نتایج جستجو برای: fish biodiversity

تعداد نتایج: 138899  

Journal: :Science 2001
N Knowlton

Coral reefs are the most diverse of all marine ecosystems (1), with estimates of reef species ranging from 600,000 to more than 9 million species worldwide (2, 3). This biodiversity is most pronounced in the western Pacific and Indian Oceans (1, 4), but decreases with increasing distance from the Indo-Australian archipelago. For example, reefs in the central Indo-Pacific have more than 10 times...

The objective of the present study was to determine the effects of fish aggregation device (FAD) deployment on biodiversity, catch composition and length frequency distribution in the Qeshm Island handline fishery. Two FADs were deployed in the Qeshm Island. Four biodiversity indices including Margalef, Shannon-Weaver, Simpson and Pielou and also catch composition and length frequency distribut...

2012
Jacobus Vijverberg Eshete Dejen Abebe Getahun Leopold A.J. Nagelkerke

Fish populations of nine Ethiopian freshwater lakes were quantitatively sampled with a standardized protocol, using multi-mesh gill nets. In total, 27 species were identified, but only 14 species were common. Based on the common species, the fish communities showed large differences in their species composition, except for Lake Abaya and Lake Chamo which were similar. Most fish species were obs...

2010
Miguel Clavero Francisco Blanco-Garrido José Prenda

1. We used a basin approximation to analyse distribution patterns of different components of biodiversity (taxonomic richness, endemicity, taxonomic singularity, rarity) and conservation status of freshwater fish fauna in 27 Mediterranean Iberian rivers. 2. Basin area alone explained more than 80% of variation in native species richness. Larger basins featured not only a higher number of native...

Jenyo-Oni Adetola Obe Bernardine Wuraola

For the purpose of sustainable exploitation of the fishery resources of Oni River, Ogun State, Nigeria, the fish biodiversity assessment was carried out. This was conducted by enumerating and identifying fish species composition, measuring the fish length, fish weight, assessing the fish abundance and biomass, determining the length-weight relationships and the length-frequency of the fishes. A...

2002
Nancy Knowlton

The author is with the Marine Biology Research Division, Scripps Institution of Oceanography, University of California-San Diego, San Diego, CA 92093-0202, USA and Smithsonian Tropical Research Institute, Balboa, Republic of Panama. E-m ail: [email protected] Rainforests of the sea. Biodiversity in the Indo-Pacific region was measured by counting the total numbers of species in the 13 most spe...

2015
Tak Fung Keith D. Farnsworth David G. Reid Axel G. Rossberg

Public concern over biodiversity loss is often rationalized as a threat to ecosystem functioning, but biodiversity-ecosystem functioning (BEF) relations are hard to empirically quantify at large scales. We use a realistic marine food-web model, resolving species over five trophic levels, to study how total fish production changes with species richness. This complex model predicts that BEF relat...

2016
Katherine L. Yates Camille Mellin M. Julian Caley Ben T. Radford Jessica J. Meeuwig

Prioritising biodiversity conservation requires knowledge of where biodiversity occurs. Such knowledge, however, is often lacking. New technologies for collecting biological and physical data coupled with advances in modelling techniques could help address these gaps and facilitate improved management outcomes. Here we examined the utility of environmental data, obtained using different methods...

2012
Philip Francis Thomsen Jos Kielgast Lars Lønsmann Iversen Peter Rask Møller Morten Rasmussen Eske Willerslev

Marine ecosystems worldwide are under threat with many fish species and populations suffering from human over-exploitation. This is greatly impacting global biodiversity, economy and human health. Intriguingly, marine fish are largely surveyed using selective and invasive methods, which are mostly limited to commercial species, and restricted to particular areas with favourable conditions. Furt...

2011
Harry W. Palm

Global warming scenarios combined with political and public awareness have led to increasing funding and research efforts on the measurement and prediction of effects of a changing world on the ecosystems. Fish parasites represent a major part of aquatic biodiversity, and consequently become affected either directly through the environment or indirectly through their respective hosts. On the ba...

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