scholarly journals A simulation framework for evaluating fisheries management decisions using environmental information

2013 ◽  
Vol 70 (4) ◽  
pp. 743-754 ◽  
Author(s):  
Dankert W. Skagen ◽  
Mette Skern-Mauritzen ◽  
Dorothy Dankel ◽  
Katja Enberg ◽  
Olav S. Kjesbu ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Fisheries Management ◽  
Environmental Information ◽  
Environmental Indicators ◽  
Environmental Drivers ◽  
Simulation Framework ◽  
Management Decisions ◽  
Management Scenarios ◽  
Environmental Signals ◽  
Fish Stocks

Abstract Skagen, D. W., Skern-Mauritzen, M., Dankel, D., Enberg, K., Kjesbu, O. S., and Nash, R. D. M. 2013. A simulation framework for evaluating fisheries management decisions using environmental information. – ICES Journal of Marine Science, 70: 743–754. The population dynamics of marine fish stocks are influenced by both physical and biological conditions. Yet, such environmental impacts on stock dynamics, and hence stock production, are rarely included in applied fisheries management. To test the utility of taking ecosystem information into account in management decisions requires efficient tools. We propose a simulation framework for evaluating fisheries management schemes that use environmental information as part of the decision basis. A key feature is to link environmental signals to parameters in functions that define the population dynamics. This allows a direct incorporation of environmental drivers into models of population dynamic processes and emphasizes the need for a quantitative understanding of the influence of environmental drivers on such processes. The utility of the simulation framework is demonstrated through a worked example with different management scenarios, where decisions to increase or decrease the exploitation rely on environmental indicators only, or also on information on stock abundance. In this example, a management that was based on indicators only, without updated measures of the state of the stock itself, failed to respond adequately to changes in stock productivity.

scholarly journals Physiological biomarkers and fisheries management

2021 ◽  
Author(s):  
Pablo Brosset ◽  
Steven J. Cooke ◽  
Quentin Schull ◽  
Verena M. Trenkel ◽  
Philippe Soudant ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Species Conservation ◽  
Population Level ◽  
Fish Stock ◽  
Stock Management ◽  
Management Scenarios ◽  
Fish Stocks ◽  
Fisheries Science ◽  
Mechanistic Basis ◽  
Species Specific

AbstractThe benefits of physiological biomarkers, knowledge and concepts are well-established in fish and wildlife management as they confer the ability to understand mechanistic processes, identify cause-and-effect relationships, and develop predictive models. Although this approach is gaining momentum in the context of species conservation, the use of physiological biomarkers in exploited marine fish stock management and recovery plans remains relatively rare. Here, we present five essential issues to consider to implement physiological biomarkers in fisheries management: (i) choice of relevant biomarkers that have a well-known mechanistic basis, (ii) identification of species-specific biomarkers reflecting a meaningful timespan for management, (iii) selection of biomarkers compatible with data collection during routine scientific fisheries surveys, (iv) use of biomarkers as early-warning signals and complementary indicators of population-level changes in life history traits and (v) how physiological biomarkers may help to refine long-term population dynamic projections under climate change and management scenarios. Overall, if based on well-established mechanisms linked to individuals’ fitness, a focus on physiological biomarkers should help to better understand the mechanisms behind stock declines, changes in stock characteristics, and thus more efficiently manage marine fisheries and conserve populations. As this approach is transferable among species, locations, and times, the integration of physiological biomarkers in fisheries science has the potential to more broadly enhance assessments and management of fish stocks.

Implementing Existing Tools: Turning Words Into Actions – Decision-Making Processes of Regional Fisheries Management Organisations (RFMOs)

2005 ◽  
Vol 20 (3) ◽  
pp. 423-457 ◽  
Author(s):  
Ted McDorman
Keyword(s):  
Decision Making ◽  
Fisheries Management ◽  
Sustainable Management ◽  
Decision Making Process ◽  
Migratory Fish ◽  
Management Decisions ◽  
Fish Stocks ◽  
Management Measures ◽  
Decision Making Processes ◽  
Regional Fisheries Management

AbstractThis paper deals with decision-making processes within those regional fisheries management organisations (RFMOs) with the capacity to adopt management measures respecting either straddling or highly migratory fish stocks. The perception is that the decisions emanating from RFMOs are not achieving the goal of sustainable management of the fish stocks. Concerns raised in this regard are the perceived: non-adherence of RFMO decisions to science; lack of timeliness in making decisions; ability of RFMO members to avoid certain decisions; and adoption of management decisions that are not sufficiently rigorous. This contribution does not seek to evaluate the validity of the perception, rather it explores the manner in which RFMO conventions (the constitutive texts of RFMOs) deal with the decision-making process by looking at the trends within RFMOs, the challenges that exist and suggests ways to meet the challenges.

scholarly journals Environmental Drivers and Age Trends in Site Productivity for Oak in Southern Poland

