Coastal Ecology and Fisheries Management

1. Introduction to This Special Issue

Coasts, including estuaries, wetlands, mangroves, etc., have long been recognized for their critical role in providing and maintaining the ecological services on which we depend [1]. Even so, in the face of human development, the quality and quantity of coastal ecology worldwide are declining [2,3]. Although some estuaries, wetlands, and mangroves are protected, considerable investment in academic research is still required. At the same time, the aforementioned habitats have also been affected by coastal development and engineering projects [4,5]. In order to consider ongoing climate change and its impact on fishery resources, the identification and adoption of sustainable management practices for fish stocks have become global priorities [6]. The stock status of some selected fish species will be assessed by an expert working group based on country-specific requirements. These academic studies include: primarily, the economic (and/or ecological) importance of each species. Assessments are based on available data, the best available methods and/or biological knowledge about the species under consideration. Once inventory status has been assessed, decision makers are responsible for defining, evaluating and adopting management measures [4,5,7,8]. Recently, interest in multi-species and multi-trophic models has grown significantly, especially regarding the growing importance of assessing the health of different ecosystems [9,10,11,12,13]. In this context, it is believed that for the Special Issue, it is very important to determine the ecological status of estuaries, wetlands, mangroves, etc., to link multi-species fisheries management models, trophic relationships of exploited species and ecosystem responses to fishing pressure [14]. As well as other interacting drivers of polytrophic levels, identify the key environmental factors that drive the spatial distribution and habitat use of species [15,16,17]. This era has also fostered extraordinary collaboration among ecologists, environmental scientists, engineers, government officials, wildlife biologists and non-government officials.

This Special Issue was announced to advance research in this field. Researchers were invited to present their results related to estuaries ecology and management, wetlands protection and management, mangroves restoration and construction, fishery resource assessment, coastal fishery management, fishery management policy, coral ecology and protection, ecosystem services, coastal culture and aquaculture, and marine farming and construction.

In our opinion, the intended goal of this Special Issue was successfully reached: fifteen original papers have been published. Authors from China, South Korea, Costa Rica, Taiwan, and the United States presented their research findings, and these valuable contributions demonstrate the diversity of research topics and applied methods. To help readers familiarize themselves with the contents of this Special Issue, we provide a brief overview of the articles published below. The articles are arranged in the order in which they were published.

2. This Special Issue List and Summaries of the Contributions

All submissions to this Special Issue underwent rigorous peer review. In total, 15 papers were accepted for publication and are included in this special issue. A list of papers can be found in List of Contributions. As shown in

Table 1. Analysis of the published contributions in the Special Issue.

