Fishery Catch Research Articles

어업관리수단으로서의 어업권제도의 의의와 개편 필요성

Korea"s fishery management system is operated by managing fishery catch effort through license, permit, and reporting system. Fishery license system, also called the fishery right system, includes village fishery, set-net fishery, and aquaculture. The fishery right system, which was introduced over 110 years ago, has many problems. Evaluating in terms of fishery management, the system lacks in efficient resource allocation, fair income distribution, and effective fishing ground management. It cannot actively adapt to market changes since only the property rights of those with fishing permits are reinforced. For improvement, strict enforcement of and fishermen"s compliance with laws and regulations is necessary, and in the long run, should be changed into the fishery permit system. Since there were more problems than advantages with the fishery license system, the fishery permit system will reduce the side-effects and help achieve the purpose of fishery management.

Fish harvesting advice under climate change: A risk-equivalent empirical approach.

The rate of climate change (CC) has accelerated to the point where it now affects the mid- to long-term sustainability of fishing strategies. Therefore, it is important to consider practical and effective ways to incorporate CC into fisheries advice so that the advice can be considered conditioned to CC. We developed a model to characterise the empirical relationship between a variable affected by climate and fish production. We then used model projections as a foundation for a risk analysis of CC effects on harvesting of Greenland halibut Reinhardtius hippoglossoides in the Gulf of St Lawrence, Canada. The risk-based approach quantified a) the relative change in risk of a status quo fishing strategy under various CC scenarios, and b) the change in fishery exploitation rates required to achieve a management objective over a specified time period at a level of risk considered acceptable (risk equivalent fishery exploitation advice). This empirical approach can be used to develop risk-based advice for any other external variable that affects stock production in addition to climate-related variables and it can be applied in most situations where there is an index of stock biomass and fisheries catch. Shifting the focus from process-based understanding of the responses of fish stocks to CC to quantification of how CC-contributed uncertainty can alter the risks associated with different fishing strategies and/or management options, can ensure timely delivery of robust scientific advice for fisheries under non-stationary environmental conditions.

Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids

Abstract Piscivorous wildlife is often perceived as competitors by humans. Great cormorants of the continental subspecies (Phalacrocorax carbo sinensis) in the Baltic and North Sea increase, while local cod (Gadus morhua) stocks decline. In contrast, numbers of the Atlantic subspecies (Phalacrocorax carbo carbo), breeding along the Norwegian and Barents Seas, have been relatively stable. We investigated the diet of both great cormorant subspecies in breeding colonies along the Norwegian Coast from Lofoten to the Skagerrak and estimated the biomass of fish consumed annually by great cormorants in Norwegian waters. The birds’ consumption was compared with estimated fish stock sizes and fishery catches. Cod and saithe (Pollachius virens) dominated the diet in the Norwegian Sea and wrasses in the North Sea and Skagerrak. Estimated total fish consumption of cod and saithe by great cormorants was <1.7% of estimated fish stocks and <9% of that of human catches and therefore considered minor. Cormorant consumption of wrasses amounted to 110% of human catches. The practice of using wrasses as cleaner fish in the salmon farming industry leads to a conflict with cormorants, and we urge for a better understanding and management of wrasse populations, taking ecosystem functioning and natural predation into account.

Bringing the right fishermen to the table: Indices of overlap between endangered false killer whales and nearshore fisheries in Hawaiʻi

Incidental bycatch in fisheries is a pressing conservation issue for marine mammal populations across the globe. However, the ability to detect and therefore mitigate this issue is challenging for several reasons. Fishermen are unlikely to voluntarily report bycatch due to fear of penalization or apathy towards it. While fisheries observer programs are sometimes in place to record bycatch, many fisheries have no observers. In Hawaiian waters there are no observer programs in nearshore fisheries, yet interactions with fisheries are likely the greatest threat to the endangered main Hawaiian Islands insular population of false killer whales (Pseudorca crassidens). We assess spatiotemporal overlap between false killer whales and nearshore fisheries in Hawai‘i to identify fisheries and regions where interactions are most likely to occur. Interactions with fisheries was cited as the greatest threat to this population's viability as a result of growing evidence over recent decades. We used false killer whale location data from 38 satellite tag deployments (2007–2018) and commercial fishery catch logs from a corresponding period to develop fishery overlap indices (FOIs) from a perspective that should reflect the experience of local fishermen. The area off Kona has the highest levels of fishing effort, but a low FOI, while high FOI values (up to several thousand times higher than Kona) were found off O‘ahu, Moloka‘i, Maui, Lāna‘i and the north end of Hawai‘i. Our findings provide direction for where efforts should be focused to effectively monitor and mitigate bycatch for this endangered population of false killer whales.

