Fisheries Ecosystem Research Articles

Estimating ecological carrying capacity for stock enhancement in marine ranching ecosystems of Northern China

Marine ranching has been proposed as a promising solution to manage the depleted coastal fishery ecosystem in recent decades across China. Marine ranching integrates the practices of artificial habitat-based with aquaculture-based enhancement. Assessing the ecological carrying capacity of target species for enhancement is a precondition for determining the optimal numbers for release, particularly for those species whose habitat restrictions have been eliminated through the construction of artificial habitats in the marine ranch. A responsible approach to stock enhancement aims not only to increase total yield and stock abundance but also to consider any potential effects on ecosystem structure and function. A time-dynamic, ecosystem model was constructed using Ecopath with Ecosim for the Laizhou Bay (Bohai Sea) marine ranching ecosystem in the nearshore waters of northern China. Two sedentary target species with potential for stock enhancement, i.e., the carnivorous red snail Rapana venosa and the detritivorous sea cucumber Apostichopus japonicus, were selected to simulate and estimate their ecological carrying capacities and project their overall effects on the ecosystem. Ecological carrying capacity was defined as the maximum standing stocks of the target species that would not cause “unacceptable” impacts on the ecosystem function and resilience, i.e., not cause any other group’s biomass to fall below 10% of its original biomass. The ecological carrying capacities estimated for R. venosa and A. japonicus were 623.46 and 200.57 t·km−2, respectively, corresponding to 7.8 and 5.0 times higher than their current standing stocks. Simulations of R. venosa enhancement showed distinct effects of increased target species abundance on other functional groups and ecosystem properties. An increase in red snail biomass caused negative impacts on the biomass of most other functional groups and ecosystem indicators, such as Finn’s cycling index, transfer efficiency, and Kempton’s Q index. In contrast, the simulated A. japonicus enhancement had relatively few impacts, and the biomasses of most other functional groups and ecosystem indicators did not change or changed very slightly (<5%). The current model framework provides a means of estimating the ecological carrying capacity in commercial-scale stock enhancement practices and avoiding potential ecological risks for marine ranching in northern China.

Analysis of the Ecological Carrying Capacity of Fish Resources in Shengjin Lake, Anhui Province, China.

The carrying capacity of fish is related to the sustainability of fisheries’ activities in water bodies. The fish carrying capacity of a water body is the maximum fish yield that can be carried by the natural bait organisms in the water body under the ideal natural conditions without feeding and fertilization. The evaluation of fish productivity is an important basis for rational stocking, rational fishing, and the scientific utilization of natural bait resources in a water area. This paper adopts the background data of the Shengjin Lake fishery ecosystem and uses the bait-based estimation method. The results show that (1) the annual yield of silver carp fed on phytoplankton is 1.5 million kg; (2) the annual yield of bighead carp fed on zooplankton is 1.295 million kg; (3) the annual yield of benthos is 310,000 kg; (4) the annual yield of organic detritus is 280,000 kg; and (5) as the coverage of water grass in Shengjin Lake is less than 10%, it should be protected and restored rather than used by fish. In general, the annual maximum carrying capacity of fish in Shengjin Lake is 3.385 million kg, except for water and grass.

The Anthropology of Aquaculture

Aquaculture is nothing new. It has a long, fascinating history that stretches from antiquity at least 8,000 years ago. What is new is the evolution of aquaculture in modern times into highly intensive monocultures which arose in the 1970–1980's. Modern aquaculture production has grown worldwide but remains concentrated in Asia due to the: (1) increased demands for aquatic foods as explosive population growth occurred in coastal cities with increasing affluence, (2) expansion of scientific and engineering breakthroughs, (3) high export values of aquatic foods, and (4) sharp decline of costs of global to local transport/shipping. The pioneering anthropologist Claude Levi-Strauss brought the idea of “structuralism” to anthropology: the concept that societies throughout history followed universal patterns of behavior. A qualitative document analysis of the key anthropological literature to assess aquaculture developments from antiquity to the beginning of the modern era was conducted to evaluate if there was adequate evidence to support a theory of anthropological “structuralism” for aquaculture in human history. Seven case studies of the cultural/environmental history of aquaculture were reviewed in diverse parts of the world (China, Australia, Egypt, Europe, South America, Canada/USA, Hawai'i). Analysis supports the structural theory that whenever the demands of aquatic/seafood-eating peoples exceeded the abilities of their indigenous fishery ecosystems to provide for them, they developed aquaculture. Modern aquaculture concepts and new communities of practice in “restoration aquaculture” have beginnings in Indigenous anthropology and archeology in aquaculture and point the way for Indigenous nations to engage as leaders of the United Nations Food and Agriculture Organization (FAO) ecosystem approach to aquaculture worldwide. Bringing ancient knowledge of Indigenous aquaculture into the modern context is an essential part of an alternative, “radical transformation” of modern aquaculture. There is an urgent need to develop and promote locally designed and culturally appropriate aquaculture systems that fit into the livelihoods of communities as part of a larger, diverse portfolio of food security.

