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Freshwater fish are threatened globally and in addition, knowledge of their diversity is incomplete and species richness is underestimated. Within the ichthyofauna of the Cape Fold Ecoregion of South Africa, many undescribed lineages exist and for most of these, information is limited regarding their ecology, distribution and threats. The Tradouw redfin Pseudobarbus sp. 'burchelli Tradouw' is a novel and range-restricted lineage within the Breede River redfin Pseudobarbus burchelli. Annual monitoring conducted between 2012 and 2016 investigated spatial and temporal trends in the distribution and population dynamics of this taxon. Results indicated that it is highly fragmented within its distribution range, likely a result of the combined pressures of invasive fish and poor land use practices. Short-term monitoring results indicated that invasive fish are established in most of the catchment and that the relative abundance of redfins remained constant only in the limited section of river where alien fish were absent. Poor land use practices such as water over-abstraction and surface water pollution, are pervasive threats, but the extent to which these affect the redfins requires further investigation. The long-term survival of this taxon remains uncertain, and short-term and long-term conservation and management options are explored. [ABSTRACT FROM AUTHOR]

Freshwater-limited fish populations are often tightly constrained by river drainage boundaries. As a case in point, the distribution of lineages within New Zealand's diverse Galaxias vulgaris complex is broadly structured by geographic barriers, reflecting tectonic processes. However, several drainages of the Central Otago region have been locally modified by past gold-mining activities, with artificial water races connecting formerly isolated headwaters of distinct river drainage systems. Here we synthesise published genetic data to highlight the role of anthropogenic catchment modification in redistributing fish diversity. These data show that several local phylogeographic anomalies for stream-resident Galaxias fishes are closely linked to anthropogenic connections across major drainage divides. While these anthropogenic translocations may parallel natural geologically-driven mixing events that occur on deeper time scales, they nevertheless have potential conservation implications given the increasing fragmentation of native fish populations. Our review also highlights the role of sub-catchment units in shaping the hierarchical structure of intraspecific biodiversity. [ABSTRACT FROM AUTHOR]

In view of the growing global demand for electricity, many countries have been looking for ways to diversify production. However, in countries such as Brazil, hydroelectric power plants still constitute the predominant generating source, occupying important drainage systems, such as the Upper Paraná River. At the same time, hydroelectric dams are among the main sources of impacts on freshwater fish, interfering, for example, in the genetic distribution of populations. Although the same could be expected from Small Hydroelectric Plants, very little genetic information has been obtained along Neotropical drainages. Based on this, the present study analyzed the DNA (microsatellite loci) of non-migratory fish species (seven) upstream and downstream of three Small Hydroelectric Plants in the Upper Paraná River basin, obtaining information about the genetic distribution of fish populations in this scenario. In general, the data suggest that populations have been genetically subdivided by Small Hydroelectric Plants and that other factors, such as the number of Small Hydroelectric Plants along a drainage and connectivity with long free stretches, could also influence genetic differentiation levels, which provides information of great relevance to global discussions about the impacts of hydroelectric power plants, as well as for the implementation and management of projects. [ABSTRACT FROM AUTHOR]

The life cycles of potamodromous fishes are generally interrupted by the presence of a dam, and populations often display different life history traits between upstream and downstream. This study compared the age and growth rates of grass carp and silver carp above and below Changzhou Dam in the Pearl River. Standard length (SL) composition and back-calculated SL at ages one and two years were greater for grass carp upstream than for downstream individuals; and the length–weight relationship differed between upstream and downstream populations, while the sex ratio, age structure and growth were not significantly different. For silver carp, only SL compositions differed between upstream and downstream populations; sex ratio, age structure, SL-at-age and growth rates were similar. Mean SL-at-age and growth rates of both species were lower at high latitudes than at middle and low latitudes, and populations in the Yangtze River had greater mean SL-at-ages and faster growth relative to silver carp at low latitudes. There were no differences in mean SL or growth among populations at middle and low latitudes. For grass carp, age and growth varied with small-scale ecological processes and regions or latitude, while for silver carp, such variations were proportionate to latitude and the large-scale geographical range. This study provides not only guidelines for fisheries management and conservation of exploited potamodromous fishes, but also insights into the relationship between life history trait variation and adaptive capacity. Size composition, the relationship between SL and body weight, size-at-age of grass carp were different, and silver carp only had difference in size composition between upstream and downstream of Changzhou Dam in Pearl River, China. Grass and silver carp showed similar age structure, sex ratio and growth rate between upstream and downstream of Changzhou Dam in Pearl River, China. Size at age and growth rate varied with latitudes to some extent and showed variations among populations at middle and low latitudes in China. [ABSTRACT FROM AUTHOR]

It's essential to identify the priority conservation species in the habitat restoration and biodiversity conservation. Generally, people select the valuable fishes or the commercial fishes as target species in basins, according to experts' experience rather than the scientific evaluation. With the influence of urban development, construction of water conservancy facilities and human activities, the river habitat of the Shaying River (Xuchang section) is poor. Fish conservation studies play an important part in the habitat restoration of this river section. Thus, we studied the evaluation method for the priority protection of fishes based on multiple ecological dimensions. The method including six multidimensional indicators, namely, habitat suitability, ecological stability, species endangerment criteria, intensity of human interference, genetic value, and species value. Then, we determined the indicator weights by the analytic hierarchy process (AHP), and assessed the protection priority of fishes based on various assessment criteria and comprehensive qualitative or quantitative analyses. The result shows that Ctenopharyngodon idellus, Opsariichthys bidens, and Culter alburnus Basilewsky have priority for protection, coinciding with the status in the basin. Overall, this study complements the existing indicator species selection methods, and is more scientific and comprehensive, providing an effective method for priority protection species and river habitat restoration projects. [ABSTRACT FROM AUTHOR]

