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Fisheries science and practice are challenging and require learning, thinking, and sharing across boundaries. The idea of boundary crossing can be described as some form of multiple disciplinarity (e.g. interdisciplinarity, transdisciplinarity), yet that inherently implies that the boundaries crossed are purely disciplinary in nature. After working across various other boundaries (i.e. realms, regions, disciplines, sectors, domains, and knowledge systems) for most of our educational journeys and professional careers, we reflect on our lived experiences with a focus on identifying the benefits and challenges of engaging in different types of boundary crossing. We submit that our personal and professional lives have been enriched by stepping outside of our immediate comfort zones and expertise (i.e. fish ecology) and engaging in active listening and learning with colleagues in other disciplines (i.e. various social sciences) and with stakeholders and policymakers. We have learned much from working across boundaries and encourage others, especially early career professionals, to do the same. What may superficially appear to be a bridge too far may in fact provide novel ways of thinking about a given issue or topic that generates actionable science for sustainable fisheries management and conservation. Many of the projects that we consider to be our greatest successes represent ones that involved boundary crossing, examples of which we provide in this essay. There is a need to prepare the next generation of problem solvers for engaging in boundary crossing and celebrating examples of where such efforts have led to meaningful advances in fisheries science and practice. Ensuring that institutional and cultural barriers that may constrain boundary crossing are addressed while also supporting those doing such work will be key to address the many fisheries and aquatic science challenges of today and tomorrow in both marine and freshwater systems. [ABSTRACT FROM AUTHOR]

The article discusses the U.S. Supreme Court's decision in Sackett vs. U.S. Environmental Protection Agency, which narrows the definition of "waters of the United States" (WOTUS) under the Clean Water Act. The court ruled that wetlands must have a continuous surface connection to a larger water body to be protected under the act, disregarding the goals and objectives of the law. This decision leaves the responsibility of protecting wetlands and streams to states that may lack the resources and political will to do so effectively. The article highlights the importance of wetlands and nonpermanent water bodies for ecosystem services and biodiversity, and calls for continued advocacy and education on the importance of safeguarding these resources. [Extracted from the article]

Fishers' Indigenous and local knowledge (ILK) has multidimensional contributions to improve fisheries and aquatic ecosystems science, ranging from algae to whales and including management, conservation, ecology, and impact assessment. The challenges are to sustain this knowledge, recognize its value, and to include ILK holders in resource management and decision-making. [ABSTRACT FROM AUTHOR]

Surmounting evidence supports that infectious agents play a critical role in shaping fish physiology, behaviour, and survival. The exclusion of disease-causing agents from fisheries research has resulted in major knowledge gaps that may limit the predictive capacity of ecological models. A major barrier in wild fisheries epidemiology is the logistical constraints associated with observing disease and obtaining samples from free-ranging fish, restricting the vast majority of research to laboratory studies or aquaculture facilities. For fisheries ecologists, including infectious agents can provide greater insight into observed phenomena, particularly with respect to fish physiology (e.g., metabolism), movement (e.g., migration rates), behaviour (e.g., habitat selection), personality (e.g., bold versus shy), and survival. Here we provide a brief introduction to the current understanding of disease ecology in wild fish and describe technological advances in both epidemiology and fisheries and aquatic sciences that can be used in tandem to create comprehensive studies of disease ecology in wild fishes. Combining nonlethal sampling and molecular genetic-based identification methods with field studies creates vast opportunities for innovative study designs that have the potential to address the true complexity of aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Theodore Nicholas Gill's misconception of Lorenz Okenfuss's use of the Latvian vernacular name Sander for Cuvier's French vernacular name Les Sandres, as a properly coined Latin name, led to Gill's and subsequent authors' incorrect acceptance of Sander as the senior synonym for Stizostedion. However, some authors, aware Sander is a common name and never proposed as a valid generic name, have continued using the correct generic name Stizostedion. American Fisheries Society guidelines for publication in their journals and the Canadian Journal of Fisheries and Aquatic Sciences requires authors to use the current edition of Common and Scientific Names of Fishes from the United States, Canada, and Mexico, which has incorrectly used Sander in the last two editions. Thus, fishery biologists have been forced to use an incorrect generic name for one of the most important freshwater fisheries of North America. [ABSTRACT FROM AUTHOR]

The River Continuum Concept (RCC) is a milestone in stream ecology because of its comprehensive evaluation of the structure and function of lotic ecosystems. Linking stream physical and geomorphological attributes with patterns in biodiversity, functional traits, and metabolism dynamics, this theory describes downstream gradients in community composition and ecosystem processes. The aim of this review is to evaluate how the RCC, 40 years from its publication in the Canadian Journal of Fisheries and Aquatic Sciences, has influenced basic and applied research in stream ecology, focusing on the most important contributions and recent developments. This work puts into perspective the historical importance of the RCC in the scientific process and integrates past and recent theories, including metacommunity and metaecosystem theories and the river network perspective, to predict taxonomic and functional diversity of benthic communities. Thus, this review provides a unifying overview of the historical context of the field for exploring basic and applied ecological questions to the next generation of stream ecologists. [ABSTRACT FROM AUTHOR]