Exploring Influences on Environmental Stewardship of Fishing Communities in Fisheries Management in the Philippines.

Fisheries compliance has been explored conceptually and empirically in numerous contexts but in many fisheries, compliance with rules is not sufficient to return to sustainable levels of effort. Failing to understand the context and what drives fishers to behave the way they do, has the potential to misdirect investments. The authors present a conceptual model of fisheries ecosystem stewardship (FES) that expands upon fisheries compliance with the addition of moral obligation for fishing communities. This paper uses household survey data from fishing communities in three marine key biodiversity areas (MKBA) in the Philippines to test part of the FES model using logistic regression and multiple regression analysis with empirical data to test the model. Data shows that apart from the respondents' location (i.e., which MKBA is adjacent to their community), knowledge of laws protecting coastal/marine resources was the most important predictor of environmental stewardship, followed by support for limiting fishing effort and knowledge of illegal fishing. Individual decisions about if and how-to fish are influenced by the economic context and available livelihood opportunities. However, the moral obligation to "do the right thing" is equally, if not more important to consider for fisheries ecosystem stewardship in fishing communities.

Traditional Fishermen in The Context of Modernization: A Case Study in Holimombo Jaya Village, Buton Regency, Southeast Sulawesi Province

This study analyzes the existence of traditional fishermen in the context of modernization in Holimombo Jaya Village, Pasarwajo District, Buton Regency, Southeast Sulawesi Province. The aims of this study is to answer a key question, whether modernization has caused a cultural lag in traditional fishermen; or have they succeeded in innovating and adapting to the values of modernity so that they still exist and achieve sustainable progress? Using the historical method through four stages of work, namely: heuristics, criticism, interpretation, and historiography. The results show that modernization has brought significant changes in the socio-economic life of the fishing community of Holimombo Jaya. There is no patron-client relationship as is often found in fishing communities in Indonesia. All fishermen have their own fishing gear, operated by themselves without involving a third party. In this way, income becomes evenly distributed so that fishermen are able to get out from absolute poverty trap. They reject the use of fishing gear that has the potential to damage environmental sustainability and the balance of the fishery ecosystem. They also prioritize the interests of consumers by using only ice in fish preservation. They refuse the use of preservatives that endanger health such as formalin and borax.

Seasonal succession and spatial heterogeneity of the nekton community associated with environmental factors in Hangzhou Bay, China

Spatiotemporal variations of nekton communities in estuaries are closely associated with habitat quality and environmental shifts. However, the importance of environmental conditions in shaping the spatial heterogeneity and seasonal succession of nekton in Chinese estuaries has rarely been reported. We collected nekton seasonally between 2018 and 2019 from 10 sites in the semi-enclosed Hangzhou Bay (HZB) and investigated the spatiotemporal dynamics of the nekton assemblage structure. A wide taxonomic diversity was identified, including 57 taxa from 23 families (36 fish, 15 shrimp, and six crabs). The nekton was mainly composed of small coastal, nearshore, and estuarine species, dominated by Miichthys miiuy, Collichthys lucidus, Exopalaemon annandalei, and Palaemon gravieri. The nekton biomass and abundance distribution were higher in the upper and middle bay than in the lower bay. The year-round northeast–southwest front zone was high related to the high-value dense area of nekton. Diversity and evenness indices of nekton biomass were higher during July and October than January and April. The unstable and high variability of the nekton community composition was reflected in the species diversity indices, seasonal alternate index, and seasonal migration index. Significant differences were found between fauna clusters among seasons, revealing the relationship between the habitat adaptability of species and seasonal variation of water masses. The nekton assemblage structure and distribution pattern were predominantly correlated with seasonal variations in natural and anthropogenic factors. In this study, the observed effects of anthropogenic and natural stressors on the seasonal variation of the nekton community and density distribution in the estuarine-bay ecosystems provide new insight into fishery ecosystems and ecosystem functioning.

