Comment: Toward a definition of conservation principles for fisheries management

1997 ◽  
Vol 54 (11) ◽  
pp. 2720-2723 ◽  
Author(s):  
Stephen S Crawford ◽  
Bruce Morito
1995 ◽  
Vol 52 (7) ◽  
pp. 1584-1594 ◽  
Author(s):  
C. H. Olver ◽  
B. J. Shuter ◽  
C. K. Minns

Conservation, like beauty, is clearly in the eye of the beholder. The lack of a clear definition of what is meant by the term conservation, however, may encourage misconceptions about the degree to which biological objectives can be traded off against pressing economic and social objectives. Our purpose is to promote a dialogue about the meaning and practice of conservation, which might lead toward consensus on essential biological objectives. We present a brief history of the philosophical evolution of the term conservation and offer a definition of conservation based on the argument for an ecological ethic. This ethic requires that human benefits be derived in a sustainable manner and recognizes that human uses need to be reconciled with intrinsic and necessary ecosystemic functions and structures. We then present a preliminary set of operating principles applicable to the management of fish stocks that are consistent with an ecological or ecosystemic view of conservation. By proposing a set of conservation principles for fisheries management we hope to initiate a debate about just what those principles ought to be.


Marine Policy ◽  
2019 ◽  
Vol 100 ◽  
pp. 238-248 ◽  
Author(s):  
Abdul Halim ◽  
Budy Wiryawan ◽  
Neil R. Loneragan ◽  
Adrian Hordyk ◽  
M. Fedi A. Sondita ◽  
...  

1987 ◽  
Vol 44 (4) ◽  
pp. 913-918 ◽  
Author(s):  
M. P. Sissenwine ◽  
J. G. Shepherd

Biological reference points are used to guide fisheries management decisions. The reference points most often used are expressed in terms of fishing mortality rate (F). Fmsy relates to the maximization of sustainable yield. In principle, it is a most useful reference point, but in practice it is difficult to estimate. Fmax and F0.1 relate to certain levels of yield per recruit and are easily estimated, but they ignore conservation of the resource. Recruitment overfishing has usually been understood to occur when a population has been fished down to a point where recruitment is substantially reduced or fails. It has not been used as a basis for a biological reference point because the definition is vague and cannot be readily related to fishing mortality. Levels of spawning biomass below which recruitment seems to be reduced have been used, but their determination from available data is usually difficult and controversial. We propose an alternative definition of recruitment overfishing in terms of the level of fishing pressure that reduces the spawning biomass of a year class over its lifetime below the spawning biomass of its parents on average. Conventional models and types of data can be used to determine this level of F, denoted as Frep, which clearly relates to the replacement of spawning biomass and thus to sustainability of a population and yield in the long term.


1995 ◽  
Vol 31 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Willi Gujer ◽  
Tove A. Larsen

The Activated Sludge SIMulation program ASIM is introduced as a didactic tool to be used in design courses for the simulation of the dynamic behaviour of modern nutrient removal activated sludge systems. It allows for free definition of the biokinetic model, the flow scheme, process control strategies and load variation. Its user interface is simple enough to be used in the classroom but powerful enough to support even professional work. The most difficult aspect of ASIM is the preparation of the biokinetic model (transformation processes) to be used. A systematic use of stoichiometric conservation principles simplifies this task and at the same time reduces the number of empirical parameters. The practical application of conservation principles for charge, elements and theoretical COD is presented in detail. Composition equations are introduced as a link to the wastewater treatment plant reality.


2015 ◽  
Vol 73 (4) ◽  
pp. 1042-1050 ◽  
Author(s):  
Tara E. Dolan ◽  
Wesley S. Patrick ◽  
Jason S. Link

Abstract Ecosystem management (EM) suffers from linguistic uncertainty surrounding the definition of “EM” and how it can be operationalized. Using fisheries management as an example, we clarify how EM exists in different paradigms along a continuum, starting with a single-species focus and building towards a more systemic and multi-sector perspective. Focusing on the specification of biological and other systemic reference points (SRPs) used in each paradigm and its related regulatory and governance structures, we compare and contrast similarities among these paradigms. We find that although EM is a hierarchical continuum, similar SRPs can be used throughout the continuum, but the scope of these reference points are broader at higher levels of management. This work interprets the current state of the conversation, and may help to clarify the levels of how EM is applied now and how it can be applied in the future, further advancing its implementation.


