Reviews in Fish Biology and Fisheries最新文献

Abstract

Fisheries management and conservation require consideration of fish, habitat, and people. In fisheries science, a growing body of research on human values, perspectives, and behaviours around fish—known as ‘human dimensions’ research—has emerged from the realization that management and conservation require a better understanding of people. Surveys are a common and versatile tool in human dimensions research, but not all surveys are equal. Large-scale, probabilistic surveys draw random samples from known populations (e.g., all license-holding recreational fishers in a jurisdiction) and represent the ‘gold standard’ in survey research. However, these surveys may fall short of this standard for various reasons. Surveys using non-probabilistic sampling are also common in human dimensions research. Non-probabilistic surveys are attractive to researchers facing time, cost, and other constraints, but differ notably from their probabilistic counterparts: data from non-probabilistic samples are typically unfit for population estimates and other inferences due their uncertain representativeness. Nonetheless, a wealth of research with non-probabilistic data within and outside of fisheries (e.g., in health sciences) suggests that these methods have valid applications and advantages in some contexts. We reviewed the literature on non-probabilistic surveys and sampling in the human dimensions of fisheries, and explored seminal literature from other thematic areas where such methods are common, to better understand their strengths, weaknesses, and applications relative to probabilistic methods. Here, we describe (1) how researchers have used non-probabilistic methods to study the human dimensions of fisheries, (2) how mismatching research questions, objectives, and methods can produce ‘awkward surveys,’ and (3) how researchers can use non-probabilistic surveys in ways that invoke their methodological strengths. While uncertain representativeness may limit the utility of non-probabilistic data in some contexts, non-probabilistic methods are time- and cost-effective, and have distinct advantages in studies of niche groups and phenomena, emergent or understudied phenomena, and in supplementary roles.

In aquaculture studies, Spirulina can be used to replace fish meal in aquafeed to lower the cost of producing fish feed while adding therapeutic and health benefits. Proteins, carbohydrates, vitamins, minerals, pigments, and fatty acids from Spirulina could enhance the cellular and humoral immunities of a variety of fish species. This review focuses on the functions of various Spirulina components that play a role in haematopoiesis, haemato-biochemical variables, pro-inflammatory and anti-inflammatory cytokine production, stress prevention, disease resistance, and immune responses in a variety of finfish species. Herein, we also presented the overlooked areas on the functionality of Spirulina on the immune response pathway and connected the missing link with the help of a better knowledge of the mammalian system, albeit these must be proved experimentally. This review will inspire the scientific community to investigate the biological role of Spirulina in fish, which is critical to the commercial viability of Spirulina as fish feed.

Abstract

Accurate and low-impact monitoring of scallop abundance is critical for stock assessment, especially in sensitive habitats. The possibility of using low-impact hyperspectral imaging (HSI) for differentiating scallop species in the marine environment was investigated. Live saucer (Ylistrum balloti) and mud (Ylistrum pleuronectes) scallops (N = 31) were scanned inside a sea simulator using a visible to near infrared (400–1000 nm) line-scanner HSI camera. Partial least square discriminant analysis (PLS-DA) was trained to distinguish between the species using their spectral signatures. Important wavelengths were identified and new models were developed using these wavelengths to reduce the model complexity and potentially increase the imaging speed when applied under at-sea conditions. The PLS-DA model distinguished between saucer and mud scallops using any area of the left valve that was exposed above the sediments, with 90.73% accuracy when all 462 available wavelengths were used. Using the subset of important wavelengths (N = 13) reduced the classification accuracy to 84%. Overall, our results showed that HSI has potential for detecting, distinguishing and counting commercially important saucer scallops for low-impact monitoring and resource management, and to complement RGB imaging that relies solely on morphological properties.

Reef fisheries are multispecific and employ a variety of fishing gears across marine environments, even in remote areas. This intricate and multifaceted nature of reef fisheries is often overlooked in management strategies, leading to global management failures. In Brazil, information about reef fisheries is often scarce and scattered. This stems from inadequate policies and an unrecognized societal value of reef fisheries. Here, we combine nationwide reef fish landing data (1950–2015) with an extensive literature review on Brazilian reef fisheries. We explore temporal and spatial patterns in total landings, species traits, functional diversity and composition to understand the current scenario, identify drivers of change and highlight information gaps. Brazilian reef fisheries rapidly increased in landing volume, number of targeted species and exploited traits in the 1980’s, despite mainly targeting carnivorous fish (groupers, snappers, jacks and trevallies). Exploited functional space increased over time, mainly due to the incorporation of smaller and lower-trophic level species that gradually were added to the pool of fished species. Local and international markets have been the main drivers behind these patterns, while subsistence fishing is marginal. Lack of proper management and enforcement of existing regulations have led to population declines, dwindling total catches since the early 2000’s, and numerous threatened species. Artisanal fishing accounts for the majority of catches, raising concern on the social impacts of degraded reef fisheries. We highlight the urgent need for adequate fishing statistics, and the use/application of science-based management and policy actions to secure productive fisheries and healthy reef ecosystems in Brazil.