A tag-recapture study was undertaken on the Natal seacatfish Galeichthys troworum in the Pondoland Marine Protected Area (PMPA) on the east coast of South Africa. A total of 473 fish were tagged over a period of 8 years, and 136 individuals (28.8%) were recaptured over a period of 16 years, some of them on multiple occasions. Most recaptures (82%) were caught within 200 m of their release site, with movements ranging between 0 and 617 m, and time-at-liberty ranging between 0 and 3 407 days (9.3 years). Data analysis showed that all recaptured fish remained in relatively small home ranges (of ∼360 m linear distance) and none of them abandoned their home range and moved out of the 2-km2 sampling blocks. While the no-take area of the PMPA provided effective protection for these fish, their relative abundance was similar in an adjacent exploited area. This is likely because G. troworum is not a desired linefish species, with most individuals caught being released, coupled with high post-release survival. [ABSTRACT FROM AUTHOR]

Major threats to South African estuaries include freshwater flow alterations, urbanisation, habitat transformation, deteriorating water quality, increased biological invasions and resource over-exploitation. Although South African estuary restoration is in its infancy, important lessons have been learnt through past efforts undertaken in some of the most impacted systems. This review presents case studies focused on hydrological and physical restoration actions, while recognizing the need to implement urgent remedial measures to restore the populations of targeted estuary-associated marine fish species. Common interventions designed to arrest declining estuary health include artificial management of estuary mouths and the use of artificial structures to restore tidal action and remediate erosion damage. Limited natural habitat restoration actions have been conducted on the subcontinent. Fortunately, estuaries are resilient ecosystems and can recover fairly rapidly if appropriate restoration interventions are successfully applied. Restoration needs to be co-ordinated through a national strategy which is currently not in place. It is particularly important to address the root cause of deterioration through active restoration and/or rehabilitation measures rather than only managing symptoms. The implementation of existing and future conservation legislation regarding the exploitation of natural resources within estuaries needs to be prioritised, so that over-exploited angling and subsistence fish species populations can recover. [ABSTRACT FROM AUTHOR]

Scientific output has proven the value of the Oceanographic Research Institute's Cooperative Fish Tagging Project (ORI-CFTP) to biological and fisheries research, with more than 95 published manuscripts based on data from the ORI-CFTP. This study reviews the project from the perspective of participating anglers. A total of 267 members of the ORI-CFTP responded to an online survey designed to gather data on the profile of tagging members, their preferred methods of communication, attitudes towards fish tagging and fish conservation in general, changes in angling behaviour since becoming a member of the project, and support for the continuation of the ORI-CFTP. The results reveal that the ORI-CFTP has indeed made a considerable contribution towards improving the conservation ethics and behaviour of marine recreational anglers in South Africa. Improved communication with anglers— both taggers and non-taggers—through the ORI-CFTP has the potential to amplify much-needed conservation information to the broader angling community and thereby enhance environmental awareness. Recommendations on how to improve the ORI-CFTP and other angling-related citizen science projects are provided. [ABSTRACT FROM AUTHOR]

The results of a large study of vertebrate remains from two shell rings on St. Catherines Island, Georgia, are presented: the St. Catherines (9LI231) and McQueen (9LI1648) Shell Rings. The vertebrate archaeofaunal collections are used to infer foodways of Late Archaic people on St. Catherines Island, which centered on a limited suite of small-bodied, estuarine fishes. Given the prevalence of small-bodied fishes, Late Archaic people deployed a number of mass-capture fishing technologies which may have necessitated shared labor and community cooperation. Although there are similarities in the vertebrate assemblages at these two rings, suggesting a shared foodways tradition, differences are notable. These differences may indicate that the occupants of the two rings had unique preferred or controlled fishing grounds. The zooarchaeological collections also are used to contextualize the vertebrate data within the current formational models proposed for Late Archaic shell rings. Vertebrate remains align with models that interpret shell rings as the result of Late Archaic people living in circular villages, discarding refuse from daily meals; however, these animals were also featured in a ritualized event highlighting their relevance and meaning beyond food. [ABSTRACT FROM AUTHOR]

The queen conch (Aliger gigas) is a culturally and economically important molluskan fishery resource in the Caribbean region showing increasing signs of over harvest. Shallow-water distribution and large size facilitate capture, and internal fertilization and density-dependent reproduction make managing for reproductive biology critical to stock rehabilitation. In fact, the natural lifetime fecundity of conch is very high but most fisheries in the region harvest conch before even a small fraction of that reproductive potential can be attained. The goal of this review is to provide an up-to-date synthesis of the vast research literature on queen conch biology (spanning >60 years) and to discuss how knowledge of reproduction in conch can help to guide field surveys, fishery management decisions, and stock recovery projects. The review covers the subjects of anatomy, maturation and fecundity as they relate to conch age and size, reproductive behavior including migrations, seasonality, mating, and egg-laying, and the influences of both environmental and demographic variables on reproductive potential. Successes and failures under different forms of management practice are discussed as they relate to reproductive biology and recommendations are made for future research and fishery management alternatives. Successful management will require multiple regulatory approaches. [ABSTRACT FROM AUTHOR]

Associational effects such as "associational resistance" or "aposematic commensalism" may facilitate the subsequent evolution of mimicry. However, such effects are usually expected to be contingent on a spatiotemporal co-occurrence of defended and undefended species. Associational resistance may emerge in communities of larval anurans where tadpoles of different species share a generalized morphology but vary in chemical defences. In Europe, the marsh frog Pelophylax ridibundus reproduces in fish-containing habitats that earlier in the season can be used by the common toad Bufo bufo, a species with chemically defended larvae. In a mesocosm experiment, we investigated if the associational protection against predation provided by the defended species could be strong enough to last even after the defended prey metamorphose and leave the system. We expected that the higher abundances (both absolute and relative) of chemically defended B. bufo in the tadpole assemblage exposed to predation by the common carp Cyprinus carpio prior to the occurrence of P. ridibundus tadpoles would be related to the increased later survival of P. ridibundus in the presence of the same fish. The tadpoles of P. ridibundus were highly vulnerable to predation during a 2-week cohabitation with fish. We found no relationship between the survival of P. ridibundus and the absolute density or relative proportion of B. bufo. Although associational effects may be ecologically relevant in aquatic animal communities, they apparently require the co-presence of the defended prey in fish-tadpole interactions. [ABSTRACT FROM AUTHOR]

