منابع مشابه
Marine Ecology Progress Series
The urgent need to reduce the intense pressure and destructive power that modern fishing practices apply to the world’s fisheries, and the oceans that support them, is now widely recognized (e.g. FAO 2002a, Hilborn et al. 2003). However, there is far less agreement over the exact levels to which fishing mortality must be reduced and over how to reduce the indirect effects of fishing (e.g. bycat...
متن کاملMarine Ecology Progress Semes
Nanoplankton and picoplankton abundance and community grazing on picoplankton were deterrnined in surnmer and autumn at several stations in a productive coastal environment (Georges Bank. NW Atlantic Ocean) and in an oligotrophic oceanic ecosystem (Sargasso Sea). Ranges of heterotrophic nanoplankton (HNAN) abundance were 1.2 to 3.6 X 103 ceils rnl-' on Georges Bank, and 2.2 to 6.8 X 10' ceiis m...
متن کاملMarine Microplankton Ecology Reading
Microbes dominate our planet, especially the Earth’s oceans. The distinguishing feature of microorganisms is their small size, usually defined as less than 200 micrometers (μm); they are all invisible to the naked eye. As a group, sea microbes are extremely diverse, and extremely versatile with respect to their abilities to make and eat food. All marine microbes are too small to swim against th...
متن کاملMarine Ecology Progress Series
Previous work has shown freshwater macrophytes from lake littoral zones to be "C-enriched compared to the same species collected from fast movlng nvers It is thought that carbon fixation In aquatic plants having thicker, stagnant boundary layers, such as that w h ~ c h occurs withln low turbulence lentic systems, will result in more positive F' 'C values due to greater d~ffusion resistance and ...
متن کاملMarine Ecology Progress Series
A model for nutrient uptake rate (V) in phytoplankton is derived: V = n A v S / ( l + h A v S ) where n is cellular number of uptake sites, A is area of the uptake site, h is time required for handling one nutrient ion, vis the mass transfer coefficient, and S i s substrate concentration. The model is based on 2 time requirements necessary for active uptake of nutrients: (i) time required for r...
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ژورنال
عنوان ژورنال: Zoologica Africana
سال: 1968
ISSN: 0044-5096
DOI: 10.1080/00445096.1968.11447358