Number of Contribution	Research Area	Focus	Research Methods	Potential Applications
1	Marine fish diversity	Fish diversity monitoring in the Clarion–Clipperton Zone using eDNA metabarcoding	eDNA metabarcoding	Biodiversity management, environmental baseline for the International Seabed Authority
2	Coastal fisheries management	Estimation of fish richness in the Minjiang Estuary	Non-parametric estimation (Chao 2, Jackknife 1/2, Bootstrap), data collection and comparison	Marine biodiversity conservation, fisheries management decision-making
3	Coastal governance	Transformation of coastal governance model in Jimei Peninsula from human ecology to local state	Scale politics, local state research approach, interviews, observation, content analysis	Coastal governance optimization, cultural ecology protection
4	Fishery-solar power symbiosis	Effects of solar shading on growth of Litopenaeus vannamei and Chanos chanos and water quality	Comparative experiment (integrated system vs. traditional fishponds)	Sustainable marine resource management, green energy development in aquaculture
5	Crustacean population differentiation	Morphometric differentiation of Portunus sanguinolentus populations in East Asia	Allometric method, cluster analysis, canonical variate analysis (CVA), randomization tests	Stock identification and targeted fisheries management
6	Recreational fisheries sustainability	Population dynamics of Ranina ranina in South Penghu Marine National Park	Field sampling, literature comparison	Recreational fishing sustainable development, marine protected area management
7	Mangrove wetland ecology	Changes of meiofauna and marine nematode communities after Spartina alterniflora removal	Field sampling, community structure analysis, biodiversity index calculation	Estuarine wetland restoration monitoring, mangrove ecosystem protection
8	Fish stock dynamics	Long-term dynamics of walleye pollock stocks in relation to oceanographic changes in the East Sea	Long-term data analysis (length/sex composition, catch, oceanographic condition)	Fishery resource conservation, adaptive fisheries management
9	Intertidal sediment carbon cycle	Carbon reduction by sediment reworking through burrows of Laomedia sp.	In situ measurement, carbon concentration comparison	Coastal carbon sequestration assessment, intertidal ecosystem management
10	Heavy metal pollution in fish	Heavy metal concentrations and health risks in wild and cultured Oplegnathus fasciatus	Heavy metal detection, single factor pollution index (SFI), metal pollution index (MPI), health risk assessment, discriminant analysis	Food safety guarantee, public health protection
11	Mangrove wood anatomy	Variation in annual ring and wood anatomy of six mangrove species in Nicoya Gulf	Ecological anatomy method, wood property analysis	Mangrove adaptation research, coastal wetland ecological protection
12	Coastal engineering ecological assessment	Ecological effectiveness of Taiwan’s Ecological Check and Identification (ECI) mechanism	Case analysis (35 coastal engineering projects), participation in engineering projects	Sustainable coastal engineering construction, ecological protection in infrastructure development
13	IUU fishing control	Improvement of international cooperation frameworks for combating IUU fishing	Vessel characteristic analysis (independent-sample/paired-sample comparisons)	Transparent governance of fishery resources, sustainable use of fisheries
14	Squid fishery management	Refining management strategies for Todarodes pacificus fishing vessels in Korean waters	Bioeconomic analysis, scenario-based simulations, stepwise cost allocation	TAC system optimization, balanced biological conservation and economic sustainability
15	Fisheries regulation and community resilience	Political ecology of fisheries regulation and community resilience in Mississippi River Delta	Historical analysis, ethnographic interviews, participant observation	Fisheries regulation improvement, coastal community resilience enhancement

, these papers cover a wide range of areas related to coastal ecology and fisheries management. Topics covered include: marine fish diversity, coastal fisheries management, coastal governance, the symbiotic relationship between fisheries and solar energy, crustacean population differentiation, recreational fisheries sustainability, mangrove wetland ecology, fish population dynamics, intertidal sediment carbon cycling, heavy metal pollution in fish, mangrove wood anatomy, coastal engineering ecological assessment, illegal fishing reporting and non-fishing (IUU) and fisheries management regulations.

3. Overview of Contributions to This Special Issue

He et al. used environmental DNA (eDNA) metabarcoding technology to explore fish diversity in the Clarion-Clipperton area of the Eastern Pacific Ocean. A total of 22 samples were collected on board R/V XIANG YANG HONG 03 during the China Ocean 45 cruise in July 2017 and the China Ocean 45 cruise in August 2018, through WTS-LV Large Volume Water Transfer System (McLANE, Carrollton, TX, USA). The results showed relatively high abundance of the genera Mugil, Scomberomorus, and Scomber in the mesophyll and demersal zones. Fish diversity varied from sampling site to sampling site, with the highest species abundance observed at a depth of 2500 m. Environmental changes drove fish aggregation, showing a negative correlation between chlorophyll a concentration and fish community activity, while dissolved oxygen concentration showed a positive correlation. This study reveals the fish diversity patterns and environmental impacts of the CCZ, providing useful information for biodiversity management and environmental baseline data for the International Seabed Authority [contribution 1].

