Search

Fisheries, as part of the human food chain, have an environment that affects fisheries resources. The view of slowing the number of fish catches in the sea due to factors that drive such as economic growth, population and effort effectiveness will decrease the power of fish in the sea. This study carried out the circumstance of fisheries in sea Indonesia and analyzed empirically the relationship between economic factors, population, and effort effectiveness on the catch volume. We apply the random effect (RE) estimator method which is reviewed for 33 provinces for the period 2000-2015. We use catch as a proxy for marine ecosystems. Our results confirmed that the growth of fish catchment in the sea Indonesia experienced a positive trend and the relationship between economic factors, population and effort effectiveness positive and significant on the volume of catch thus we conclude that catch fisheries in Indonesia is sustainable

На основе материалов серии экспедиций, проведённых Морским гидрофизическим институтом (г. Севастополь) и Южным научно-исследовательским институтом морского рыбного хозяйства и океанографии (г. Керчь) в 2002–2015 гг., получено уравнение регрессии, свидетельствующее о наличии тесной обратной корреляционной связи между солёностью и концентрацией окрашенного растворённого органического вещества в прибрежных водах северной части Азовского моря. При помощи этого уравнения по схемам средней месячной солёности рассчитаны сезонные поля содержания исследуемого вещества для всей прибрежной акватории моря, которая испытывает влияние речного стока. Показано, что у подверженных распреснению северного и восточного берегов моря поле исследуемой величины содержит существенную терригенную составляющую, которая значительно трансформируется на стоковых фронтах впадающих в Азовское море рек. Мористее фронтов в центральной, западной и южной областях Азовского моря поле окрашенного растворённого органического вещества однородно.

A biomass dynamics modelling study to derive biological reference points and management requirements of 223 commercially important fish stocks in different maritime states of India was conducted. Two decades (1997–2016) of fishery-related data on the harvest of resources by different types of fishing fleets formed the input. The multigear nature of the fishery situation was solved by introducing a gear standardization parameter into the biomass dynamics model. The relative positions of the fish stocks were depicted through Kobe plots generated for the ten maritime states/union territory, and the fish stocks were categorized, based on the status, into sustainable, overfished, recovering, and overfishing. The results indicate that 34.1% of the assessed fish stocks in the country are sustainable, 36.3% are overfished, 26.5% are recovering, and 3.1% are in the overfishing status. Regionally, the percentage of sustainable fish stocks were high along the southwest coast (51.6%), overfished stocks were high along the northwest coast (54.2%), and recovering fish stocks were high along the northeast coast (47.8%). The national mean B/BMSY was estimated as 0.86, which is a strong reason for strengthening fisheries management. Fishing fleets harvesting overfished stocks were examined for each maritime state, and recommendations regarding reduction in annual fishing hours are made.

The study was conducted to analyze the fish landings from Iraqi artisanal marine fisheries, northwest Arabian Gulf from January 2017 to December 2019. The monthly data of fish landings were collected from the main landing site at Al-Fao port, south Iraq and were analyzed using descriptive statistics. A total of 35 taxa in 18 families were identified in the artisanal catches, in addition to two species of shrimps. The highest total landings were 11,944 t in 2018 and 11,305 t in 2019. The annual total landing of the marine fisheries increased by 270% during 2017-2019 as compared with the annual landing during 2008-2016. Threadfin bream contributed 14.1%, followed by river shad (11.1%) and mullets (11.1%), whereas shrimps formed 15.2% to the total catch. The overall values of biomass diversity of fish ranged from 1.82 in 2017 to 2.85 in 2018. There were 320 registered fishing boats motorized by 65 to 950 hp. Multi gears fishing were observed. The trends of the landings of all fish groups were increased substantially, except river shad, threadfin bream and shrimps. The study suggests some of the management measures must be put into place, especially for the river shad in the regions of their migration reproductive and the nursery.

Bycatch and mortality in fishing gear poses a conservation threat worldwide to many marine species. Resource managers and conservation scientists face challenges in identifying bycatch mitigation solutions that work for multiple taxa while maintaining acceptable levels of target fish catch. The most successful mitigation measures to address bycatch concerns are those that (1) minimize bycatch with limited or no impact on target species catch, (2) have been proven through at-sea experimental research, (3) are practical, affordable, and easy to use, and (4) do not risk the safety of the fishing vessel crew or the bycaught animals. We conducted a review of mitigation measures in fishing gears that target tuna and tuna-like species and that either prevent capture of non-target species in fishing gear or facilitate alive post-capture release, and evaluated these against 4 defined criteria: effective, proven, practical, and safe. This paper outlines the most effective bycatch mitigation measures, as based upon the best scientific information available, in commercial and artisanal pelagic longline and purse seine fisheries, specifically those that target tuna and tuna-like species. This review includes information on gear and operational changes to fishing practices that reduce bycatch for protected and threatened species across taxonomic groups, with a focus on cetaceans, sea turtles, seabirds, sharks, and istiophorid billfishes. The information provided can guide future research and management efforts in Regional Fisheries Management Organizations that are specific to tuna fishing and that aim to minimize impacts to protected and threatened species while maintaining viable commercial fisheries.