Electronic monitoring (EM) systems incorporating cameras and other devices can collect a broad range of data to support fisheries management. We reviewed the data collection capabilities of EM and considered approaches to increasing efficiency, including cost effectiveness, of EM review. EM can provide information on catch, effort, catch handling, bycatch mitigation, fishing gear and operational data, which are relevant for fisheries management including by Regional Fisheries Management Organisations (RFMOs). Methods to increase efficiency and decrease costs of EM review apply from the programme design phase, through data collection and review. At review, costs may be reduced by sampling imagery optimally to meet monitoring objectives. Considering RFMOs as users of EM-collected information, we applied EMoptim, an open-source simulation model developed in R that estimates the amount of EM review necessary to meet one or more user-specified monitoring objectives. EMoptim uses stratification to increase review efficiency and incorporates a function to explore review costs against the monitoring objectives set. We evaluated the amount of EM review needed to estimate catch with specified precision, using fishery data available from the Western and Central Pacific Fisheries Commission. Model outputs show that EM review requirements increase as catch frequency decreases, dispersion of catch events increases, and when more precise catch estimates are required. Geographical stratification reduced the amount of review required for more commonly caught species and when catch events were focused in a limited area. Optimising review rates across multiple monitoring objectives was most effective for more commonly caught species. We highlight opportunities for future use and development of this prototype modelling package.

Supplementary information: The online version contains supplementary material available at 10.1007/s11160-024-09895-7.

Fishes represent the most diverse group of vertebrates, having inhabited the Earth for approximately 480 million years during which they evolved many specialised adaptations. One such adaptation is the evolution of a venom system, which has convergently arisen on at least 19 separate occasions across their evolutionary history. Venom evolution across fishes has taken two forms: chemical weaponisation of previously evolved defensive spines and the development of an oral venom system. Fish venoms have been shown to contain a myriad of toxin types, some of which may have pharmacological potential. However, due to the labile nature of many toxins, fish venom has not been extensively investigated compared to other venomous groups such as reptiles and arachnids. This review provides an updated scope of our current knowledge regarding the biology, biochemistry, and evolution of fish venom systems. It also attempts to provide a coherent assessment of the dated literature while seeking to address particular issues in order to drive fish venom research further.

Patterns of Chondrichthyes species richness (CSR) are widely recognized as being influenced by environmental conditions. However, untangling the intricate interplay between anthropogenic impacts and spatial patterns of CSR remains a challenging endeavor. In this study, we evaluate the influence of thirteen human-related variables, encompassing human-induced effects and marine protected areas, on global CSR. Additionally, we explore their effects on threatened species, those declining, those utilized and traded, and those facing direct human-induced threats. Utilizing simple, multiple, and simultaneous regression models, we comprehensively investigated the relationship between human-altered variables and marine protected areas on CSR across oceanic regions. Our findings distinctly reveal a compelling convergence of human-related variables with CSR. Notably, factors such as global ocean acidification, demersal destructive practices (e.g., bottom trawling), pelagic low bycatch techniques (e.g., hook and line), and demersal non-destructive high bycatch methods (e.g., pots, traps) exhibit robust negative associations. Intriguingly, a positive association emerges with the presence of marine protected areas. Furthermore, our study underscores the profound impact of diverse human activities on CSR, significantly heightening their vulnerability to threats and imminent extinction risks. These results accentuate the critical significance of conservation strategies centered on marine protected areas, maximizing the optimized preservation of Chondrichthyes across marine ecosystems. In light of these insights, we stress the paramount role of planners and managers in mitigating direct human impacts on marine ecosystems, which is crucial for ensuring the enduring presence of Chondrichthyes across the oceans.

Age determination is an important tool in fishery research and management, providing key data for growth modelling and population dynamics. Knowledge of longevity and growth performance of fishes is especially important in defining their life history strategies. In this review we summarize all published data on the ageing of notothenioid fishes of the Southern Ocean, and evaluate factors influencing growth performance and longevity in a phylogenetic context. Most age estimates in notothenioids are based on otolith readings and application of the von Bertalanffy growth model to describe body growth throughout the life span. Growth performance and longevity both exhibit wide ranges between 3.5 and 5.5 and 7–52 years, respectively. However, growth performance is positively related to asymptotic fish size, whereas longevity is negatively related to the Brody growth rate coefficient. Lifestyle and latitudinal and depth distributions are the main factors influencing the life history traits of notothenioids. Growth performance significantly increases from benthic to pelagic species and declines toward higher latitudes. Conversely, longevity is higher in pelagic species and shows a positive trend with latitude and depth of occurrence. There is a trend toward an increase of both traits in the phylogenetically derived families, such as bathydraconids and channichthyids. Compared to Arctic fishes, notothenioids have similar values for growth performance and longevity. Currently the major gaps in our knowledge of age determination of notothenioids are the lack of validation of age estimates and the relatively low number of species studied. Future efforts have to provide more reliable and objective estimates of age through multiple comparisons among different laboratories and application of validation tools.

Abstract

Passive acoustic monitoring (PAM) is useful for monitoring vocal fish but has had so far limited application in fisheries management. Here, four years (2016–2019) of concurrent daily catch and effort fishery data in Portugal and species-specific vocal activity in the Tagus estuary are compared to describe biological and small-scale fishery dynamics for a large sciaenid fish, the meagre (Argyrosomus regius), that aggregates to spawn. Consistent patterns in seasonality of acoustic and fisheries variables indicate that most fishing takes place within the Tagus estuary in spring and summer months, when higher vocal activity related to spawning aggregations is detected in the PAM station. Good fit of statistical models shows that PAM (sound pressure level in the third-octave band with centre frequency at 500 kHz during dusk) and PAM-supported variables (mean weekly catch per first sale transaction) can provide useful surveillance indicators to improve local management. Signs of overexploitation and hyperstability are detected and communicated to the estuarine fishing communities with the aim to initiate an adaptive local management cycle. The approach can be relevant for fisheries targeting other vocal fish that seasonally aggregate and face similar threats of overexploitation.