scholarly journals Recreational fishing impacts on threatened river sharks: A potential conservation issue

2017 ◽  
Vol 18 (3) ◽  
pp. 209-213 ◽  
Author(s):  
Peter M. Kyne ◽  
Pierre Feutry
Keyword(s):  
Recreational Fishing ◽  
Fishing Impacts

SELECTED MORPHOMETRIC AND BIOLOGICAL CHARACTERISTICS OF IDE LEUCISCUS IDUS (LINNAEUS, 1758) IN THE LOWER IRTYSH

2017 ◽  
pp. 46-53
Author(s):  
Elizaveta L'vovna Liberman ◽  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Maximum Rate ◽  
Linear Growth ◽  
Age Groups ◽  
Annual Growth ◽  
Recreational Fishing ◽  
Opisthorchis Felineus ◽  
Gonad Maturity ◽  
Study Results ◽  
Leuciscus Idus ◽  
Old Females

Ide Leuciscus idus (Linnaeus, 1758) belongs to Cyprinidae family and is used in commercial and recreational fishing. Ide is an intermediate host of Opisthorchis felineus . In the control catches (summer 2015, the Lower Irtysh, Uvatsky, Tobolsky and Vagaysky regions of Tyumenskaya Oblast’) there were observed species with lengths 11.9-38.1 cm, with a total weight 45-1085 g. Some species aged 9 years old and even older. The maximum rate of linear growth was registered in ide species younger than 3 years old, at this age annual growth made 5 cm. The annual growth of four-year-old females made 5.4 cm, males - 2.8 cm. Females aged 3+ exceeded males in body weight and length. Species at the age 1+…2+ years old added 204.6% in their mass; at the age 2+…3+ years old - 65.3%, at 3+…4+ years old - 29.4%. Gender and gonad maturity were determined in species older than 2+, but not in all species. Among females aged 2+…4+ there were found species with I and II stage of gonad maturity. Females aged 5+ were spawned-out species having VI-II stage of gonad maturity (48%); female species aged 6+ having IV stage of gonad maturity made 33.4%. Among males in the age groups of 2+ and 3+ there were registered species with I stage (38.5 and 20%, respectively) and II stage (61.5 and 80%, respectively) of maturation only. Fatness degree of studied species ranged from 0 to 5. Species aged 2+ had I stage (24% species); in the aged groups the proportion of such species decreased (5+ years old - 7.8%; 6+ years old - 12.1%; 8+ years old - 5.9%); species aged 2-7 had II stage of fatness; proportion of older species also decreased. Species with III and IV stage of fatness were found more often (III stage was observed in 100% of the fish species at the age of 1+). Proportion of species with V stage was minor, it increased with age. According to the analysis of the study results, nutritive base in the basin is found satisfactory for ide growth and development.

scholarly journals Contributions to Management Strategies in the NE Atlantic Regarding the Life History and Population Structure of a Key Deep-Sea Fish (Mora moro)

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 522
Author(s):  
Régis Santos ◽  
Wendell Medeiros-Leal ◽  
Osman Crespo ◽  
Ana Novoa-Pabon ◽  
Mário Pinho
Keyword(s):  
Population Structure ◽  
Life History ◽  
Deep Sea ◽  
Management Strategies ◽  
Size Composition ◽  
Large Size ◽  
The Common ◽  
Fishing Impacts ◽  
Sea Fish

With the commercial fishery expansion to deeper waters, some vulnerable deep-sea species have been increasingly captured. To reduce the fishing impacts on these species, exploitation and management must be based on detailed and precise information about their biology. The common mora Mora moro has become the main deep-sea species caught by longliners in the Northeast Atlantic at depths between 600 and 1200 m. In the Azores, landings have more than doubled from the early 2000s to recent years. Despite its growing importance, its life history and population structure are poorly understood, and the current stock status has not been assessed. To better determine its distribution, biology, and long-term changes in abundance and size composition, this study analyzed a fishery-dependent and survey time series from the Azores. M. moro was found on mud and rock bottoms at depths below 300 m. A larger–deeper trend was observed, and females were larger and more abundant than males. The reproductive season took place from August to February. Abundance indices and mean sizes in the catch were marked by changes in fishing fleet operational behavior. M. moro is considered vulnerable to overfishing because it exhibits a long life span, a large size, slow growth, and a low natural mortality.

scholarly journals The value of recreational fishing in Sweden – Estimates based on a nationwide survey

2021 ◽  
Author(s):  
Ola Carlén ◽  
Göran Bostedt ◽  
Runar Brännlund ◽  
Lars Persson
Keyword(s):  
Nationwide Survey ◽  
Recreational Fishing

scholarly journals Giant otter Pteronura brasiliensis density and abundance in Llanos Orientales de Colombia in the Orinoco basin

Oryx ◽  
2020 ◽  
pp. 1-4
Author(s):  
Germán Garrote ◽  
Beyker Castañeda ◽  
Jose Manuel Escobar ◽  
Laura Pérez ◽  
Brayan Marín ◽  
...  
Keyword(s):  
South America ◽  
Population Size ◽  
20Th Century ◽  
Conservation Status ◽  
Species Conservation ◽  
Iucn Red List ◽  
Red List ◽  
Recreational Fishing ◽  
Pteronura Brasiliensis ◽  
Direct Counts