What's wrong with the coastal waters of Spelman Strait, Indonesia: Sustainable reef fisheries management is required

Reef fish in Spelman strait, Indonesia, is one of the fishery resources of considerable economic value. Unfortunately, there is still the use of unfriendly resources equipment (destructive fishing) that cause potential social problems. In this study, all components of the EAFM (Ecosystem Approach to Fisheries Management) composed of 6 domains, namely (1) fish stocks, (2) environment and ecosystem, (3) fishing techniques, (4) culture, (5) social, and (6) institutional are analyzed combining with MDS (Multidimensional Scaling). The main aim of this research is to find out the root solution for managing coral reefs in the coastal waters of Spelman Strait. The sustainability status review in the fishery resource domain, the environment and ecosystem domain, the fishery technique domain, the social domain, and the economic domain were respectively were 87.69, 88.17, 51.22, 51.61, and 72.67 which were in the category sustainable. Meanwhile, the sustainability status review in the institutional domain was 42.15, which was in the category of less sustainable. Institutions are the primary base for reef fishery protection in the Spelman Strait.

Filling in knowledge gaps: Length–weight relations of 46 uncommon sharks and rays (Elasmobranchii) in the Mediterranean Sea

Large sharks and rays are generally understudied in the Mediterranean Sea, thus leading to a knowledge gap of basic biological characteristics that are important in fisheries management and ecosystem modeling. Out of the 76 sharks and rays inhabiting the Mediterranean Sea, the length–weight relations (LWR) are available for 28 (37%) of them, usually for common small-sized species that are not protected and may be marketed. The aim of the presently reported study was to fill in the knowledge gap through the estimation of LWR of rare and uncommon sharks and rays in the Mediterranean Sea using the information from single records or few individuals. The analysis was based on a Bayesian hierarchical method for estimating length–weight relations in fishes that has been recently proposed for data-deficient species or museum collections and uses the prior knowledge and existing LWR studies to derive species-specific LWR parameters by body form. The use of this method was applied to single records of rare and uncommon species and here we report the LWR of 46 uncommon sharks and ray species, 14 of which are first reported LWR at a global scale and 21 are the first reported LWR for the Mediterranean Sea; the remaining 11 species are first time records for the western or eastern Mediterranean regions. Museum collections and sporadic catch records of rare emblematic species may provide useful biological information with the use of appropriate Bayesian methods.

Factors affecting fluctuations in China's aquatic product exports to Japan, the USA, SouthKorea, Southeast Asia, and the EU.

Seafood has important health benefits, and the growing demand for aquatic products has stimulated rapid trade development. Using 2000–2018 data from the UN Comtrade Database, this study first introduced the export scale, product structure, and market distribution of China’s aquatic products. Then, using an extended constant market share model, we investigated the factors affecting fluctuations in China’s aquatic product exports to the USA, Japan, South Korea, the Association of Southeast Asian Nations (ASEAN), and the European Union (EU). Import demand was found to be the most important factor affecting China’s aquatic product exports. Moreover, China’s export structure and market distribution for aquatic products have become increasingly consistent with global demand. In recent years, China’s aquatic product competitiveness has declined while its market destinations have diversified. Regarding China’s aquatic product types, the main focus has been on labor- and resource-intensive products with low competitiveness. More recently, however, China’s competitiveness of product types 0371 and 0372 (Standard International Trade Classification) has been improving in the world market. To further develop China’s aquatic product exports, policy should aim to maintain the fisheries ecosystem, encourage seafood operators to adopt good practices, increase investment in science and technology, overcome technical barriers to trade, strengthen research on the needs, preferences, and requirements of major importing countries, expand domestic demand, and strengthen international cooperation.