Financial Feasibility Analysis of Gourami Farming in A Collaborated Business Association System

As catch fisheries have experienced overfishing symptoms, which resulted in a decrease in fish resources, the government must develop freshwater aquaculture. Sleman Regency has known for its growing freshwater aquaculture development, which supplies about 70% of the total fish production in Yogyakarta Special Province. Despite the rising demand for fish consumption, fish cultivators face problems in the capital, infrastructure, weak bargaining power, quality problems, and long distribution chains. One way to overcome these problems is to strengthen the bargaining position through the fish farmer groups. This study aims to analyze the financial feasibility of gourami farming, whose owners are members of business associations. In the business association, fish farmers agree to collaborate in running their business to cultivate gourami in a supply chain process ranging from production to marketing. The collaboration of fish farmers integrates four segments of the fish-raising chain system, consist of seedling handling from 0 to1.5 months old, raising fish from 1.5-to 3.5 months, from 3.5 to 6.5 months, and 6.5 to 12 months. Using a quantitative research method, this study analyzes 40 fish farmers in Seyegan, Sleman District of Yogyakarta. The financial feasibility analysis uses the net present value, benefit-cost ratio, internal rate of return, and break-even point. Results of these analyzes indicate that financially, the collaborative gourami farming in Seyegan District is feasible with an NPV of segment I is Rp 11,122,952.00, of segment II, is Rp 2,174,940.00, of segment III, is Rp 9,748,705.00. Of the segment, IV is Rp 18,691,435,86. The B/C Ratio for segment I is 1.87, segment II is 1.55, segment III is 2.13, and segment IV 2.05. The BEP value for segment I is Rp 1,709,228.00, for segment II is Rp 1,779,290.00, for segment III is Rp 852,100.00, and for segment IV is Rp 2,000,672.00.

Regional Algae Bloom: Natural Disaster Causes Economic Setback in Private Fishing Charter in Southwest Florida

In recent years, water eutrophication has become an environmental problem of general concern. In some drinking water sources, the proliferation of algae has a great impact on the operation of water plants and the quality of drinking water. At present, many scholars at home and abroad are studying the methods of algae monitoring and algae removal, and seek ways to solve the algae pollution, so as to improve the water quality of urban water supply and ensure the safety of water use for residents. In GB5749-2006, the national Ministry of health and the Standardization Administration stipulated that the index value of total microcystins was 0. Oolmg / L. Although this is an unconventional index, it reflects that the eutrophication of fresh water resources and the micro pollution of drinking water sources have become a global problem of great concern. Water eutrophication not only affects the basic life of human beings, but also has caused serious economic impact. Algal outbreaks and fish deaths caused by eutrophication in water bodies often result in economic losses to tourism, recreation, catch fisheries and aquaculture.

Coastal recreational fisheries: A case study in the southeastern Brazil

Recreational fishing has been poorly studied along the Brazilian coast and, despite its sharp increase, little effort has been made to estimate real catches that contribute to an adequate fisheries assessment. To evaluate the catches of recreational fisheries, samples were collected between May 2016 and May 2017 along the central coast of the state of Sao Paulo, Brazil. Both the size and weight of the majority of species caught were evaluated. A total of 2,402 individuals from 74 different species were recorded, with six species most representative (Menticirrhus gracilis, Centropomus parallelus, Micropogonias furnieri, Genidens genidens, Mugil curema and Orthopristis ruber). After checking the normality of data distribution (Shapiro–Wilk test), the Kruskal–Wallistest was applied to verify statistical differences for catch localities, seasonality, lunar cycle and bait type. Five of the six most abundant species were caught below the size at first maturity. Adopting strategies to improve recreational catches reports is essential to ensure better fisheries management and data collection.

The Role of Environmental Factors on the Fishery Catch of the Squid Uroteuthis chinensis in the Pearl River Estuary, China

The Pearl River Estuary (PRE) is one of the major fishing grounds for the squid Uroteuthis chinensis. Taking that into consideration, this study analyzes the environmental effects on the spatiotemporal variability of U. chinensis in the PRE, on the basis of the Generalized Additive Model (GAM) and Clustering Fishing Tactics (CFT), using satellite and in situ observations. Results show that 63.1% of the total variation in U. chinensis Catch Per Unit Effort (CPUE) in the PRE could be explained by looking into outside factors. The most important one was the interaction of sea surface temperature (SST) and month, with a contribution of 26.7%, followed by the interaction effect of depth and month, fishermen’s fishing tactics, sea surface salinity (SSS), chlorophyll a concentration (Chl a), and year, with contributions of 12.8%, 8.5%, 7.7%, 4.0%, and 3.1%, respectively. In summary, U. chinensis in the PRE was mainly distributed over areas with an SST of 22–29 °C, SSS of 32.5–34‰, Chl a of 0–0.3 mg × m−3, and water depth of 40–140 m. The distribution of U. chinensis in the PRE was affected by the western Guangdong coastal current, distribution of marine primary productivity, and variation of habitat conditions. Lower stock of U. chinensis in the PRE was connected with La Niña in 2008.

Strengths and weaknesses in the long-term sustainability of two sympatric seabreams (Argyrops spinifer and Rhabdosargus haffara, Sparidae).

Argyrops spinifer and Rhabdosargus haffara are two sympatric seabream species making important contributions to fisheries landings in the western Arabian/Persian Gulf. We identified the strengths and weaknesses in the long-term sustainability of A. spinifer and R. haffara stocks by integrating multiple sources of data, including fisheries catch and effort statistics, life history traits, scientific trawl surveys and historical length frequency distribution. Four strengths were identified in A. spinifer: wide distribution of juveniles, positive association to the network of de facto fishing exclusion areas created by hundreds of oil-gas facilities, early maturation and the existence of large and old individuals. A. spinifer suffers from two potential weaknesses: slow growth rate and higher exploitation pressure on the small-sized individuals. R. haffara, on the other hand, has a strength of having a short life span and a fast growth rate, characteristics that make it robust to unfavourable conditions. R. haffara suffers from two weaknesses: the lack of association to the oil and gas facilities, and the preference for nearshore shallow waters with stronger negative anthropogenic impacts. Identified strengths and weaknesses of these two sparids provided a preliminary assessment about their long-term sustainability, as well as a roadmap about how to develop different management strategies to meet specific objectives.

Pulse recruitment and recovery of Cayman Islands Nassau Grouper (Epinephelus striatus) spawning aggregations revealed by in situ length-frequency data

Abstract Fish spawning aggregations (FSAs) are vulnerable to overexploitation, yet quantitative assessments of FSA populations are rare. We document an approach for how to conduct such an assessment, evaluating the response of Critically Endangered Nassau Grouper (Epinephelus striatus) to protections in the Cayman Islands. We assessed pre-protection status on all islands using length data from fishery catch. We then used 17 years of noninvasive length-frequency data, collected via diver-operated laser calipers, to estimate recruitment and spawning biomass of Nassau Grouper on Little Cayman following protection. Bimodal length distributions in 2017–2019 indicated a large recruitment pulse (4–8× average) derived from spawning in 2011. Biomass recovered to 90–106% of the pre-exploitation level after 16 years, largely driven by the strong 2011 year class. Length distributions were also bimodal in 2017–2019 on nearby Cayman Brac, implying a synchronous recruitment pulse occurred on both islands. Our results demonstrate that: (i) in situ length data can be used to monitor protected FSAs; (ii) spatiotemporal FSA closures can be effective, but success takes time if population recovery depends upon sporadic recruitment; and (iii) FSA fishery management targets may need to be higher than commonly recommended (i.e. spawning potential ratio >0.6 instead of 0.4).

Multidisciplinary assessment of nearshore nursery habitat restoration for an exploited population of marine fish