Karachi shoreline is more than 135 Km long significant for marine fishery breeding and spawning. During 2005 to 2018 the mangrove forest areas in Karachi increased in extent but declined in density. The main cause of mangrove cover change in this region are coastal region development (port building, industrial area and waterfront project). This study aims to monitor both extent and density changes of mangrove forest at Karachi coast. For this purpose, the Landsat imagery was used of the years 2005 and 2018 covering a span of 14 years. The imageries were processed through Normalized Difference Vegetation Index (NDVI) analysis. Simultaneously, random sample locations were identified for mapping and validation of mangrove forest extent and density during 2005 to 2018. The sample locations were categorized as dense, normal and sparse classes. In the next step, sample locations were plotted on NDVI images to determine mean, minimum and maximum values for each class of mangrove forest. In the final step, the accuracy assessment was done using Kappa statistics. Results show that overall accuracy of 2018 imagery is better than 2005 Landsat imagery. The overall extent of mangrove forest increased in the past years.

Trawl fishing constitutes an important part of the marine fisheries sector in Southeast Asia. It provides livelihoods and food for millions of people in coastal communities as well as feed for the ...

The actors’ welfare of marine fishery supply chain in the three sub-districts in Kangean Islands, namely Sapeken, Arjasa and Kangayan, are different even though they access to the same marine fisheries resources. The marine fisheries in Sapeken are more prosperous than those in Arjasa and Kangayan. This study aimed at identifying the distribution channel patterns of marine fishery products supply chain in Kangean Islands which providing an explanation of the actors’ welfare differences. In-depth interviews with various actors were conducted to formulate the distribution channel patterns of marine fishery products. Quantitative survey data of 102 respondents from marine fisheries were processed descriptively to determine the actors’ welfare. Research showed that the distribution channel patterns in Arjasa and Kangayan vary but are limited in the local market and the islands communities as the final consumers. It causes the low products prices. Meanwhile, the distribution pattern in the Sapeken is able to penetrate markets outside the Kangean Islands with high product prices. Therefore, it is not surprising if the actors’ welfare in Arjasa and Kangayan sub districts are lower than the actors’ welfare in Sapeken.

Alien species may be a valuable resource for marine fisheries, yet their contribution to the catch might be balanced by negative effects on indigenous species. In this study, we explored a unique high-resolution time series of catch data from a highly invaded ecosystem in the eastern Mediterranean. We analyzed over 5000 fishing hauls digitalizing from fishers’ logbooks. We found that the catch per unit effort (CPUE) of alien species increased over time, while for indigenous species, CPUE remained relatively stable between 1996 and 2013. This suggests a lack of competitive exclusion of indigenous target species due to the proliferation of alien species. From the perspective of the fishers’ revenues, alien species gradually became a more important part of the catch, while overall fishers’ revenues showed temporal stability. This was the combined result of alien species increasing CPUE and fishers shifting their effort toward shallower water where alien species were dominant. Our findings demonstrate that alien species can become a valuable resource for a local fishing industry with little effect on indigenous species, which is highly relevant to worldwide fisheries experiencing range redistribution of commercial species.

The paper reviews critical findings regarding the influence of fish marketing on local livelihoods and resources in a near shore African marine fishery. Literature search was conducted using search engines google scholar, scopus, and web of science using the key words: Fish, fish trade, global market, livelihood, marine/coastal, with the objectives of exploring the relationship between fish markets, livelihoods (at the household level) as well as the resource itself. In addition, country reports from research organizations (both published and unpublished) as well as FAO reports were consulted. The search was undertaken in November 2019. Results from literature search were analyzed thematically based on livelihood indicators including fish marketing channels, determinants of income, occupations and fish price transmission. Linkages vary with respect to fish type, species and usage type, highlighting the need for disaggregated analyses to respond to specific objectives and market factors. The review points out that not all fish types are exported/linked to the tourism industry and that even for those linked to the global market, the benefits do not trick down. A strong interaction between fish and local staple is evident, an indication that small scale fisheries are likely to have local benefits than benefits attributed to global market linkages.

Place: Lausanne Publisher: Frontiers Media Sa WOS:000760695700001; International audience; Pelagic fish communities are shaped by bottom-up and top-down processes, transport by currents, and active swimming. However, the interaction of these processes remains poorly understood. Here, we use a regional implementation of the APex ECOSystem Model (APECOSM), a mechanistic model of the pelagic food web, to investigate these processes in the California Current, a highly productive upwelling system characterized by vigorous mesoscale circulation. The model is coupled with an eddy-resolving representation of ocean currents and lower trophic levels, and is tuned to reproduce observed fish biomass from fisheries independent trawls. Several emergent properties of the model compare realistically with observations. First, the epipelagic community accounts for one order of magnitude less biomass than the vertically migratory community, and is composed by smaller species. Second, the abundance of small fish decreases from the coast to the open ocean, while the abundance of large fish remains relatively uniform. This in turn leads to flattening of biomass size-spectra away from the coast for both communities. Third, the model reproduces a cross-shore succession of small to large sizes moving offshore, consistent with observations of species occurrence. These cross-shore variations emerge in the model from a combination of: (1) passive offshore advection by the mean current, (2) active swimming toward coastal productive regions to counterbalance this transport, and (3) mesoscale heterogeneity that reduces the ability of organisms to return to coastal waters. Our results highlight the importance of passive and active movement in structuring the pelagic food web, and suggest that a representation of these processes can help to improve the realism in simulations with marine ecosystem models.