The high‐impact practice of undergraduate research has expanded exponentially over the past 2 decades and has become a much more integrated pursuit across all levels of the educational landscape. Such a rapid expansion and diversity of approaches to these programs have resulted in the need to better understand and evaluate their efficacy in all disciplines. The fisheries profession has long been a leader in providing outstanding career preparation, which includes providing opportunities for students to engage in undergraduate research. To maintain this distinction, it is imperative that we as a field continuously evaluate how our current mentoring practices align with academic pedagogy recommended in the broader literature. Here, we review the extensive literature on undergraduate mentoring and construct a set of success criteria that represents a temporal sequence of best practices in undergraduate mentoring. We also present the results of a survey of fisheries faculty that was undertaken in order to understand what undergraduate mentoring practices are currently being used in our field. Collectively, this information can be used by individuals, departments, or institutions as a practical framework with which to evaluate and improve current mentoring programs or as a foundational starting point from which to design and implement new mentoring programs. [ABSTRACT FROM AUTHOR]

In the manuscript and reference list, Charapata et al 2020 should read, respectively, "Charapata et al (2022)", and "Charapata P, Oxman D, McNeel K, Keith A, Mansouri F, Trumble S (2022) Lifetime hormone profiles for a long-lived teleost: Opercula reveal novel estimates of age-specific reproductive parameters and stress trends in yelloweye rockfish ( I Sebastes ruberrimus i ). The end of the caption of Figure 3 should read: "(Charapata, Oxman, and Trumble, unpublished)". [Extracted from the article]

We examine the role of one Abstracting and Indexing (A&I) service (Aquatic Sciences and Fisheries Abstracts - ASFA) as an interface between open science and grey literature. As an A&I service known for its coverage of grey literature, ASFA is evolving its technologies and partnerships to capitalize on the opportunities presented by Open Science. A Grey Literature strategy was implemented to ensure ASFA made the necessary changes to its monitoring, recording and reporting of grey literature coverage on its database. We describe how the strategy incorporates the Open Science movement into ASFA, by making use of the opportunities such as the increased number of repositories and literature; and vice-versa by providing increased access to grey literature and working with institutions to ensure their literature is captured on ASFA. Specifically we describe how ASFA is: (1) increasing access to grey literature by working in partnership with OA repositories (including harvesting from OAI-PMH compliant repositories); (2) using open source software to manage its indexing and search tools, allowing them to be utilized by, and receive contributions from, a greater number of users to aid the discoverability of grey literature; (3) ensuring comprehensive and timely coverage of grey literature among its global partnership, and providing funding for small specific projects which meet ASFA's grey literature priorities regards subject scope and content type; (4) working with the Open Science community in a Virtual Research Environment (VRE) - such as iMarine - to ensure a two way interaction between the Open Science movement and the promotion of grey literature in the future. We demonstrate that by taking the above steps to capitalize on the opportunities presented by Open Science and new technologies, an A&I service such as ASFA becomes a valued interface between Open Science and grey literature - ensuring the recording and discovery of grey literature from aquatic sciences and fisheries institutions around the world. [ABSTRACT FROM AUTHOR]

A correction to the article "Spatial patterns and environmental factors related to arsenic bioaccumulation in boreal freshwater fish," published online on April 11, 2023 is presented.

Modeling has become the most commonly used method in fisheries science, with numerous types of models and approaches available today. The large variety of models and the overwhelming amount of scientific literature published yearly can make it difficult to effectively access and use the output of fisheries modeling publications. In particular, the underlying topic of an article cannot always be detected using keyword searches. As a consequence, identifying the developments and trends within fisheries modeling research can be challenging and time-consuming. This paper utilizes a machine learning algorithm to uncover hidden topics and subtopics from peer-reviewed fisheries modeling publications and identifies temporal trends using 22,236 full-text articles extracted from 13 top-tier fisheries journals from 1990 to 2016. Two modeling topics were discovered: estimation models (a topic that contains the idea of catch, effort, and abundance estimation) and stock assessment models (a topic on the assessment of the current state of a fishery and future projections of fish stock responses and management effects). The underlying modeling subtopics show a change in the research focus of modeling publications over the last 26 years. [ABSTRACT FROM AUTHOR]