Nearshore habitats are essential for many marine fish species but are subject to anthropogenic stressors. Assessing the consequences of essential fish habitat degradation on population dynamics and productivity is challenging. We address this by focusing on a metapopulation of the common sole Solea solea, a high-value, exploited flatfish in the Eastern English Channel (EEC). Multidisciplinary data and expert knowledge were compiled to build feasible restoration scenarios for the availability of suitable habitat (measured in habitat surface extent) and chemical quality of juvenile habitats in the highly anthropized Seine estuary, the largest estuary and potentially a sole nursery area of primary interest in the EEC. Scenarios were simulated with a spatially structured life-cycle model to investigate the consequences of local restoration on restricted nursery habitats in the estuary. Restoring surface extent and habitat quality in the Seine estuary dramatically enhances spawning stock biomass (+18%) and fishery catches (+13%) in the EEC. Restoring habitat quality has a greater effect than restoring habitat surface. Because of the low connectivity between subpopulations of sole in the EEC, most of the local restoration benefits remain regional and affect the subpopulation that directly depends on the Seine nursery, with only moderate spread to the entire EEC. Our study emphasizes the utility of spatial simulation models for integrating multidisciplinary knowledge and assessing the consequences of local anthropogenic pressures at wider metapopulation scales. We provide a means of building robust methods to assess the benefits of nearshore habitat restoration for enhancing fish populations and fisheries and integrate habitat value into the sustainable management of exploited species.

Relationship of Group Dynamics and Fishermen Independence in Fisheries Agribusiness Attaining Maximum Sustainable Yield

This study aimed to examine the factors and the influence of group dynamics and the independence of fishing group members in catch fisheries agribusiness activities. This research was carried out using a survey method in the Rukun Nelayan Blimbing in Paciran District, Lamongan Regency, East Java Province, Indonesia from February to March 2019. The result showed the group dynamics and independence of fishermen in catch fisheries was high, but group dynamics did not influence the independence of fishermen in catching fisheries agribusiness. The factors that influence group dynamics were structuring, coaching and development, atmosphere, effectiveness. The factors affected the independence of the group were the addition of production facilities, prices, market, and fishermen. Those factors are needed to attain the good management in maximum sustainable yield (MSY).

The effect of LED lights on trap catches in signal crayfish fisheries

The effect of LED lights on trap catches in signal crayfish fisheries

Long-term spatiotemporal variation in Miyazaki Prefecture coastal fishery catch in relationship to oceanographic conditions

Long-term spatiotemporal variation in Miyazaki Prefecture coastal fishery catch in relationship to oceanographic conditions

Impacts on fisheries assessed by local ecological knowledge in a reservoir cascade in the lower São Francisco River, northeastern Brazil

Abstract Our study assessed the fishers’ perception (local ecological knowledge, LEK) concerning environmental impacts on fisheries and fish species in the final portion of Sub-Middle and Lower São Francisco. The river was divided into four areas where 107 fishers from 22 locations (4 states) were surveyed. The dam was the most significant impact on fisheries. The loss of connectivity, changing the environmental complexity, and its secondary effects (e.g., flow control, interruption of migratory routes) were determining factors. Other impacts were pointed out, such as pollution, macrophytes, overfishing, non-native species, and aquaculture. Among migratory species, Pseudoplatystoma corruscans and Salminus franciscanus have been absent from fishery catches for decades. Prochilodus argenteus records in fisheries are likely associated with migration routes to small tributaries. The environmental disturbance favored the establishment of non-native species such as Oreochromis niloticus, Cichla monoculus, and Metynnis lippincottianus along the studied section. Over the final portion of the São Francisco River, the more significant seawater intrusion changed the target species for fisheries activities. Thus, our data validate the importance of fishers’ LEK and reinforce the adverse effects of the reservoir cascade on fishing and migratory fishes.

Factors of long-term variation in the fishery catch of red sea bream in Miyazaki Prefecture

Factors of long-term variation in the fishery catch of red sea bream in Miyazaki Prefecture

Estimation of small-scale fisheries production development trend in Nepal

Nepal is a landlocked country with enormous natural diversity ranges from the world's highest peak, Mt. Everest to the Tarai area. Nepalese aquaculture is still in its early stages, and fish production is still insufficient in comparison to global levels. Fish is a popular cuisine in Nepal, and it is enjoyed by people of all ages, genders, and religions. The total national fish production is currently 77,000 m.t., with 28 percent coming from catch fisheries and 72 percent from aquaculture. Aquaculture and open-water capture fisheries account for around 2% of agricultural gross domestic product; this little share of the fisheries sector is promising, with an annual growth rate of 8–9%. Total fisheries production in Nepal was reported at 81070 metric tons in 2018, according to the World Bank assortment of development indicators, compiled from officially recognized bases. Small-scale fishermen's catch production and secondary data in Nepal's Chitwan District, Bagmati Province, from 2010 to 2019. Regression estimates model and multivariate regression analysis of time series data, the Cobb-Douglas production function equation rational technique is applied. Changes in the number of fish caught have an impact on the home economics and spending. The length of the river, outboard engine power, and regional differences in area were found to have a positive impact on small-scale fishermen's catch production, whereas gasoline, schooling, and family dependents had a negative impact, though fishing gear, kerosene, and fishermen's age had no considerable impact.