Wang et al. proposed a sustainable development perspective for nearshore fisheries management in the Minjiang Estuary based on estimates of fish species richness. The coastal districts of Minjiang Estuary, located in the coastal area of Fujian Province, were taken as a case study. This study collected and compared eight literature and survey data from 1990 to 2021, and used nonparametric estimation methods such as Chao 2, Jackknife 1, Jackknife 2, and Bootstrap to estimate fish species richness in the Minjiang Estuary and its adjacent waters. The estimated expected values for fish species richness are: 250 (Chao 2), 204 (Jackknife 1), 241 (Jackknife 2), and 174 (Bootstrap). The authors concluded that the Minjiang Estuary is affected by multiple factors, including freshwater erosion, ocean tides, waves, and ocean currents, resulting in complex and variable physicochemical conditions. These results reveal the possibility of fish species disappearing or becoming completely absent. Estuarine environmental conditions and their influencing factors are more complex and variable. To manage fishery resources in Fujian Province’s waters and achieve their sustainable development, it is essential to obtain biological information and conduct population assessments. This important information, especially for endemic species and species of significant economic value, can establish baselines. Once species changes exceed these baselines, they can provide a basis for marine biodiversity conservation and fisheries management decisions. Future research should refine these methods by employing appropriate survey methods based on the habits of different fish species. The overall reliability of the species richness estimation study in the Minjiang Estuary is crucial for improving water resource protection measures, formulating management policies, and protecting fishery resources [contribution 2].

Zou et al. analyzed the transformation of governance models along the Jimei Peninsula in Xiamen: from human ecology to local state. This study employs the methods of scale politics and local state to elucidate governance models in the transformation of coastal areas. From the theoretical perspective of local government, this paper effectively points out the political characteristics of local government and bridges the loss of cultural ecology during the transformation of governance models. The authors presented their findings in three parts: 1. Changes in governance along the Jimei Peninsula coastline; 2. Scale politics and functional shifts in coastal governance; and 3. The collapse of the coastal human ecosystem. The study found that local governments’ misappropriation of international plans to transform coastal areas into tourist cities was the first step leading to the ecological decline of coastal regions. This move directly deprived fishermen of their right to access the coast, completely dismantling centuries-old clan-based fishing organizations and ultimately causing the collapse of the coastal ecosystem. On the other hand, those who continued to work at sea were subject to discipline and punishment. Compensated fishermen were integrated into the outsourced workforce of tourist cities. The local government-led coastal governance model resulted in a smooth, quiet transition without conflict. The Xiamen case presented in the conclusion is both a representative example of exploring coastal governance models in China and a validation of existing local government theories. However, due to limited access to internal organizational data on local governments, future discussions extending the role of governance to include the composition and nature of governance organizations would help deepen the positioning of governance subject theories [contribution 3].

Chang et al. assessed the impact of solar panel-generated shading on the growth of Litopenaeus vannamei and black-spotted sunfish, as well as water quality, and further analyzed the optimization of fisheries-solar symbiosis models for sustainable marine resource management. This study was conducted at an aquaculture farm integrated with a floating solar photovoltaic facility. The farm belongs to the Marine Aquaculture Research Center of the Fisheries Research Institute, Council of Agriculture, Executive Yuan. The study was conducted from October 2018 to May 2019, with solar photovoltaic panels installed on aquaculture rafts. The experimental group’s farm covered 0.03 hectares and consisted of a floating platform. Results showed no significant difference in the growth of black-spotted shrimp between the two systems. However, the body weight of L. vannamei in conventional fishponds was significantly higher than in the integrated system. Dissolved oxygen levels were higher in the integrated system than in the conventional polyculture system, while ammonia nitrogen and nitrite nitrogen levels were lower. Furthermore, this study explored the impact of shading on the fisheries-solar symbiosis model, revealing its potential benefits for countries lacking domestically produced energy [contribution 4].