Impacts of climate change on any individual species can cascade through biological systems, affecting other species, many of which may be responding to climate change themselves. These complex ecosystem impacts are among the most important in climate change biology because they impact the services these ecosystems deliver for human well-being and livelihoods. Impacts on tropical forests, marine fisheries, coral reefs and other systems are explored.

Crucial point of fishery management is to let the fish or other species reproduce at least once during their life. Therefore it is very important to determine the length at maturity (Lm) for given species before the first capture. Focus of this study is to determine the consistency between scientific results and minimum landing size (MLS) regulations in the marine fishery of Turkey. For this purpose, 4/1 communique on commercial fishery (2016/35) published by the Republic of Turkey Ministry of Agriculture and Forestry was investigated in order to expose the MLS of given species in Turkey. Literature survey on Lm was also conducted preferably on studies which were performed in Turkish waters or from the Mediterranean basin in order to avoid regional differences. While 86 marine species were reported to be landed in the official fishery statistics, only 49 of them were appointed with a MLS in the commercial fisheries regulation. It was determined that MLS of 27 species were below the Lm according to the selected literature, 7 of them require result on Lm, status of the 2 species couldn‘t be decided due to different length types and 13 (27% of the decisions on MLS) of them were found to be in accordance with the scientific literature on Lm. This study shows that MLS regulation must be revised for most of the species in the surrounding waters of Turkey and comprehensive maturity studies are urgently needed in order to fulfill the scientific gap.

Bycatch in marine fisheries is the leading source of human-caused mortality for marine mammals, has contributed to substantial declines of many marine mammal populations and species, and the extinction of at least one. Schemes for evaluating marine mammal bycatch largely rely on estimates of abundance and bycatch, which are needed for calculating biological reference points and for determining conservation status. However, obtaining these estimates is resource intensive and takes careful long-term planning. The need for assessments of marine mammal bycatch in fisheries is expected to increase worldwide due to the recently implemented Import Provisions of the United States Marine Mammal Protection Act. Managers and other stakeholders need reliable, standardized methods for collecting data to estimate abundance and bycatch rates. In some cases, managers will be starting with little or no data and no system in place to collect data. We outline a comprehensive framework for managing bycatch of marine mammals. We describe and provide guidance on (1) planning for an assessment of bycatch, (2) collecting appropriate data (e.g., abundance and bycatch estimates), (3) assessing bycatch and calculating reference points, and (4) using the results of the assessment to guide marine mammal bycatch reduction. We also provide a brief overview of available mitigation techniques to reduce marine mammal bycatch in various fisheries. This paper provides information for scientists and resource managers in the hope that it will lead to new or improved programs for assessing marine mammal bycatch, establishing best practices, and enhancing marine mammal conservation globally.

Establishing the distribution of marine fishery resources can help to investigate the changes in fishery resources and help management agencies establish fishing plans for catches, further to determine the scope of ecological protection. However, fishery data based on sea data cannot be collected directly as a result of the vast area of ocean. Fishermen are also reluctant to share their fishing situation. This paper mines the distribution of fishery resources by mining the navigation data of fishing vessels. We have expanded the features of the data by setting hard thresholds to filter the occasional locations, and the locations of ports, docks, and routes, and using isolated forests to detect abnormal data in the filtered data to improve the accuracy of the data. The mined data have obvious regional distribution characteristics through the display of heat map, which can indicate the important areas of ecological protection.

The time-tested indigenous fishing knowledge (IFK) of the Pacific Islands is seriously threatened due to the commercialization of fishing, the breakdown of traditional communal leadership and oral knowledge transmission systems, modern education and the movement of the younger generations to urban areas for work and/or study. As a consequence, IFK, which has been orally transmitted for generations, has been lost, not learned by the current generation, or remains undocumented. This desktop study focuses on the critical need for conserving and including IFK as a basis for assessing the conservation status of ecologically and culturally important keystone fisheries species as a basis for planning and site-specific management of marine and freshwater fisheries in Fiji and the Pacific Islands. The study reviews information on IFK from Fiji and elsewhere in the small oceanic islands of the Pacific as a basis for the conservation, documentation and intergenerational transfer of this knowledge as the foundation for sustainable fisheries management in these nations. The study spanned over documents from the last two and a half centuries. The results include a review of the nature and conservation status of IFK and the conservation status of species considered to be of particular ecological and cultural importance, reasons for the loss of species/taxa and associated knowledge and practices, and actions that need to be taken to address this loss. Moreover, it also highlights ways to counter the erosion of the threatened IFK so that the future generations can have access to it.

