Does Fencing of British Lowland Streams Encourage Greater Salmonid Fish Stocks?

2010 ◽  
pp. 183-193
Author(s):  
David Summers
Keyword(s):  
Salmonid Fish ◽  
Fish Stocks ◽  
Lowland Streams

scholarly journals Statistical and ecological challenges of monitoring parasitic salmon lice infestations in wild salmonid fish stocks

2015 ◽  
Vol 7 (3) ◽  
pp. 267-280 ◽  
Author(s):  
IP Helland ◽  
I Uglem ◽  
PA Jansen ◽  
OH Diserud ◽  
PA Bjørn ◽  
...  
Keyword(s):  
Salmonid Fish ◽  
Fish Stocks ◽  
Salmon Lice ◽  
Lice Infestations

Relationships between temperature and Pacific hake distribution vary across latitude and life-history stage

2020 ◽  
Vol 639 ◽  
pp. 185-197 ◽  
Author(s):  
MJ Malick ◽  
ME Hunsicker ◽  
MA Haltuch ◽  
SL Parker-Stetter ◽  
AM Berger ◽  
...  
Keyword(s):  
Life History ◽  
Environmental Effects ◽  
Environmental Conditions ◽  
Vancouver Island ◽  
Additive Models ◽  
Life History Stage ◽  
Fish Stocks ◽  
Merluccius Productus ◽  
Multiple Dimensions ◽  
Effects Of Temperature

Environmental conditions can have spatially complex effects on the dynamics of marine fish stocks that change across life-history stages. Yet the potential for non-stationary environmental effects across multiple dimensions, e.g. space and ontogeny, are rarely considered. In this study, we examined the evidence for spatial and ontogenetic non-stationary temperature effects on Pacific hake Merluccius productus biomass along the west coast of North America. Specifically, we used Bayesian additive models to estimate the effects of temperature on Pacific hake biomass distribution and whether the effects change across space or life-history stage. We found latitudinal differences in the effects of temperature on mature Pacific hake distribution (i.e. age 3 and older); warmer than average subsurface temperatures were associated with higher biomass north of Vancouver Island, but lower biomass offshore of Washington and southern Vancouver Island. In contrast, immature Pacific hake distribution (i.e. age 2) was better explained by a nonlinear temperature effect; cooler than average temperatures were associated with higher biomass coastwide. Together, our results suggest that Pacific hake distribution is driven by interactions between age composition and environmental conditions and highlight the importance of accounting for varying environmental effects across multiple dimensions.

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.

Pescadores migrantes: análisis de su dinámica e integración Social

2019 ◽  
Vol 37 (3) ◽  
pp. 18
Author(s):  
Fernando González Laxe
Keyword(s):  
Renewable Resources ◽  
Sustainable Management ◽  
Social Groups ◽  
Technological Innovations ◽  
Social Competition ◽  
Factors Affecting ◽  
Fish Stocks ◽  
Fishery Resources ◽  
Migration Dynamics ◽  
The Many

The globalization of the economy encourages massive population displacements and inevitably generates a cosmopolitization of societies. This leads to concern, misunderstanding and rejection. The most vulnerable social groups in society can perceive the population as intruders and enemies in social competition. Undoubtedly, the extreme spatial instability of fishery resources is among the many factors affecting migration dynamics. Various reasons for the mobility of fishermen are relevant around this concept. These include aspect related to traditions, to the capitalisation of activity, to technological innovations, and to innovation exchanges concerning the location of fish stocks. This article reflects on spatial increase of fishermen’s. The analyse are part of the paradigm of the sustainable management of common renewable resources, in particular fishery resources. It presents three lines of analysis: the reason for mobility; the choice of destination; and are the integration into host units.

Within year representativity of fish assemblage surveys in two small lowland streams

2012 ◽  
Vol 61 (2) ◽  
pp. 97-105 ◽  
Author(s):  
Péter Takács ◽  
Péter Sály ◽  
András Specziár ◽  
Péter Bíró ◽  
Tibor Erős
Keyword(s):  
Fish Assemblage ◽  
Lowland Streams

RECLAMATION AND CULVERT CROSSINGS MADE OF CORRUGATED PIPES ON SPAWNING STREAMS

2020 ◽  
pp. 68-77
Author(s):  
O.N. CHERNYKH ◽  
◽  
A.V. RBURLACHENKO
Keyword(s):  
Single Point ◽  
Experimental Studies ◽  
Fish Passage ◽  
Future Research ◽  
Fish Stocks ◽  
Metal Structures ◽  
Natural Reproduction ◽  
Spiral Shape ◽  
Corrugated Metal ◽  
Spawning Streams

Recommendations are presented for solving issues that arise in the design and operation of tubular transport crossings of corrugated metal structures through spawning streams while ensuring the safety and natural reproduction of fish stocks. There are discussed the results of experimental studies of culverts made of metal corrugated pipes with a normal and spiral shape of corrugation the bottom of which is buried and filled with suitable granular material to the level of the natural channel of a small watercourse. It is established that when 10% of the area of the corrugated pipe is occupied by stone filling, its throughput is reduced by about 10-12%. Based on the review of the existing literature and the results of laboratory experiments, data is provided to estimate the values of the roughness coefficients of the composite cross-section of a single-point junction and directions for future research on culvert reclamation are outlined. Studying of the structure of the velocity distribution in culverts can lead to the improved conditions for fish passage without installing special structural elements in the transit path of the fish passage structure.

Sign in / Sign up

Export Citation Format

Share Document