Monitoring marine protected areas (MPAs) is critical for evaluating their effectiveness and for improving management. In this study, a single-camera baited remote underwater video system (mono-BRUVS) was deployed quarterly at four sites (10–30-m depths) to quantify the reef fish communities in protected (no-take) and adjacent exploited areas of the Pondoland MPA on the east coast of South Africa (Indian Ocean). To assess size (biomass) of the fish communities, we used 10 years of research linefishing data (2006–2016) from the same areas. Univariate and multivariate analyses were used to compare abundance and biomass of the fish communities between protected and exploited areas. Significant differences were detected between fish communities in protected and exploited areas based on their abundance and biomass. These differences are primarily ascribed to linefishing and the removal of larger, predatory species such as yellowbelly rockcod Epinephelus marginatus, Scotsman Polysteganus praeorbitalis and black musselcracker Cymatoceps nasutus in the adjacent exploited areas. Removal of such predators may have caused trophic cascading or prey release, resulting in very different fish communities. These results highlight the importance of investigating the entire fish community and not only target fishery species when evaluating MPA effectiveness. [ABSTRACT FROM AUTHOR]

The Mekong, the largest river in Southeast Asia, is of fundamental cultural, ecological, and economic importance to the entire Mekong region. It supports the highest fish diversity after the Amazon and the largest inland fishery in the world and is at serious threats of intensifying environmental disaster and human activities. Mismatched the high attention worldwide, few related studies were concerning fishes in the whole basin. In this paper, 899 freshwater fish species were recorded, which could be grouped into 9 biogeographical regions based on their distribution information; each region owed its unique fauna with different dominance/or endemism at the genus level. The species richness was positively related to temperature, precipitation, and longitude, but negatively to latitude and slope. Seven migratory systems were deduced from spatial distribution information of 321 migratory species, and these systems were separate but not independent. Mekong fisheries were highly diversified with an estimation of a maximum worth of around $17 billion. Fisheries played an irreplaceable role in Cambodia, and aquaculture was of growing importance in the Delta and the Upper Mekong. Cascade dams, as well as climate change, overfishing, aquaculture, and pollution, posed threats to fish diversity and resources by habitat homogenization, migratory channel blockage, parents population decline, and diseases. Integrated management, a combination of capture and aquaculture fisheries, and collaboration among scientists, fishermen, and the public were advocated to address the issues facing Mekong fishes. [ABSTRACT FROM AUTHOR]

Herbivorous and detritivorous fish display complex feeding behaviour, and research into how feeding behaviour changes with environmental and social variables is lacking. Such knowledge is imperative to infer how herbivory/detritivory will differ, in light of shifting resources and communities and specifically whether reefs can recover from disturbance. Fish abundance, feeding rate, body size, diet and schooling feeding of three major functional groups (scrapers, grazers and browsers) were examined across reef types under different fishing regulations. Scrapers and grazers (parrotfishes and surgeonfishes) were more abundant and displayed the highest feeding rates on reef flats. Scrapers mainly resided inside the restricted zone, while more grazers were found in the general use zone, where macroalgal abundance was highest. Browsers (rabbitfishes) were seldom observed and patchily gathered on the reef flat and reef slope in both zones. Thus, fishing protection did not appear to benefit grazers and browsers, whereas more scrapers gathered on shallow reef flats in the protection zone. Scraper and grazer feeding rates increased from an individual to a pair and increased with body size, these factors led to variations in feeding behaviours across reef types and protection regulations. Protection appears to benefit scrapers and variations in feeding rates were largely related to school size. Lastly, grazer density was associated more with macroalgal coverage than protection status. The opposite feeding behaviours of scrapers and grazers indicates not only protection status, but fishing restrictions and size limit regulations are needed to maintain coral reef fisheries and functional diversity on coral reefs in Taiwan. [ABSTRACT FROM AUTHOR]

'Coexisting with wildlife' and 'living with wildlife' are commonly used in communication efforts designed to mitigate human-wildlife conflicts. However, there is little information on how the public understands these terms and how their understanding compares to wildlife managers' intended message. In 2019 we surveyed 1,045 Florida residents and 140 Florida Fish and Wildlife Conservation Commission (FWC) officials to examine their understanding of, and preferences for, the terms 'coexisting with wildlife' and 'living with wildlife.' We analyzed data using qualitative and quantitative methods. FWC officials were more likely to interpret both terms as people changing their behavior to mitigate human-wildlife conflicts or tolerating conflicts with wildlife, whereas the public tended to focus on reduced nuisance behavior by wildlife. Wildlife managers should clearly define terms to avoid confusion or miscommunication, which may result in the public not altering their behavior or mistakenly taking actions that exacerbate human-wildlife conflicts such as domesticating wildlife. [ABSTRACT FROM AUTHOR]

The origins and early history of the pentateuchal prohibition against eating finless and scaleless aquatic species (Lev 11:9–12; Deut 14:9–10) has yet to merit a detailed investigation. The present study is an initiatory attempt to attend to this lacuna by analysing 56 zooarchaeological assemblages of fish remains from 30 sites throughout the southern Levant from the Late Bronze Age through to the end of the Byzantine period (ca. 1550 BCE to 640 CE). A central conclusion of the study is that consumption of scaleless fish— especially catfish—was not uncommon at Judean sites throughout the Iron Age and Persian periods. Unlike the pentateuchal prohibitions against eating pork, the ban against finless and scaleless aquatic species apparently deviated from longstanding Judean dietary habits. The pentateuchal writers appear to have legislated this dietary restriction despite the lack of an old and widespread dietary tradition at its root. This conclusion should encourage us to rethink commonly held assumptions that other pentateuchal dietary proscriptions emerged out of earlier dietary 'taboos'. [ABSTRACT FROM AUTHOR]