Abstract The giant otter Pteronura brasiliensis, categorized as Endangered on the IUCN Red List, was once widely distributed throughout South America. By the middle of the 20th century the giant otter had become locally extinct along the main rivers of the Orinoco basin. Although some populations seem to have recovered, the paucity of information available does not permit a full evaluation of the species' conservation status. The objective of this study was to estimate the abundance and density of the giant otter population along the Orinoco river in the municipality of Puerto Carreño, Vichada, Colombia, where there is important commercial and recreational fishing. Thirty-nine linear km were surveyed, repeatedly, with a total of 315 km of surveys. Population size was estimated by direct counts of individuals. All individuals detected were photographed and identified individually from their throat pelage patterns. In total, 30 otters were identified, giving a minimum density of 0.77 individuals per km, one of the highest reported for the species in Colombia. Given the high density in this well-developed area, our results highlight the importance of this population for the conservation of the species.

Preface: A Nested Logit Model of Recreational Fishing Demand in Alaska

2009 ◽  
Vol 24 (2) ◽  
pp. 99-100
Author(s):  
GEORGE R. PARSONS ◽  
JAMES L. ANDERSON
Keyword(s):  
Logit Model ◽  
Recreational Fishing ◽  
Nested Logit ◽  
Nested Logit Model

scholarly journals Natura 2000 sites and fisheries in German offshore waters

2008 ◽  
Vol 66 (1) ◽  
pp. 155-169 ◽  
Author(s):  
Søren Anker Pedersen ◽  
Heino Fock ◽  
Jochen Krause ◽  
Christian Pusch ◽  
Anne L. Sell ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Fishery Management ◽  
Conservation Status ◽  
Natura 2000 ◽  
Management Measures ◽  
Favourable Conservation Status ◽  
Management Plans ◽  
Natura 2000 Site ◽  
Environmentally Sound ◽  
Fishing Impacts

Abstract Pedersen, S. A., Fock, H., Krause, J., Pusch, C., Sell, A. L., Böttcher, U., Rogers, S. I., Sköld, M., Skov, H., Podolska, M., Piet, G. J., and Rice, J. C. 2009. Natura 2000 sites and fisheries in German offshore waters.–ICES Journal of Marine Science, 66: 155–169. The principal objective of sites selected as part of Natura 2000 is to achieve or maintain a favourable conservation status of habitats and species named in the EU Birds and Habitats directives. In the German exclusive economic zone, the habitat types protected by this legislation are sandbanks and reefs; protected species include marine mammals, seabirds, and specific migratory fish species. The ICES project Environmentally Sound Fishery Management in Protected Areas (EMPAS) aims to answer two questions: (i) To what extent do specific fishing activities significantly threaten attainment of the conservation objectives of the Natura 2000 sites? (ii) What management measures would reduce these conflicts and how effective would they be at helping to ensure the favourable condition of these sites? Assessments of fishing impacts on Natura 2000 sites require basic data on the conservation status of individual habitats and species, as well as data for fine-scale distributions of ongoing fishing activities. This paper describes and discusses the process used by the EMPAS project in developing fishery-management plans for each Natura 2000 site in German offshore waters.

scholarly journals Investigation of seabed fishing impacts on benthic structure using multi-beam sonar, sidescan sonar, and video

2007 ◽  
Vol 64 (5) ◽  
pp. 1053-1065 ◽  
Author(s):  
Mashkoor A. Malik ◽  
Larry A. Mayer
Keyword(s):  
Gulf Of Maine ◽  
Fishing Ground ◽  
Sidescan Sonar ◽  
Data Sets ◽  
Frequency Filtering ◽  
Data Set ◽  
Detection And Identification ◽  
Spatial Frequency Filtering ◽  
Disparate Data ◽  
Fishing Impacts

Abstract Malik, M. A., and Mayer, L. A. 2007. Investigation of seabed fishing impacts on benthic structure using multi-beam sonar, sidescan sonar, and video. – ICES Journal of Marine Science, 64: 1053–1065. Long, linear furrows of lengths up to several kilometres were observed during a recent high-resolution, multi-beam bathymetry survey of Jeffreys Ledge, a prominent fishing ground in the Gulf of Maine located about 50 km from Portsmouth, NH, USA. These features, which have a relief of only a few centimetres, are presumed to be caused either directly by dredging gear used in the area for scallop and clam fisheries, or indirectly through the dragging of boulders by bottom gear. Extraction of these features with very small vertical expression from a noisy data set, including several instrumental artefacts, presented a number of challenges. To enhance the detection and identification of the features, data artefacts were identified and removed selectively using spatial frequency filtering. Verification of the presence of the features was carried out with repeated multi-beam bathymetry surveys and sidescan sonar surveys. Seabed marks that were clearly detected on multi-beam and sidescan sonar records were not discernible on a subsequent video survey. The inability to see the seabed marks with video may be related to their age. The fact that with time, the textural contrasts discernible by video imagery are lost has important ramifications for the appropriateness of methodologies for quantifying gear impact. The results imply that detailed investigations of seabed impact are best done with a suite of survey tools (multi-beam bathymetry, sidescan sonar, and video) and software to integrate the disparate data sets geographically.

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