Blue Carbon Ecosystem Services Through a Vulnerability Lens: Opportunities to Reduce Social Vulnerability in Fishing Communities

Ecosystem services (ES) are benefits nature provides to humans; these services change in space and time and are largely dependent on context. Coastal habitat that provides key ES are blue carbon ecosystems, namely seagrass and mangroves. One important ES they provide is the provisioning of seafood, which benefits coastal populations with livelihoods and food security. We employed a social-ecological approach that draws from the vulnerability literature for social, ecological, and economic criteria to map ES provision in ten communities on Busuanga Island, Palawan Province, Philippines. We assess the spatial dynamics of ES provision for small-scale fisheries in seagrass and mangroves, in relation to local beneficiaries. Using a mixed-methods approach with ecological assessments of seagrass beds, spatial analysis, landing surveys, household and key informant interviews, we overlaid biophysical variables on social data, mapping sensitivities and adaptive capacities to compare communities’ social vulnerabilities. Spatial analysis revealed healthy blue carbon ecosystems in ten local communities (barangays) as measured by proportion of coastline covered, low patchiness and high continuity along the coastline, and the presence of adjacent habitat. We found seagrass ecosystems were more vulnerable than mangroves. Rural barangays had less exposure and lower sensitivity to blue carbon ecosystem loss than urban barangays. Blue carbon ecosystem fisheries are highly sensitive fisheries, due to their catch composition and low catch per unit effort, with mangrove fisheries having a slightly lower sensitivity than seagrass fisheries due to greater catch per unit effort. Diversified livelihoods and the presence of NGOs and People’s Organizations (POs) increased adaptive capacity and reduced overall vulnerability. We aim to highlight a coastal human community’s relationship with blue carbon ecosystems using context-specific vulnerability criteria. Our site-specific social vulnerability assessment may be adapted for use in other coastal communities within the coral triangle. This work suggests opportunities for conservation interventions to manage local communities’ sensitivities and adaptive capacity around the use of blue carbon ecosystems.

Resensi Sumber Daya Perikanan Zona Ekoton Ekosistem Mangrove-Lamun Di Teluk Youtefa Kota Jayapura Provinsi Papua

Mangrove and seagrass ecosystems have important functions and roles in coastal and marine waters, as an ecological buffer system, habitat for various types of fish and aquatic biota, as well as a biosystem of energy flow for the aquatic environment in Youtefa Bay, Jayapura. This study was conducted to calculate and review the mangrove and seagrass ecosystem fisheries affected by ecosystem damage and pollution. Data collection using fishing methods, vertical plankton sampling, and measurement of water quality parameters. Analysis of the data used: (1) analysis of the level of diversity using the Shannon-Wiener index, (2) analysis of dominance, (3) analysis of species composition (4) analysis of fish abundance, and (5) descriptive analysis. This study succeeded in obtaining 99 fish samples from 11 families and 12 fish species. The level of diversity is moderate (2.21) and the abundance of species is 73 individuals/ha. There were 5 dominant fish species associated with the ecotone zone of mangrove and seagrass ecosystems, namely Valamungil buchanani, Chanos-chanos, Gerres oyena, Pempheris schwenkii, and Pentapodus aureofasciatus. More fish were found in the seagrass and coral reef ecotone zones, namely 180 fish individuals caught from 11 families and 17 species of fish, with a high level of diversity (2.77), an abundance of species as many as 150 individuals/ha, and no dominant species. The review study of fishery resources in the ecotone zone shows very rapid degradation and decline in diversity, composition, and abundance in the waters of the mangrove, seagrass, and reef ecosystems of Youtefa Bay, Jayapura.Key Words: Fisheries; Mangroves; Seagrass; Youtefa Bay; Jayapura

A Case Study in Connecting Fisheries Management Challenges With Models and Analysis to Support Ecosystem-Based Management in the California Current Ecosystem

One of the significant challenges to using information and ideas generated through ecosystem models and analyses for ecosystem-based fisheries management is the disconnect between modeling and management needs. Here we present a case study from the U.S. West Coast, the stakeholder review of NOAA’s annual ecosystem status report for the California Current Ecosystem established by the Pacific Fisheries Management Council’s Fisheries Ecosystem Plan, showcasing a process to identify management priorities that require information from ecosystem models and analyses. We then assess potential ecosystem models and analyses that could help address the identified policy concerns. We screened stakeholder comments and found 17 comments highlighting the need for ecosystem-level synthesis. Policy needs for ecosystem science included: (1) assessment of how the environment affects productivity of target species to improve forecasts of biomass and reference points required for setting harvest limits, (2) assessment of shifts in the spatial distribution of target stocks and protected species to anticipate changes in availability and the potential for interactions between target and protected species, (3) identification of trophic interactions to better assess tradeoffs in the management of forage species between the diet needs of dependent predators, the resilience of fishing communities, and maintenance of the forage species themselves, and (4) synthesis of how the environment affects efficiency and profitability in fishing communities, either directly via extreme events (e.g., storms) or indirectly via climate-driven changes in target species availability. We conclude by exemplifying an existing management process established on the U.S. West Coast that could be used to enable the structured, iterative, and interactive communication between managers, stakeholders, and modelers that is key to refining existing ecosystem models and analyses for management use.