Kao et al. investigated the morphometric differentiation of the Swimming Crab Portunus sanguinolentus (Herbst, 1783) populations in East Asia, further analyzing its implications for stock identification and management. These crab samples came from eight different locations: Kyushu (KS), Fuzhou (FZ), Yilan (YL), Xiamen (XM), Tainan (TN), Hong Kong (HK), Vietnam (VN), and Singapore (SG). Allometric growth was used to standardize 12 morphological measurements based on body size. Subsequently, cluster analysis and canonical variable analysis (CVA) were performed on the data. The results showed that the eight sample populations could be divided into at least two distinct groups. The first group included three samples from China (specifically FZ, XM, and HK), and the second group included samples from East Asia (including KS, YL, TN, VN, and SG). CVA revealed a ternary division of the samples: the China group (FZ, XM, and HK), the Kuroshio group (KS, YL, and TN), and the Southeast Asia group (VN and SG). The morphological variations between groups were statistically significant for both sexes. These differences may be attributed to evolutionary origins, geographical events, or environmental adaptations. The study indeed reveals complex details of its population structure in East Asia. Despite this complexity, it inevitably raises further questions about the multifaceted interactions between genetics, environment, and evolution. An important conclusion is that ocean currents have an undeniable influence on the formation and maintenance of these variations, both hindering and promoting gene flow. The significant differences between Kuroshio group and China group highlight the importance of understanding regional ocean dynamics in species distribution. Furthermore, the significant differences within each subgroup in the Kuroshio region, particularly between the SG and VN samples, raise questions about possible microenvironmental adaptations or historically divergent lineages. The striking differences between subgroups may also indicate responses to local environmental stresses [contribution 5].

Shih studied the population dynamics of the frog crab/red frog crab (Ranina ranina), including its growth and reproduction. The study area, located in southern Penghu, encompasses Dongji Islet, Xiji Islet, Dongyu Pingyu Islet, and Xiyu Pingyu Islet, collectively known as the South Penghu Marine National Park (SPMNP). Samples were collected from 742 female and 473 male crabs. Carapace length was measured for each crab, and they were classified by sex and analyzed using the ELEFAN program in the FiSAT software. The authors emphasize the importance of understanding the delicate balance between recreational fishing, local conservation strategies, and global sustainability goals. The frog crab is both a symbol of ecological health and an important economic species in East Asia, representing the complex challenges facing marine biodiversity conservation. The conclusions highlight the importance of collaboration with government agencies in enabling targeted initiatives such as selective fishing restrictions during the breeding season, reduction of plastic waste, and implementation of sustainable island management measures to protect marine habitats while balancing conservation and recreational uses. In conclusion, the protection and management of frog crab at SPMNP sets a model for the sustainable management of marine resources, balancing different conservation needs with the interests of recreational fishing [contribution 6].

Hu et al. pointed out that the invasion of Spartina alterniflora is one of the main threats facing the mangrove wetlands of Quanzhou Bay, Fujian Province. To effectively control the spread of S. alterniflora and ensure the ecological security of coastal wetlands, China launched a special management action plan, which includes mangrove afforestation. Hu et al. compared the changes in meiofauna and marine nematode communities before and after S. alterniflora removal. They collected samples four times: in September 2022 (before S. alterniflora removal), October 2022 (after removal), December 2022, and March 2023 (after mangrove afforestation). This study investigated the changes in the composition, abundance, and biomass of meiofauna and marine nematodes at different time periods, and compared their community structure and biodiversity indices in S. alterniflora and mangrove habitats. The results showed that in September, 20 genera and 12 families of marine nematodes were identified in the S. alterniflora habitat, with 6 genera being dominant (5%): Ptycholaimellus, Parodontophora, Terschellingia, Halichoanolaimus, Metachromadora, and Parasphaerolaimadora. In December, 23 genera and 15 families of marine nematodes were identified in the mangrove habitat, with 6 genera being dominant: Daptonema, Admirandus, Parodontophora, Ptycholaimellus, Terschellingia, and Anoplostoma. The authors compared the marine nematode communities in the two habitats and found that the diversity of marine nematodes in the mangrove habitat was higher than that in the S. alterniflora habitat. Therefore, a clear conclusion was drawn: the dominant genera changed, and the dominance decreased. This indicates that suppressing S. alterniflora growth by planting mangroves significantly altered both the abundance and the structure before and after habitat change. This demonstrates the effectiveness of the proposed approach and provides a valuable reference for restoration measures in estuarine wetland reserves [contribution 7].