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 209
Author(s):  
Luiza Tymińska-Czabańska ◽  
Jarosław Socha ◽  
Marek Maj ◽  
Dominika Cywicka ◽  
Xo Viet Hoang Duong
Keyword(s):  
Nitrogen Deposition ◽  
Management Practices ◽  
Additive Model ◽  
Climatic Conditions ◽  
Environmental Indicators ◽  
Environmental Drivers ◽  
Site Productivity ◽  
Site Factors ◽  
Wide Range ◽  
Si Model

Site productivity provides critical information for forest management practices and is a fundamental measure in forestry. It is determined using site index (SI) models, which are developed using two primary groups of methods, namely, phytocentric (plant-based) or geocentric (earth-based). Geocentric methods allow for direct site growth modelling, in which the SI is predicted using multiple environmental indicators. However, changes in non-static site factors—particularly nitrogen deposition and rising CO2 concentration—lead to an increase in site productivity, which may be visible as an age trend in the SI. In this study, we developed a geocentric SI model for oak. For the development of the SI model, we used data from 150 sample plots, representing a wide range of local topographic and site conditions. A generalized additive model was used to model site productivity. We found that the oak SI depended predominantly on physicochemical soil properties—mainly nitrogen, carbon, sand, and clay content. Additionally, the oak SI value was found to be slightly shaped by the topography, especially by altitude above sea level, and topographic position. We also detected a significant relationship between the SI and the age of oak stands, indicating the long-term increasing site productivity for oak, most likely caused by nitrogen deposition and changes in climatic conditions. The developed geocentric site productivity model for oak explained 77.2% of the SI variation.

Taking Stock of Genetic Concepts in Fisheries Management

1991 ◽  
Vol 48 (4) ◽  
pp. 722-731 ◽  
Author(s):  
R. W. Gauldie
Keyword(s):  
Fisheries Management ◽  
Growth Rates ◽  
Allele Frequencies ◽  
Frequency Variation ◽  
Sustainable Yield ◽  
Fish Stocks ◽  
Meristic Count ◽  
Intuitive Idea ◽  
Selection Mechanisms ◽  
Insight Into

The historical development of the idea of isolated stocks of fish that can be managed as separate management units has been as strongly tied to the intuitive idea of separate races as it has been to the practical necessities of jurisprudence and the estimation of both biomass and sustainable yield by fisheries managers. Demonstrating the existence of isolated fish stocks and delineating their boundaries has generally proved unsuccessful. Various techniques ranging from meristic count differences to polymorphic allelism have usually failed. However, in the pursuit of isolated stocks, biochemists have uncovered a great deal of information about the variation of polymorphic allele frequencies over time and space. Following the shift in opinion away from stochastic to natural selection mechanisms in allele frequency variation, it is evident that the observed variation in allele frequencies allows more insight into the biology of fishes than into the breeding structure of populations. These insights argue against the idea of isolated stocks of fish with homogeneous growth rates that are the basis of the sustainable yield models in favour of migration-linked stocks with heterogeneous growth rates.

scholarly journals Depleted marine fish stocks and ecosystem-based management: on the road to recovery, we need to be precautionary

2010 ◽  
Vol 68 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Anna Gårdmark ◽  
Anders Nielsen ◽  
Jens Floeter ◽  
Christian Möllmann
Keyword(s):  
Fisheries Management ◽  
Marine Fish ◽  
Assessment Model ◽  
Fishing Mortality ◽  
Fish Stocks ◽  
The Road ◽  
Stock Status ◽  
Ecosystem Based Management ◽  
Management Plans ◽  
On The Road

Abstract Gårdmark, A., Nielsen, A., Floeter, J., and Möllmann, C. 2011. Depleted marine fish stocks and ecosystem-based management: on the road to recovery, we need to be precautionary. – ICES Journal of Marine Science, 68: 212–220. Precautionary management for fish stocks in need of recovery requires that likely stock increases can be distinguished from model artefacts and that the uncertainty of stock status can be handled. Yet, ICES stock assessments are predominantly deterministic and many EC management plans are designed for deterministic advice. Using the eastern Baltic cod (Gadus morhua) stock as an example, we show how deterministic scientific advice can lead to illusive certainty of a rapid stock recovery and management decisions taken in unawareness of large uncertainties in stock status. By (i) performing sensitivity analyses of key assessment model assumptions, (ii) quantifying the uncertainty of the estimates due to data uncertainty, and (iii) developing alternative stock and ecosystem indicators, we demonstrate that estimates of recent fishing mortality and recruitment of this stock were highly uncertain and show that these uncertainties are crucial when combined with management plans based on fixed reference points of fishing mortality. We therefore call for fisheries management that does not neglect uncertainty. To this end, we outline a four-step approach to handle uncertainty of stock status in advice and management. We argue that it is time to use these four steps towards an ecosystem-based approach to fisheries management.