There is still a need for appropriate livelihood strategies to improve livelihoods of small-scale fishers, despite several roles the African inland fisheries play to fishers' wellbeing. This study assessed the nexus between small-scale fishing and fishers' livelihoods at Lake Itezhi-Tezhi, Zambia. Using the mixed-methods approach under a sustainable livelihood framework, findings revealed the fishing income was insufficient to improve their livelihood assets due to the low fish catches per fisher. Deficiency in fishing income was compounded by fishers' vulnerability to shocks caused mainly by the effects of the closed fishing season and crop/livestock production failures. As such, the study suggests, among other strategies, the support of fishery stakeholders towards alternative income sources and development of a livelihood-inclusive fisheries policy framework to help enhance the livelihoods of fishers at Lake Itezhi-Tezhi fishery. Beyond this lake fishery, this study contributes similar strategies as lessons for addressing the fishers' livelihood challenges and promoting sustainable fishing. [ABSTRACT FROM AUTHOR]

Fishes are an important group of vertebrates in the animal world and make a significant contribution to global biodiversity. Fish is used as a source of food and contains many essential vitamins and fatty acids. The study of fish and their stability is important because, from year to year, fish stocks are often very important. For the conservation and management of these dwindling resources, correct identification of species is a prerequisite. Character-based methods of identification are of considerable use in this context, which classify specimens into species using classification rules that compactly describe species in terms of key diagnostic nucleotides in the gene sequences chosen. In this study, a total of 56 species of fishes distributed in Pulicat lake waters is taken as the target group. Mitochondrial CO1 sequences of each species were downloaded and modified. The species-specific diagnostic nucleotides for the selected group of species were identified using the BLOG version 2.0 software. Species-specific probes with a length range of 18–37 bp were designed on the basis of identified diagnostic nucleotide sites. The method is an effective tool for quickly and easily obtaining a significant amount of reliable information and could be used for forensic applications and conservation of fishes in Pulicat Lake. [ABSTRACT FROM AUTHOR]

The current geometric designs of fish guidance structures with vertical bars for run-of-river hydropower plants result in high head losses and asymmetric turbine admission flow. To address these issues, we develop innovative curved bar designs and experimentally investigate different rack configurations with curved bars in a laboratory flume. The present paper (Part II) focuses on the hydraulic performance of the novel curved bar designs with regard to flow fields, while the companion paper (Part I) reports the results on the head losses. The detailed flow fields obtained by 3D velocity measurements show that the curved bars promote flow conditions favourable for both fish guidance and turbine operation. The flow straightening effect of the curved bars leads to quasi-symmetrical turbine admission flow and reduced head losses. The findings are discussed with regard to fish protection and guidance, and optimal engineering application. [ABSTRACT FROM AUTHOR]

The hydraulic performance of fish guidance structures such as louvres and angled bar racks is an important design criterion to achieve high fish guidance efficiencies with a minimum impact on hydropower production. The current geometrical designs of such structures result in high head losses and asymmetric turbine admission flow and hence need to be optimized. We therefore developed an innovative curved bar design for fish guidance structures and experimentally investigated different rack configurations in a laboratory flume. The present paper (Part I) focuses on the hydraulic performance of the novel curved-bar racks with regard to head losses, while in the companion paper (Part II) we report the results on the flow fields. The effects of the main rack angle, bar angle, bar spacing, bar depth, and top or/and bottom overlays were systematically studied. The curved bar shape leads to significantly lower head losses compared to straight bar shapes. An existing head loss prediction formula was extended to account for the new bar shape and the application of overlays. [ABSTRACT FROM AUTHOR]

Catch-and-release (C&R) angling has increased in popularity through its mandatory and voluntary use in fisheries conservation and management. However, research has shown that fish can experience considerable stress during a C&R event. The physiological response of fishes is typically assessed by measuring the concentrations of blood-plasma cortisol, blood glucose and blood lactate. Members of the family Sparidae are extensively targeted in many warm-temperate coastal fisheries, and the bronze bream Pachymetopon grande is one of the most commonly captured sparids in the South African marine shore-based fishery. The aim of this study was to map the time-course of the physiological-stress response (PSR) after a simulated C&R event to determine the optimal blood-sampling time for assessing the physiological impact of C&R angling in the field. A general additive mixed model identified a significant effect of time on plasma cortisol (p = 0.005), blood glucose (p < 0.001) and blood lactate (p = 0.037), with plasma cortisol peaking at approximately 65 minutes and blood glucose at 86 minutes post-stress. In contrast, blood lactate continued to rise with no clear peak during the 125-minute sampling period. These results suggest that blood sampling should take place between 50 and 75 minutes after a C&R event. Despite a clear response, the PSR of P. grande will likely be greater in a true C&R event as this study made use of a simulated fight and used best handling practices. In addition, the prolonged physiological impacts of C&R may have negative consequences for the survival of this species in the high-energy, predator-rich coastal marine environment. [ABSTRACT FROM AUTHOR]

Yellowstone National Park implements a native fish conservation plan to control translocated trout species competing with native cutthroat trout. Under the plan, millions of lake trout are removed from Yellowstone Lake and park streams are poisoned to eradicate other translocated trout species. Killing trout introduced by officials decades earlier is a significant reversal in fisheries management. This article employs a biopolitical analysis of data derived qualitatively from semistructured interviews, relevant documents, and participant observation in the field. Results reveal a diversity of sometimes antagonistic stakeholders subjecting themselves to the practice of killing formerly revered fish based on truth claims circulating around the crisis-based conservation of native fish populations and ecosystem health. Stakeholders support logics of killing in relation to their varied engagements with fish, leading to a multiplicity of biopolitical motivations endorsing nativism in Yellowstone. From this multiplicity emerges a conservation hegemon where power over life and death is enacted in many corners of the biosocial collective but trends toward dominant knowledge and practice vested in the National Park Service. Theorizing killing for conservation as a hegemonic political ecology reconceptualizes the place of species outside of problematic dichotomies like native and nonnative. Instead, species are either hegemonic or counterhegemonic based on their lively positions relative to the conservation hegemon, leading to more honestly articulated motivations behind resource management goals associated with the practice of killing for conservation. [ABSTRACT FROM AUTHOR]

