Decline Of Fisheries Research Articles

Population asynchrony within and between trophic levels have contrasting effects on consumer community stability in asubtropical lake.

Clarifying the effects of biodiversity on ecosystem stability in the context of global environmental change is crucial for maintaining ecosystem functions and services. Asynchronous changes between trophic levels over time (i.e. trophic community asynchrony) are expected to increase trophic mismatch and alter trophic interactions, which may consequently alter ecosystem stability. However, previous studies have often highlighted the stabilising mechanism of population asynchrony within a single trophic level, while rarely examining the mechanism of trophic community asynchrony between consumers and their food resources. In this study, we analysed the effects of population asynchrony within and between trophic levels on community stability under the disturbances of climate warming, fishery decline and de-eutrophication, based on an 18-year monthly monitoring dataset of 137 phytoplankton and 91 zooplankton in a subtropical lake. Our results showed that species diversity promoted community stability mainly by increasing population asynchrony both for phytoplankton and zooplankton. Trophic community asynchrony had a significant negative effect on zooplankton community stability rather than that of phytoplankton, which supports the match-mismatch hypothesis that trophic mismatch has negative effects on consumers. Furthermore, the results of the structural equation models showed that warming and top-down effects may simultaneously alter community stability through population dynamics processes within and between trophic levels, whereas nutrients act on community stability mainly through the processes within trophic levels. Moreover, we found that rising water temperature decreased trophic community asynchrony, which may challenge the prevailing idea that climate warming increases the trophic mismatch between primary producers and consumers. Overall, our study provides the first evidence that population and trophic community asynchrony have contrasting effects on consumer community stability, which offers a valuable insight for addressing global environmental change.

The Breeding colonies, population growth and breeding success of the Dalmatian pelican Pelecanus crispus in Greece: a country-wide perspective, 1967-2021

Greece holds the third larger breeding population of Dalmatian Pelican in the world. We present data about the establishment and growth, breeding performance and conservation status for all six colonies of the species in Greece for 40 years. Main features of wetlands and colonies are described. We discuss the local, regional and global natural and anthropogenic factors that may have affected colony growth. After 1982 colony surveys were carried out with various methods, adapted to the particularities of each wetland and availability of resources, and targeted estimating number of nests and number of near-fledged young via direct counting either during on-site visits or from vantage points, and recently, counts on photos taken by drones flown one or more times during breeding. Number of nests in Lake Mikri Prespa rose from ca. 100 to 1200-1500 and levelled-off. DPs from Prespa started breeding successfully in Kerkini in 2004 after placement of artificial nesting rafts. The Karla Reservoir was colonised in 2011, just two years after it started filling with water. The DP colony on Lake Chimaditis, an important stop over and feeding site, probably initiated around 2016 and continues growing. The two colonies at the western coastline have limited exchanges with those in the eastern part of the country. Amvrakikos increased and levelled off recently as conservation and management measures restricted disturbance, whilst emigrants re-established the old colony at Messolonghi in 2011 which continues to grow. The overall breeding population in Greece grew from ca 100 to over 2000 br pairs showing an annual growth rate of 7.9%. Younger colonies show high annual growth rates clearly attributed to immigration, while older colonies have growth rates less than 10%. Interacting natural and anthropogenic factors are assumed to have contributed to pelican increase in Greece the last 40 years: better legal protection status, increasingly effective protection, patrolling and conservation measures; public awareness campaigns; provision of artificial nesting structures; increased winter survival due to higher temperatures owed to climate change; less disturbance and persecution due to decline of fisheries; increasing abundance and availability of fish due to eutrophication and climate change; increasing numbers of sympatric great cormorants rendering pelican fishing more efficient; appearance of new wetlands and change of wetlands due to human intervention works.