The heat is on: Gulf of Alaska Pacific cod and climate-ready fisheries

Abstract Rapidly changing ocean conditions pose substantial challenges for coastal communities, fishermen, and managers. From 2014 to 2016, the Gulf of Alaska (GOA) experienced a marine heatwave and corollary decline in Pacific cod (Gadus macrocephalus). Here, we explore the 2020 closure of the directed Pacific cod federal fishery in the GOA as a case study of the needs and opportunities for managing fisheries in the context of environmental change. We build on climate-ready fishery research and conversations with experienced commercial fishermen, including Alutiiq fishers, and fishery managers to: (i) discuss ecosystem-based management in Alaska, (ii) explore early warning signs and management challenges preceding the decline of Pacific cod, (iii) recommend tools to enhance adaptive capacity in fishery management. We conclude that a strong foundation of science-based management that incorporates ecosystem information and multiple ways of knowing, increased monitoring and evaluation of indicators, and new tools for managers to respond and adapt will be essential to sustainable fishery management. New mechanisms highlighted in this essay include: a GOA Fishery Ecosystem Plan, climate risk and vulnerability analyses, habitat protections, and the development of original metrics, such as food web production or function targets to inform stock assessments and fishery management.

A trophic model of the coastal fisheries ecosystem of the northern Persian Gulf using a mass balance Ecopath model

An Ecopath ecosystem modeling was applied to describe the trophic model of coastal fisheries ecosystem of the northern Persian Gulf. A total of 32 functional groups and species were used to determine the key features of the aquatic system. We also examined the stability and developmental stage of the Persian Gulf ecosystem. Total primary production/total respiration was calculated to be >1 indicating that more energy is produced than respired within the system. Indicators of ecosystem stability and development were estimated as follows: ominivory index = 0.29; connectance index = 0.14; Path length = 1.005; relative low biomass to throughput ratio = 0.0008; ascendency = 12.26; Finn’s cycling index = 2.01; high primary production to biomass ratio = 81.57 and ratio of total primary production to total respiration = 23.92. The trophic levels of the groups varied from 1 for primary producers and detritus to 4.42 for piscivorous fish in the coastal system. These indicators show that the coastal system of the Persian Gulf are in their developing stage with high exploitation pressure, especially on demersal fish resources.

Acetes as a Keystone Species in the Fishery and Trophic Ecosystem Along Northeastern Arabian Sea

Diet composition of nine commercially exploited fishery resources which contributes 55–60% of the total fish landings in the northwest coast of India were analyzed in this study. Gut content analysis of the selected fish groups has shown significant variations in the prey composition and predator preference on a prey item. The diet matrix revealed Acetes sp. (32.74%) as a key and common shared prey item, followed by mesopelagic fishes (30.51%), other shrimps (11.00%), digested material (7.42%), crabs (4.03%) and cephalopods (2.77%), etc. In this study, Acetes sp was considered as a proxy for the non-penaeid prawns due to its significant contribution (92%) to the total non-penaeid landings. Targeted exploitation of Acetes sp. has intensified recently (from 0.44 lakh t in 2004 to 1.40 lakh t in 2018) with an average annual growth rate of 11.2% due to the demand from fish meal plants. By considering its ecological and fishery importance, Acetes sp. should be considered as keystone species in the ecosystem. The Schaefer surplus production model was used to calculate the Biological Reference Points (BRPs) and model parameters MSY, FMSY, r, EMSY, and K. The model fit was fair (R2 = 0.630) and significantly positive correlation was observed between CPUEobserved and CPUEmodel. The estimated optimum exploitation limits (p < 0.05) for the fishery were Maximum Sustainable Yield (MSY) as 1.20 lakh t and fishing effort required to harvest MSY (EMSY) as 51.30 lakh fishing hours. However, the recent exploitation yield and fishing effort are beyond the optimum exploitation limits. Further increase in exploitation of the resources may hamper the sustainability of the stocks and may lead to detrimental impact on the trophic interactions of the fishery resources. Technical interventions are needed in the field of post-harvest and value addition for attaining fair economic returns from the harvest which at present forms a low-value high-volume fishery. Sustainable exploitation and management measures need to be introduced and implemented for the Acetes sp. in order to sustain the stocks and to maintain the integrity of the fishery ecosystem.