The inclusion of nanotechnologies in aquaculture and seafood preservation confronts a new edge that deserves attention in the recent trends of global food sector. Nanotechnology, being a novel and innovative approach has paved way to open up new perspective for the analysis of biomolecules, targeted drug delivery, protein or cells, clinical diagnosis, development of non-viral vectors for gene therapy, as transport vehicle for DNA, disease therapeutics etc. The current and potential use of nanotechnology would show the way to progression of smart and high performing fish. The comparative evaluation of extremely sophisticated nanotechnology with conventional process engineering proposes new prospectus in technological developments for superior water and wastewater technology processes. Nanoparticles have comprehensive advantages for management of drugs as liberation of vaccines and therefore hold the assurance for civilized protection of farmed fish against disease-causing pathogens. This review article explores the present concerns of food security, climate change as well as sustainability that are explored by the researchers in the area of nanotechnology, development of marine produce, along with its preservation and aquaculture. [ABSTRACT FROM AUTHOR]

The expression "mastering the environment" may inspire conflicting associations depending on whether we focus on the temporality of targeted fishers, marine biologists, or policymakers. This study presents an emic perspective on how natural and social environments are understood and managed during the short fishing season for Greenland halibut. In the context of this paper, mastering has to do with communication, social relations, and efforts to live up to moral standards of behaviour and to adapt to sea bottom topography, fish-finding technology, weather conditions, and vessel safety. A particular focus is the knowledge generated through informal teaching and intergenerational support and respect. Nevertheless, this bank fishery displays characteristics of frontier behaviour, as state-induced quotas and particular events and practices onboard elicit unintended results. [ABSTRACT FROM AUTHOR]

Wild Atlantic salmon and sea trout are in danger in several fisheries of the northern hemisphere due to anthropic activities. The pressures on fish stocks include excessive commercial and recreational harvests, as well as habitat depletion. In this paper, we present a choice experiment assessment of recreational anglers' preferences for conservation options, aiming to reduce harvest and improve ecosystem quality of salmon fisheries using Ireland as a case study. Data were collected by online survey and analysed with a latent class logit model. Results indicate two groups of anglers with diverging opinions and preferences on salmon conservation priorities, which will likely be reflected in different levels of acceptance of conservation initiatives. [ABSTRACT FROM AUTHOR]

Catch-and-release (CR) has become a pervasive practice and "social norm" with anglers for some inland recreational fisheries. This practice has been promoted for fish conservation and to meet angler and manager desires of greater fish abundances, angler catch rates, and trophy growth potential. Catch-and-release in north-temperate inland recreational fisheries was reviewed over time and documented the subsequent responses of fish populations to the practice in catch rates, recruitment, abundance, size structure, growth, and trophy potential primarily focusing on black bass Micropterus spp., muskellunge Esox masquinongy, walleye Sander vitreus, and panfish (sunfishes Lepomis spp., crappies Pomoxis spp., yellow perch Perca flavescens). This review suggested that angler and manager desires may not be met when fisheries are almost exclusively CR, CR may create situations where managers are unable to structure fish communities to meet such desires, and CR can cause imbalances in fisheries managed for multiple species. Because CR may be one of the biggest challenges facing inland recreational fisheries management in the 21st century and beyond, recommendations and future research considerations are provided and aimed to alleviate concerns identified from this review to better balance fisheries, meet angler and manager desires, and to keep fisheries within a safe operating space. [ABSTRACT FROM AUTHOR]

Genomic data can be a useful tool in the management and conservation of biodiversity. Here, we report the development of genomic resources for the spotted ragged-tooth shark Carcharias taurus using genome-wide DNA data from Illumina next-generation sequencing. We explored two commonly used genetic marker types: microsatellites and mitochondrial DNA. A total of 4 394 putative microsatellites were identified, of which 10 were tested on 24 individuals and found to have ideal properties for population genetic analyses. Additionally, we reconstructed the first complete mitochondrial genome of a South African spotted ragged-tooth shark, and highlight the most informative gene regions to facilitate future primer design. The data reported here may serve as a resource for future studies and can ultimately be applied in the sustainable conservation and fisheries management of this apex predator. [ABSTRACT FROM AUTHOR]

This review summarizes what is known about the influence of water temperature and velocity on the migration and spawning success of an inland population of Chinook salmon Oncorhynchus tshawytscha. Models are then developed and used to illustrate how migration and spawning success might change if temperatures and velocities increase under a future climate. The illustration shows the potential for moderate increases in temperature and velocity to reduce homing and increase energy expenditure. Those two outcomes would reduce the abundance, productivity, and diversity of the population studied. Under the future scenario illustrated, it would become difficult for fish management actions alone to recover conservation-reliant populations of inland Chinook salmon. [ABSTRACT FROM AUTHOR]

The introduction of exotic species is a key global threat to biodiversity. Beyond an increased risk of native species extinction, there exists a loss of biodiversity distinctiveness. Nevertheless, quantitative information on biotic homogenization at the taxonomic level in relation to basin features is rare. We used freshwater fish distribution data in Spain at three different time periods (1952, 1995, and 2007) to assess the species introduction process and the temporal dynamics of taxonomic homogenization among river basins in relation to basin size, native species richness and dam construction variables. The degree of alteration of original faunas by species introduction has increased through time, especially in native richer species, which suggest that the number of non-native and native species covariate with environmental heterogeneity. On the other hand, neither basin size nor habitat modification by dam construction seems to explain the number of introduced species. Our results indicate that the taxonomic homogenization of Spanish fish fauna is a temporally and spatially dynamic process; initial local increases in β-diversity through species introduction could be blurred because of scaling to regional and national levels or by the continuous expansion of a reduced number of exotic species. [ABSTRACT FROM AUTHOR]

The Yangtze Estuary is the largest estuary in the western Pacific Ocean, and harbors a high diversity of fish fauna. In this study, larval fish were surveyed monthly across three sections within the southern branch of the Yangtze Estuary (SBYE). A total of 49 taxa were collected, with 51.4% of the identified species being freshwater fishes. The collected numbers of larval taxa in the upper, middle, and lower sections were 22, 28, and 43, respectively. Species with differing salinity adaptations displayed different patterns along the direction of freshwater input. The collected numbers of larval taxa were 47 and 29 in the near-shore and mid-stream areas, respectively; and the abundances of larval fish in the near-shore areas tended to be higher than in the mid-stream areas in all the three sections. Larval fish occurred year-round with two peaks of abundance. Our results suggest that the freshwater input was the dominant factor shaping larval fish assemblage structure and dynamics within the SBYE. Influences of the Three Gorges Dam and South-to-North Water Transfer Project on larval fish assemblages within the SBYE should be considered with regard to conservation practices. [ABSTRACT FROM AUTHOR]