As global warming makes the Arctic Ocean more accessible, concerns have been raised about the environmental consequences of a possible expansion of commercial fisheries into pristine marine ecosystems. Using a recently released global dataset, we quantify for the first time how fishing activities are responding to diminishing sea ice and a warmer Arctic Ocean. We show that trawling dominates Arctic fisheries and that this activity penetrates rapidly into Arctic shelf areas previously protected by extensive ice-cover as a response to interannual sea ice loss. We model the development of trawling activity under a climate change scenario and use the model to identify areas with high risk of increased trawling activity and estimate the amount of trawling avoided in recently established fishery protection zones. Stronger responsibility must be undertaken by Arctic coastal states to regulate increased fishing pressure and protect vulnerable Arctic shelf ecosystems.

14 pages, 6 figures, 1 table, supplementary material https://www.frontiersin.org/articles/10.3389/fmars.2021.621961/full#supplementary-material.-- Data Availability Statement: The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: https://github.com/Jrehren/Frontiers-2020-Rehren-Supporting-spatial-management-with-Bayesian-approach.git, Marine conservation areas are an important tool for the sustainable management of multispecies, small-scale fisheries. Effective spatial management requires a proper understanding of the spatial distribution of target species and the identification of its environmental drivers. Small-scale fisheries, however, often face scarcity and low-quality of data. In these situations, approaches for the prioritization of conservation areas need to deal with scattered, biased, and short-term information and ideally should quantify data- and model-specific uncertainties for a better understanding of the risks related to management interventions. We used a Bayesian hierarchical species distribution modeling approach on annual landing data of the heavily exploited, small-scale, and data-poor fishery of Chwaka Bay (Zanzibar) in the Western Indian Ocean to understand the distribution of the key target species and identify potential areas for conservation. Few commonalities were found in the set of important habitat and environmental drivers among species, but temperature, depth, and seagrass cover affected the spatial distribution of three of the six analyzed species. A comparison of our results with information from ecological studies suggests that our approach predicts the distribution of the analyzed species reasonably well. Furthermore, the two main common areas of high relative abundance identified in our study have been previously suggested by the local fisher as important areas for spatial conservation. By using short-term, catch per unit of effort data in a Bayesian hierarchical framework, we quantify the associated uncertainties while accounting for spatial dependencies. More importantly, the use of accessible and interpretable tools, such as the here created spatial maps, can frame a better understanding of spatio-temporal management for local fishers. Our approach, thus, supports the operability of spatial management in small-scale fisheries suffering from a general lack of long-term fisheries information and fisheries independent data, This project was funded by the German Research Foundation (DFG) within a research fellowship program (RE 4358/1-1). The data used in the analysis was collected in 2014 within a program (SUTAS) funded by the Leibniz Gemeinschaft. MC acknowledges the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC)

Three new species of small snailfishes, with maximum lengths up to only 60 mm, are described from collections in the Aleutian Islands taken during fisheries resource assessment surveys conducted by the U.S. National Marine Fisheries Service. Previous molecular analyses demonstrated that two of the species are closely related; the third species was found among material thought to consist only of one of these two species. Two of the new species are distinguished from all other species of Careproctus on the basis of an anterior dorsal-fin lobe with exserted rays and bodies with widespread small rounded bumps covered with tiny prickles. They are distinguished from each other on the basis of fin ray and vertebral counts, as well as differences in body shape. The third new species is diagnosed from all other species of Careproctus by having a small teardrop-shaped body, with loose thin skin and without an anterior dorsal-fin lobe, as well as by high counts of meristic characters, especially pectoral-fin rays. Each species is found widely within the Aleutian Islands from west of Kiska Island in the west to north of Umnak Island in the east at depths of 90 to 447 m.

American Shad (Alosa sapidissima), Hickory Shad (A. mediocris), and river herrings (Alewife A. pseudoharengus and Blueback Herring A. aestivalis) are anadromous pelagic fishes, which as adults spend most of the annual cycle at sea, but enter the coastal rivers in spring to spawn. Once as one of the most valuable fisheries along the Atlantic coast, Alosa populations have declined in recent decades and current populations are at historic lows. Various management actions have been conducted to restore the populations, and stocks in different river systems display different demographic trends. Demonstration of synthetic diagnostics on the factors impacting these populations is important to better conserve this species group. We developed a Bayesian hierarchical spatiotemporal model to identify the population trends of these species among rivers in the Chesapeake Bay based on results of surveys conducted by the Virginia Department of Game and Inland Fisheries and Maryland Department of Natural Resources and to identify environmental and anthropogenic factors influencing their distribution and abundance. The hierarchical model structure helped to diagnose river-specific population trends and impacts of surrounding factors, and decrease uncertainties in rivers with less samples available. The results demonstrate river-specific heterogeneity of spatiotemporal dynamics of these species and indicate river-specific impacts of multiple factors, including water temperature, river flow, chlorophyll a concentration, and total phosphorus concentration, on their population dynamics. Atlantic Multidecadal Oscillation and Gulf Stream meanders displayed significant influence on the inter-annual trends of Alosa species in rivers with more data available. The results would help to develop river- and species-specific management strategies to recover these species. Virginia Tech; Virginia Department of Game and Inland Fisheries; Maryland Department of Natural Resources; Atlantic States Marine Fisheries Commission Published version We acknowledge supporters, including Virginia Tech, Virginia Department of Game and Inland Fisheries, Maryland Department of Natural Resources, and Atlantic States Marine Fisheries Commission. We would like to thank Dr. Can Zhou for his help on model development. We also acknowledge Advanced Research Computing at Virginia Tech () for providing computational resources and technical support that have contributed to the results reported within this paper. Attention to the comments of the associate editor and anonymous reviewers led to strengthening of the manuscript.