POTENTIAL OF BIOFLOC TECHNOLOGY IN AQUACULTURE WASTEWATER TREATMENT

The increasing global demand for aquatic products and decline in wild fisheries pose a challenge in achieving the United Nations’ Sustainable Development Goal 14, which is to conserve and sustainably use marine resources. The depletion of fish populations due to overfishing, destruction of aquatic habitats as well as climate change has adversely affected aquatic ecosystems, which leads to further pressure in establishing food security. To meet the rising demand for fish products, countries have turned to aquaculture, but the industry itself faces many environmental challenges, particularly in wastewater management. This review explores the potential of using biofloc technology (BFT) to treat wastewater. BFT utilises microbial ecosystem processes to remove excess nutrients and acts as a natural “cleaning” mechanism. It transforms organic waste into valuable microbial biomass, which enhances water quality and minimises the ecological footprint of aquaculture. In this way, BFT reduces the amount of solid waste generated, increases the level of dissolved oxygen and creates an environment that is less conducive for the growth of harmful bacteria, thus reducing the need for chemical treatments. This paper also discusses the role of BFT in toxic remediation by analysing the nature and composition of aquaculture wastewater. This study provides a comprehensive overview of the mean values for various water quality parameters in aquaculture and biofloc water, and compares them with aquaculture standards.

Century‐scale loss and change in the fishes and fisheries of a temperate marine ecosystem revealed by qualitative historical sources

AbstractPolicies aiming to restore ecosystems, achieve thriving fisheries and reverse biodiversity loss require knowledge of their former status and long‐term variation. As quantitative fish data is typically only available for recent decades long after changes may have occurred, a greater use of qualitative sources has been encouraged in marine historical ecology. We examined diverse historical information (including maritime history, fisheries reports, naturalists' accounts, recipes, nautical charts and newspapers) across a multi‐century time span (13th–20th century) for a wide range of species to document their long‐term trajectories in an understudied Northeast Atlantic ecosystem (Irish Sea coast of Wales). We find strong evidence of the loss of both a pelagic fishery for herring, which was of fundamental socio‐ecological importance since at least the 13th century, and the loss of significant multi‐species demersal and intertidal fisheries. Local, commercial and/or functional extinction has occurred for taxa spanning a wide range of diversity (crustacean, elasmobranchs, sturgeon, and teleosts), body size and ecological role, suggesting far‐reaching changes to food webs. This raises fundamental questions about the present‐day health and integrity of this coastal ecosystem and the long‐term viability of current fisheries which depend on a few shellfish species. Our century‐scale synthesis of qualitative data for multiple taxa allows the collective breadth of losses to be fully appreciated and may reduce the risk of ‘shifting baselines’. Restoration to historical baselines may not be achievable, but our findings provide evidence of long‐term change relevant to policies for recovery, and prevention of further decline of fishes, fisheries and ecosystems.

Rehabilitasi Mangrove untuk Mendukung Perikanan Berkelanjutan dan Mitigasi Iklim di Desa Labuhan Kuris Kabupaten Sumbawa

The mangrove ecosystems in Labuhan Kuris Village, Lape Subdistrict, Sumbawa Regency are degraded. The area of mangrove ecosystems is categorized as good; it has decreased, potentially impacting the decline in fisheries' productivity, global warming, and other effects. This community service activity aims to rehabilitate mangroves through education and mangrove planting. The stages of this activity include an initial survey of community knowledge (pre-test) regarding mangroves, education and discussion sessions (talk shows), mangrove planting, and monitoring and evaluation. Meanwhile, the target audience for this activity is adult community members. Interviews using questionnaires were conducted to assess the community's initial understanding of mangroves. An educational session on the roles of mangroves was conducted by providing materials and distributing stickers about the roles of mangroves, and sessions. An evaluation of understanding levels was performed through post-tests, while monitoring and evaluation were conducted using direct observation methods in the field. Post-test results showed that 88% of the target audience understand the function of mangroves, 96% stated that mangroves ' role is to protect fish and crabs, while only 60% answered that mangroves have roles in climate mitigation. The number of participants in the educational session was 50 people. The mangrove species planted was Rhizophora sp. On this occasion, 1000 mangrove seedlings were planted, and the number of community members involved in mangrove planting was 220. Monitoring and evaluation results indicated that some plants were damaged due to trampling by livestock. Thus, mitigation was done by fencing around the planting area. Overall, the community actively participated from the beginning to the end of the activities. This condition indicates that the community is highly concerned about mangrove management. However, community participation in mangrove management should be improved.

