نتایج جستجو برای: fish assemblages

تعداد نتایج: 115654  

Journal: :Ecotoxicology and environmental safety 2004
Consuelo Aguilar Gaspar González-Sansón Kelly R Munkittrick Deborah L MacLatchy

It is difficult to separate effects on fish community assemblages due to anthropogenic stressors from natural factors. We examined small-bodied-fish communities along the northern coast of Cuba near Havana Harbor during the dry (February/March of 2000) and wet (June 2000) seasons. Over 35,000 individual fish were visually counted at 15 sites along the coast in three areas located 0-2.4, 2.4-6.1...

Journal: :Dong wu xue yan jiu = Zoological research 2014
Xiao-Yun Sui Zhi Lu Yun-Zhi Yan Yi-Feng Chen Yin-Tao Jia

Using seasonally collected data (2009-2010) from 15 sampling sites that represent first- to fifth-order streams within the Qingyi watershed, we examined the spatio-temporal patterns of fish assemblages along two longitudinal gradients to explore the effects of a large dam on fish assemblages at the watershed scale. No significant variation was observed in either species richness or assemblage s...

Journal: :Environmental management 1999
LAMMERT ALLAN

/ Fish and macroinvertebrate assemblage composition, instream habitat features and surrounding land use were assessed in an agriculturally developed watershed to relate overall biotic condition to patterns of land use and channel structure. Six 100-m reaches were sampled on each of three first-order warm-water tributaries of the River Raisin in southeastern Michigan. Comparisons among sites and...

2018
Timothy D Counihan Ian R Waite Andrew F Casper David L Ward Jennifer S Sauer Elise R Irwin Colin G Chapman Brian S Ickes Craig P Paukert John J Kosovich Jennifer M Bayer

Understanding trends in the diverse resources provided by large rivers will help balance tradeoffs among stakeholders and inform strategies to mitigate the effects of landscape scale stressors such as climate change and invasive species. Absent a cohesive coordinated effort to assess trends in important large river resources, a logical starting point is to assess our ability to draw inferences ...

Journal: :Brazilian journal of biology = Revista brasleira de biologia 2016
J C Silva É A Gubiani P A Piana R L Delariva

Geographical barriers influence species distribution and play an important role in the segregation of fish assemblages. The present study aims to test the influence of a small natural barrier on the spatial distribution of fish species in the Verde River, Upper Paraná River Basin, Brazil, considering two biotopes: upstream and downstream of the Branca Waterfall. We observed the highest species ...

Journal: :Frontiers in Marine Science 2015

Journal: :International journal for parasitology 2000
R Poulin J F Guégan

Nested species subset patterns consist in a hierarchical structure of species composition in related assemblages, with the species found in depauperate assemblages representing non-random subsets of progressively richer ones. This pattern has been found at the infracommunity level in about a third of the fish ectoparasite assemblages studied to date. Here we present evidence for another non-ran...

2014
Paolo Guidetti Pasquale Baiata Enric Ballesteros Antonio Di Franco Bernat Hereu Enrique Macpherson Fiorenza Micheli Antonio Pais Pieraugusto Panzalis Andrew A. Rosenberg Mikel Zabala Enric Sala

Marine protected areas (MPAs) were acknowledged globally as effective tools to mitigate the threats to oceans caused by fishing. Several studies assessed the effectiveness of individual MPAs in protecting fish assemblages, but regional assessments of multiple MPAs are scarce. Moreover, empirical evidence on the role of MPAs in contrasting the propagation of non-indigenous-species (NIS) and ther...

2016
Pierre D Thiriet Antonio Di Franco Adrien Cheminée Paolo Guidetti Olivier Bianchimani Solène Basthard-Bogain Jean-Michel Cottalorda Hazel Arceo Joan Moranta Pierre Lejeune Patrice Francour Luisa Mangialajo

In Mediterranean subtidal rocky reefs, Cystoseira spp. (Phaeophyceae) form dense canopies up to 1 m high. Such habitats, called 'Cystoseira forests', are regressing across the entire Mediterranean Sea due to multiple anthropogenic stressors, as are other large brown algae forests worldwide. Cystoseira forests are being replaced by structurally less complex habitats, but little information is av...

Journal: :Parasitology 2004
J L Luque D Mouillot R Poulin

Recent studies of the forces behind the diversification of parasite assemblages have shed light on many aspects of parasite biodiversity. By using only parasite species richness as their measure of diversity, however, previous investigations have ignored the relatedness among parasite species and the taxonomic structure of the assemblages, which contain much information about their evolutionary...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید