scholarly journals Regional trade-offs from multi-species maximum sustainable yield (MMSY) management options

2014 ◽  
Vol 498 ◽  
pp. 1-12 ◽  
Author(s):  
R Voss ◽  
MF Quaas ◽  
JO Schmidt ◽  
J Hoffmann
Author(s):  
Ken H. Andersen

This chapter uses the community model to repeat many of the classic impact calculations of a single stock on the entire community. Here, a focus is the appearance of trophic cascades initiated by the removal of large predators. When a component of an ecosystem is perturbed, the effects are not isolated to the component itself but cascade through the ecosystem. Perturbations are mainly propagated through the predator–prey interactions. The chapter also considers the trade-offs between a forage fishery and a consumer fishery, and the extension of the maximum sustainable yield (MSY) concept to the community, before finally returning to the single-stock aspects.


2018 ◽  
Vol 75 (10) ◽  
pp. 1663-1679 ◽  
Author(s):  
Manuel Bellanger ◽  
Claire Macher ◽  
Mathieu Merzéréaud ◽  
Olivier Guyader ◽  
Christelle Le Grand

An individual-based bio-economic model is presented and applied to the Bay of Biscay sole (Solea solea) fishery to investigate alternative quota management systems from a multicriteria perspective. For this study, the model integrates several institutional arrangements related to catch share management. The current French co-management system with nontransferability of quota is compared with an alternative individual transferable quota (ITQ) system in a context of transition to maximum sustainable yield. Trade-offs between ecological and socioeconomic impacts are highlighted and the effectiveness of governance scenarios is discussed in regard to the challenge of capacity adjustment. Results emphasize that the introduction of ITQs is expected to reduce by 40% the number of vessels in the fishery. While effectively mitigating the economic impacts of the transition phase to maximum sustainable yield, ITQs are also expected to increase substantially the fishing effort by trawlers, which may cause ecological concerns. The scenarios tested also include the simulation of a decommissioning scheme where subsequent decommissioned vessels are considerably different from the vessels that would lease out their quotas in an ITQ system, resulting in differentiated ecological and socioeconomic impacts between scenarios.


2016 ◽  
Vol 74 (2) ◽  
pp. 566-575 ◽  
Author(s):  
Clara Ulrich ◽  
Youen Vermard ◽  
Paul J. Dolder ◽  
Thomas Brunel ◽  
Ernesto Jardim ◽  
...  

Achieving single species maximum sustainable yield (MSY) in complex and dynamic fisheries targeting multiple species (mixed fisheries) is challenging because achieving the objective for one species may mean missing the objective for another. The North Sea mixed fisheries are a representative example of an issue that is generic across most demersal fisheries worldwide, with the diversity of species and fisheries inducing numerous biological and technical interactions. Building on a rich knowledge base for the understanding and quantification of these interactions, new approaches have emerged. Recent paths towards operationalizing MSY at the regional scale have suggested the expansion of the concept into a desirable area of “pretty good yield”, implemented through a range around FMSY that would allow for more flexibility in management targets. This article investigates the potential of FMSY ranges to combine long-term single-stock targets with flexible, short-term, mixed-fisheries management requirements applied to the main North Sea demersal stocks. It is shown that sustained fishing at the upper bound of the range may lead to unacceptable risks when technical interactions occur. An objective method is suggested that provides an optimal set of fishing mortality within the range, minimizing the risk of total allowable catch mismatches among stocks captured within mixed fisheries, and addressing explicitly the trade-offs between the most and least productive stocks.


Author(s):  
Daniel Pauly ◽  
Rainer Froese

Abstract The maximum sustainable yield (MSY) concept is widely considered to be outdated and misleading. In response, fisheries scientists have developed models that often diverge radically from the first operational version of the concept. We show that the original MSY concept was deeply rooted in ecology and that going back to that version would be beneficial for fisheries, not least because the various substitutes have not served us well.