The aim of this research was to define the participation rates of freshwater anglers in Croatia, their changes over the years and their differences across the counties of Croatia. In spite of a continuous population decline ever since Croatia joined the EU, the number of anglers has slightly increased to around 1%. The counties can be divided into three groups – counties on the Adriatic coast where marine fisheries are dominant, a very urbanized City of Zagreb and the remaining inland counties. In freshwater recreational fisheries in Croatia, the tradition and availability of fishing grounds dominate the participation rate of anglers. However, there are indications of the influence of GDP values so the counties with GDP over 6,500 euros per capita expressed positive relationship to the percentage of anglers (p

Effective sustainable management of marine fisheries requires that assessed management units (that is, fish stocks) correspond to biological populations. This issue has long been discussed in the context of Atlantic bluefin tuna (ABFT, Thunnus thynnus) management, which currently considers two unmixed stocks but does not take into account how individuals born in each of the two main spawning grounds (Gulf of Mexico and Mediterranean Sea) mix in feeding aggregations throughout the Atlantic Ocean. Using thousands of genome-wide molecular markers obtained from larvae and young of the year collected at the species’ main spawning grounds, we provide what is, to the best of our knowledge, the first direct genetic evidence for “natal homing” in ABFT. This has facilitated the development of an accurate, cost-effective, and non-invasive tool for tracing the genetic origin of ABFT that allows for the assignment of catches to their population of origin, which is crucial for ensuring that ABFT management is based on biologically meaningful stock units rather than simply on catch location., Sí

Shrimp is a type of crustacean and is included in the marine fishery commoditywhich has important economic value and is currently hunted by fishermen and iscommonly found in coastal waters. The purpose of this study was to determine the ShrimpProduction and Seasonal Catching Pattern in the Waters of Pangkep Regency. Itsusefulness is as a foundation material in the use of shrimp resources in the waters ofPangkep Regency. Data collected consists of primary data and secondary data. Primarydata is obtained by direct observation in the field through a field survey method (visualrecall) to portray the conditions of crab resources. While secondary data was collectedfrom the relevant agencies according to the attributes that will be reviewed and recordeddata from collecting fishermen in the coastal areas and small islands of PangkepRegency. Shrimp production from trammel net and mini trawl catches in the waters of theSigeri District of Pangkep Regency in 2015 consisted of 706 tons of white shrimp anddogol shrimp 4,481 tons, while in 2016 706 tons of white shrimp and dogol shrimp 4,481tons. Analysis of the percentage of shrimp fishing season index in the waters of PangkepRegency, occurred in January, February, March and April. The highest percentage offishing season index occurs in January each year.

Heavy metals have been detected in coastal regions, in the vicinity of former mining sites. The level of these heavy metals frequently exceed the safe limits in what represents an important aquatic source of food for human consumption. A thorough and conventional study into the levels of contamination in the suspected area is a costly but necessary exercise in order to inform any appropriate mitigating actions. This study demonstrates the benefits of integrating scientific investigating methods comprising chemical analysis using aqua regia and geo-electrical surveys, i.e., electrical resistivity imaging and induced polarization, to attain the approximate levels of contamination for both lateral and vertical landscapes in an efficient way. The demonstration to present the conformity and reliability of this joint methods is at Saphan Hin, situated on the southeastern coast of Phuket, Thailand. The site is located downstream of Bang-Yai canal; a potential intermediary carrying heavy metals especially Lead and Zinc from a number of mines where the nearest is approximately 4 km away. Saphan Hin is an important place marine fishery to supply to an increasing number of tourists to Phuket. The combined results from using all methods in this study are consistent in showing that the extent of the over-the-limit contamination can be found up to at least 200 m from the estuary, and with the decreasing depths from around 20 m to 50 cm at further distances from mainland, demanding urgent measures for the health of local people as well as tourists. A model to adapt these monitoring methods for implementation in operating mines is proposed as an early warning system to prevent any leakage probably occurring under normal conditions.