Almost forgotten: Historical abundance of eel-tail catfish populations in south-western Australian estuaries and their decline due to habitat loss and historical overfishing

The decline of Estuary Cobbler (Cnidoglanis macrocephalus) stocks in south-western Australia since European settlement of the region in 1829 is described, based on evidence from historical documents, fishery statistics and scientific surveys. Estuary cobbler is a relatively large, long-lived, benthic carnivore that was once abundant in the three largest west coast estuaries, where it was a major component of fishery catches for decades. The breeding stock in each estuary declined dramatically between 1960 and 2000, after which time exploitation effectively ceased. Two stocks appear to have largely disappeared, while the third still persists at a relatively low level. In each estuary historical overfishing coincided with a period of severe habitat degradation including flow modification, eutrophication, benthic habitat loss and hypoxia. Hence there is no obvious, primary driver of decline for these stocks. Exploitation probably acted synergistically with environmental impacts to cause each stock decline. In degraded environments, fisheries management should be highly precautionary to reflect the elevated risk to exploited species posed by multiple simultaneous stressors. A risk-based ‘weight-of-evidence’ approach that can accommodate both quantitative and qualitative lines of evidence, including fishing and non-fishing impacts, is recommended to assess the status of exploited species in such environments.

МОЖЛИВОСТІ ІМПОРТОЗАМІЩЕННЯ ПРОДУКЦІЇ АКВАКУЛЬТУРИ В УКРАЇНІ

Purpose. The role of aquaculture products in imports of Ukraine given the importance of imports in providing demand of the population on seafood and fish products and prospects are assessed, opportunities for import substitution of the main species of imported fish originating from aquaculture. Findings. Food security of any country is formed by the balance of its own production, exports and imports. In most European countries, the leading role in satisfaction of demand of the consumers for fish and seafood as of today is played by the import of fish and seafood (HS groups of commodoties 03, 1604, 1605 and 230120), and not their production in the country. Imports play a very important role in saturating the Ukrainian fish and seafood market. Due to the growing role of fish farming (aquaculture) in the world, the role of aquaculture products in Ukrainian imports for the period from 1996 to 2019 includes has been analyzed. The leading role of aquaculture products in the import of fresh and chilled products and relatively small in the subgroup of frozen products is noted. The higher prices of aquaculture products compared to catch fishery products has been confirmed. Assumptions are made about the possible replacement of import of the leading categories of imported products originating from aquaculture and about probably the most advanced technologies of fish farming and species of aquaculture in Ukraine with the current structure and traffic of commodities in global aquaculture and current expenditures of Ukraine on R & D in aquaculture. Practical value. The data obtained can be useful and used by scientists, practitioners, students, specialists, whose areas of interest include aquaculture and imports, exports of fish products. Keywords: import, aquaculture, fish farming, replacement of import.

Facing the challenge of discarded fish: improving nutritional quality of two insect species larvae for use as feed and food

Fishery discards represent 10% of total fishery catches, and insect rearing can be accomplished using this wasted resource. Considering that fish are the main source of n-3 very long-chain polyunsaturated fatty acids for human nutrition, and that fish contain both eicosapentaenoic acid and docosahexaenoic acid, this study focused on monitoring the accumulation of such n-3 very long-chain polyunsaturated fatty acids in insect larvae. To determine the feasibility of this process, we monitored nutritional changes achieved in two insect larvae – black soldier fly (Hermetia illucens Linnaeus, 1758) and mealworm (Tenebrio molitor Linnaeus, 1758) – fed using two different fish species from discards, i.e. round sardinella (Sardinella aurita Valenciennes, 1847) and blackspot seabream (Pagellus bogaraveo, Brünnich, 1768). Five different diets were prepared: control (broiler feed), 50% discarded fish (round sardinella and blackspot seabream) +50% broiler feed, and 100% discarded fish. The 100% blackspot seabream fedH. illucens accumulated eicosapentaenoic acid and docosahexaenoic acid up to 2.4 g /100 g and 0.8 g /100 g, respectively.T. molitor accumulated lower amounts of both n-3 very long-chain polyunsaturated fatty acids due to the low intake of fish-containing feed by the larvae.