How influential is the role of oligotrophication on the integrity of fish assemblages in the littoral zone?

Food web theory predicts that one of the consequences of oligotrophication is the decline in fisheries following the establishment of nutrient-deficient conditions and low biogenic production. However, emerging evidence suggests that more complex trophic interactions, induced by plankton composition, dietary diversification, temporal and spatial heterogeneity, variations in fish age and size structure can lead to ecosystem responses that deviate from theoretical predictions; especially in the shallow littoral zone. In this study, two end-to-end modelling strategies are used to characterize potential food web structural shifts and overall ecosystem productivity in response to oligotrophication. Our modelling strategy draws upon empirical and theoretical evidence from the Bay of Quinte, a semi-enclosed embayment in northeastern Lake Ontario that has been subjected to phosphorus (P) abatement strategies in the 1970s. We first show that the role of food abundance has been a primary factor shaping fish production, but the fish community gradually responded to the reduced availability of pelagic staples of their diet by displaying greater reliance upon alternative sources, including benthic and other autochthonous (or even allochthonous) food items. Our analysis further suggests that degree of diet overlap between competing trophic guilds can significantly modulate realized biomass levels. The composition of the autotrophic community is another major confounding factor that can induce significant variations from the predicted food web productivity patterns in response to oligotrophication. Overall, our analysis suggests that the proposed reduction of the ambient total phosphorus levels may not necessarily trigger a significant decline in fish biomass in the Bay of Quinte.

Decline of Artisanal Fisheries in the Croatian Section of the Sava River

Abstract The aim of this research is to analyse the trends of the total artisanal fish catch in the Croatian section of the Sava River. All 17 years of the study (2004-2020) showed a negative trend that became highly statistically significant (p<0.01) in the last eight years. In addition to the total catch, the catch per unit effort (CPUE) also decreased significantly (p<0.05) throughout the study. The reasons for these negative trends are discussed, including a possible decline in artisanal interest, higher fishing pressure from anglers from the Croatian side and both groups of fishermen from the river bank of Bosnia and Herzegovina, as well as negative influence of the polluted waters of the large Bosnian river Bosna, which prior to flowing into the lower section of the Sava River, passes through urban and industrial cities. It is suggested to activate the old idea of a common fisheries management body that would include both groups of fishermen (anglers and artisanal fishermen), government representatives and scientists from both countries.

지방 항구도시의 토지이용 변화에 관한 연구 - 전라남도 여수시를 중심으로 -

This study is on the formation and the development process of urban space by referring to the literature in Yeosu where is the important location in logistics & transportation and maritime since the Japanese colonial period. There are many factors and results of the development process in Yeosu by the opening port, railroads, loads and industries. The purpose of this study is to understand the characteristics of the formation process of urban space and the characteristics of physical space in Yeosu. The results are as follow; The urban formation and development process in Yeosu where was a small fishing village in the 1910s is largely divided into four processes. Formation: the population increased due to constructions such as of a railroad, a port, and roads and there were many reclamations around the center of the old city center in the Japanese colonial period. Stagnation: There was no urban development due to stagnation, war, and the Yeo-sun Incident. Expand: the industrialization of the Yeocheon Industrial Complex and Gwangyang Steel and other areas around Yeosu led to a surge in Yeosu's population. To cope with this, the city was expanded through three land readjustment projects and the development of large-scale residential complexes. Decline and Remodeling: Yeosu's urban space declined due to the decline of fisheries and the decrease in marine and railway logistics. And the expansion and improvement of the transportation network for hosting the Yeosu World Expo increased the accessibility of the old city center, transforming it into a tourist city using cultural heritage and nature.