In the Northern Humboldt Upwelling System (NHUS), one of the most productive ecosystems in the world, the large jellyfish Chrysaora plocamia exhibits high inter-annual variability in population size, often resulting in massive blooms. In this study, we examined the geographic patterns C. plocamia in the NHUS and their spatial overlap with ichthyoplankton, zooplankton, and chlorophyll a concentration (Chl a) during two El Niño (EN) years (1982–1983 and 1986–1987), and a neutral year (2014). During EN years, the spatial extent of C. plocamia medusae was larger than in the neutral year. In 1982–1983, medusae were concentrated mainly in the central-southern and southern regions of Peru, where they were associated with zooplankton, sardine larvae, and Chl a. In 1986–1987, medusae occurred in the northern and southern regions and spatially overlapped with sardine larvae and Chl a , and with zooplankton and anchoveta larvae, respectively. In 2014, medusae occurred mainly in the northern region, where they were associated with zooplankton, Chl a , and anchoveta eggs and larvae. Our results indicate strong EN effects on the distribution and abundance of C. plocamia , which can have consequences for zooplankton and ichthyoplankton abundance, as well as fisheries, in the NHUS. [ABSTRACT FROM AUTHOR]

Studies on scientific winches installed on oceanographic/fisheries research vessels (ORVs and FRVs, respectively) are distinguished by the winches’ unique design features and the important role they play with scientific experiments. It is impossible to draw general conclusions when analysing scientific winches used for fisheries sampling experiments on recently built ORVs. Few vessels are built each year and their dimensions and mission vary greatly. Thus, to consider the concept of traction factor and the possible ways in which equipment on fishing trawlers could be arranged and manoeuvred, a statistical analysis was carried out on newly built and refitted vessels from Spanish shipyards. The starting point was a sample of 125 boats, to which linear regression models were adjusted to explain the relationship between total traction and the traction for the fishing winch. As a result, three regression models-one for each kind of arrangement-were obtained. The next step involved analysing and modelling the dependence of the auxiliary winch traction on fishing winch traction. [ABSTRACT FROM AUTHOR]

A prerequisite for an international fisheries agreement (IFA) to be stable is that parties expect the benefits from joining the agreement to exceed the benefits from free riding on the agreement, and parties only comply with the agreement as long as this is true. The agreement, therefore, implicitly builds on an expectation of the ecological condition of the natural resource. Game theoretical models often assume that all parties have the same (often perfect) information about the resource and that the exploitation is an equilibrium use of the stock. As stated by experts in natural science, the fish ecology still has many open questions, for example how to predict population dynamics, migration patterns, food availability, etc. In some cases, parties disagree about the state, abundance, and migration of a stock, which can reduce the possibilities of reaching an agreement for exploitation of the stock. This paper develops a model and applies it to the North-East Atlantic mackerel fishery, in order to analyze an IFA under different ecological scenarios, and also combines the model with the economic theory of entry deterrence. The model is used empirically to determine whether the parties with original access to the resource have an advantage when forming an agreement with a new party in having the ability to fish the stock down to a smaller size and thereby prevent another party from entering into the fishery. With a basis in entry deterrence, combined with lack of information, the paper illustrates the obstacles that have made an agreement for the North-East Atlantic mackerel so difficult to achieve. [ABSTRACT FROM AUTHOR]

A biography of fisheries research biologist Jean Richard Dunn, who was born on June 27, 1934, and attended local California schools, earned a B.S. in fisheries from Oregon State University. Jean joined the Age Analysis Unit of the Seattle Biological Laboratory of the Bureau of Commercial Fisheries in 1962. He received National Marine Fisheries Service Special Achievement Awards in 1968, 1974, 1976, and 1980, and a Sustained Superior Performance Award in 1982.

A correction to the article "Drivers of Walleye Recruitment in Minnesota's Large Lakes" that was published in a 2020 issue is presented.

This paper reviews the last twenty two years (1993 to 2015) of inland aquatic science and its application in Queensland and assesses the achievements and learnings, and then proposes a way forward for the future. Many science initiatives and programs have come and gone with various degrees of success. Currently, there seems to be a strong focus on short-term, operational needs. There is very limited investment and capability in long-term strategic research, particularly to address recurring and emerging issues. The preferred way forward would be a mixture of partnership approaches underpinned by a strategic science plan and long term funding. The effectiveness of such research and partnership models should regularly be assessed for their cost and benefit. [ABSTRACT FROM AUTHOR]

For each of the data streams (base data or data products) that feed the new data portal, the data provider has to provide the address of the microservices. The development of the new ICES Data Portal (https://data.ices.dk) was done in an agile way and with the option of moving the data portal to the cloud. Future developments would include user authorisation for data types with separate data licenses restricting data access, not covered by the ICES data policy (https://www.ices.dk/marinedata/Documents/ICES-Data-policy.pdf), which allows full access and re-use rights. [Extracted from the article]