Reproduction of the threadfins of the costal shelf of Grand-Lahou was studied with a monthly sampling frequencies range from may 2009 to april 2011. 534 specimens of Polydactylus quadrifilis, composed of 315 males and 219 females and 648 Galeoides decadactylus composed of 420 males and 228 females, then 453 individuals of Pentanemus quinquarius composed of 210 males and 243 females were used. The sexual maturity parameters of threadfins fishes indicate a size of first maturity (L50 = 67.5 cm) for females of Polydactylus quadrifilis and (L50 = 55.5 cm) with their males. Concerning the specimens of Pentanemus quinquarius, females present (L50 = 15 cm) and their males (L50 = 14.5 cm). This parameter has identical values ​​with the females of Galeoides decadactylus (L50 = 15.5 cm) and their males (L50 = 15.5 cm). The individuals of Polydactylus quadrifilis and the specimens of Galeoides decadactylus and Pentanemus quinquarius become mature at 1 year of age. The sex ratio determination show that specimens of Polydactylus quadrifilis show a predominance of males during the warm season, from October (73.68%) to March (64.28%) which weakens during the cold season, from May (30%) to July (58%). For Galeoides decadactylus, the sex ratio shows a predominance of males, from August (88%) to March (94.73%). Concerning specimens of Pentanemus quinquarius, the sex ratio is in favor of the females whose lowest value is during the cold season in July (21.74%). All threafin species reach sexual maturity from their first year of life with different sex ratios variations.

Accounting for a warming oceanFisheries provide food and support livelihoods across the world. They are also under extreme pressure, with many stocks overfished and poorly managed. Climate change will add to the burden fish stocks bear, but such impacts remain largely unknown. Freeet al.used temperature-specific models and hindcasting across fish stocks to determine the degree to which warming has, and will, affect fish species (see the Perspective by Plagányi). They found that an overall reduction in yield has occurred over the past 80 years. Furthermore, although some species are predicted to respond positively to warming waters, the majority will experience a negative impact on growth. As our world warms, responsible and active management of fisheries harvests will become even more important.Science, this issue p.979; see also p.930

The main trends in fisheries are considered by the fishery basins, including dynamics of annual catches and changes in their structure, both for inland and marine areas, on the data of fishery statistics for 2005–2017. The landing in the inland waters of Russian Federation is estimated as 8.4–10.0 % of the total national annual catch. Its mean annual volume for this period was 375.103 t; it grew on average in 2.2 % annually. This volume was landed mainly (85 %) in four inland basins: Volga-Caspian, Far Eastern, Azov-Black Sea, and West Siberian ones. About ⅓ of the volume was provided by cultivated fish, in particular in the Azov-Black Sea basin (87 % of the total freshwater catch) and Northern basin (69 %). Marine fishery produced 2990–4644 . 103 t, or 90.0–91.6 % of the total Russian catch. Its annual landing has increased by more than a half since 2005, with the average growth in 3.7 % annually. This volume was landed mainly within the exclusive economic zone (EEZ) of Russia — 74.7 %, the rest was landed in the neutral areas of the World Ocean (5.9 %) or in EEZ of foreign states (19.4 %). The main region of marine fishery is the Far-Eastern basin, which portion in the national catch increased in 13 years from 62.6 % to 68.7 %, whereas the portion of the Northern and Western basins decreased in 3.7 % (to 21.5 %) and 3.0 % (to 7.9 %), respectively. In the Far-Eastern basin almost whole catch was landed within EEZ of Russia (3149 . 103 t), though in the Northern and Western basins the catch was obtained mainly in EEZ of foreign states (on average 557 . 103 t and . 103 t, respectively) and beyond EEZ (116 . 103 t and 94 . 103 t, respectively). Influence of the export supplies on the fish supply to the domestic market of Russia is analyzed. The landings increase contributes to the export increasing, but other factors are likely to be the main drivers of the export growth. This information on quantitative structure of the national annual catch could be used in economical forecasts and for developing of programs and strategies for the fishery industry of Russia. Examples of its practical using for solving of some applied problems in the economics are presented.

Harmful algal blooms (HABs) are one of primary worldwide environmental problems with severe consequences for aquatic ecosystems, human health, marine fisheries and local economy. During the past few decades, coastal waters of China Seas have experienced a significant increase in the occurrence of the HAB events, which is common across the vast majority of coastal waters of the world. Here we report the absence of the widespread increase over the early 21st century in China Seas. Both frequency and coverage area of annual HAB events have decreased at statistically significant rates for the 2000-2017 period. Despite the multiple factors determining the outbreak of HABs, the improvement of water quality in the marginal sea off China and changes in the sea surface temperature in the early 21st century may play an important role in the decrease in the HABs.