Restoration of degraded freshwater ecosystems has gained considerable attention in the USA over the past decades. However, most projects focus almost entirely on the restoration of physical habitat or specific water quality parameters, while ignoring critical ecological processes related to food web re-establishment. In this study, we investigate the impact of riparian habitat in different stages of restoration on food availability for fish in four streams in Pennsylvania, USA. The riparian buffer habitats ranged from open meadow to mature forest and included new to long-term restoration sites. We quantified abundance and community composition of aquatic macroinvertebrates and riparian arthropods with aerial and ground-dwelling life history strategies. We found that riparian habitat and water temperature exert a strong influence over potential food resources for fish, with the open meadow habitat having highest abundance of terrestrial and aquatic insects, lowest taxa richness, and possible multivoltine aquatic insect life-history. Our results provide insight into the importance of riparian buffer habitat and water temperature on the composition of food availability for fish species of concern such as brook trout. The significant differences emphasize the need to include food web dynamics into riparian habitat restoration design to guide future rehabilitation projects focusing on fish conservation. [ABSTRACT FROM AUTHOR]

The giant trevally Caranx ignobilis (Forsskål) is an important apex predatory fish typically associated with coral reef communities. It is prized in recreational and commercial fisheries, yet little is known about its aggregation dynamics and susceptibility to fishing pressure. This study reports on a previously undocumented aggregation of mature giant trevally observed over a period of eight years (2010-2017) at Ponta do Ouro Partial Marine Reserve in southern Mozambique. The aggregation is one of the few recorded for this carangid in the western Indian Ocean and represents the first subtropical aggregation of giant trevally. The aggregation is also the largest recorded for this species, with up to 2 413 individuals representing an estimated biomass of approximately 30 tonnes. The size and predictability of this annual aggregation make it vulnerable to overexploitation and point towards the need for an appropriate conservation management strategy. [ABSTRACT FROM AUTHOR]

The long-run sustainable management of recreational fisheries in North America relies on license revenues to pay for conservation. This article examined the effect of changing license prices on purchases using time series data from Pennsylvania. I measured the effect of prices on yearly sales for three types of licenses: resident annual, nonresident annual, and 3-day tourist licenses. Results showed that demand is price inelastic for the annual licenses but slightly price elastic for the 3-day tourist license. An across-the-board increase in all license prices would not be an efficient way to increase revenues. In Pennsylvania, increasing the current price of the 3-day tourist license would likely decrease participation and revenues. [ABSTRACT FROM AUTHOR]

In this paper,Megastygarctides sezginiisp. nov., a new marine species from the Black Sea (Turkey), is described. Morphological and morphometric studies have revealed thatM. sezginiisp. nov. is most similar toM. setolosoMorgan & O’Reilly, 1988, but differs from it through the presence of two types of fibrils, a lack of cuticle granulation, the presence of three lateral projections with fibrils, leg fibrils arranged in transverse stripes and the presence of clumps of fibrils near the clavae. In the studied environment, the new species is frequently found in summer and almost absent in winter. Additionally, a taxonomic key for allMegastygarctidesspecies is presented. http://zoobank.org/urn:lsid:zoobank.org:pub:53AA1D57-8700-4A18-9099-1CDDBAEB4D3A [ABSTRACT FROM AUTHOR]

Teesta river basin in Eastern Himalaya is being subjected to cascade hydropower development. To assess the impacts of this developmental activity on fish fauna of the basin, fish habitats of the four largest tributaries in the basin were selected for the present study. A total of 18 large hydroelectric projects are planned on these rivers. Here, a total of 11 EIAs and 2 carrying capacity studies in Teesta basin were reviewed. Our investigations show that after commissioning all the projects, 52–88% of the free-flowing river stretches will be diverted and 7.6–24% of the riverine ecosystems will be converted into semi lacustrine ecosystems in different rivers. The cascade hydropower development is likely to affect more than 100 fish species. All the EIA reports reviewed have investigated fish species richness, impacts on fish fauna and fishery management plans. EIA studies and management plans, however, do not adequately address important ecological and conservation issues due to various limitations. An integrated fish conservation plan for the upper Teesta basin is suggested in this contribution. [ABSTRACT FROM PUBLISHER]

Locally managed marine areas (LMMAs) are often recommended as a strategy to achieve conservation and fisheries management, though few studies have evaluated their performance against these objectives. We assessed the effectiveness of eight periodically harvested closures (PHCs), the most common form of management within Fijian LMMAs, focusing on two outcomes: protection of resource units and biodiversity conservation. Of the eight PHCs, only one provided biodiversity benefits, whereas three were moderately successful in protecting resource units (targeted fish biomass). Protection of resource units was more likely when PHCs were harvested less frequently, less recently, and when total fish biomass in open areas was lower. Our findings further suggest that monitoring, enforcement, and clearly defined boundaries are critical, less frequent harvesting regimes are advised, and culturally appropriate management incentives are needed. Although PHCs have some potential to protect resource units, they are not recommended as a single strategy for broad-scale biodiversity conservation. [ABSTRACT FROM PUBLISHER]

To investigate distribution, habitat characteristics, and current conservation status of the endangered endemic species, rapid small gudgeonMicrophysogobio rapidus(Cyprinidae), we surveyed a total of 79 sites from the historic records (20 sites) plus additional sites (59 sites) with good habitat conditions, analyzed their sites, and compared them with historic recorded sites to reveal the factors of extinction threats and causes. We found only eight out of 79 sites in the Nam River areas. The habitats were greatly reduced and restricted compared with the historic sites, which mainly cause from habitat modification, such as various types of river renovations at the main stream and tributary streams of the Nakdong River. The present habitats are higher water temperature and more number of fish species than the absent ones, but conductivity, total nitrogen, and number of weir are lower. In addition, the present sites are lower low velocity at pool and higher mean substrate at pool. From this study, we suggest that maintaining good water quality and preventing anthropogenic impacts greatly aid conservation of theM.rapidusin South Korea. [ABSTRACT FROM AUTHOR]