Integrated watershed management solutions for healthy coastal ecosystems and people

AbstractTropical coastal ecosystems are in decline worldwide due to an increasing suite of human activities, which threaten the biodiversity and human wellbeing that these ecosystems support. One of the major drivers of decline is poor water quality from land-based activities. This review summarises the evidence of impacts to coastal ecosystems, particularly coral reefs, from sediments, nutrients, chemicals and pathogens entering coastal zones through surface and groundwater. We also assess how these pollutants affect the health of coastal human populations through: (1) enhanced transmission of infectious diseases; (2) reduced food availability and nutritional deficit from decline of fisheries associated with degraded habitat; and (3) food poisoning from consumption of contaminated seafood. We use this information to identify opportunities for holistic approaches to integrated watershed management (IWM) that target overlapping drivers of ill-health in downstream coastal ecosystems and people. We demonstrate that appropriate management requires taking a multi-sector, systems approach that accounts for socio-ecological feedbacks, with collaboration required across environmental, agricultural, public health, and water, sanitation and hygiene sectors, as well as across the land–sea interface. Finally, we provide recommendations of key actions for IWM that can help achieve multiple sustainable development goals for both nature and people on coasts.

Ichthyotoxicity of bloom-forming dinoflagellates in an Egyptian saline lake: potential role of PUFA

Lake Qarun, the third-largest saline lake in Egypt, has been plagued with algal blooms and experienced decline in fisheries. However, the toxicity of these blooms has not explored yet. Therefore, the present study is the first to evaluate the toxicity of the most frequently recorded harmful algal blooms (HABs) in Lake Qarun. The results showed an occurrence of dinoflagellate bloom in site1 located near El-Bats drain (1.4 × 108 cells L−1) and site 2 located near El-Wadi drain (1.9 × 108 cells L−1), but not found in site 3 located away from drains. This bloom associated with high nutrient concentrations and low salinity in these sites. Both intact cells and cell lysate of bloom samples and cultured species, but not cell-free supernatants, exhibited toxicity towards Artemia salina and cytotoxicity for the gill assay, with higher toxicity incurred by lysed cells. The cytotoxicity varied significantly among bloom-constituting species, with highest obtained by the most dominant species; Protoperidinium quinquecorne (LC50= 445 cells ml−1for lysed cells), Prorocentrum micans (LC50= 757 cells ml−1), Gymnodinium lantzschii (LC50= 1151 cells ml−1) and Amphidinium carterae (LC50= 1289 cells ml−1). These LC50s showed greater correlation with the percentages of the polyunsaturated fatty acids (PUFA): octadecatetraenoic (OTA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) in these microalgae, indicating the role of these fatty acids in ichthyotoxicity. No detectable levels of known phycotoxins were found in bloom or cultured species. This study suggests regular monitoring and systematic assessment of HABs and their toxins in Lake Qarun to mitigate their occurrence and maintain fisheries and seafood safety.

Incorporating traditional ecological knowledge into holistic watershed management: Fishery forests in Japan

In Japan, fishers plant trees in upstream watersheds, known as “fishery forests,” to improve coastal environments and secure fishery production. Based on observation and experience, fishers have traditionally believed that their practices are fit for their intended purpose. Fishers have found it difficult to continue their practices due to budget constraints caused by a recent decline in coastal fisheries. As such, they are currently faced with the dilemma of deciding whether to restore watershed forests to improve the coastal environments or minimize expenses in an effort to secure financial sustainability. This draws attention to further issues: whether or not fishers can obtain a net return on their efforts, and if so—when. To this end, we examine the economic value of the traditional ecological knowledge using data of terrestrial and aquatic ecosystems in Hiroshima, Japan. The results show that, while fishery forests mostly pay their costs in the long run, the costs are higher than the benefits for the first several years because of the initial costs of afforestation. With the aim of contributing to holistic watershed management, we propose policy instruments that could be employed to alleviate front-loaded costs so that fishers can engage in traditional ecological knowledge-based practices.

