","DOIUrl":"10.1051/alr/2023015","url":null,"abstract":"<div><div>Though the narrow-barred Spanish mackerel (<em>Scomberomorus commerson</em>) is considered to be migratory, the species is nevertheless thought to be locally overexploited in the northwest Indian Ocean. At the regional level, this local depletion is a major concern for food security. As the population structure and connectivity between sub-populations are poorly understood for this species, we examined the spatio-temporal dynamics of narrow-barred Spanish mackerel via elemental concentrations (P, Mg, Sr and Ba) along otolith transects using LA-ICPMS for samples from 6 sites: Egypt, Djibouti North and South, Somalia, Mozambique and South Africa. For homogeneous size class samples (70–90 cm), otolith chemical signatures immediately preceding capture were used to accurately group individuals sharing a spatial proximity and/or season of capture. Notable differences in otolith edge signatures were found among individuals from north and south of the equator and contrasting cluster compositions from nearby sites in the Gulf of Aden of individuals captured in summer versus winter. Otolith core chemistry identified two spawning chemical compositions. The first common composition was characterized by relatively high concentrations of Sr and lower concentrations of P, Ba and Mg. The second less common spawning chemical composition was particularly rich in P, Ba and Mg and corresponded primarily to individuals caught off Mozambique, Somalia and Djibouti. These results are broadly consistent on one hand with patterns of water mass circulation in the Red Sea and western Indian Ocean and on the other hand with the observed spawning seasons. Though further research using, for example, archival tagging is needed to clarify the mechanisms behind these patterns, these results reveal the potential of otolith chemistry to provide insights into the spatio-temporal dynamics of narrow-barred Spanish mackerel.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57825392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic diversity and structure assessment of Macrobrachium nipponense populations: implications for the protection and management of genetic resources","authors":"Carlos Saavedra,&nbsp;Yiwei Xiong ,&nbsp;Sufei Jiang ,&nbsp;Lijuan Zhang ,&nbsp;Jisheng Wang ,&nbsp;Wenyi Zhang ,&nbsp;Shubo Jin ,&nbsp;Yongsheng Gong ,&nbsp;Yan Wu ,&nbsp;Hui Qiao ,&nbsp;Hongtuo Fu","doi":"10.1051/alr/2023002","DOIUrl":"10.1051/alr/2023002","url":null,"abstract":"<div><div>This article presents a study of D-loop sequences to characterize the genetic diversity of wild <em>Macrobrachium nipponense</em> populations in Yixing natural waters including two reservoirs (Hengshan reservoir, HS; Youche reservoir, YC), 3 brooks (Linjin Dang, LJD; Magong Dushan Dang, MDD; Yangshan Dang, YSD) and 3 shallow lakes (Dongjiu lake, DJ; Xijiu lake, XJ; Tuanjiu lake, XJ), and compared the genetic differentiation and population structure with wild populations of Taihu Lake (TH), Yangtze River (YZ), and the main local artificially bred varieties “Taihu No. 2” (TH-2). A 747 bp D-loop sequence fragment was amplified in 321 individuals and the results exhibited a higher content of A+T (80.03%) than C+G (19.97%). A total of 110 haplotypes were identified. The <em>h</em> and π value proved the diversity of these populations was at the same level with high genetic diversity. TH-2 and YZ showed remarkable diversity, and XJ is even better. <em>Fst</em> estimates suggested that YZ and TH-2 were significant differentiation with other Yixing populations (<em>P</em> &lt; 0.05). Three populations from shallow lake (DJ, XJ and TJ) displayed significant differentiated with the left Yixing ones (<em>P</em> &lt; 0.05). The pairwise genetic distance, as well as haplotype network results, also suggested that all these 11 populations did not diverge at the species level (&lt;15%). The <em>P</em> values of Tajima's <em>D</em> and Fu <em>Fs</em> were relatively greater than 0.1 (<em>P</em> &gt; 0.1) and the nucleotide mismatch distribution analysis showed multiple peaks, giving a conclusion that the populations did not exhibited expansion. All these results suggested that TH-2 and YZ have remarkable diversity, and the germplasm resources and genetic diversity of <em>M. nipponense</em> in Yixing are very good and are suitable for original materials of breeding.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regional disparities and dynamic evolution of competitiveness of marine fish aquaculture industry − A study of China","authors":"Olivier Thebaud,&nbsp;Xun Cao ,&nbsp;Xin Shen","doi":"10.1051/alr/2023027","DOIUrl":"10.1051/alr/2023027","url":null,"abstract":"<div><div>China has emerged as a major player in marine fish aquaculture, contributing significantly to economic, social, and environmental development. Analyzing the competitive evolution pattern of regional marine aquaculture is critical to promote the synergistic development of this industry. The “vertical and horizontal” scatter degree method was employed to examine the dynamic evolution trend and spatial non-equilibrium of the competitiveness level of marine fish aquaculture in nine Chinese provinces and cities. Using the <em>σ</em>-convergence model and absolute <em>β</em>-convergence model, the evolution of absolute differences was characterized. The study reveals the existence of stage and regional characteristics of marine fish aquaculture in the nine provinces and cities, with an observable gradient effect. The overall difference is observed to decrease, indicating a trend towards regional synergistic development in the marine fish aquaculture industry. This finding holds practical significance and theoretical value in promoting the growth of the industry.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"36 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143306547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}