Jung et al. analyzed the long-term dynamics of the walleye pollock (Gadus chalcogrammus) stocks in the East Sea and its relationship with changes in the marine environment. Long-term changes in the catches of adult and juvenile pollocks were estimated using data from the Korean statistical yearbook (Korean Statistical Information Service; KOSIS). Pollock sampling was conducted in the mid-eastern waters of Korea during the winter months (January to March). Samples were collected using gill net fishery techniques over four distinct periods by the National Institute of Fisheries Science (NIFS): Period A (1973–1979), Period B (1980–1985), Period C (1991–1995), and Period D (2016–2018). By analyzing long-term changes in biological factors, including length, sex, catch, and marine environmental conditions, they explored the complex dynamics affecting the population size of pollock in the East Sea. The results showed that before the mid-1980s, the catch ratio of juveniles was higher than that of adults, and the proportion of females in both juveniles and adults was higher than that of males. This suggests that high fishing pressure on female pollock may be an important factor leading to a decline in their reproductive capacity. The study subsequently revealed a sharp decline in juvenile catches after the mid-1980s. By the late 1980s, sea surface temperatures in spawning grounds had risen rapidly, leading to a decrease in both the duration of suitable spawning temperatures and the proportion of suitable spawning areas. Therefore, the authors concluded that the decline in pollock stocks caused by overfishing in the mid-1980s was further exacerbated by the rising sea surface temperatures in the late 1980s. In conclusion, these findings highlight the impacts of overfishing and environmental factors on walleye pollock stocks and demonstrate the need for appropriate fisheries management measures to ensure the sustainable use of fishery resources [contribution 8].

Seo and Koo investigated the carbon reduction effect of Thalassinid mud shrimp Laomedia sp. (Crustacea: Shrimpidae) burrows on intertidal sediments in Korea. The study was conducted in the upper tidal zone of Anmyeon Island off the west coast of Korea. The authors noted that mud shrimp are among the most common burrowing organisms of benthic macroinvertebrates and have a significant impact on the biogeochemical processes of intertidal sediments. The importance of bioturbation to the dynamics of organic carbon in coastal wetland sediments has only recently been recognized, as large benthic disturbers can alter carbon storage in sediments. This study assessed the biotic and abiotic factors influencing the mud shrimp modification rate (SRR) through in-situ measurements and evaluated the reduction of organic carbon by comparing carbon concentrations in water particles and modified sediments. The results indicate that Laomedia sp., as an important bioturbation factor, capture organic carbon from intertidal sediments through their burrows, playing a crucial role in enhancing carbon cycling. Therefore, the bioturbation effects of macrobenthic invertebrates should be considered when assessing carbon sequestration in intertidal sediments [contribution 9].

Lu et al. analyzed the heavy metal concentrations and associated health risks in wild and cultured Oplegnathus fasciatus in the East China Sea. This study used 88 samples of this species, 44 from the wild population and 44 from the cultured population. Wild samples were collected in the winter of 2022 in waters connecting the Yangtze River estuary and the northern coastal waters of Zhejiang Province, China, using the 44-m-long gillnet fishing vessel “Zhepuyu 32128” with a mesh size of 40 mm. This study compared the concentrations of eight heavy metals (Fe, Mn, Cu, Zn, Cr, As, Cd, and Hg) in wild and cultured O. fasciatus. The single factor pollution index (SFI), metal pollution index (MPI), and health risk assessment methods were used to assess the pollution levels and health risks. The results showed significant differences in the concentrations of Zn, Cr, As, and Hg between wild and cultured O. fasciatus. The SFI values for Cu, Zn, Cr, and Cd in both wild and farmed O. fasciatus were below 1, far below the marine organism quality standards. The MPI values for wild and farmed striped pufferfish were 0.188 ± 0.051 and 0.172 ± 0.054, respectively, both far below the safety limit of 2 for uncontaminated aquatic products. The hazard index (HI) for both wild and cultured O. fasciatus was below 1. The authors concluded that long-term consumption of O. fasciatus does not pose a health risk. Discriminant analysis based on Zn, Cd, As, and Hg concentrations could distinguish between wild and cultured O. fasciatus with an accuracy of 96.0%, and the accuracy remained stable above 94.9% after cross-validation. These results accurately assess that consuming striped grouper does not pose a risk to human health, which is of great significance for protecting public health [contribution 10].

