Multiple‐model stock assessment frameworks for precautionary management and conservation on fishery‐targeted coastal dolphin populations off Japan

2021 ◽  
Author(s):  
Yu Kanaji ◽  
Hikari Maeda ◽  
Hiroshi Okamura ◽  
André E. Punt ◽  
Trevor Branch
Keyword(s):  
Stock Assessment ◽  
Multiple Model ◽  
Management And Conservation ◽  
Precautionary Management

A framework to incorporate environmental effects into stock assessments informed by fishery-independent surveys: a case study with American lobster (Homarus americanus)

2020 ◽  
Vol 77 (10) ◽  
pp. 1700-1710
Author(s):  
Cameron T. Hodgdon ◽  
Kisei R. Tanaka ◽  
Jocelyn Runnebaum ◽  
Jie Cao ◽  
Yong Chen
Keyword(s):  
Environmental Variability ◽  
Stock Assessment ◽  
Homarus Americanus ◽  
Assessment Model ◽  
American Lobster ◽  
Multiple Model ◽  
Environmental Covariates ◽  
Model Based ◽  
Stock Assessments ◽  
Abundance Indices

Stock assessments for a majority of the world’s fisheries often do not explicitly consider the effects of environmental conditions on target species, which can raise model uncertainty and potentially reduce forecasting quality. Model-based abundance indices were developed using a delta generalized linear mixed model that incorporates environmental variability for use in stock assessment to understand how the incorporation of environmental variability impacts our understanding of population dynamics. For this study, multiple model-based abundance indices were developed to test the incorporation of environmental covariates in a length-structured assessment of the American lobster (Homarus americanus) stock in the Gulf of Maine – Georges Bank on the possible improvement of stock assessment quality. Comparisons reveal that modelled indices with environmental covariates appear to be more precise than traditional indices, but model performance metrics and hindcasted fishery statuses revealed that these improvements to indices may not necessarily mean an improved assessment. Model-based abundance indices are not intrinsically better than design-based indices and should be tested for each species individually.

Demographic and risk analyses applied to management and conservation of the blue shark (Prionace glauca) in the North Atlantic Ocean

2007 ◽  
Vol 58 (6) ◽  
pp. 570 ◽  
Author(s):  
Alexandre M. Aires-da-Silva ◽  
Vincent F. Gallucci
Keyword(s):  
Risk Analysis ◽  
North Atlantic ◽  
Stock Assessment ◽  
Assessment Process ◽  
Population Increase ◽  
Population Doubling ◽  
Blue Shark ◽  
The North ◽  
The North Atlantic ◽  
Management And Conservation

Management and conservation of the North Atlantic blue shark are handicapped by a fishery-data-limited stock-assessment process. The status of this stock is ambiguous at a time when catch appears to be on the rise and new trade and exploitation patterns are emerging. This research provides fishery-independent demographic and risk analysis results for use in conservation and management. An age-structured matrix population model in which the vital rates are stochastic was constructed. A mean finite rate of population increase (λ) of 1.23 year–1 and a mean population doubling time (t2) of 3.08 years suggests that the blue shark is one of the most productive shark species. However, this concept of high productivity could be misleading because an elasticity analysis shows a strong dependence of the population growth rate on the survival of juveniles (0–4 years). An analysis of the risk that the harvested population will decline to levels below an assumed threshold of 50% of pre-exploited levels was conducted. The risk analysis is proposed as a supplement to the data-limited stock assessment, to better evaluate the probability that a given management strategy will put the population at risk of decline.

FIRST RECORD AND INITIAL HYDROACOUSTIC STOCK ASSESSMENT OF POLLAN COREGONUS AUTUMNALIS PALLAS IN LOUGH ALLEN, IRELAND

2010 ◽  
Vol 110 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Andrew J. Harrison ◽  
Fiona L. Kelly ◽  
Robert S. Rosell ◽  
Trevor W.S. Champ ◽  
Lynda Connor ◽  
...  
Keyword(s):  
Stock Assessment ◽  
First Record

THE STOCK ASSESSMENT OF OTOLITHES RUBER IN NORTH-WEST ARABIAN GULF

2010 ◽  
Vol 23 (0) ◽  
pp. 1-14
Author(s):  
Amina A. Hashim ◽  
A.R.M.Mohamed ◽  
Amjad K. Resen
Keyword(s):  
Stock Assessment ◽  
Arabian Gulf ◽  
North West ◽  
Otolithes Ruber

IoT-TD: IoT Dataset for Multiple Model BLE-based Indoor Localization/Tracking

2021 ◽  
Author(s):  
Mohammad Salimibeni ◽  
Zohreh Hajiakhondi-Meybodi ◽  
Parvin Malekzadeh ◽  
Mohammadamin Atashi ◽  
Konstantinos N. Plataniotis ◽  
...  
Keyword(s):  
Indoor Localization ◽  
Multiple Model

Fecundity and Gonado-somatic Index of Trichiurus lepturus (Linnaeus, 1758) Along the Zamboanga del Norte Coast

2018 ◽  
Vol 6 (7) ◽  
pp. 120
Author(s):  
Ma. Dulce C. Guillena
Keyword(s):  
Sex Ratio ◽  
Stock Assessment ◽  
Chi Square ◽  
Moon Phases ◽  
Ovary Weight ◽  
Moment Coefficient ◽  
Trichiurus Lepturus ◽  
Significant Difference ◽  
The Relationship ◽  
Somatic Index

Gonado-somatic index and fecundity are tools for measuring the sexual maturity and ability of animals to reproduce.  This study investigates the reproduction of Trichiurus lepturus. Specifically, this aimed to determine the sex ratio, the GSI, the relationship between fecundity and total length, fecundity and total weight, fecundity and ovary weight. The Descriptive Method of research was used.  Percentage and chi-square was utilized in determining the percentage of occurrence and sex ratio respectively.   Pearson r Product Moment Coefficient of Correlation was used to determine the relationships of the parameters. The study revealed that females outnumbered males and the sex ratio for different month showed significant difference.  Spawning season was observed to occur in November and December as revealed in its GSI values and it synchronized with the full and new moon phases.  Fecundity is positively correlated with body weight, body size, and ovary weight where ovary weight is observed to be the best index for fecundity.  The results of this study could be used further for formal stock assessment of cutlassfish fishery.

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