Hasil untuk "Aquaculture. Fisheries. Angling"

J. Bostock, B. McAndrew, R. Richards et al.

Aquaculture contributed 43 per cent of aquatic animal food for human consumption in 2007 (e.g. fish, crustaceans and molluscs, but excluding mammals, reptiles and aquatic plants) and is expected to grow further to meet the future demand. It is very diverse and, contrary to many perceptions, dominated by shellfish and herbivorous and omnivorous pond fish either entirely or partly utilizing natural productivity. The rapid growth in the production of carnivorous species such as salmon, shrimp and catfish has been driven by globalizing trade and favourable economics of larger scale intensive farming. Most aquaculture systems rely on low/uncosted environmental goods and services, so a critical issue for the future is whether these are brought into company accounts and the consequent effects this would have on production economics. Failing that, increased competition for natural resources will force governments to allocate strategically or leave the market to determine their use depending on activities that can extract the highest value. Further uncertainties include the impact of climate change, future fisheries supplies (for competition and feed supply), practical limits in terms of scale and in the economics of integration and the development and acceptability of new bio-engineering technologies. In the medium term, increased output is likely to require expansion in new environments, further intensification and efficiency gains for more sustainable and cost-effective production. The trend towards enhanced intensive systems with key monocultures remains strong and, at least for the foreseeable future, will be a significant contributor to future supplies. Dependence on external feeds (including fish), water and energy are key issues. Some new species will enter production and policies that support the reduction of resource footprints and improve integration could lead to new developments as well as reversing decline in some more traditional systems.

J. Purcell, S. Uye, Wen-Tseng Lo

V. Smetacek, A. Zingone

A. El‐Sayed

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Mohammad Mahfujul Haque, M. Zulfikar Rahman, Md. Abdus Salam et al.

ABSTRACT This study investigates the widespread degradation of river ecosystems in Bangladesh and its impact on fish biodiversity and identifies potential strategies for ecosystem restoration. Combining community perceptions from focus group discussions (FGDs) with fish market study for spatial analyses of fish species diversity across the Barak–Meghna, Brahmaputra–Jamuna and Ganges–Padma basins, the research identifies pollution, destructive fishing practices, habitat destruction and mismanagement of water bodies as major threats. Results from 36 FGDs indicated that pollution from poultry farms, industrial waste from factories and pesticide runoff from agriculture were major contributors to the degradation of the Barak–Meghna basin, collectively affecting fish biodiversity. Fish market study identified a total of 57 fish species across the basins, far fewer than the over 260 species known to inhabit the freshwaters of Bangladesh. The Shannon–Wiener Diversity Index revealed low indices in Dhaka (0.00) and Rajshahi (1.73), signifying ecological degradation and anthropogenic stress, respectively, while Chandpur (2.52) and Pabna districts (2.30) exhibited comparatively higher diversity, pointing to potential conservation hotspots. The study highlights the perceptions of declining fish biodiversity with the percentages of FGDs reporting a decline of 83.3%, 90.9% and 91.7% in Barak–Meghna, Brahmaputra–Jamuna and Ganges–Padma basins, respectively. The study recommends an integrated approach combining physical interventions like collaborative dredging of rivers with pollution control measures, strengthened fisheries governance, community‐based co‐management, equitable water body leasing policies and transboundary coordination to ensure sustainable river restoration and biodiversity conservation.

T. Garlock, F. Asche, James L. Anderson et al.

Abstract Blue foods are highly diverse and are supported by a wide range of ecosystems, production practices, and markets. This diversity influences resiliency of aquatic food systems, their capacity to contribute to global food security, and the spread of knowledge and adoption of innovations. Here, trends in diversity and determinants of diversity in capture fisheries and aquaculture production were examined at the global and country level. Results show that fisheries production is more diverse than aquaculture production, and that social and economic factors appear to be as important for species diversity as biophysical factors. The diversity of fisheries is diminished when governance is weak, and this poses challenges for managing fisheries for nutrition-sensitive food production. It also illustrates the greater potential of aquaculture to address challenges related to access given that less diversity in aquaculture is created by economies of scale making food more accessible among lower income groups.

Jessica A. Bolin, K. Evans, David S. Schoeman et al.