Identification of keystone predators in Haizhou Bay food web based on the revised SURF index

Keystone predator species play an important role in regulating the number, richness and distribution of prey species. Based on the bottom trawl surveys in Haizhou Bay, keystone predator species in fish communities were identified by the revised SURF (supportive role to fishery ecosystems) index. Conger myriaster, Saurida elongata, Hexagrammos otakii, Chelidonichthys spinosus, and Larimichthys polyactis were the keystone predators in the fish community. They had high number of nodes degree, and were also the main predators of many species. Further, they had strong ability of clustering. The fluctuations of their density would have great impacts on ecosystem energy flow and food web structure. The method not only considered the feeding ratio between species, but also took the amount of catch and abundance of species as important factors in the identification of keystone predators. Compared with the traditional method, this method had great improvement and provided a new one for the identification of key predators. Our results showed that the strong inter-specific interactions played an important role in maintaining the structure and function of food webs. Protection of key predators would benefit the stability of biological communities and species diversity. Therefore, ecosystem-based fisheries management (EBFM) should give priority to the protection of key species. The important economic fish species, C. myriaster and L. polyactis, should be protected with high priority as they suffered from higher fishing pressure.

Shifting Trophic Control of Fishery–Ecosystem Dynamics Following Biological Invasions

Increasing human population size and mobility have accelerated the translocation of nonnative species globally, which has become a major threat to conservation of biodiversity and ecosystem services. Introduced species can disrupt species interactions of the recipient ecosystem, triggering system-wide events, and amplify or dampen effects of existing pressures. We show how two pervasive intercontinental invasive consumers in North American lakes, dreissenids (filter-feeding mussels) and Bythotrephes (carnivorous zooplankton), nonlinearly modify consumer-resource dynamics and undermine management interventions to rebuild cold-water predatory fish biomass. Synthesizing 30 yr (1986-2015) of lake-wide monitoring data with a dynamic mass-balance food-web model (consisting of 61 species and trophic groups), we reconstructed historical food-web dynamics of Lake Simcoe, a large, temperate lake in Ontario, Canada that has shifted from a turbid to clear-water state. We then analyzed patterns of biomass fluctuations of three recreationally harvested, ecologically connected populations; lake trout (Salvelinus namaycush, a piscivore), lake whitefish (Coregonus clupeaformis, a benthivore), and cisco (C. artedi, a planktivore) before and after the invasions by testing hypotheses on their delayed recoveries under management interventions-predator manipulations (fishery removal and stocking) and nutrient (phosphorus) load reduction. Analyses suggest that fishery harvest primarily regulated early recovery trajectories of the piscivore and planktivore, weakening top-down control prior to the establishment of the invasive consumers. By contrast, the benthivore biomass patterns were shaped, in part, by the invasive mussels (via diet shift), independently of management actions. Although improved water quality (with reduced hypoxia in deeper water) and, in turn, higher macrophyte production are projected to expand the predation refuge for young fish, intensified planktivory (by Bythotrephes) and herbivory (by dreissenids) have triggered shifts in community composition (from pelagic to demersal dominance). These system-wide shifts, in turn, have substantially diminished ecosystem productivity, thereby shrinking fishery yields. Novel consumers can rewire food webs, disrupt energy flows, and suppress predator recoveries, underscoring the need to account for altered ecological reality when sustainably managing fishery resources in invaded ecosystems.