Studying rare and sensitive species is a challenge in conservation biology. The problem is exemplified by the case of the imperiled delta smelt Hypomesus transpacificus, a small delicate fish species endemic to the San Francisco Estuary, California. Persistent record-low levels of abundance and relatively high sensitivity to handling stress pose considerable challenges to studying delta smelt in the wild. To attempt to overcome these and other challenges we have developed the SmeltCam, an underwater video camera codend for trawled nets. The SmeltCam functions as an open-ended codend that automatically collects information on the number and species of fishes that pass freely through a trawled net without handling. We applied the SmeltCam to study the fine-scale distribution of juvenile delta smelt in the water column in the upper San Francisco Estuary. We learned that during flood tides delta smelt were relatively abundant throughout the water column and that during ebb tides delta smelt were significantly less abundant and occurred only in the lower half and sides of the water column. The results suggest that delta smelt manipulate their position in the water column to facilitate retention in favorable habitats. With the application of the SmeltCam we increased the survival of individual delta smelt by 72% compared to using a traditional codend, where all of the fish would have likely died due to handling stress. The SmeltCam improves upon similar previously developed silhouette photography or video recording devices and demonstrates how new technology can be developed to address important questions in conservation biology as well as lessen the negative effects associated with traditional sampling methods on imperiled species. [ABSTRACT FROM AUTHOR]

In 1982, Frank Rigler challenged limnologists and fisheries biologists to address gaps in theory, experimental research, and management practices that have limited the advancement of both fields. We followed up on Rigler’s concerns using a literature study to determine the objectives and methodologies of studies across a range of subdisciplines within aquatic science. We surveyed both recent and historical literature from five leading journals that range in emphasis to include a broad array of subjects in aquatic science. Literature from 1982 was compared with recent publications to determine how communication and integration within aquatic science has changed. We found limited changes in the breadth of coverage provided by any journal. We further analyzed contemporary literature according to subject matter, methods of analysis, location of the research, and scale of study. We used correspondence analysis to identify the differences and associations across these fields and to uncover those particular research areas that have more clearly bridged some of these gaps previously identified. Our findings indicate that there are still clear divisions within modern aquatic science literature and that the journals considered typically show specific emphasis in the types of questions posed, methods of analysis, and the geographic representation of authors. [ABSTRACT FROM AUTHOR]

To investigate the effect of oxidative stress on the survival of two Brachionus species of rotifer, we examined the effective dose of juglone, which generates reactive oxygen species, and compared survival times between the two species. First, we observed that juglone affected survival in the rotifers in a dose-dependent manner between 0.02 to 20 μM, and that treatment at above 2 μM showed acute toxicity causing the animals to die within a few hours. Next, we found the difference in survival time between the two species exposed to 20 μM juglone: B. rotundiformis was significantly more tolerant against the substance than the allied species B. plicatilis. The findings suggest that exploring the basis of species-specific abilities to persist under oxidative stress will be of great interest to uncover the underlying mechanisms governing the stress resistance of the rotifer, as well as contributing to their stable mass production for aquaculture. [ABSTRACT FROM AUTHOR]

A correction to the article "Understanding Gas Bubble Trauma in an Era of Hydropower Expansion: How Do Fish Compensate at Depth?" by Naomi K. Pleizier, Charlotte Nelson, Steven J. Cooke and Colin J. Brauner which appeared in a 2020 issue is presented.

Recent reports suggest that most of the world's commercial fisheries could collapse within decades. Although poor fisheries governance is often implicated, evaluation of solutions remains rare. Bioeconomic theory and case studies suggest that rights-based catch shares can provide individual incentives for sustainable harvest that is less prone to collapse. To test whether catch-share fishery reforms achieve these hypothetical benefits, we have compiled a global database of fisheries institutions and catch statistics in 11,135 fisheries from 1950 to 2003. Implementation of catch shares halts, and even reverses, the global trend toward widespread collapse. Institutional change has the potential for greatly altering the future of global fisheries. [ABSTRACT FROM AUTHOR]

Summary: Digital elevation models (DEMs) are widely used in topographically-based hydrology models. Most researchers dealing with DEMs have worked exclusively with either grid or contour based techniques. Intercomparisons of these techniques are empirical in nature, few in number and limited to a small number of catchments. We examine the relative effects of these techniques on the distribution of the topographic index (TI) for nine idealised hillslope types and eight natural catchments (4.4–83km2) in southeast Australia. In particular we investigate the underlying causes for the frequently observed increase in the TI with grid size. A simple analytical model for a parallel-planar hillslope indicates that median TI is asymptotic with respect to the number of grid cells and a linear function of grid size. We demonstrate that the latter result holds for hillslopes with more complex geometry. Using a multiple flow direction algorithm, we find that hillslope geometry and flow partitioning affect the spatial pattern of the TI and the rate of change (M) of median TI with grid size. This makes it impractical to recommend general guidelines for the value of the directional parameter in flow partitioning algorithms. For the natural catchments we show that median TI is also a linear function of grid size and that there is some evidence for a linear relationship between M and the inverse of the median topographic slope. Throughout the investigation we find that contour DEMs are less sensitive to changes in resolution than grid DEMs. [Copyright &y& Elsevier]