Using fishery-dependent observer data from National Marine Fisheries (NMFS) provides insight into the location and intensity of bottom-trawl fishing effort, and allows those areas most exposed to fishing pressure to be identified. In this study, the spatial and temporal extent of Alaskan bottom-trawl fishing effort in the Bering Sea, Aleutian Islands and Gulf of Alaska between 1993 and 2015 is explored within a space-time cube in ArcGIS Pro. The variables analysed were number of hauls per area and total catch per area. Statistical techniques were used to examine spatiotemporal clustering within the data. Results indicate that fishing was significantly clustered over space and time. A three-dimensional hotspot analysis shows which areas were most intensely fished and illustrates the trends over the relatively long study period. The data were then compared with sea ice concentration to determine the effect of changing climate on fishing activity. Sea ice had a limited effect on the spatial patterns of fishing effort, but certain areas in the Bering Sea exhibited increased fishing effort in years with less sea ice.

The marine fishery resources in the West Coast of Peninsular Malaysia are overexploited by fishing effort by the trawlers. The encroachment of trawlers to the near-shore fishery and conflic...

Source at https://doi.org/10.1016/j.dib.2018.10.095. Licensed CC BY-NC-ND 4.0. In this data article, we present the 2004–2014 average European seafood production volume by production sector, country, and species. The production data originates from the Food and Agriculture Organisation of the United Nations (FAO) and covers three production sectors: Marine fisheries, marine aquaculture, and freshwater production. We present the main ecological characteristics of each species produced or harvested. These species characteristics were retrieved from various published sources and include biological sensitivity to harvesting and temperature ranges for the most important species. These indices were weighted by each species production volume in order to produce maps of European country’s color-coded by their overall temperature range, maximum temperature, and biological sensitivity within each production sector.

Although different fisheries can be tightly linked to each other by human and ecosystem processes, they are often managed independently. Synchronous fluctuations among fish populations or fishery catches can destabilize ecosystems and economies, respectively, but the degree of synchrony around the world remains unclear. We analyzed 1,092 marine fisheries catch time series over 60 yr to test for the presence of coherence, a form of synchrony that allows for phase‐lagged relationships. We found that nearly every fishery was coherent with at least one other fishery catch time series globally and that coherence was strongest in the northeast Atlantic, western central Pacific, and eastern Indian Ocean. Analysis of fish biomass and fishing mortality time series from these hotspots revealed that coherence in biomass or fishing mortality were both possible, though biomass coherence was more common. Most of these relationships were synchronous with no time lags, and across catches in all regions, synchrony was a better predictor of regional catch portfolio effects than catch diversity. Regions with higher synchrony had lower stability in aggregate fishery catches, which can have negative consequences for food security and economic wealth.

The livelihoods of more than 30 per cent of the total population in India residing in nine maritime states and four Union Territories are dependent on the diverse ecosystem services offered by coastal and marine systems. Marine fisheries contribute significantly to the Indian economy through the foreign exchange from the export of seafood which corresponds to nearly 5 per cent of the overall export and 20 per cent of the agro-export. In recent times, the anthropogenic pressures due to extensive marine fishing introduce challenges in the marine environment. Marine anthropogeomorphology, capable of transforming the natural settings of the continental shelf dominantly, is often not studied in detail from the perspective of sustainable fishing. For example, the use of the assorted fishing gears can damage the sea floor, apart from the capture of juvenile and non-target fishes. Bottom trawling by mechanised crafts as a part of marine fishing affects the geomorphology of the continental shelf and continental slope by displacing boulders, interrupting the structure of the sediment column, resuspending sediments, and imprinting deep holes on the muddy sea bottom. Occasionally, the abandoned fishing nets/gears on the seafloor are also responsible for the geomorphological damages to the bottom of the sea and death of several marine benthic flora and fauna, a phenomenon referred to as ‘ghost fishing’. Further, Illegal, Unreported and Unregulated (IUU) fishing in the ocean also poses major threats for the marine environment. Thus, it is essential to quantify these impacts of anthropogeomorphology in order to achieve the targets of the Sustainable Development Goal (SDG) 14, promulgated by the United Nations Organisation. Marine Fishery Advisories, especially, Potential Fishing Zones (PFZ) advisories may be helpful in reducing the impacts by aiding sustainable harvesting of pelagic fishes under the current scenario. The ESSO-Indian National Centre for Ocean Information Services (INCOIS) is the nodal agency, which disseminates PFZ advisory since 1999 using remotely sensed datasets of sea surface temperature and chlorophyll-a to reduce the uncertainty during marine fishing. PFZ advisory can help to promote environment-friendly fishing by reducing the search time and hence, ensuring minimal damage to the marine environment.

The fisheries represent one of the oldest occupations of the coastal population of Montenegrin Sea and the Skadar Lake. Even though fishery in Montenegro is still relatively undeveloped compared to other Adriatic countries, without industrial fishing, this activity has great importance for the local population in terms of tradition, culture, and history. This paper provides an overview of the state of fishery in Montenegro in recent times, main fishing gears and types of the fishery, fishing fleet size and characteristics, the importance of the fishing sector, etc. Additionally, the history and tradition of the fishery in Montenegro, both in the Skadar Lake and the Adriatic coast, is described. Main limitations and threats to Montenegrin fishery, as well as possibilities of its further development, are also presented in this paper.

