Enjoying Catch and Fishing Effort: The Effort Effect in Recreational Fisheries

2013 ◽  
Vol 57 (3) ◽  
pp. 393-404 ◽  
Author(s):  
Max T. Stoeven
Keyword(s):  
Fishing Effort ◽  
Recreational Fisheries ◽  
Effort Effect

Statistical Bias Problem in On-Site Surveys: the Severity of the Problem and its Potential for Solution

1975 ◽  
Vol 32 (12) ◽  
pp. 2520-2524
Author(s):  
William F. Sinclair ◽  
R. W. Morley
Keyword(s):  
Fishing Effort ◽  
Recreational Fisheries ◽  
Statistical Bias ◽  
Relative Probability ◽  
Fishing Vessels ◽  
Frequency Of Use ◽  
Unbiased Estimates ◽  
Weighting Procedures ◽  
Use Category

Commercial and recreational fisheries managers often develop catch and effort estimates from information gathered in location or on-site surveys. However, a limited on-site sample cannot produce unbiased estimates of fishing effort or socioeconomic traits of the anglers unless weighting procedures are adopted to account for the varying frequencies of fishing of the fishermen. The corrective procedure involves establishing the relative probability of capturing a fisherman in the sample, then weighting the number of contacts with anglers in each frequency of use category. Unless information on the probability of including particular fishermen and fishing vessels in the sample is available the sample must be drawn with replacement.

scholarly journals Numerical Model of Fish Exploitation – structure and application

2019 ◽  
Vol 27 (2) ◽  
pp. 86-101
Author(s):  
Paweł Buras ◽  
Wiesław Wiśniewolski
Keyword(s):  
Numerical Model ◽  
Simulation Models ◽  
Fishing Effort ◽  
Natural Mortality ◽  
Recreational Fisheries ◽  
Fisheries Resources ◽  
Fish Exploitation ◽  
The Common ◽  
Common Bream ◽  
The Impact

Abstract Fisheries simulation models are tools used for forecasting the effects of exploitation and determining the directions of managing fisheries resources. The Numerical Model of Fish Exploitation (NMFE) and its capabilities were tested on a population of common bream, Abramis brama (L.) in a dam reservoir that is exploited by commercial and recreational fisheries. Based on the designated population parameters of N0, Fij, Mi, and ei and the size and structure of the common bream population in the reservoir, the model was used to examine hypothetical simulation variants of changes in fishing intensity E1 with nets and rods, changes in fishing intensity based on actual fishing effort with nets, changes in natural mortality, changes in the size of fish caught, and the impact of this on the size of the resources. Initial catches with nets and rods were calculated. Increasing fishing effort did not translate proportionally to increased catches, and the function was curvilinear. The results of simulations that reduced the intensity of fishing with nets and decreased catch sizes concurred with data from actual catches. Simulations of changes in natural mortality had various effects on the size of catches. Reducing parameter M did not impact the level of catches, while increasing parameter M reduced the size of catches significantly.

Recreational Fishing

2019 ◽  
pp. 83-91
Author(s):  
Ray Hilborn ◽  
Ulrike Hilborn
Keyword(s):  
Economic Value ◽  
Developed Countries ◽  
Fishing Effort ◽  
Recreational Fishing ◽  
Commercial Fisheries ◽  
Recreational Fisheries ◽  
The World ◽  
The Developed Countries ◽  
Do So

Recreational Fishing. Recreational fisheries involve far more people than commercial fisheries do in most of the developed countries, and their economic value is often estimated to be larger than that of commercial fisheries. The main objective of most recreational fisheries is the opportunity to fish rather than the number or value of fish caught, and very different management methods are appropriate. Ideally, the total fishing effort should be maximized rather than reduced, to keep costs down as for commercial fisheries. Access to recreational fishing differs greatly around the world and ranges from effectively privatizing fishing opportunity to allowing anyone wishing to fish to do so.

scholarly journals Danger beyond the catches: a review of conservation threats posed by commercial and non-commercial fisheries in Guaratuba Bay, southern Brazil

2020 ◽  
Author(s):  
P. T. C. Chaves
Keyword(s):  
Critical Size ◽  
Fishing Effort ◽  
Shallow Waters ◽  
Commercial Fisheries ◽  
Southern Brazil ◽  
Recreational Fisheries ◽  
Catch And Release ◽  
Fishing Gears ◽  
Popular View ◽  
Conservation Threats

Abstract Comparisons between the implications of commercial and recreational fisheries for estuarine conservation have been a topic of debate. A review on the available data from Guaratuba Bay, Southern Brazil, identifies six threats for conservation, other than those concerning the fishing effort on target resources. Differing from the popular view that fishing for pleasure could be innocuous for the environment, the identified threats concern both commercial and non-commercial fisheries: (1) catching of reproductive individuals; (2) catch of big old fat fecund females; (3) loss and abandonment of fishing gears; (4) use of natural baits; (5) bycatch of rays, turtles and non-target finfish; and (6) bad practices associated with catch-and-release or discarding. Environmental disturbances and fauna depletion are detected as potential impacts. Recommended actions for estuary conservation include fishing closures in mangrove and shallow waters areas, release of fish larger than the critical size, and measures against abandoned, lost or otherwise discarded fishing gears.

CRITICAL FACTORS OF WATER CONTENT FOR FISH STOCKS IN THE WATER RESERVOIRS OF KAZAKHSTAN

2017 ◽  
pp. 9-18
Author(s):  
Saule Zhangirovna Asylbekova ◽  
Kuanysh Baibulatovich Isbekov ◽  
Evgeniy Vyacheslavovich Kulikov
Keyword(s):  
Water Content ◽  
Water Level ◽  
Water Availability ◽  
Hydrological Regime ◽  
Fishing Effort ◽  
Water Reservoirs ◽  
The Caspian Sea ◽  
Annual Fish ◽  
Commercial Fish ◽  
Fish Stocks

The hydrological regime of water reservoirs in different years has a decisive impact on the abundance of commercial fish stocks and the quality of ichthyocenoses. In this connection in 2015-2016 there was conducted a retrospective analysis and ranking of hydrological regime impact on these factors. The paper gives evaluation of catches and fish stocks under different scenarios of water availability in the main fishing ponds of the Republic of Kazakhstan that give about 80% of the annual fish catch of the country (except the Caspian Sea). There were analyzed 2000 factors of hydrological regime (water level, annual discharge) and 1845 factors of fishing stocks (catches, abundance, fish biomass). The paper determines the critical characteristics of water availability for fish stocks. There have been proposed a number of administrative decisions and actions in case if water content would approach to the critical level. Among them: limitation of fish catches in the following year; widening zones restricted for fishing; intensification of safety measures of the fish young in residual ponds during arid periods; introduction of catch standards for a unit of fishing effort in low-water years, high-water years and years with normal water level in rivers.

Studi pengembangan unit perbenihan ikan laut di Pulau Gumilamo Kabupaten Halmahera Utara

2015 ◽  
Vol 3 (3) ◽  
Author(s):  
Yitzhak Koloba ◽  
Hengky J Sinjal ◽  
Ockstan Kalesaran
Keyword(s):  
Local Government ◽  
Development Strategy ◽  
Marine Fish ◽  
Government Regulation ◽  
Swot Analysis ◽  
Fishing Effort ◽  
Government Support ◽  
Fish Hatchery ◽  
The Development Strategy ◽  
Internal And External Factors

This research intended  to evaluate the development strategy of Marine Fish Hatchery Unit at Gumilamo Island, North Halmahera. Analysis SWOT was used to determine the development strategy. Data were collected by questionnaire, interview and literature relevant to the research. SWOT analysis showed the internal and external factors that affected the development of Marine Fish Hatchery at Gumilamo island. The strenght were location, water quality , local government support, and availability of seeds and feed. Weakness were lack of public interest, lack of extension and human resources. Opportunity were the high value of the sale, business opportunities and  local government regulation. Treat were  dependence on fishing effort and safety.   Keywords : hatchery, gumilamo, north halmahera, SWOT analysis

Preliminary observations on abundance and distribution of fish fauna in a canyon of the Bay of Biscay (ICES Division 8c)

2021 ◽  
pp. 1-10
Author(s):  
G. Diez ◽  
L. Arregi ◽  
M. Basterretxea ◽  
E. Cuende ◽  
I. Oyarzabal
Keyword(s):  
Deep Sea ◽  
Basque Country ◽  
Fish Fauna ◽  
Fishing Effort ◽  
Fishing Gear ◽  
Clear Trend ◽  
Depth Ranges ◽  
Abundance And Distribution ◽  
Sea Fish ◽  
Distribution Of Fish

