Size Composition of Invertebrate Drift and Fish Predation in a Texas Stream

1988 ◽  
Vol 33 (2) ◽  
pp. 177 ◽  
Author(s):  
David E. Bowles ◽  
Robert A. Short
Keyword(s):  
Size Composition ◽  
Fish Predation ◽  
Invertebrate Drift

Testing a model of drift-feeding using three-dimensional videography of wild brown trout, Salmo trutta, in a New Zealand river

2003 ◽  
Vol 60 (12) ◽  
pp. 1462-1476 ◽  
Author(s):  
Nicholas F Hughes ◽  
John W Hayes ◽  
Karen A Shearer ◽  
Roger G Young
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Focal Point ◽  
Three Dimensional ◽  
Size Composition ◽  
Invertebrate Drift ◽  
Intake Rate ◽  
Drift Feeding ◽  
Foraging Area ◽  
Brown Trout Salmo Trutta

We tested the assumptions and predictions of a foraging model for drift-feeding fish. We used three-dimensional videography to describe the foraging behavior of brown trout, Salmo trutta, mapped water depth and velocity in their foraging area, sampled invertebrate drift to determine length class specific drift densities, and captured trout to determine the size composition of their diet. The model overestimated the fish's prey capture rate and gross energy intake rate by a factor of two. Most of this error resulted from the fact that prey detection probabilities within the fish's foraging area averaged only half the expected value. This was the result of a rapid decrease in capture probability with increasing lateral distance from the fish's focal point. Some of the model's assumptions were accurate: equations for predicting reaction distance and minimum prey size supported reliable predictions of the shape and size of the fish's foraging area and the size composition of the diet. Other assumptions were incorrect: fish detected prey within the predicted reaction volume, not on its upstream surface as expected, fish intercepted prey more slowly than the expected maximum sustainable swimming speed, and fish captured about two-thirds of their prey downstream of their focal point, rather than upstream.

Patterns of conduct of Argentine SMEs with respect to ICT investments

2020 ◽  
pp. 47-78
Author(s):  
Guillermo Alberto Tricoci ◽  
Pablo Alejandro Corral ◽  
María Cecilia Oriolo
Keyword(s):  
Size Composition ◽  
Field Work ◽  
Mixed Methodology ◽  
Small Companies ◽  
Consulting Services ◽  
Empirical Scheme ◽  
Composition Of Capital

Various authors have concluded that there are different groupings that make it possible to explain the differences between companies in terms of their size, composition of capital or the degree of their evolution in terms of ICT and that within medium and small companies there are special dynamics that are necessary understand. This work is focused on this type of firms and a mixed methodology has been used to obtain data, which included the preparation of a field work supported by consultations with relevant personalities from academia, industry and consulting services in the area. It is proposed to draw an empirical scheme of the SME sector in Argentina, and results are presented in relation to the investment and adoption of ICT in these type of firms.

Grain size composition of broken rocks under different conditions of blasting

2019 ◽  
Vol 8 ◽  
pp. 83-94 ◽  
Author(s):  
B.R. Rakishev ◽  
◽  
A.A. Orynbay ◽  
A.M. Auezova ◽  
A.E. Kuttybaev ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Composition ◽  
Grain Size Composition

ANALYSIS OF THE MODERN GRAIN-SIZE COMPOSITION VARIABILITY OF THE ANAPA BAY-BAR BEACH SEDIMENTS

2018 ◽  
Author(s):  
В. Крыленко ◽  
V. Krylenko ◽  
Р. Косьян ◽  
R. Kos'yan ◽  
М. Крыленко ◽  
...  
Keyword(s):  
Grain Size ◽  
Bottom Sediments ◽  
Size Structure ◽  
Size Composition ◽  
Potential Danger ◽  
Grain Size Composition ◽  
Beach Sediments ◽  
Sediment Particles ◽  
Sand Material

The results of realized in 2010 field researches of the spatial and time grain-size structure variability of beach and bottom sediments of the bay-bar Anapskaya southern part are presented in this paper. Irretrievable carrying out of sediment particles to depths more than 7 m intensifies with their size decrease to 0,1 mm. As over 70 % bottom and about 60 % beach sediments are presented by fractions less 0,16 mm on bay-bar Anapskaya southern part, namely at this part there is sand material massive carrying out to depth. Potential danger of the investigated site geosystem degradation is revealed.

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.

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