Author(s):  
John Tzilivakis ◽  
Kathleen Lewis ◽  
Andrew Green ◽  
Douglas Warner

Purpose – In order to achieve reductions in greenhouse gas (GHG) emissions, it is essential that all industry sectors have the appropriate knowledge and tools to contribute. This includes agriculture, which is considered to contribute about a third of emissions globally. This paper reports on one such tool: IMPACCT: Integrated Management oPtions for Agricultural Climate Change miTigation. The paper aims to discuss these issues. Design/methodology/approach – IMPACCT focuses on GHGs, carbon sequestration and associated mitigation options. However, it also attempts to include information on economic and other environmental impacts in order to provide a more holistic perspective. The model identifies mitigation options, likely economic impacts and any synergies and trade-offs with other environmental objectives. The model has been applied on 22 case study farms in seven Member States. Findings – The tool presents some useful concepts for developing carbon calculators in the future. It has highlighted that calculators need to evolve from simply calculating emissions to identifying cost-effective and integrated emissions reduction options. Practical implications – IMPACCT has potential to become an effective means of provided targeted guidance, as part of a broader knowledge transfer programme based on an integrated suite of guidance, tools and advice delivered via different media. Originality/value – IMPACCT is a new model that demonstrates how to take a more integrated approach to mitigating GHGs on farms across Europe. It is a holistic carbon calculator that presents mitigation options in the context other environmental and economic objectives in the search for more sustainable methods of food production.


1978 ◽  
Vol 35 (9) ◽  
pp. 1249-1261 ◽  
Author(s):  
G. H. Winters

From recent and historical data the natural mortality rate of adult harp seals (Pagophilus groenlandicus) is estimated to be 0.10 which is within the range of previous estimates (0.08–0.11). New estimates of bedlamer and 0-group natural mortality rates were not significantly different from those of adult seals. Pup production estimates from survival indices agreed well with those from sequential population analyses and indicated a decline from about 350 000 animals in the early 1950s to about 310 000 animals in the early 1970s. Over the same period the 1+ population size declined from 2.5 to 1.1 million animals but has been increasing at the rate of 3%/yr since the introduction of quotas in 1972. The relative contribution of the "Front" production to total ("Front" plus Gulf) production during the past decade has fluctuated from 49 to 87%, the average of 64% being very similar to the 61% obtained previously. These fluctuations suggest some interchange between "Front" and Gulf adults and it is concluded that homing in the breeding areas is a facultative rather than obligatory aspect of seal behavior. Thus the heavier exploitation of the "Front" production is probably sufficiently diffused into the total population to avoid serious effects on "Front" production. The maximum sustainable yield of Northwest Atlantic seals harvested according to recent patterns is estimated to be 290 000 animals (80% pups) from a 1+ population size of 1.8 million animals producing 460 000 pups annually. The sustainable yield at present levels of pup production (335 000 animals) is calculated to be 220 000 animals which is substantially above the present TAC of 180 000 animals and coincides with present harvesting strategies designed to enable the seal hunt to increase slowly towards the MSY level. Key words: mortality, production, sustainable yield, population dynamics, marine mammal


2013 ◽  
Vol 70 (6) ◽  
pp. 1075-1080 ◽  
Author(s):  
Christopher M. Legault ◽  
Elizabeth N. Brooks

Abstract Legault, C. M., and Brooks, E. N. 2013. Can stock–recruitment points determine which spawning potential ratio is the best proxy for maximum sustainable yield reference points? – ICES Journal of Marine Science, 70: 1075–1080. The approach of examining scatter plots of stock–recruitment (S–R) estimates to determine appropriate spawning potential ratio (SPR)-based proxies for FMSY was investigated through simulation. As originally proposed, the approach assumed that points above a replacement line indicate year classes that produced a surplus of spawners, while points below that line failed to achieve replacement. In practice, this has been implemented by determining Fmed, the fishing mortality rate that produces a replacement line with 50% of the points above and 50% below the line. A new variation on this approach suggests FMSY proxies can be determined by examining the distribution of S–R points that are above or below replacement lines associated with specific SPRs. Through both analytical calculations and stochastic results, we demonstrate that this approach is fundamentally flawed and that in some cases the inference is diametrically opposed to the method's intended purpose. We reject this approach as a tool for determining FMSY proxies. We recommend that the current proxy of F40% be maintained as appropriate for a typical groundfish life history.


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