1981 ◽  
Vol 38 (12) ◽  
pp. 1889-1898 ◽  
Author(s):  
J. A. MacLean ◽  
D. O. Evans

This paper examines the concept and definition of fish stocks and the processes that influence discreteness of these stocks in light of the tactics necessary for the application of the concept in management. Two approaches to the definition of stocks are discussed. These differ in the extent to which management inputs other than biological ones are considered. We consider definition to be less important than the adoption and development of a stock concept to provide a genetic perspective for fisheries management. The two central levels of the stock concept — the subdivision of species into local populations and the adaptive nature of genetic differences between these populations — are discussed with respect to the interlinked set of ecological and genetic processes that result in subdivision and determine the discreteness of these stocks. Genetic discreteness usually implies some restriction of gene flow, and spatial and temporal mechanisms of isolation are discussed with examples from the STOCS symposium. The structure of subdivided populations is seen as the result of behavioral processes that are one component of a set of coadapted traits, which collectively constitute a life history strategy. The necessity for managers to develop a new integrated view of species, which incorporates both ecological and genetic arguments, is discussed.Key words: stock concept, life history, gene flow, ecological and genetic discreteness, local adaptation stock management


2008 ◽  
Vol 65 (10) ◽  
pp. 2305-2314 ◽  
Author(s):  
Peter A. Shelton ◽  
Alan F. Sinclair

We review and evaluate the sustainability paradigm as it applies to wild capture fisheries in the context of a recently developed harvest strategy framework that, if implemented, will meet Canada’s national and international obligations with regard to sustainable fisheries. This framework is based on an operationally explicit definition of sustainability that includes a commitment to managing for maximum sustainable yield. Although Canadian policy strongly supports sustainable fisheries management in principle, usage of the term has been vague and implementation of sustainable fisheries management strategies has lagged. Fisheries managed under the recently developed framework would be better able to meet new ecocertification and ecolabelling standards. An emerging governance structure discussed herein with respect to fisheries management is conducive to implementing sustainable management practices that meet long-term public good objectives.


2020 ◽  
Vol 643 ◽  
pp. 145-158
Author(s):  
JD Zottoli ◽  
JS Collie ◽  
MJ Fogarty

Balanced harvesting has been proposed as a fisheries management strategy to mitigate the impacts of fisheries removal on ecosystem structure. One definition of balanced harvest is that all species should be harvested in proportion to their annual production. However, most marine ecosystems lack comprehensive production estimates necessary to empirically measure the degree of balance. We developed and tested 2 new methods for estimating fish biomass production at the species level with limited data requirements. Application of our techniques to 4 ecological production units in the northwest Atlantic (Mid-Atlantic Bight, Georges Bank, Gulf of Maine, and western Scotian Shelf) from 1991-2013 provided a direct estimate of 1.9 million t yr-1 of total fish production. The degree of balance between catch and production distributions at the species level, assessed using the proportional similarity index, ranged from 0.34 to 0.83 on a scale from near 0 to 1. Increased balance was positively associated with yield in the Gulf of Maine (Spearman’s, p = 0.04). Increased balance was negatively associated with an ecosystem impact indicator in the Gulf of Maine (Spearman’s, p = 0.03) and Mid-Atlantic Bight (Spearman’s, p = 0.02). These case studies provide some evidence of benefit to humans and reduced ecosystem harm from more balanced harvest. More importantly, we provide a unique empirical metric of balanced harvest at the species level, and develop potential indicators and methods for ecosystem-based fisheries management.


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