152 research outputs found
Long-term changes and recurrent patterns in fisheries landings from Large Marine Ecosystems (1950â2004)
The regional dynamics of industrial fisheries within Large Marine Ecosystems (LMEs) boundaries were investigated by means of a historical-descriptive approach. Landings data from the Sea Around Us Project database were used to detect trends in total yields and variations in landings composition by functional groups over time. The temporal and spatial scales covered by this study allowed general issues to be addressed such as the detection of recurrent patterns and synchronies in fisheries landings. An unsuper-vised artificial neural network, Self Organizing Map (SOM), is used as a tool to analyze fisheries landings composition variation over five decades in 51 LMEs all over the world. From the historical analysis of âfishing behaviorsâ within LMEs a broad distinction between two main types of fisheries emerged: (1) small and medium pelagics fisheries, with stable compositions or cyclic behaviors, occurred in LMEs which share common productive features, despite different geographical locations and (2) demersal fisheries, which are more affected by economic drivers and tend to concentrate in LMEs in the Northern Hemisphere. Our analysis can be regarded as a first step towards the challenging scope of describing the relative influence of environmental and economic drivers on exploited ecosystems
The influence of environmental variables on the functional structure of headwater stream fish assemblages: a study of two tropical basins in Central Brazil
Divergent reaction of fish metrics to human pressures in fish assemblage types in Europe
The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper ParanĂĄ River basin, Brazil
Changes in the structure of fish assemblages in streams along an undisturbed-impacted gradient, upper ParanĂĄ River basin, Central Brazil
Estudo comparado da taxocenose de peixes em dois ambientes aquĂĄticos do Parque Estadual de ItapuĂŁ, sul do Brasil
Patterns in fish species composition and assemblage structure in the upper Salado River lakes, Pampa Plain, Argentina
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