Meat quality is of paramount importance in the fisheries and aquaculture industries, but the quality of seafood can be affected by environmental variability and change, creating uncertainties in the delivery of consistent, high‐end product. Reports from fishers operating in an Australian fishery catching broadbill swordfish (Xiphias gladius) suggest that anomalously warm waters are linked with myoliquefaction of muscle tissue. The condition affects the marketability of fish by turning the meat into a soft, mushy texture post‐mortem and is caused by infection by the myxozoan parasite Kudoa musculoliquefaciens. Here, we combine microscopy, molecular techniques and ecological modelling to explore potential environmental drivers of the prevalence and intensity of K. musculoliquefaciens in swordfish, as a first step in understanding how a warming ocean might exacerbate the risk of harvesting an infected swordfish and the resultant potential risk of myoliquefaction. We develop predictive dynamic risk surfaces on seasonal timescales, with results revealing both the likelihood of harvesting an infected swordfish and the intensity of parasite load increase during the Austral summer. The prevalence of the parasite further increases in the region dominated by the East Australian Current, when locally warm areas are atypically cool and when average monthly temperatures are more variable. These findings provide information useful in predicting the conditions under which the risk of harvesting infected swordfish might be intensified, enabling adaptation to climate change impacts and optimisation of decision‐making when fishing under risky conditions.

S. Midway, Frederick S. Scharf, M. Dance et al.

Abstract Southern flounder are an iconic coastal finfish through the Southeast U.S. Atlantic and Gulf of Mexico. Southern flounder spend the early part of their lives in coastal and estuarine habitats, later moving offshore to spawn. Several decades of research have provided much clarity to the biology, life history, and aquaculture aspects of southern flounder—this information is summarized and reviewed in this study. Despite substantial improvement in understanding the species, major questions remain about their recruitment, offshore behaviors, captive rearing, and management. Recently, southern flounder have also been in focus because of substantial synchronous population declines throughout their range with specific concerns that recruitment failure and possibly climate change may be implicated. Management of southern flounder has thus far taken place within individual states, but coming into focus is the possibility that larger coastwide management approaches may need to be considered due to both the migratory nature of the species and the possibility of population stressors acting at regional scales. Many states have already begun aquaculture and enhancement efforts, with an eye toward supplementing wild populations. Large group efforts, like the symposium that led to this study, will likely be needed to tackle the complex challenges confronting southern flounder.

L. van den Heuvel, Øystein Aas, S. Agnarsson et al.

Recreational fisheries are dynamic social‐ecological systems. Identification of anticipated future trends supports the design of policies and management to deliver outcomes for fisheries resources, users, and communities. To this end, we applied a forecasting method (i.e., Delphi survey) to recreational fisheries in five Nordic countries. The survey consisted of three rounds and included 20 diverse experts from each country. The study focused on expert perceptions of future trends in angler behaviors linked to specific angling activities (e.g., gear used, species targeted), and more general behavior (e.g., social media use, stewardship). Experts unanimously expected increases in fly fishing, stewardship, and use of angling‐related technologies and social media platforms in the upcoming decade. Results can guide future research, management, and collaboration related to recreational fishing in the Nordic countries and beyond.

R. Otwey, A. Atter, Christopher Galley et al.

Aquaculture is a key component of Ghana's food system strategies, promoting sustainable animal protein production. Aquaculture complements traditional marine capture fisheries to close the gap between demand and supply. However, about one third of fish produced globally have been reported to go to waste yearly. Among the various cultured fish, the Nile tilapia Oreochromis niloticus is a predominant species. This study aimed to estimate the extent of Nile tilapia wastage by consumers in Ghana. A web‐based cross‐sectional consumer survey was designed to assess the parts of the tilapia consumers generally classified as edible or inedible, taking into account the three primary tilapia preparation methods. The study utilised a semi‐structured online questionnaire, gathering responses from 246 participants. The parts of Nile tilapia investigated included the flesh, fins, offal, head, scales, bones, and gill flaps/opercula. The analysis of consumed and wasted parts of Nile tilapias by weight showed that, on average, the flesh made up the majority of the fish at 55.26%, followed by the head at 26.46%, offal at 8.51%, scales at 3.10%, fins at 2.93%, bones at 2.76%, and operculum at 0.98%, which was the smallest component. The study concluded that approximately 30%–45% of waste is generated from Nile tilapia in the Ghanaian supply chain. Tilapia was widely consumed by all groups, with an average liking score of 7.69 ± 1.95 on a 10‐point hedonic scale. A significant association was found between gender and consumption patterns with females showing a higher degree of liking. There was a strong association between the method of preparation and consumption patterns; the fried parts were classified as more edible compared to those that were boiled or grilled. To reduce waste in the aquaculture industry, tilapia and other fishes could be processed in a way that various edible and inedible parts are sold separately.