The establishment of appropriate taxonomic designations is essential for the effective management of fishery resources. Despite over a century of explorations and research, the cyprinid genus Tor represents a group of large-bodied freshwater fishes whose taxonomy and systematics remains poorly known. While five species of Tor are currently listed as "endangered" on the IUCN Red List, a further five out of 18 species currently recognized are assessed as "data deficient," with at least one undescribed species, believed to be on the brink of extinction (i.e., the Humpback Mahseer endemic to the Cauvery River in India). Tor mahseers represent a suitable model for the application of an integrated approach using morphology, genetics, and historical records to resolve species identities, where one or more of these fundamental approaches may have been deficient in the past. Focusing specifically on the taxonomy and nomenclature of the Tor species recorded from Peninsular Malaysia, one of the aims of this review is to define the identity of two nominal species, T. tambra and T. tambroides. Original descriptions of these two nominal species contain little or practically no characters to distinguish them, and partly explains why secondary literature fails to conclusively determine species boundaries. A phylogenetic analysis of mahseer specimens from this region, based on publicly available and newly sequenced mitochondrial COX1 genes, does not support species designation based on previously established morphological features. More importantly, multiple tree-based species delimitation approaches showed that previously sequenced T. tambroides from Peninsular Malaysia and the newly described Tor species from Vietnam could not be delimited from the topotypic Tor tambra. A wider investigation of mahseer taxonomy covering all of Southeast Asia, using such an integrated approach is recommended to resolve the ambiguous taxonomy and is of profound importance for the conservation and management of exploited and farmed populations of these highly valued and iconic fish. [ABSTRACT FROM AUTHOR]

Seahorses are currently experiencing an unprecedented level of anthropogenic pressure promoted by habitat destruction and increasing fishing effort to supply premium markets. This study provides an overview of the scientific literature on seahorses in the 21st century and critically discusses five major knowledge gaps and research opportunities to advance the state of the art on this research field. The average number of publications per year increased from 10 (2001–2002) to ∼40 (2001–2015), the majority addressing issues on seahorse ecology, biology, and aquaculture, with the most studied species being Hippocampus kuda, H. guttulatus, H. reidi, H. abdominalis, H. erectus, H. hippocampus, and H. trimaculatus. This study explores the opportunity of using seahorses as flagship species to foster mangrove conservation and decrease trawling fisheries. It also suggests that further scientific studies are needed to better understand and manage the populations of the most heavily traded seahorse species, as well as the need to monitor their vulnerability to emerging pollutants and climate change. Sustainable seahorse aquaculture can play an important role in seahorse conservation, as well as in the development of reliable traceability tools to fight the illegal trade of these highly priced organisms. [ABSTRACT FROM AUTHOR]

The anadromous sea lamprey Petromyzon marinus native range extends across the Northern Atlantic and includes much of Europe. Their complex lifecycle, involving freshwater spawning, juveniles (ammocoetes) that remain in freshwater for up to eight years, and adults migrating to sea before returning to reproduce, means native populations in Europe are threatened by multiple stressors, especially migration blockages and habitat loss. This has resulted in population declines across their European range, despite their ecological, evolutionary, and economic significance. Information on their population demography and long-term patterns are also scarce, with focus primarily on their ammocoete freshwater phase. This is inhibiting the development of biological reference points for utilization in population monitoring programs. In the Great Lakes of North America, however, P. marinus is invasive and the high damage caused to commercial fisheries resulted in their populations being controlled through a long-term, multi-method and integrated research and management approach over the last 40 years, with the development and application of a range of novel methods. Successful knowledge transfer to Europe could therefore facilitate the monitoring of threatened populations and develop new conservation actions, including modifying migration blockages to facilitate passage, implementing adult trapping programs, and applying pheromone treatments to manipulate adult movements and behaviors. This reveals the potential utility of using invasive fish populations to inform conservation practices in native ranges, and how pheromone research could further enhance fish conservation and monitoring. [ABSTRACT FROM AUTHOR]

Six heavy metals (chromium [Cr], nickel [Ni], copper [Cu], arsenic [As], cadmium [Cd], and lead [Pb]) were measured in sediments and soft tissues of eleven commonly consumed fish species collected from an urban river in the northern part of Bangladesh. The abundance of heavy metals in sediments varied in the decreasing order of Cr > Ni > Cu > Pb > As > Cd. The ranges of mean metal concentrations in fish species, in mg/kg wet weight (ww), were as follows: Cr, 0.11–0.46; Ni, 0.77–2.6; Cu, 0.57–2.1; As, 0.43–1.7; Cd, 0.020–0.23; and Pb, 0.15–1.1. Target hazard quotients (THQs) and target carcinogenic risk (TR) showed the intake of As and Pb through fish consumption were higher than the recommended values, indicating the consumption of these fish species is associated with noncarcinogenic and carcinogenic health risks. [ABSTRACT FROM PUBLISHER]

We investigated the breeding season, growth rate and dispersal of the dark chub,Candidia sieboldii, an endangered species in Japan. A mark–release–recapture survey was performed in three branches of the Ishizu River system in Osaka Prefecture, Japan, between May 2012 and August 2013. A total of 963 individuals were marked in one river branch and 275 (29%) were recaptured at least once in the same river section. The breeding season was determined to be June–August, and the size at maturity for both males and females was estimated at about 70 mm standard length. Growth rates calculated from standard lengths of recaptured individuals were higher between April and September than between October and March. Among 963 marked individuals, only a single fish was found 500 m downstream from the release point. Moreover, although we released 409 more marked individuals in the three branches to follow inter-branch dispersal between September and December 2013, we observed none. These results indicate that this species has low dispersal and a short lifespan of 1–2 years. This short lifespan could increase the risk of breeding failure, and the low frequency of dispersal, restricted by weirs, could make population re-establishment and recovery difficult. [ABSTRACT FROM PUBLISHER]