This research investigated effects of changing the diamond mesh size on codend selectivity in Mediterranean fisheries. The selectivity of a typical 50-mm diamond knotless polyethylene (PE) codend used in the Turkish fishery in the Aegean Sea was measured for commercially important species, in particular hake ( Merluccius merluccius), horse mackerel ( Trachurus trachurus), anglerfish ( Lophius piscatorius) and John Dory ( Zeus faber). Fishing trials were carried out on the commercial trawler ‘Hapuloğlu’ between 9 and 12 December 2006 using a modified trawl net. Selectivity data were collected by the covered codend method and analysed by means of a logistic equation (Maximum Likelihood Method). The mean selectivity curve was estimated from individual hauls, taking between-haul variations into account. Mean mesh size of the codend was 49.4 mm as measured by digital calliper. Mean values for 50% retention length of hake and horse mackerel were estimated to be 11.4 and 15.6 cm total length; corresponding selection ranges were 4.1 and 5.5 cm respectively. The 50-mm diamond mesh codend showed adequate selectivity compared to the minimum landing size (MLS) for horse mackerel, while for hake it selected specimens in a size range far lower than the MLS. No selectivity values could be determined for anglerfish or John Dory. To design a more selective codend for the Turkish demersal trawl fishery, not only mesh size regulations but also other codend characteristics and netting material properties must be urgently considered. [ABSTRACT FROM AUTHOR]

The changes in physical habitats and responses of fish, e.g. the Kirikuchi charr Salvelinus leucomaenis japonicus, were examined by placing instream structures in a stream on the upper drainage of the Totsu River system of the Kii Peninsula, Japan, over a two-year period. Instream structures created pools below the structures, and these pools have maintained their functions as fish habitats over two years. In two treatment sections, sections A and B (some red-spotted masu salmon were removed in advance in section B), mean water depth increased soon after placing the structures, but decreased over two years. Mean water velocity slowed after placing the structures in both sections. Total fish abundance has been relatively high at the two treatment sections compared with a control section after placing the structures. Age 1 Kirikuchi charr, however, increased only in section B. These results indicate that instream structures can serve as habitat enhancement for fish, including Kirikuchi charr, in the study area if other appropriate habitat factors for respective species are taken into consideration. [ABSTRACT FROM AUTHOR]

A small number of fishers in Chiba Prefecture of eastern Japan use cotton gill nets to catch Japanese spiny lobster Panulirus japonicus. To examine the advantages of cotton gill nets, we analyzed changes in mesh breaking load of a new cotton gill net used in a fishing operation. A new cotton gill net was also soaked in a seawater tank to simulate ghost fishing conditions. The average mesh breaking load of new cotton mesh was 50.3 N. This value decreased to 19.0 N after 38 days (∼912 h), and after 82 days (∼1968 h) the mesh could be easily torn (breaking load 0.07 N). Under fishing conditions, the cumulative soak time was only 744.4 h over 19 months. The average breaking load at the end of this period was 43.1 N, a strength 86% that of the presoaked mesh. The mesh breaking load of a cotton gill net continuously soaked for 744.4 h was 26.1 N, as estimated from tank experiment data. Thus, a cotton gill net maintains reasonable strength under typical use conditions, but will degrade if lost at sea. [ABSTRACT FROM AUTHOR]

Deploying artificial reefs is a proven technique for increasing both the number of fish and the diversity of the marine ecosystem in a particular area of the sea body. Previous investigations in this field have generally focused on the influence of the reef block design on flow phenomena. By contrast, the effects of the seabed topography on the performance of the reef have received comparatively little attention. Accordingly, in the present study numerical simulations are performed to investigate the effect of different seabed topographies on the flow field structures created both in and around artificial reefs. The simulations focus specifically on the effects induced by concave and convex seabed features, i.e. mounds and trenches, respectively, characterized by various degrees of inclination. The simulations are performed using a finite volume numerical method, in which the seabed features are modeled using simple trapezoidal blocks. A total of 18 different reef block–seabed topography systems are considered. The simulation results provide a valuable reference for marine engineers and ecologists when formulating deployment strategies aimed at enhancing the performance of artificial reefs. [ABSTRACT FROM AUTHOR]

The reliability of a mass-processing aging method for walleye pollock Theragra chalcogramma was examined. The method is a half-otolith method, in which 10–20 otoliths are embedded simultaneously in black resin and the mass-processed half plane section is viewed under reflected light (black-resin method). Seasonal periodicity of otolith growth was confirmed by the monthly observations of the percent of translucent zone at the otolith edge, and interannual variation in age distribution detected the progression of dominant year-classes. These results support the assumption that the translucent zone is formed once a year. The black-resin method was compared to the break–burn method, which is the standard technique for this species. The estimated ages of these methods were not biased throughout the age range examined. The coefficient of variation in the black-resin method (4.9–5.7%) was similar to those of the break–burn method (3.5–5.5%). These results suggest that the black-resin method is reliable as an aging method for walleye pollock. [ABSTRACT FROM AUTHOR]