Reflecting on 25 years of quota management in a spiny lobster fishery: Lessons learned from a harvest strategy perspective

The Southern Zone rock lobster fishery of South Australia has been managed by individual transferable quotas since 1993, with annual catch limits set using harvest strategy decision rules. This work describes the performance of strategies over 25 years focusing on challenges experienced during periods of poor fishery recruitment. Early strategies identified indicators and performance ranges for the fishery but lacked detail on required management action when reference points were breached. Between 2002 and 2009, the fishery experienced a considerable decline in recruitment resulting in catch rate, the primary indicator, decreasing by 70%. The harvest strategy in place failed to reduce catch levels appropriately and despite consecutive years of decreasing catch rate, was unable to arrest the fishery decline. Explicit harvest control rules for quota setting were developed in 2010 and refined in both 2014 and 2019, with the specific focus of ensuring sustainability and rebuilding lobster biomass. Application of these strategies have been successful at achieving this objective, most notably since 2015. The study highlights that harvest strategies must include control rules that respond rapidly to recruitment declines. Specifically, based on harvest strategy testing and evaluation, required levels of quota reduction should be clearly defined. In combination with limit reference points that mandate the point of fishery closure, metarules and quota caps that promote biomass increase, such strategies serve to meet fishery objectives and ensure sustainability.

An assessment of the viability of a commercial lionfish fishery in the US Virgin Islands

The presence of invasive lionfish in the U.S. Virgin Islands and the difficulties experienced by commercial fishers and concerned stakeholders presents an oddly complementary set of dilemmas. Local stakeholders have difficulties implementing a financially sustainable means of reducing the lionfish population. Meanwhile, commercial fishers are frustrated by the decline in traditional fisheries. In many cases, this decline is in part accelerated by the presence of lionfish outcompeting the native species for the same prey. In other words, the successful development of a market for lionfish could solve several problems including: providing an additional fishing target for commercial fishers, increasing the diversity and amount of fresh fish landed and consumed locally, providing a stable income stream to supplement commercial fishing related businesses (i.e., fishing/dive suppliers, restaurants, etc.), and reduce pressure on wild stocks and the coral reefs (i.e., improve and protect the diversity and resilience of the ecosystem). This study examines the barriers and opportunities in developing a lionfish market for local consumption in the USVI.

Diversification of farmed fish species: A means to increase aquaculture production in Nigeria

AbstractAquaculture produces about half the fish consumed globally and is the fastest‐growing food sector. In Africa, fish is one of the major sources of animal protein, and although the need for increased production of farmed fish to make up for the decline in capture fisheries is acknowledged, efforts put into aquaculture in the continent have not yielded commensurate results. The success recorded in aquaculture in Nigeria is based on the production of the African catfish. However, a high level of production and resilience within the aquaculture sector has been shown to be positively correlated with the culture of several species or species items. Thus, enhanced diversification of species and farming systems may boost aquaculture in Nigeria, as diversification of farming systems would allow optimum utilization of the abundant natural resources in the country. Many indigenous fish species that can be domesticated for culture have been identified. A great deal of scientific research and collaboration between major stakeholders, including the government, private industries, research institutions, and researchers, is required, so the production of these species can thrive like the already farmed catfish in Nigeria. As the successful domestication of any fish species takes a lot of time, effort, and resources, the species that have already proven to some extent to thrive in Nigeria, should be explored first. It is recommended that the best strategy for diversification of aquaculture for Nigeria is to increase the use of some already farmed species and the employment of a variety of production systems.

A new hope for small-scale fisheries through local action groups? Comparing Finnish and Swedish experiences

New forms of institutional support within modern multi-level fisheries governance are urgently needed to address the decline of coastal and inland fisheries. The EU-funded Fisheries Local Action Group (FLAG) initiative promises new hope to small-scale fishers by channelling support for the development of local fishing communities. This paper analyses the potential of FLAGs to contribute towards revitalizing small-scale fisheries in Nordic settings. Drawing on documents, surveys and interviews, we compare the implementation of FLAGs in Finland and Sweden. These countries were selected for analysis because they exhibit major differences in the implementation of FLAGs, alongside similarities in their coastal fisheries and social contexts. A special structural feature in Sweden is that FLAGs have been entirely integrated into Local Action Groups set up under the LEADER programme, an EU initiative that supports development projects in rural, coastal and urban areas. As a result, fisheries issues that used to be addressed by sectoral fishery groups are now subsumed into broader territorial initiatives. In Finland, the FLAG system still comprises independent fishery groups, which collaborate with LEADER groups. Our comparison of the two cases demonstrates the importance of dedicated institutional support for small-scale fisheries to enable them to access funding opportunities provided by the EU’s FLAG initiative. Our comparative perspective enables conclusions to be drawn regarding the pros and cons of different approaches to the implementation of this hierarchical funding system, and the extent to which they can help restore fishers’ self-reliance and benefit local fishing livelihoods.