Climate Change Impacts on a Tropical Fishery Ecosystem: Implications and Societal Responses

The present study aimed to map out the current threats and anticipated impacts of climate change on the most important hilsa shad (Tenualosa ilisha) fishery and the associated fishing communities based on fieldwork in six coastal fishing communities. To collect empirical data, individual interviews, focus group discussions, oral history, and key informant interviews were conducted. To supplement the empirical findings, time-series data of cyclones and sea-borne depressions in the Bay of Bengal were also analyzed. Analysis of secondary data regarding climate change-induced events and regional studies suggested that the biophysical conditions of the Bay of Bengal are likely to be aggravated in the future, potentially causing more frequent extreme events and affecting the livelihoods of coastal fishing communities in Bangladesh. The fisher respondents revealed that the main target hilsa shad fishery is particularly vulnerable to climate change in terms of alterations to migration patterns and breeding and growth performance. The fishers reported constant climate-related risks because they live in seafront locations, exposed to extreme events, and their occupation entails risky sea fishing. Fishers claimed that they often need return to the coast due to unsuitable weather conditions related to cyclones and frequent tropical depressions, which can cause financial losses or even causalities. Such events negatively affect fishers’ livelihoods, and wellbeing. To cope with the impacts of climate change the fishers have adopted various strategies at both sea fishing and household levels. However, these strategies only support the fishers in terms of immediate survival; they are not enough for long-term resilience. To improve the resilience of the hilsa fishers, the study argues for the implementation the Small-Scale Fisheries Guidelines (SSF Guidelines), which call for longer-term development goals, including in the immediate relief phase, and rehabilitation, reconstruction, and recovery to reduce vulnerabilities to climate and anthropogenic risks.

Supply network design to address United Nations Sustainable Development Goals: A case study of blockchain implementation in Thai fish industry

Sustainable Development Goals present an opportunity for industries to (re)design their supply chains. It is understood that digital technologies like blockchain can be helpful in achieving certain Sustainable Development Goals linked to livelihoods, food security, and the environment, by identifying issues and implementing interventions in real-time. However, there is limited understanding over data structure requirements for blockchain technology implementation in digitally-enabled food supply chains. Therefore, this research studies the design of blockchain-centric food supply chains that promote Sustainable Development Goals, within the context of the Thai fish industry. Key findings suggest that data asymmetry exists in supply chains to achieve Sustainable Development Goals. This research presents four design principles and an integrated technology implementation framework, derived from empirical data, for blockchain-centric food supply chains. The research outcome contributes to the supply chain management field and could ultimately impact the resilience of fishery ecosystems and the achievement of Sustainable Development Goals.

Shifting trophic control of fishery-ecosystem dynamics following biological invasions.

Increasing human population size and mobility have accelerated the translocation of nonnative species globally, which has become a major threat to conservation of biodiversity and ecosystem services. Introduced species can disrupt species interactions of the recipient ecosystem, triggering system-wide events, and amplify or dampen effects of existing pressures. We show how two pervasive intercontinental invasive consumers in North American lakes, dreissenids (filter-feeding mussels) and Bythotrephes (carnivorous zooplankton), nonlinearly modify consumer-resource dynamics and undermine management interventions to rebuild cold-water predatory fish biomass. Synthesizing 30yr (1986-2015) of lake-wide monitoring data with a dynamic mass-balance food-web model (consisting of 61 species and trophic groups), we reconstructed historical food-web dynamics of Lake Simcoe, a large, temperate lake in Ontario, Canada that has shifted from a turbid to clear-water state. We then analyzed patterns of biomass fluctuations of three recreationally harvested, ecologically connected populations; lake trout (Salvelinus namaycush, a piscivore), lake whitefish (Coregonus clupeaformis, a benthivore), and cisco (C.artedi, a planktivore) before and after the invasions by testing hypotheses on their delayed recoveries under management interventions-predator manipulations (fishery removal and stocking) and nutrient (phosphorus)load reduction. Analyses suggest that fishery harvest primarily regulated early recovery trajectories of the piscivore and planktivore, weakening top-down control prior to the establishment of the invasive consumers. By contrast, the benthivore biomass patterns were shaped, in part, by the invasive mussels (via diet shift), independently of management actions. Although improved water quality (with reduced hypoxia in deeper water) and, in turn, higher macrophyte production are projected to expand the predation refuge for young fish, intensified planktivory (by Bythotrephes) and herbivory (by dreissenids) have triggered shifts in community composition (from pelagic to demersal dominance). These system-wide shifts, in turn, have substantially diminished ecosystem productivity, thereby shrinking fishery yields. Novel consumers can rewire food webs, disrupt energy flows, and suppress predator recoveries, underscoring the need to account for altered ecological reality when sustainably managing fishery resources in invaded ecosystems.