Moya et al. used methods and principles of ecological anatomy to study the relationship between wood characteristics (e.g., ring formation, anatomical characteristics) and ecological factors of six mangrove species growing in three locations in the Gulf of Nicoya, Costa Rica. They selected three locations in the Gulf of Nicoya, located on the central and northern Pacific coast of Costa Rica, to represent salinity gradients. The six mangrove species studied were: Avicennia bicolor Standl (Acanthaceae), Avicennia germinans L. (Acanthaceae), Laguncularia racemosa (L.) C.F. Gaertn (Combretaceae), Pelliciera rhizophorae Planch. & Triana (Tetrameristaceae), Rhizophora mangle L. (Rhizophoraceae) and Rhizophora racemosa G. Mey. (Rhizophoraceae). These mangrove species were selected due to their abundance and their location in the Gulf of Nicoya.

They found that the mangrove at sampling site 1 exhibited the most anatomical variation, with 38 observed variations, while sampling sites 2 and 3 had similar but fewer variations. This is likely due to the different growth conditions at sampling site 1 compared to sites 2 and 3; factors such as freshwater, salinity variations, and direct tidal action influence tree anatomy. These ecological variations are reflected in the growth ring formation of A. bicolor, A. germinans, P. rhizophorae, and two species of Rhizophora, but not L. racemosa. Ray dimensions (height and width) is a functional element, exhibiting greater adaptability to the growth environment. This plasticity allows the mangroves in the Gulf of Nicoya to ensure water transport even under unfavorable growth conditions and physiological limitations. The grouping and arrangement of vessels also showed important anatomical variation, as expected in most mangrove trees, meaning that this type of structure must ensure efficient hydraulic conductivity. L. racemosa was the species that presented the highest number of changes in anatomical characteristics across the different sites, which was followed by P. rhizophorae with a similar number of changes for Avicennia spp. and Rhizophora. Therefore, they can thus conclude that the variations in the quantitative wood anatomical characteristics in L. racemosa, growing at different sites, are adaptations to fluctuating environmental conditions in the intertidal areas [contribution 11].

Wei et al. mentioned that Taiwan has implemented Ecological Inspection and Identification (ECI) since 2003, but challenges remain in terms of standards, resource allocation, and effectiveness. Therefore, they explored the ecological validity of Taiwan’s coastal engineering ecological inspection and identification mechanism. They analyzed 35 coastal engineering cases from five key perspectives and participated in two of the projects. They found differences in the types of projects implementing ECI across different regions. Landscape engineering was the dominant type in northern Taiwan (31%), water resource engineering in southern Taiwan (43%), while no such cases were found in eastern Taiwan. Most inspections occurred at the scheme (24%), planning (22%), and design (22%) stages, while post-construction monitoring was relatively limited (14%). Furthermore, 49% of the cases lacked ecological assessments, and aquatic ecosystem assessments were also relatively insufficient. Inconsistent inspection methods and incomplete species records (57% of cases) reduced data comparability and affected conservation effectiveness. To address these shortcomings, the study proposes recommendations including standardizing inspection procedures, incorporating Sustainable Development Goals (SDGs), promoting low-carbon approaches, strengthening public participation, and establishing long-term monitoring mechanisms. The findings provide policy guidance for strengthening ECI, helping to support sustainable coastal engineering construction while balancing infrastructure benefits and environmental protection [contribution 12].