Assessing Livelihood Resilience of Artisanal Fisherfolk to the Decline in Small-Scale Fisheries in Ghana

The concept of livelihood resilience provides a unique framework for understanding challenges in complex social–ecological systems (SESs) and fostering sustainability. Despite the crises many small-scale fisheries (SSFs) are facing, few studies have operationalized the concept in the context of declining SSFs in developing countries. This study aims to assess the resilience of artisanal fisherfolk livelihoods and its predicting factors in three fishing communities—Elmina, Jamestown, and Axim—in Ghana. A total of 1180 semi-structured interviews were conducted with fishers, fish processors, and mongers. Descriptive and multivariate statistical techniques were used to analyze the data. The results show that the livelihood resilience of fisherfolk increases with an increased level of education and varies by gender. Male fisherfolk with secondary/post-secondary level education had the highest proportion (50%) of more resilient livelihoods. Only 36% of female fisherfolk with secondary/post-secondary level education had more resilient livelihoods. While 40% of male fisherfolk with no formal education had less resilient livelihoods, the livelihoods of half (51%) of females fisherfolk with no formal education were less resilient. The sociodemographic characteristics including wealth status, dependency ratio, marital status, religion, and ethnicity; contextual factors (community); and other relevant factors (experience in fishing, membership of fisherfolk association/group, and beneficiary of livelihood interventions) were found as predictors of the resilience of fisherfolks livelihoods. The findings suggest that interventions towards improving the livelihood resilience of fisherfolk need to consider individual- and household-level characteristics, as well as contextual factors such as marital status, religious affiliation, ethnicity, wealth status, dependency ratio, community, etc.

Enhancing adaptive capacity of wetland fishers through pen culture in the face of changing climate: A study from a tropical wetland, India

Abstract Wetlands are among the most productive of all aquatic ecosystems. In developing countries, millions of marginal fishers rely solely on wetlands for security of both nutrition and livelihood. The decline in wetland fisheries owing to anthropogenic and climatic changes has made fishers increasingly vulnerable. Pen culture can be an effective climate-resilient technology for enhancing fish production in shallow, macrophyte-choked, and multi-stake floodplain wetlands, especially in eastern and north-eastern India. In this context, pen culture was implemented as an adaptive measure in a tropical Gangetic wetland (Mathura) to enhance fish production and increase the adaptive capacity of fishers. Indian Major Carps, Gibelion catla, Labeo rohita, and Cirrhinus mrigala of initial size 10.4±.21g, 8.2 ± 0.48g, and 6.5 ± 0.23g respectively, were stocked at the ratio of 4:4:2 and at the rate of 30 fish m-2 each in pens of 100 m2 in duplicate. For purposes of conservation, Labeo bata and Gudusia chapra, 4.3 ± 0.18g and 3.8±.34g initial size, respectively, were stocked at the rate of 20 Nos.m-2 each at the ratio of 1:1. The fish were fed with commercial feed at the rate of 4% of body weight. A net survival of 82%, 87%, and 75% was recorded in Indian Major Carps, L. bata and G. chapra. A production of 380 kg IMC was achieved during 120 days of the culture period. L. bata achieved an average weight of 21.40 ± 0.34g during the 90-day culture period, with a survival rate of 87%. G. chapra attained an average weight of 16.5 ± 0.42g during the culture period, with a recorded survival rate of 75%. G. chapra was observed to spawn in the pen. The water quality inside pens and reference sites did not differ significantly (p >0.05). The produced fish were released in the wetland for fisheries enhancement. The present communication discusses the technological suitability and economic feasibility of adopting climate-resilient pen culture as an adaptation measure for enhancing the adaptive capacity of wetland fishers in the face of a changing climate.