Juveniles of carangid fishes including jack mackerel Trachurus japonicus are known to associate with jellyfishes. The function of this association behavior was studied through rearing experiments and underwater visual observations. Association behavior of jack mackerel with moon jellyfish in experimental tanks was more frequent in the presence compared to the absence of predators (chub mackerel Scomber japonicus). In the experimental tanks, the presence of jellyfish, however, did not mitigate predation by these predators. Although jack mackerel did not feed on the jellyfish itself, they frequently fed on the captured prey ( Artemia nauplii) whilst in the gut cavity of the jellyfish. Underwater observations of giant jellyfish Nemopilema nomurai off Kyoto and Fukui prefectures revealed that approximately 30% of these jellyfish were accompanied by jack mackerel juveniles with body sizes ranging 10–45 mm standard length (SL). Considering that jack mackerel juveniles found in subtidal rocky reefs ranged 40–120 mm SL, we considered that jack mackerel from 10 to 45 mm SL associate with jellyfish as a hiding place as well as a food collector, until they find a suitable reef habitat when they attain approximately 40 mm SL. [ABSTRACT FROM AUTHOR]

From 2002 to 2006, the fish fauna associated with sea weeds drifting in the Chikuzen Sea, northern Kyushu, Japan, was examined. The total numbers of species and individuals collected were 51 and 5475, respectively. The five dominant species, accounting for approximately 80% of the total individuals, were Rudarius ercodes, Stephanolepis cirrhifer, Petroscirtes breviceps, Sebastes thompsoni and Paramonacanthus japonicus. The number of species and individuals increased significantly with the increase in water temperature, reaching maxima during early summer and autumn, respectively. Combining the present and previous data (∼50 years ago), the appearance patterns of the fishes associated with drifting sea weed were classified into the following four types: (i) long periods (continuously for 3 months or more) and autumn (LA); (ii) spring (SP); (iii) summer (SU); and (iv) rare (R). In more than half of the species, there were no changes in the appearance patterns between the present and previous studies. However, in the present study, the appearance patterns of several species changed from LA to R ( Oplegnathus punctatus and Kyphosus cinerascens) and from R to LA and SU ( Abudefduf vaigiensis and Hyperoglyphe japonica, respectively). [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effect of dietary taurine and cholyltaurine (C-tau) on growth and body composition of juvenile red sea bream Pagrus major. Semi-purified casein-based diets supplemented with 0 (control diet), 0.1, 0.3, 0.5 and 0.7% taurine and 0.5% C-tau were fed to red sea bream (average body weight 4.7 g) for 6 weeks at 20°C. The growth and feed efficiency were the lowest in fish fed the control diet. Taurine supplementation improved the growth and feed efficiency of fish dose-dependently, and the taurine requirement was estimated as 0.52% in terms of optimizing growth and 0.48% in terms of optimizing feed efficiency. Taurine content in the whole body and liver increased with the dietary taurine level. Supplemental C-tau at the 0.5% level had limited effects on the growth and no effect on body taurine, biliary bile salt and liver fat contents. From these results it can be inferred that the optimal dietary taurine requirement of juvenile red sea bream is 0.5% on a dry weight basis, and that the supplementation of taurine in the diet not only improves the growth but also increases hepatic lipid levels of red sea bream juveniles. [ABSTRACT FROM AUTHOR]

Feeding activity was examined at high temperatures by using a demand feeder for thermally selected and normal rainbow trout Oncorhynchus mykiss strains. When the water temperature was raised in experiment 1 from 17.5 to 25.7°C at 0.3°C/day in 21 days, the average daily food consumption rate in the thermally selected strain rose to 7.1%, which was significantly higher than that of the normal strain (4.1%, P < 0.05). The corresponding rate was also significantly higher in the thermally selected (0.8%) than in the normal strain (0.2%, P < 0.05) of fish in experiment 2 where water temperature was raised to 24.1°C in 0.5°C/day increments. When water temperature was raised rapidly in experiment 3 from 16.7 to 21.7°C in one day and gradually to 24.4°C in 28 days at 0.1°C/day, the average daily food consumption rates were 1.0 and 0.1% for the thermally selected and normal strains, respectively, with significant difference ( P < 0.01). These results suggest that the thermally selected strain has acquired thermal tolerance as a result of artificial selection. [ABSTRACT FROM AUTHOR]

