The Development of Environmental Regimes

2020 ◽  
pp. 87-163
Author(s):  
Pamela S. Chasek ◽  
David L. Downie
Keyword(s):  
Environmental Regimes

Detecting environmental regimes in fish stock-recruitment relationships by fuzzy logic

2001 ◽  
Vol 58 (11) ◽  
pp. 2139-2148 ◽  
Author(s):  
D G Chen
Keyword(s):  
Fuzzy Logic ◽  
Environmental Variable ◽  
Clupea Harengus ◽  
Fish Stock ◽  
Environmental Regimes ◽  
Fuzzy Logic Approach ◽  
Stock Recruitment ◽  
Logic Approach ◽  
Traditional Approaches ◽  
The Impact

A fuzzy logic approach is developed to model and test the impact of environmental regimes on fish stock–recruitment relationships. Traditional methods use environmental variables to classify stock–recruitment data into different membership percentiles followed by fitting the stock–recruitment models for each subset. In contrast, the fuzzy logic approach uses a continuous membership function to provide a rational basis for the classification. Thus, parameter estimation is based on a more logically consistent foundation without resorting to subjective partitions. This new approach is applied to herring stock from the west coast of Vancouver Island (Clupea harengus pallasi) using sea surface temperature as the environmental variable and to Pacific halibut stock (Hippoglossus stenolepis) using the Pacific Decadal Oscillation as the environmental variable. From these applications, the herring stock–recruitment relationships were found to vary significantly during different regimes, whereas this was not the case for halibut. However, in both instances, the fuzzy logic approach demonstrated that density-dependent effects differed between regimes. The fuzzy logic model consistently outperformed traditional approaches as measured by several diagnostic criteria. Because fuzzy logic models address uncertainty better than traditional approaches, they have the potential to improve our ability to understand factors influencing stock–recruitment relationships and thereby manage fisheries more effectively.

The Swordfish Dispute between the EU and Chile at the ITLOS and the WTO

2002 ◽  
Vol 71 (1) ◽  
pp. 55-81 ◽  
Author(s):  
Keyword(s):  
International Law ◽  
World Trade Organisation ◽  
Law Of The Sea ◽  
The European Union ◽  
Environmental Regimes ◽  
The World ◽  
Core Elements ◽  
Distant Water Fishing ◽  
Gatt 1994 ◽  
The Eu

AbstractDuring the 1990s and beyond, the European Union (EU) and Chile have been engaged in a controversy over highly migratory swordfish stocks in the South Pacific. Following disputes over Cod, Turbot, and Tuna, the Swordfish Case reveals outstanding problems in the international law of fisheries. The Swordfish Case attracts further attention, as it involves proceedings both at the International Tribunal for the Law of the Sea and at the World Trade Organisation, with potentially inconsistent decisions. At the WTO, the EU's assertion of a right to access Chilean ports on the grounds of GATT 1994 freedom of transit provisions bears an impact on the use of ports in countries around the world. At the ITLOS Chamber, the long-standing conflict between distant water fishing nations and coastal states is once again to the fore. Although the parties to the dispute arrived at a provisional agreement, setting out to establish a scientific fisheries program and a conservation framework, the issues involved in the swordfish controversy highlight the tensions among the international maritime, economic, and environmental regimes. The article offers an overall account of the core elements of the swordfish dispute.

scholarly journals Changes in size at maturity of European hake Atlantic populations in relation with stock structure and environmental regimes

2008 ◽  
Vol 71 (3-4) ◽  
pp. 260-278 ◽  
Author(s):  
Rosario Domínguez-Petit ◽  
María Korta ◽  
Fran Saborido-Rey ◽  
Hilario Murua ◽  
María Sainza ◽  
...  
Keyword(s):  
Stock Structure ◽  
Size At Maturity ◽  
Environmental Regimes ◽  
European Hake

scholarly journals Selection on wing allometry in Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 126 (4) ◽  
pp. 975-989 ◽  
Author(s):  
K E Weber
Keyword(s):  
Drosophila Melanogaster ◽  
Additive Genetic Variance ◽  
Bivariate Distribution ◽  
Local Optimum ◽  
Phenotypic Variance ◽  
Isofemale Lines ◽  
Developmental Patterns ◽  
Environmental Regimes ◽  
The Mean ◽  
Lateral Offset

Abstract Five bivariate distributions of wing dimensions of Drosophila melanogaster were measured, in flies 1) subjected to four defined environmental regimes during development, 2) taken directly from nature in seven U.S. states, 3) selected in ten populations for change in wing form, and 4) sampled from 21 long inbred wild-type lines. Environmental stresses during development altered both wing size and the ratios of wing dimensions, but regardless of treatment all wing dimensions fell near a common allometric baseline in each bivariate distribution. The wings of wild-caught flies from seven widely separated localities, and of their laboratory-reared offspring, also fell along the same baselines. However, when flies were selected divergently for lateral offset from these developmental baselines, response to selection was rapid in every case. The mean divergence in offset between oppositely selected lines was 14.68 SD of the base population offset, after only 15 generations of selection at 20%. Measurements of 21 isofemale lines, founded from wild-caught flies and maintained in small populations for at least 22 years, showed large reductions in phenotypic variance of offsets within lines, but a large increase in the variance among lines. The variance of means of isofemale lines within collection localities was ten times the variance of means among localities of newly established wild lines. These observations show that much additive genetic variance exists for individual dimensions within the wing, such that bivariate developmental patterns can be changed in any direction by selection or by drift. The relative invariance of the allometric baselines of wing morphology in nature is most easily explained as the result of continuous natural selection around a local optimum of functional design.

The role of the geophysical template and environmental regimes in controlling stream-living trout populations

2015 ◽  
Vol 72 (6) ◽  
pp. 893-901 ◽  
Author(s):  
Brooke E. Penaluna ◽  
Steve F. Railsback ◽  
Jason B. Dunham ◽  
Sherri Johnson ◽  
Robert E. Bilby ◽  
...  
Keyword(s):  
Fish Habitat ◽  
Spatiotemporal Variability ◽  
Sensitivity Analyses ◽  
Low Flow ◽  
Aquatic Biota ◽  
Relative Role ◽  
Oncorhynchus Clarkii ◽  
Environmental Regimes ◽  
Multiple Processes

The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus environmental regimes on biomass of trout (Oncorhynchus clarkii clarkii). We parameterized the model with observed data from each of the four headwater streams (their local geophysical template and environmental regime) and then ran 12 simulations where we replaced environmental regimes (stream temperature, flow, turbidity) of a given stream with values from each neighboring stream while keeping the geophysical template fixed. We also performed single-parameter sensitivity analyses on the model results from each of the four streams. Although our modeled findings show that trout biomass is most responsive to changes in the geophysical template of streams, they also reveal that biomass is restricted by available habitat during seasonal low flow, which is a product of both the stream’s geophysical template and flow regime. Our modeled results suggest that differences in the geophysical template among streams render trout more or less sensitive to environmental change, emphasizing the importance of local fish–habitat relationships in streams.

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