Defining Success for A Declining Resource: Mental Models of Oyster Management in Apalachicola, Florida

Wild oyster populations are in decline globally, affecting communities of generational fishers and changing the cultural dynamics of coastal communities. Managers have employed a range of approaches to conserve and restore oyster populations and sustainable fisheries; yet there is little agreement among managers, scientists, and resource users regarding what constitutes success. This study uses a qualitative, mental models approach to compare understandings of management, perceptions of management success, and barriers to achieving successful management outcomes among three critical stakeholder groups: natural resource managers, oyster harvesters, and aquaculture farmers. We found similarities among the mental models of all three groups in the causes and consequences of the oyster fishery decline, but major differences in definitions of management, factors needed for successful management, and barriers to success. This study takes a more comprehensive look at the understandings of stakeholders than previous research by mapping the causes and effects, from the decline of the oyster fishery to expectations of future success. Managers can improve stakeholder investment in management projects by gaining a better understanding of the differing definitions of project success, stakeholder participation, and stakeholder understanding of the role of management.

Characterizing Industrial and Artisanal Fishing Vessel Catch Composition Using Environmental DNA and Satellite-Based Tracking Data.

The decline in wild-caught fisheries paired with increasing global seafood demand is pushing the need for seafood sustainability to the forefront of national and regional priorities. Validation of species identity is a crucial early step, yet conventional monitoring and surveillance tools are limited in their effectiveness because they are extremely time-consuming and require expertise in fish identification. DNA barcoding methods are a versatile tool for the genetic monitoring of wildlife products; however, they are also limited by requiring individual tissue samples from target specimens which may not always be possible given the speed and scale of seafood operations. To circumvent the need to individually sample organisms, we pilot an approach that uses forensic environmental DNA (eDNA) metabarcoding to profile fish species composition from the meltwater in fish holds on industrial and artisanal fishing vessels in Ecuador. Fish identified genetically as present were compared to target species reported by each vessel’s crew. Additionally, we contrasted the geographic range of identified species against the satellite-based fishing route data of industrial vessels to determine if identified species could be reasonably expected in the catch.

Stakeholder Perceptions on the Governance of Fisheries Systems Transformed by Hydroelectric Dam Development in the Madeira River, Brazil

Hydroelectric dams often have significant impacts on freshwater fisheries. Major impacts are known to be driven by changes in river hydrology and fish ecology, but the role of governance arrangements in mitigating or exacerbating fisheries impacts from hydropower development is less understood. This study presents an analysis of stakeholder perceptions about the effects of hydroelectric dam implementation on fisheries governance arrangements in the Madeira River basin, Brazil. Semi-structured interviews were conducted with 50 stakeholders representing the fishers and fish traders, government, non-governmental organizations, and the private sector. Fishers, non-governmental, and private sector agents perceived hydropower development to be the strongest factor driving fisheries decline or change over the past 10 years, while government staff perceived overfishing to be an equally or even more important factor. Most stakeholders affirmed that fisheries governance arrangements have weakened in the face of hydropower development, and that these arrangements have been insufficient to effectively mitigate or compensate for negative impacts on fisheries. Fishers, non-governmental and private sector agents saw lack of opportunities to participate in fisheries governance as a major contributing factor, while government staff emphasized lack of qualified personnel, lack of trust between agencies, and control over the decision-making process held by hydropower companies. Perspectives on other implications of governance arrangements were shared across stakeholder groups. These included increased conflicts; lack of interaction and coordination between agencies; the fragility of fishers’ social organization; lack of trust and reciprocity between organizations; and power imbalances between stakeholders. The results show that hydropower development impairs and changes relationships between diverse players involved in fisheries governance, which can exacerbate existing weaknesses and negatively affect fishery sustainability. Drawing from the perspectives and comments of the various stakeholders who participated in the study, we provide recommendations to improve freshwater fisheries governance in the Madeira River basin and in the Brazilian Amazon.