Fermentation of raw marine food is popular in Japan, but is occasionally associated with Clostridium botulinum outbreaks. Lactic acid bacteria in fermented food produce antibacterial substances (ABS). An ABS producing strain Iz.3.13 was isolated from commercially fermented ‘ izushi’. The purpose of this study was to characterize strain Iz.3.13 and the ABS it produced. Strain Iz.3.13 was identified as Pediococcus pentosaceus by morphological, biochemical characteristics and 16S rDNA sequence similarity. Strain Iz.3.13ABS produced and ABS inhibited Listeria and Cl. botulinum. The ABS was inhibited by α-chymotrypsin and proteinase K, but not by catalase, lipase, or α-amylase indicating the ABS was a bacteriocin. The bacteriocin remained active at 100°C for 15 min, and pH 2–8. Mode of action of the bacteriocin against Listeria monocytogenes was bactericidal and bacteriolytic. Partial analysis of the purified bacteriocin by Edman degradation, showed a 22-amino acid residue closely related to Pediocin AcH. However, MALDI-TOF-MS analysis estimated a molecular mass of 4621.6 Da. This is a first report of a Cl. botulinum-inhibiting bacteriocin-producer from traditional Japanese fermented marine food. The bacteriocin produced by Ped. pentosaceus Iz.3.13 might have potential to ensure the safety of fermented marine food. [ABSTRACT FROM AUTHOR]

The modulating effect of invertebrate C-type lectins on the crystallization of calcium carbonate was investigated. The multiple C-type lectins, named BRA-1, -2 and -3, isolated from the acorn barnacle Megabalanus rosa inhibited the nucleation and growth of calcium carbonate crystals. Among BRA, BRA-2 most efficiently inhibited the crystal nucleation of aragonite and calcite at the concentrations of > 3.3 and > 26 μg/mL, respectively. The inhibitory activities of BRA were enhanced by the addition of various biomolecules such as D-glucosamine, D-galactosamine, chitosan oligosaccharides, L-arginine and L-aspartic acid. Although the crystals of aragonite and calcite were formed in the presence of lower concentrations of BRA, the shape and size of the crystals were changed. These results further indicate the participation of the lectins in biomineralization. [ABSTRACT FROM AUTHOR]

Lipophilic toxin profiles associated with diarrhetic shellfish poisoning in Korean bivalves were investigated by liquid chromatography-mass spectrometry (LC-MS). Okadaic acid (OA), dinophysistoxins (DTX), pectenotoxins (PTX) and yessotoxin (YTX) in bivalves were quantified by LC-MS. Thirty-eight bivalve samples were collected from five different areas on the south coast of Korea during January to June 2006. Dinophysistoxin-1 (DTX1) and OA were found in some samples of both mussel Mytilus edulis and oyster Crassostrea gigas. The levels of DTX1 and OA found in the hepatopancreas of the samples were 0.04–0.23 µg/g and 0.03–0.08 µg/g, respectively. Dinophysistoxin-3 was found in the hepatopancreas of the short-necked clam Ruditapes philippinarum at a concentration of 0.06 µg/g. PTX and YTX were not detected from all of the samples examined. This is the first report of the unambiguous identification of OA and its derivatives, by LC-MS, in Korean bivalves. [ABSTRACT FROM AUTHOR]

Abstract: The release of organic contaminants from melting snow poses risks to aquatic and terrestrial organisms and to humans who rely on drinking water and food production from regions that are seasonally snow-covered. Measured and model-predicted spring peak concentrations in waters receiving snowmelt motivate a thorough investigation of organic contaminant behaviour during melting. On the basis of the current understanding of snow metamorphosis, snowmelt hydrology and chemical partitioning in snow, this critical review aims to provide a qualitative picture of the processes involved in the release of organic contaminants from a melting snowpack. The elution sequence of organic substances during snowmelt is strongly dependent on their environmental partitioning properties and the physical properties of the snowpack. Water-soluble organic contaminants can be discharged in greatly elevated concentrations at an early stage of melting, while the bulk of the hydrophobic chemicals attached to particles is often released at the end of the melt period. Melting of a highly metamorphosed and deep snowpack promotes such shock load releases, whereas a shallow snow cover over a relatively warm ground experiencing irregular melting over the winter season is unlikely to generate notable peak releases of organic substances. Meltwater runoff over frozen ground directly transfers contaminant shock loads into receiving water bodies, while permeable soils buffer and dilute the contaminants. A more quantitative understanding of the behaviour of organic contaminants in varying snowmelt scenarios will depend on controlled laboratory studies combined with field investigations. Reliable numerical process descriptions will need to be developed to integrate water quality and contaminant fate models. [Copyright &y& Elsevier]