Lim and Jung pointed out that despite numerous global efforts to combat illegal, unreported and unregulated (IUU) fishing, such activities remain rampant. Therefore, they conducted a study to improve the international cooperation framework to include IUU fishing in order to achieve sustainable use of fishery resources. They used existing IUU vessel lists to conduct independent and paired sample comparisons to analyze the characteristics of IUU vessels. While the proposed solution can address the current challenges, an integrated system is essential for effective implementation, capable of tracking more IUU vessels and sharing information in a timely manner among port states. Therefore, the necessity of the integrated multi-layered cooperation model proposed in this study is further emphasized. Therefore, they proposed a model framework for integrating different systems and dataset management (see the conclusion section of the paper) [contribution 13].

Lim and Jung developed an integrated bioeconomic management strategy for the common squid (Todarodes pacificus) fishery in the waters near Korea. The study aimed to address the severe depletion of resources and declining profitability in the fisheries, balancing biodiversity conservation and economic sustainability. Methodologically, they utilized recent catch data and cost structures for six Total Allowable Catch (TAC) management fishery types, employing a stepwise cost allocation method to estimate specific economic indicators for the common squid. Results showed that, based on previous studies using the Catch-Maximum Sustainable Yield (CMSY) model and with limited CPUE data, the estimated biomass of the common squid in 2020 was approximately 56% of the BMSY biomass, indicating overfishing. Scenario-based simulations determined the TAC allocation threshold for zero net profit, providing a benchmark for adaptive quota reallocation. They found differences in economic sensitivity and dependence on the common squid among different fishery types: fishing gear reliant on the common squid, such as nearshore jigging and East China Sea trawls, exhibited higher vulnerability, while mixed fisheries, such as purse seines, remained more resilient. These findings provide a basis for developing customized management strategies for each type of fishery, thereby improving the effectiveness of interventions. Therefore, their policy recommendations include dynamically adjusting the TAC, expanding monitoring coverage, introducing a system of transferable individual quotas, and conducting coordinated resource assessments with China and Japan. These findings will help improve Korea’s TAC system, aligning resource recovery targets with the economic viability of fishing operations [contribution 14].

McCall explores the political ecology of fisheries regulation and community resilience in the Mississippi Delta coastal region of southeastern Louisiana. This paper reviews the complex history of the oil and gas industry in southeastern Louisiana, including its relationship with political corruption, inequality, pollution, and environmental disasters, and its role in providing supplementary economic opportunities for coastal fishing communities. The paper examines the evolution of fisheries regulation and its impact on small-scale fishermen, focusing particularly on the 1990s ban on gillnets. Through a combination of historical data, ethnographic interviews, and participatory observation, this paper analyzes the complex political and economic forces behind regulatory frameworks and policy shifts, revealing their negative impacts on fishing communities facing existential threats such as coastal erosion, declining fisheries resources, and various macroeconomic headwinds. A flowchart illustrating the relationships between oil and gas industry economic output, commercial and subsistence fishing, ecosystem impacts, public perception, lobbying, and fisheries regulations. (a) Cases where the oil and gas industry contributes significantly; (b) Cases where the contribution is less significant. Another flowchart illustrating the relationships between various fishing activities, ecosystem impacts, public awareness, lobbying, and fisheries regulations. (a) Cases where commercial fishing models are more diversified; (b) Cases where commercial fishing is dominant. The paper argues that resilient coastal communities are crucial for addressing environmental challenges in coastal areas, and that rethinking fisheries regulations may be an effective way to enhance community resilience [contribution 15].