F. B. Soffa, Idham Sumarto Pratama, Verli Dharmawati et al.

This review paper elaborates on the Asian moon scallop ( Amusium pleuronectes ), focussing on both wild populations and its aquaculture. A. pleuronectes is one of the most widely distributed scallops in Indonesia, where the Ministry of Maritime Affairs and Fisheries is actively promoting various mollusc species to strengthen the economic contributions of the national mariculture industry. Although Indonesia has an estimated 12.3 million hectares of potential mariculture area, only 2.25% is currently utilized. Given the considerable amount of available land in designated aquaculture regions, expanding scallop aquaculture and sustainable fisheries practices is highly encouraged as a strategy for future blue-economic growth. Scallop products from both fisheries and aquaculture are currently prioritized for local and domestic consumption to enhance food security and provide a sustainable source of marine-based protein. Once domestic demands are met, scallop products also have the potential to contribute to export markets. This review highlights the significance of A. pleuronectes as a promising fisheries or aquaculture commodity for enhancing the seafood industry in Indonesia. This article aims to address the scarcity of recent studies on this species. By synthesizing existing knowledge and scientific evidence on the aquaculture of A. pleuronectes and other scallops, this article identifies critical knowledge gaps and suggests areas for future research on this species.

P. Sánchez-Jerez, J. Atalah, I. Sætra et al.

Coastal aquaculture and local fisheries interact in shared marine environments, influencing each other synergistically and/or antagonistically. Salmon farming, notably with open-net sea cages along the Norwegian coast, attracts wild fish due to increased food availability from uneaten feed, but it also exposes wild fish to farm emissions like waste and toxic chemicals (de-lice treatments, antifouling and medical agents). The attraction behaviour of wild fish can impact fatty acid composition in fish tissues, influenced by the high terrestrial fat content in salmon aquafeed. We study how the Atlantic cod, aggregating around salmon farms in a subarctic fjord in Northern Norway, can be affected, potentially altering their natural diet and fatty acid profiles. Our study compares the muscle-tissue fatty acid compositions of cod caught near aquaculture facilities (impact) versus fish caught in neighbouring fjords (control), and we hypothesise decreased omega-3 fatty acids near farms. The analysis revealed no significant differences in the fatty acid concentrations or categories between the impacted and control fish, challenging our initial expectations. However, differences were found for C18:1(n9)t (elaidic acid), with a higher value in the impacted fish. These findings suggest that salmon farming’s influence on cod’s fatty acid profiles in the flesh (i.e., relevant for the nutritional quality of the fillets that consumers eat) may be limited or minimal despite their aggregative behaviours around farms. The threshold levels of salmon feed consumed by wild cod before it affects the quality and survival of, e.g., sperm or other life stages, are not known and require new investigations. This study underscores the complexity of interactions between aquaculture and wild fisheries, impacting both ecological dynamics and consumer perspectives on seafood quality and health benefits.

Jing Wang, Zhiyuan Zhao, Hongtao Jin et al.

The fisheries industry in China is experiencing rapid growth, but it is also encountering the challenge of frequent fluctuations in aquatic product prices. Freshwater fish aquaculture plays a crucial role in China’s fisheries industry. Analyzing the characteristics of price volatility in freshwater fish is crucial to ensure a stable supply of aquatic products and promote sustainable fisheries industry development. This study focuses on four freshwater fish species, namely crucian carp, grass carp, silver carp, and carp, to analyze the price volatility characteristics of freshwater fish in China from 2006 to 2022. The study uses the price decomposition method and the ARCH model. The results indicate that, from the perspective of dominant characteristics of price volatility, the prices of freshwater fish display periodic volatility with an overall upward trend, as well as significant seasonal and random variations. From the perspective of recessive price volatility characteristics, the price volatility of freshwater fish exhibits clustering and asymmetry. This indicates that the price volatility of freshwater fish is influenced by previous price volatility. Positive news has a greater impact on the price volatility of freshwater fish than negative news. Out of the four freshwater fish species, only the price of crucian carp is characterized by high-risk and high-return volatility.

A. Salem, Mohamed E. A. El-Metwally

The sciaenid meagre ( Argyrosomus regius , Asso 1801) is a significant organism in fisheries and a promising candidate for the Egyptian aquaculture. This study presented a comparative analysis of wild and aquacultured meagre. Two size groups of fish, small (S) and large (L), from the

Camille L. Mosley, C. Dassow, C. Solomon et al.

Catch‐and‐release (C&R) angling is often used to maintain high catch rates but fish vulnerability to capture may decrease following hooking, thereby decreasing angler catch per unit effort (CPUE) (hyperdepletion). To determine if fish post‐capture response affected recapture probability and population‐level CPUE, individual capture histories of Largemouth Bass in two lakes were compared before and after doubling angling effort in a Before‐After Control‐Impact (BACI) analysis. Previous capture and day‐of‐season both affected recapture probability. Counteracting effects of previous capture and reduced late‐season catch rates caused no hyperdepletion of angler CPUE. Our results highlight the complexity of fish behavioral responses to angling and suggest that hyperdepletion of angling catch rates may not be an issue in C&R fisheries.