This article examines the promise and challenge of marine biotelemetry technologies, comparing the case of the Canadian Ocean Tracking Network (OTN) and the Australian Animal Tagging and Monitoring System (AATAMS). These technologies provide increased understanding of the marine environment and promise major advances in knowledge of species at risk. However, that utilization of marine biotelemetry raises challenges, including ensuring that knowledge obtained is translated into forms useful to and usable by decision makers. Knowledge brokering is a key to ensure that the advances seen in marine biotelemetry technologies lead to improved gover-nance of species at risk. [ABSTRACT FROM PUBLISHER]

The objective of this review was to investigate the fishery management problems and conservation challenges in Ethiopia. Published and unpublished sources were used to obtain appropriate data. More than 183 fish species were reported in Ethiopia. The production potential of these water bodies is estimated to be 51,481 tonnes/year. Of these, only 30% of them are being utilized. Utilization of fishery is based on the socio-economic factors, resource availability, and religious influence on fish consumption. Types of fishing gears, fishing methods, socio-economic factors, lack of facilities and infrastructure, ineffective administration setup, lack of expertise, land use around fish habitats, and lack of scientific data were observed as the major fishery management and conservation challenges. The demand for fishes is, however, double increasing. Thus, effective management setup, regular stakeholders follow-up, and encouraging the development of aquaculture are very important to sustain the resources and meet the demand for the product. [ABSTRACT FROM AUTHOR]

Tropical fisheries, which are considered multi-species, may show selectiveness. We analyzed the degree of selectivity of fish catches in 46 sites along the Amazon basin through the percentage of biomass corresponding to the most caught fish species. Amazonian fisheries were considered moderately selective, as 54% of the sites directed more than a quarter of fishing effort to one fish species and in 87% of the sites more than half the fishing effort was directed to five fish species. Commercial fisheries were more selective than subsistence fisheries. Eleven fish species (nine of them migratory) have received more fishing pressure in the studied Amazonian regions and the catch composition differed among regions. We thus recommend that fisheries management in the Amazon basin should distribute fishing effort among more fish species; incorporate the particularities of commercial and subsistence fisheries; evaluate fishing effects on ecosystem services; and consider the biological characteristics of preferred fish. [ABSTRACT FROM PUBLISHER]

In seeking to answer the question ‘who should be included in fisheries co-management?’, a constructive critique of the existing co-management literature is provided by filling the gaps of Habermas’s deliberative theory of democracy with Dewey’s pragmatism. Three conditions for ensuring democratic co-management are extrapolated from the theories: actors’ authority over decision making (empowerment), actors’ diversity (membership), and the right to self-nomination (procedures for external inclusion). The theoretical insights developed are supported with two examples of co-management institutions for inshore fisheries in the UK: Scottish Inshore Fisheries Groups (IFGs) and English Inshore Fisheries Conservation Authorities (IFCAs). [ABSTRACT FROM AUTHOR]

Although fish invasions have implications for conservation and resource management, research on public attitudes toward nonnative fishes is lacking. We surveyed boat and canal bank recreational anglers in the Everglades to assess their awareness, preferences, and perspectives of native versus nonnative fishes. Our findings showed that 79% of anglers were aware of the presence of nonnative fishes, and overall awareness was positively affected by the frequency of fishing, and years of angler experience at study sites. Frequency of fishing had a stronger effect on canal bank anglers. Boat anglers had higher awareness of nonnatives, higher familiarity with “nonnative” terminology, and expressed greater preferences for native fish. Most anglers favored native species (72% preference), and targeted native fishes, particularly Florida Largemouth Bass (66%). Overall, findings show that despite the prevalence of nonnative species, anglers favored native fishes and supported native fish conservation. [ABSTRACT FROM PUBLISHER]

To fill the gap between microhabitat and landscape scale habitat models for freshwater fish, it is becoming increasingly common practice to adopt a continuous view of riverscapes, thus allowing a better understanding of the processes in place at the river management level (segments of 1–100 km). The aim of this study was to test the effects of the spatial structure of habitat on fish distribution at this scale. Inferred habitat relationships were generated using spatial metrics adapted from landscape ecology. These were calculated for two species of multi-habitat cyprinid fish in a 25-km long segment of the Seine River. A spatially continuous survey was then designed to acquire fish sampling data relating to the riverscape. Explanatory models were devised to quantify the extent to which environmental and spatial variables could describe fish distribution patterns. Spatially continuous sampling of feeding habitats at dawn and dusk provided greater understanding of the spatial distribution of common barbel (Barbus barbus, L.) and nase (Chondrostoma nasus, L.). Fish observations were aggregated longitudinally in neighboring feeding habitat patches, with the highest abundance found in patches with the best local conditions. The species were present for large feeding patches, as well as for a higher proximity index for those patches. This result emphasized the importance of the supplementation of feeding habitats. By quantifying spatial habitat relationships using spatial metrics, it was possible to identify the best suited configuration of functional habitats to the needs of shoals. At present, most conservation work focuses on restoring local habitats. There is also growing interest in large-scale fish management, which has been encouraged by the advent of metapopulation theory. This study highlights the need for greater work at a third, intermediate scale that is no less significant: restoring daily and seasonal movements between functional habitats. [ABSTRACT FROM AUTHOR]

Barbus motebensisis endemic to the Groot Marico River catchment in the North West province, South Africa, and is considered of particular conservation importance due to being Red-Listed as Vulnerable. Due to its vulnerable conservation status, the aim of this study was to provide information on its condition factor, breeding season, gonadosomatic index, fecundity range and length at maturity from specimens collected by means of electrofishing and seine-netting between November 2012 and May 2014 from the Draaifonteinspruit and Kaaloog se Loop. Length at maturity was estimated as 37.5 mm TL for males and 44.5 mm TL for females. Microscopic gonad staging and gonadosomatic index demonstrated thatB. motebensishas an extended breeding season from spring to summer. Relative (578 eggs g−1) and absolute (3 728 eggs) fecundity were relatively high for small barbs. [ABSTRACT FROM AUTHOR]