scholarly journals Fisheries Management Under Cyclical Population Dynamics

2008 ◽  
Vol 42 (3) ◽  
pp. 379-410 ◽  
Author(s):  
Richard T. Carson ◽  
Clive Granger ◽  
Jeremy Jackson ◽  
Wolfram Schlenker
Keyword(s):  
Population Dynamics ◽  
Fisheries Management

scholarly journals Opportunity for marine fisheries reform in China

2017 ◽  
Vol 114 (3) ◽  
pp. 435-442 ◽  
Author(s):  
Ling Cao ◽  
Yong Chen ◽  
Shuanglin Dong ◽  
Arthur Hanson ◽  
Bo Huang ◽  
...  
Keyword(s):  
Resource Management ◽  
Fisheries Management ◽  
Cultural Context ◽  
Scientific Data ◽  
Coastal Development ◽  
Chinese Government ◽  
Marine Fisheries ◽  
Marine Resource ◽  
Fish Stocks ◽  
Marine Resource Management

China’s 13th Five-Year Plan, launched in March 2016, provides a sound policy platform for the protection of marine ecosystems and the restoration of capture fisheries within China’s exclusive economic zone. What distinguishes China among many other countries striving for marine fisheries reform is its size—accounting for almost one-fifth of global catch volume—and the unique cultural context of its economic and resource management. In this paper, we trace the history of Chinese government priorities, policies, and outcomes related to marine fisheries since the 1978 Economic Reform, and examine how the current leadership’s agenda for “ecological civilization” could successfully transform marine resource management in the coming years. We show how China, like many other countries, has experienced a decline in the average trophic level of its capture fisheries during the past few decades, and how its policy design, implementation, and enforcement have influenced the status of its wild fish stocks. To reverse the trend in declining fish stocks, the government is introducing a series of new programs for sustainable fisheries and aquaculture, with greater traceability and accountability in marine resource management and area controls on coastal development. As impressive as these new plans are on paper, we conclude that serious institutional reforms will be needed to achieve a true paradigm shift in marine fisheries management in China. In particular, we recommend new institutions for science-based fisheries management, secure fishing access, policy consistency across provinces, educational programs for fisheries managers, and increasing public access to scientific data.

scholarly journals Contrasting effects of climate change on seasonal survival of a hibernating mammal

2020 ◽  
Vol 117 (30) ◽  
pp. 18119-18126 ◽  
Author(s):  
Line S. Cordes ◽  
Daniel T. Blumstein ◽  
Kenneth B. Armitage ◽  
Paul J. CaraDonna ◽  
Dylan Z. Childs ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Life History ◽  
Environmental Conditions ◽  
Temporal Trends ◽  
Life History Strategies ◽  
Environmental Drivers ◽  
Age Classes ◽  
History Of ◽  
Colorado Rocky Mountains

Seasonal environmental conditions shape the behavior and life history of virtually all organisms. Climate change is modifying these seasonal environmental conditions, which threatens to disrupt population dynamics. It is conceivable that climatic changes may be beneficial in one season but result in detrimental conditions in another because life-history strategies vary between these time periods. We analyzed the temporal trends in seasonal survival of yellow-bellied marmots (Marmota flaviventer) and explored the environmental drivers using a 40-y dataset from the Colorado Rocky Mountains (USA). Trends in survival revealed divergent seasonal patterns, which were similar across age-classes. Marmot survival declined during winter but generally increased during summer. Interestingly, different environmental factors appeared to drive survival trends across age-classes. Winter survival was largely driven by conditions during the preceding summer and the effect of continued climate change was likely to be mainly negative, whereas the likely outcome of continued climate change on summer survival was generally positive. This study illustrates that seasonal demographic responses need disentangling to accurately forecast the impacts of climate change on animal population dynamics.

scholarly journals Costs and Returns of Fishermen in the Massachusetts Inshore Lobster Fishery

1975 ◽  
Vol 4 (2) ◽  
pp. 195-210 ◽  
Author(s):  
J. M. Gates ◽  
J. M. D'Eugenio
Keyword(s):  
Fisheries Management ◽  
Fishing Effort ◽  
The State ◽  
Economic Factors ◽  
Sufficient Criterion ◽  
Fish Stocks ◽  
The Past ◽  
Resource Managers ◽  
Lobster Fishery

The inshore lobster fishery is one of the more important ones in the Commonwealth of Massachusetts, accounting for approximately 14 percent of the total landed value of all species in Massachusetts in 1971. Until recent years this fishery accounted for virtually all the pot landings in the state. Despite numerous attempts at conservation such as gear regulation, size restrictions, and prohibitions on harvesting egg-bearing females, the fishery has been subject to rapidly increasing effort and virtually constant landings. In the past decade it has become obvious to many fishery biologists and economists that conservation of fish stocks is a necessary but not sufficient criterion for fisheries management. Resource managers have become increasingly aware of the interdependence between economic factors and the intensity, location and composition of fishing effort.

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