4. Conclusions

This Special Issue features articles covering a wide range of topics, including: marine fish diversity; coastal fisheries management; coastal governance; the symbiotic relationship between fisheries and solar energy; crustacean population differentiation; recreational fisheries sustainability; mangrove wetland ecology; fish population dynamics; intertidal sediment carbon cycle; heavy metal pollution in fish; mangrove wood anatomy; coastal engineering ecological assessment; illegal, unreported, and unregulated fishing (IUU) control; and squid fisheries management. The articles employ various methods for analysis and assessment, including: environmental DNA macrobarcoding; and nonparametric estimation (Chao 2, Jackknife 1, Jackknife 2, and Bootstrap), data collection and comparison; politics of scale, local research methods, interviews, observations, content analysis; comparative experiments (integrated systems vs. traditional fishponds); allometric growth, cluster analysis, canonical variable analysis (CVA), randomization tests; field sampling, literature comparison; field sampling, community structure analysis, marine diversity index calculation; long-term data analysis (body length/sex composition data; in-situ measurements, carbon concentration comparison; heavy metal detection, single-factor pollution index (SFI), metal pollution index (MPI), health risk assessment, discriminant analysis; ecological anatomy methods, timber characteristic analysis; case studies (35 coastal engineering projects), project participation; ship characteristic analysis (independent/paired sample comparison); bioeconomic analysis, context-based simulation, ethnic cost allocation.

These papers can be divided into two main categories: coastal ecology and fisheries management. The largest category contains eight articles, primarily exploring topics related to coastal ecology. These articles include: a paper from China that uses environmental DNA technology to monitor fish diversity in the Clarion-Clipperton Belt of the Pacific Ocean; a paper from China that explores the transformation of coastal governance from human ecology to local government, focusing on the Jimei Peninsula in Xiamen, China; a paper from Taiwan that analyzes morphological differences of the swimming crab Portunus sanguinolentus populations in East Asia: implications for population identification and management; and a paper from China that compares changes in microbenthic animal and marine nematode communities before and after the removal of Spartina alterniflora from the mangrove wetlands of Quanzhou Bay, Fujian Province. One paper from Korea analyzed the carbon reduction effect of Thalassinid mud shrimp Laomedia sp. (Crustacea: Shrimpidae) burrows on intertidal sediments in Korea; another paper from China explored the concentration of heavy metals and related health risks in wild and farmed striped grouper (Oplegnathus fasciatus) in the East China Sea; a paper from Costa Rica analyzed the variation in annual rings and wood anatomy of six mangrove species in Nicoya Bay, Costa Rica; the first group of papers also included a paper from Taiwan, which explored the ecological effectiveness of Taiwan’s coastal engineering ecological inspection and identification mechanisms.

The second group comprises seven papers focusing on issues related to fisheries management. These include a paper from China exploring a sustainable perspective on nearshore fisheries management in the Minjiang River estuary—estimating fish abundance; a paper from Taiwan analyzing the optimization of fisheries-solar symbiosis models for sustainable marine resource management: assessing the impact of shading on the growth of Litopenaeus vannamei and Chanos chanos, as well as water quality; another paper from Taiwan, uses the frog crab/red frog crab (Ranina ranina) from South Penghu Marine National Park, Taiwan as a case study to explore the population dynamics and sustainable development of this species in recreational fisheries.; a paper from Korea analyzing the relationship between the long-term dynamics of the East Sea pollock population and marine environmental changes; another paper from Korea studying the improvement of international cooperation frameworks to combat illegal, unreported, and unregulated fishing for the sustainable use of fisheries resources; next is a paper from Korea that improves fisheries management strategies for common squid (Todarodes pacificus) fishing vessels in Korean waters; finally, a paper from the United States introduces the political ecology of fisheries regulation and community resilience along the coast of the Mississippi River Delta in southeastern Louisiana.

Naturally, the papers published in this Special Issue do not exhaust all related topics under the two main themes of coastal ecology and fisheries management. However, all the papers provide new perspectives on these two themes. We firmly believe that these research findings will be of great significance to scientists and practitioners in coastal ecology and fisheries management.