Understanding the causes and consequences of species extinctions is a central goal in ecology. Faced with the difficult task of identifying those species with the greatest need for conservation, ecologists have turned to using predictive suites of ecological and life-history traits to provide reasonable estimates of species extinction risk. Previous studies have linked individual traits to extinction risk, yet the nonadditive contribution of multiple traits to the entire extinction process, from species rarity to local extirpation to global extinction, has not been examined. This study asks whether trait synergisms predispose native fishes of the Lower Colorado River Basin (USA) to risk of extinction through their effects on rarity and local extirpation and their vulnerability to different sources of threat. Fish species with "slow" life histories (e.g., large body size, long life, and delayed maturity), minimal parental care to offspring, and specialized feeding behaviors are associated with smaller geographic distribution, greater frequency of local extirpation, and higher perceived extinction risk than that expected by simple additive effects of traits in combination. This supports the notion that trait synergisms increase the susceptibility of native fishes to multiple stages of the extinction process, thus making them prone to the multiple jeopardies resulting from a combination of fewer individuals, narrow environmental tolerances, and long recovery times following environmental change. Given that particular traits, some acting in concert, may differentially predispose native fishes to rarity, extirpation, and extinction, we suggest that management efforts in the Lower Colorado River Basin should be congruent with the life-history requirements of multiple species over large spatial and temporal scales. [ABSTRACT FROM AUTHOR]

Studied were the quantities of volatile amines, total volatile bases nitrogen (TVB-N) and trimethylamine nitrogen (TMA-N) in stored sardines ( Sardina pilchardus) and herring ( Clupea harengus) over a 24-h period after defrosting. At the beginning of the experiment analyses showed TVB-N quantities in the flesh of both species to be higher than the FAO-recommended limit. TMA-N concentrations exceeded the acceptance limit 6 h after defrosting in herring samples and after 12 h in sardines. During the entire experiment TMA-N and TVB-N concentrations in sardines were above the tolerance limit. The defrosting method usually applied in tuna farms is unsuitable for maintenance of a high quality food supply. Low quality baitfish can cause reduced weight gain as well as induce health problems and mortality in farmed tuna ( Thunnus thynnus) populations. [ABSTRACT FROM AUTHOR]

Diplodus puntazzo is a species characterized by a rudimentary hermaphroditism, with a low level of protandry. The study found that the overall sex ratio was one male to 2.03 females, diverging significantly from 1 : 1, and that there was a ratio of one male to 0.11 transitional fish. The sex ratio varied with season: during the reproductive period the ratio was 1 : 1.86 (male : female), significantly lower than in the non-reproductive period in which the sex ratio was approximately 1 : 2.26. Both sexes had similar size distributions; however, females were predominant in all size intervals, especially in the larger ones. No significant difference in mean total length (TL) between females (330 mm), males (319 mm) or transitionals (321 mm) was found. The smallest functional female and male analysed were 159 and 157 mm TL, and the largest were 520 and 510 mm TL, respectively. No significant difference in length at first level of maturity, attained at the second year of life, was found between males (281 mm) and females (292 mm), respectively. A protracted spawning season was identified for the species: from September to February, with a peak in November. GSI values followed the same pattern for males and females, with values of females being similar to those of males; the highest values occurred between September and December, with a maximum in November. Occurrence of transitional fish was significantly higher during the month with highest values of GSI than in the resting period. The study found that vitellogenesis did not begin synchronously for all females, and the simultaneous presence of oocytes in all stages of development indicated an asynchronous mode of ovarian development. The presence of postovulatory, together with tertiary yolk vesicle oocytes, indicated that the species is a multiple spawner. [ABSTRACT FROM AUTHOR]

The population structure, age, growth, mortality and harvest intensity of the oyster Crassostrea madrasensis were examined in the Moheskhali Channel, Bangladesh between June 2003 and May 2004. The channel is a representative habitat for the area. C. madrasensis monthly length frequency data were analyzed using FiSAT software for estimating population parameters, including asymptotic length ( L ∝), growth co-efficient ( K) and recruitment pattern to assess the status of the stock. Asymptotic length ( L∝) and growth co-efficient ( K) were 20.88 cm and 0.35 year−1, respectively. The growth performance index (ϕ′) was calculated with 2.18. The growth pattern showed negative allometric growth ( b < 3), with an asymptotic weight ( W ∝) of about 1124.6 g. The oyster attained an average length of 6.17 cm at the end of 1 year. Total mortality ( Z) by length-converted catch curve was estimated at 1.78 year−1, fishing mortality ( F) at 0.77 year−1, and natural mortality ( M) at 1.01 year−1. The exploitation level ( E) of C. madrasensis was 0.43, while the maximum allowable limit of exploitation ( Emax) was 0.45 for the highest yield. The recruitment pattern was continuous, displaying a single major peak event per year. Habitat temperatures were 25.5–31.0°C (mean ± SD, 29 ± 1.62°C); salinity range was from 12.36 to 26.0 ppt (mean ± SD, 19.6 ± 4.7 ppt). The exploitation level (0.43) indicated that the oyster stock was exploited at almost maximum yield in this channel. [ABSTRACT FROM AUTHOR]