scholarly journals Sensitivity of a benthic, metazoan, biomass size spectrum to differences in sediment granulometry

1999 ◽  
Vol 177 ◽  
pp. 73-81 ◽  
Author(s):  
DE Duplisea ◽  
A Drgas
Keyword(s):  
Size Spectrum ◽  
Biomass Size Spectrum

Models on the Slope of, and Biomass Flow up, the Biomass Size Spectrum

1987 ◽  
Vol 44 (S2) ◽  
pp. s136-s140 ◽  
Author(s):  
Uwe Borgmann
Keyword(s):  
Somatic Growth ◽  
Production Data ◽  
Food Chains ◽  
Size Spectrum ◽  
Allometric Relationship ◽  
Complex Models ◽  
Simple Equations ◽  
Growth And Reproduction ◽  
Biomass Size Spectrum ◽  
Number Of Authors

A comparison is made between the different models of the biomass size spectrum proposed by a number of authors. Though superficially dissimilar, the models are all mathematically compatible if the differences in their underlying assumptions are taken into account. The simplest model does not consider the complexities of food webs over food chains, somatic growth, or the continuous nature of the size spectrum. Comparison with the more complex models, however, shows that these omissions do not seriously affect the slope of the size spectrum. For example, one model predicts that the effects of somatic growth and reproduction cancel if cohort biomasses remain relatively constant as the cohorts mature. If growth rate is related to body size in an allometric relationship and reproduction is ignored, then another model gives a slightly different slope (higher by roughly 0.03). If the same assumptions are used in both models, however, they give compatible results. Some simple equations are suggested for routine application in size spectrum analysis of biomass and production data.

scholarly journals Evaluation of Fish Communities in Daya Bay Using Biomass Size Spectrum and ABC Curve

2021 ◽  
Vol 9 ◽  
Author(s):  
Shannan Xu ◽  
Jianzhong Guo ◽  
Yong Liu ◽  
Jiangtao Fan ◽  
Yayuan Xiao ◽  
...  
Keyword(s):  
Fish Communities ◽  
Breeding Population ◽  
Trophic Levels ◽  
Daya Bay ◽  
Size Spectrum ◽  
The Status ◽  
Unimodal Pattern ◽  
Severe Disturbance ◽  
Main Factor ◽  
Biomass Size Spectrum

Based on the data collected by four trawl surveys during 2016–2017, we applied biomass size spectrum (BSS) and abundance–biomass comparison (ABC) curve to assess the status of fish communities’ status in Daya Bay, China. Our findings indicated a unimodal pattern and biomass size ranged from −2 to 10 grain levels and the pattern of the Sheldon-type BSS of fish in Daya Bay. Moreover, fishes in the range of four to eight size class were relatively abundant. The highest peak belonged to the two to four grain level (log2 size bins), mainly consisting of Leiognathus brevirostris, Callionymus meridionalis, Callionymus koreanus, Evynnis cardinalis, Trachurus japonicus, and other small fishes. The curves of the BSS in spring and winter were relatively flat and comprised a large curvature. The summer and autumn curves were comparatively steep, and the seasonal curvature was small. The curvatures of the curve were mainly related to a large number of small Evynnis cardinalis and a small number of large-sized Harpadon nehereus and Leiognathus ruconius. In our study, it was observed that the number and the size of the breeding population, trophic levels, migration habits, and other life history characteristics, as well as anthropogenic disturbances (especially overfishing), significantly affected the peak shape, slope, or curvature of the fish BSS, with overfishing being the main factor. The ABC curve exhibited that Daya Bay was in a critical state of disturbance throughout the year. The spring, summer, and autumn were in severe disturbance, while the winter was in moderate disturbance.

An Ecological Approach to Fisheries Assessment

1987 ◽  
Vol 44 (S2) ◽  
pp. s68-s74 ◽  
Author(s):  
L M. Dickie ◽  
S. R. Kerr ◽  
P. Schwinghamer
Keyword(s):  
Spatial Distribution ◽  
Ecological Approach ◽  
Size Spectrum ◽  
Natural Mortality ◽  
Assessment Methodology ◽  
Ecological Information ◽  
Production Parameters ◽  
Theoretical Considerations ◽  
Data Requirements ◽  
Biomass Size Spectrum

Deductions based on recent ecological information suggest that while current fishery assessment methodology has captured the main features of fishery production, it may not well anticipate the effects of early natural mortality or of major changes in fishing. We propose here a new methodology based on ecological theory related to a characteristic biomass size spectrum. Theoretical considerations coupled with empirical data on population production appear to take into account high natural mortalities at small sizes and the effects of spatial distribution on production parameters throughout the life history. The resulting models offer a somewhat modified view of the relation of fishery yield to effort and the prospect of population assessments with more modest data requirements.

A Review of Methods for Prediction of Potential Fish Production with Application to the Great Lakes and Lake Winnipeg

1987 ◽  
Vol 44 (S2) ◽  
pp. s471-s485 ◽  
Author(s):  
J. H. Leach ◽  
L. M. Dickie ◽  
B. J. Shuter ◽  
U. Borgmann ◽  
J. Hyman ◽  
...  
Keyword(s):  
Great Lakes ◽  
Empirical Models ◽  
Production Model ◽  
Size Spectrum ◽  
Fish Production ◽  
Lake Winnipeg ◽  
Fish Yield ◽  
Sustained Yield ◽  
Spectrum Model ◽  
Biomass Size Spectrum

Methods for estimating fish production in aquatic ecosystems range from simple empirically derived estimators, such as morphoedaphic indices, to complex ecosystem simulation models. As first-order estimators, the former are attractive to managers because they are simple and relatively inexpensive to apply and interpret. Application of the latter group has been limited because many of the data inputs are difficult and expensive to obtain. Between these extremes are several models, such as the biomass–size spectrum model, that provide useful information for moderate expenditures of time and effort. Existing and new methods are reviewed in the light of production theory and several are applied to Great Lakes and Lake Winnipeg data. Eight empirical models derived from limnological variables were selected from the literature and used to estimate potential fish yield for the Great Lakes and Lake Winnipeg. The models predicted a fairly narrow range of potential yields, but when compared with historic yields, none was consistent for all lakes. The best overall empirically derived estimator of potential yield in the Great Lakes was the morphoedaphic index. Potential fish production estimated from invertebrate production with Borgmann's biomass – size spectrum model was considerably greater than historic yields or the yield estimates from the empirical models. In a third approach, we calculated life history parameters for "small" and "large" fish in the Great Lakes and combined these with Borgmann's production model, empirical information on population production/biomass ratios from the literature, and classical population dynamics theory to estimate potential production and optimum sustained yield for each group. Historic sustained yield, as a percentage of optimum sustained yield, varied from a low of 6 for "small" Lake Ontario fish to 100 for "large" Lake Erie fish.

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