The EU Bioeconomy Strategy aims to support the sustainable growth and development of the EU bio-based sectors while creating jobs, innovation and services. Despite the recognized potential of the algae biomass value chain, significant knowledge gaps still exist regarding the dimension, capability, organization and structure of the algae production in Europe. This study presents and analyses the results of a comprehensive mapping and detailed characterization of the algae production at the European scale, encompassing macroalgae, microalgae, and the cyanobacteria Spirulina. This work mapped 447 algae and Spirulina production units spread between 23 countries, which represents an important addition to the reported number of algae producing countries. More than 50% of these companies produce microalgae and/or Spirulina. Macroalgae production is still depending on harvesting from wild stocks (68% of the macroalgae producing units) but macroalgae aquaculture (land-based and at sea) is developing in several countries in Europe currently representing 32% of the macroalgae production units. France, Ireland, and Spain are the top 3 countries in number of macroalgae production units while Germany, Spain, and Italy stand for the top 3 for microalgae. Spirulina producers are predominantly located in France, Italy, Germany, and Spain. Algae and Spirulina biomass is directed primarily for food and food-related applications including the extraction of high-value products for food supplements and nutraceuticals. Algae production in Europe remains limited by a series of technological, regulatory and market-related barriers. Yet, the results of this study emphasize that the European algae sector has a considerable potential for sustainable development as long as the acknowledged economic, social and environmental challenges are addressed., SI

The impacts of fisheries on ocean resources are no longer considered in isolation but should account for broader ecosystem effects. However, ongoing ecosystem-wide changes added to the inherent dynamics of marine ecosystems, create challenges for fisheries and fisheries management by affecting our ability to ensure future fishing opportunities and sustainable use of the seas. By reviewing a corpus of fisheries science literature, we contribute to informing managers and policymakers with considerations of the various threats to fisheries and the marine ecosystems that support them. We identify and describe 25 ecosystem challenges and 7 prominent families of management options to address them. We capture the challenges acting within three broad categories: (i) fishing impacts on the marine environments and future fishing opportunities, (ii) effects of environmental conditions on fish and fishing opportunities, and (iii) effects of context in terms of socioeconomics, fisheries management, and institutional set-up on fisheries. Our review shows that, while most EU fisheries are facing a similar array of challenges, some of them are specific to regions or individual fisheries. This is reflected in selected regional cases taking different perspectives to exemplify the challenges along with fishery-specific cases. These cases include the dramatic situation of the Baltic Sea cod, facing an array of cumulative pressures, the multiple and moving ecosystem interactions that rely on the North Sea forage fish facing climate change, the interaction of fishing and fish stocks in a fluctuating mixed fishery in the Celtic Sea, the bycatch of marine mammals and seabirds and habitat degradation in the Bay of Biscay, and finally the under capacity and lack of fundamental knowledge on some features of the EU Outermost Regions. In addition to these ecoregion specific findings, we discuss the outcomes of our review across the whole of European waters and we conclude by recognizing that there are knowledge gaps regarding the direction of causality, nonlinear responses, and confounding effects. All of the challenges we identify and characterize may guide further data collection and research coordination to improve our fundamental understanding of the system and to monitor real changes within it, both of which are required to inform an Ecosystem Approach to Fisheries Management (EAFM). An European EAFM could build upon an array of management measures currently tailored for fisheries management only, including promoting funding interdisciplinary research and ecosystem monitoring. Such integrative management should reduce uncertainties in environmental, social and economic trends, and lower the risk for disruptive events or ecosystem effects with far-reaching consequences, including a shift toward less productive marine ecosystems., SI

WOS:000684889700001; Climate change is rapidly becoming one of the biggest threats to marine life, and its impacts have the potential to strongly affect fisheries upon which millions of people rely. This is particularly crucial for the Mediterranean Sea, which is one of the world's biodiversity hotspots, one of the world's most overfished regions, and where temperatures are rising 25% faster than in the rest of the ocean on average. In this study, we calculated a vulnerability index for 100 species that compose 95% of the Mediterranean catches, through a trait-based approach. The Climate Risk Assessment (CRA) methodology was subsequently used to assess the risks due to climate change of Mediterranean fisheries. We found that the northern Mediterranean fisheries target more vulnerable species than their southern counterparts. However, when combining this catch-based vulnerability with a suite of socio-economic parameters, north African countries stand out as the most vulnerable to climate change impacts. Indeed, considering countries' exposure of the fisheries sector and their vulnerability to climate change, a sharp contrast between northern and southern Mediterranean appears, with Egypt and Tunisia scoring the highest risk. By integrating a trait-based approach on targeted marine species with socio-economic features, our analysis helps to better understand the ramifications of climate change consequences on Mediterranean fisheries and highlights the regions that could potentially be particularly affected.

While bycatch is well investigated in marine fisheries, relatively little is recognized about bycatch in freshwater fisheries. Yet basic data on bycatch configuration and mortality in freshwater is unobtainable, given that a few inland authorities need recording of bycatch.