Abstract The changes in abundance and biodiversity of deep-sea fish fauna are described based on an annual deep-water longline survey with data collected during the period 2015–2019 in the Basque Country continental Slope (ICES Division 8c). The sampling scheme included hauls in four 400 m strata, from 650–2250 m deep. The DST sensors installed in the main line have allowed us to set an accurate soak time for each haul, and they were used to calculate fishing effort and CPUE by haul. The catchability of the fishing gear indicated that 15% of the total hooks deployed in the five-year period were able to fish, and that the bottom longline was very effective in fishing a wide number of different species in all depth ranges. The fishing gear caught 14 different species of sharks (13 deepwater and one pelagic), two chimaeras and nine teleosts. The abundance and biomass registered on the hooks attached to the bottom were between three and four times higher than in the floating sections, and the highest CPUE and biomass were recorded between 1051–1450 m, from 2015 to 2017, and in the 1451–1850 m strata, but they do not show any clear trend throughout the five years of the series.

scholarly journals Assessing the Potential of Catch-Only Models to Inform on the State of Global Fisheries and the UN’s SDGs

2021 ◽  
Vol 13 (11) ◽  
pp. 6101
Author(s):  
Rishi Sharma ◽  
Henning Winker ◽  
Polina Levontin ◽  
Laurence Kell ◽  
Dan Ovando ◽  
...  
Keyword(s):  
Stock Assessment ◽  
Fishing Effort ◽  
The State ◽  
Sources Of Information ◽  
Ongoing Research ◽  
Traditional Assessment ◽  
Stock Status ◽  
Stock Assessments ◽  
Recent Developments ◽  
Measure Of Performance

Catch-only models (COMs) have been the focus of ongoing research into data-poor stock assessment methods. Two of the most recent models that are especially promising are (i) CMSY+, the latest refined version of CMSY that has progressed from Catch-MSY, and (ii) SRA+ (Stock Reduction Analysis Plus) a recent developments in field. Comparing COMs and evaluating their relative performance is essential for determining the state of regional and global fisheries that may be lacking necessary data that would be required to run traditional assessment models. In this paper we interrogate how performance of COMs can be improved by incorporating additional sources of information. We evaluate the performance of COMs on a dataset of 48 data-rich ICES (International Council for the Exploration of Seas) stock assessments. As one measure of performance, we consider the ability of the model to correctly classify stock status using FAO’s 3-tier classification that is also used for reporting on sustainable development goals to the UN. Both COMs showed notable bias when run with their inbuilt default heuristics, but as the quality of prior information increased, classification rates for the terminal year improved substantially. We conclude that although further COM refinements show some potential, most promising is the ongoing research into developing biomass or fishing effort priors for COMs in order to be able to reliably track stock status for the majority of the world’s fisheries currently lacking stock assessments.

scholarly journals Nonstationary Responses of Demersal Fishes to Environmental Variations in Temperate Waters of the Northwestern North Pacific under a Changing Climate

Fishes ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 22
Author(s):  
Qingsong He ◽  
Shuyang Ma ◽  
Qinwang Xing ◽  
Wenchao Zhang ◽  
Haiqing Yu ◽  
...  
Keyword(s):  
North Pacific ◽  
Negative Relationship ◽  
Demersal Fish ◽  
Fishing Effort ◽  
Asian Winter Monsoon ◽  
Changing Climate ◽  
Sst Variability ◽  
Environmental Variations ◽  
The Impact ◽  
Demersal Fishes

Although nonstationarity in marine ecosystems has attracted great attention, the nonstationary responses of demersal fishes to environmental variations induced by the changing climate are still not well understood. Here, we collected 21 time series of demersal fishes from 1956 to 2015 to investigate the climate-induced nonstationary responses in temperate waters of the northwestern North Pacific (NWP). We showed that these demersal fishes experienced state shifts in approximately 1986/87, accompanied by abrupt warming over this region. Moreover, the relationships between demersal fishes and sea surface temperature (SST) were found to change between the two identified eras (i.e., a weak relationship before 1986 and a strong negative relationship after 1986), which may be primarily caused by the alternating dominance of the East Asian winter monsoon and mega-ENSO on SST in temperate waters of the NWP. The identified climate-induced nonstationary responses of demersal fishes to SST variability in this study may provide implications for understanding climate-induced biological dynamics, predicting demersal fish fluctuations, coping with potential ecological risks, and the sustainable exploitation of fishery resources in the future climate. Note that the impact of fishing on the demersal fishes in temperate waters of the NWP was not assessed in this study due to the lack of fishing effort data and therefore the conclusions of our research should be approached with caution.

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