X. Tian, Y.S. Shan, N.N. Peng et al.

The evolution of teleost coloration is strongly linked with the fish-specific genome duplication (FSGD). Sepiapterin reductase (Spr) is commonly required in pteridine pigment synthesis and two paralogs are found in teleosts. However, the functions of spra and sprb in pigmentation have not been completely elucidated. Here we found that spra was intensively expressed in skin, fins and scales of koi carp, while sprb was ubiquitously expressed in all tissues. Then, the Spr enzyme activity inhibitor, sulfapyridine (SFD), was used to explore the phenotype and genes variation after spr inhibition. Following the administration of SFD, spra was significantly suppressed but sprb was up-regulated in skin. Additionally, the color phenotypes shifted from red to yellow due to a reduction in carotenoid concentration and the number of xanthophores/erythrophores in scales. Furthermore, the genes involved in carotenoid metabolism were influenced. However, pteridine metabolism-related genes rarely exhibited obvious changes. The results indicate that spra inhibition resulted in the dysregulation of carotenoid metabolism and pigment cells reduction, whereas sprb was likely to maintain the conserved functions in pteridine synthesis for metabolic homoeostasis. This study provided evidences for the different functions of spr paralogs in carotenoid and pteridine metabolism and for better understanding of the relationship between genome duplication and color pattern diversification.

Demtew Etisa, Yiglet Mebrat

While scientific information on the spatial variation of soda lake Microalgae is important to limnological studies, little information was reported from the Ethiopian Rift Valley Lake, Lake Chitu. This study aimed to understand the spatial distribution of the dominant Microalgae taxa in Lake Chitu, Ethiopia. The collection of samples and in situ measurements of some physico-chemical parameters were recorded at three sites for one cycle in November 2021. Fourteen species or genera of Microalgae were identified. Among those, Bacillariophyta were the most important with regard to species abundance and the rarest in species richness. Cyanophyta were the second-most important group in terms of species richness and rarity. Comparatively, all microalgae taxa were rare at both the anthropogenic areas (AA) and the flooding area (FA), which could be mainly due to intensive human and animal intervention and associated with extreme turbidity. Among Cyanophyta, Chroococcus minutus, Microcystis aeruginosa, and Spirulina platensis/fusiformis were predominant at both AA and FA, revealing their adaptation to less clear water and pollution. But S. platensis/fusiformis attained the highest abundance at the FA, indicating their preference for water in a highly nutrient-enriched area. We concluded that the spatial variation of microalgae diversity in relation to water quality parameters has implications for the importance of microalgae as a baseline indicator of water quality assessment tools in lakes.

J. Diana

O. V. Zelennikov, M. S. Myakishev

Effectiveness of the salmon juveniles feeding was examined during six cycles of fish breeding for pink salmon Oncorhynhus gorbuscha, chum salmon O. keta, cherry salmon O. masou, and coho salmon O. kisutsh at 12 fish hatcheries belonged to the Sakhalin branch of FBSI Glavrybvod with using of different starter feeds produced by Aller Aqua (Denmark) and Aquatech (Russia). All hatcheries worked in the coldwater regime of rearing. Both feeds were rather effective for all species that was evidenced by low feeding coefficients, usually 0.6–0.8. Anyway, average value of the feeding coefficient was lower for the starter feed Aquatech at all factories. Beyond a high quality of this feed, its availability in two variants of flotation was important, as the slowly sinking and floating forms. The floating food was found to be more suitable for the growing juvenile pink salmon at all farms. On the other hand, both starter feeds were suitable for chum salmon, their priority for this species depended on fish farm and obviously was determined by combination of many factors, such as temperature conditions, configuration of canals and ponds, their hydrodynamics, feed dispensers, etc.

SHAHARAH MOHD IDRIS, WAN NORHANA MD NOORDIN, FATIN OSMAN MANAH et al.

Asian sea bass, Lates calcarifer (Bloch, 1790), is one of the most farmed marine fish in Malaysia since the 1970s and is predominantly cultured at present. Although it has been farmed for some time, there is no systematic breeding programme in place. Local hatcheries rely heavily on wild and imported broodstock. However, imported stocks do not guarantee improved quality and even increase the chances of introducing pathogens into the country. Availability of superior breeding stocks, efficient dissemination and control of seed production could greatly assist in increasing Asian sea bass production. This paper presents the status of Asian sea bass production, its culture history in Malaysia and the current broodstock development programme implemented by the Fisheries Research Institute, particularly in the 11th Malaysia Plan from 2015 to 2020. In brief, broodstock from Malaysia, Thailand and Indonesia were used as base population and were mated using full diallel method to produce cohorts. Three pairs of the selected broodstock were used for each cross and spawning performance was evaluated. The growth performances of the first generation (F1) offsprings were assessed in different culture systems. Physico-chemical water quality parameters such as dissolved oxygen, temperature, pH and salinity were maintained at optimal levels during all stages of the experiment. Results indicate that the growth performance of F1 improved by more than 60 % in terms of weight gain compared with the base population. The project demonstrated the benefits of using selective breeding to enhance the production of Asian sea bass.