Contents 1. Introduction 2. Main microzooplankton groups 3. Microzooplankton grazing impacts in marine ecosystems 3.1. How much of the primary production is daily consumed by microzooplankton? 3.2. Breaking old paradigms on the role of zooplankton in marine ecosystems 4. Microzooplankton and the biogeochemical cycles 5. Microzooplankton as prey 5.1. Contribution of microzooplankton to copepod d...

Microzooplankton are an integral part of aquatic food webs, yet compared to macrozooplankton, are understudied in the Southern Ocean. The region along the Western Antarctic Peninsula (WAP) is experiencing rapid climate warming, resulting in declines in sea ice extent and duration, and affecting the marine food web. Microzooplankton community structure along the WAP was analyzed in January 2010 ...

 Phytoplankton growth and microzooplankton grazing were investigated at one station in the Homa Lagoon from February to January in 2006-2007. Our results showed significant seasonal variations in phytoplankton dynamics. Microzooplankton was mainly composed of dinoflagellates and tintinnid ciliates and nauplii. Microzooplankton grazing increased with increasing of temperature. Grazing ra...

A literature synthesis of phytoplankton growth (m) and grazing (m) rate estimates from dilution experiments reveals that microzooplankton account for most phytoplankton mortality in the oceans, averaging 60e75% of daily phytoplankton production (PP) across a spectrum of open-ocean and coastal systems. For reasonable estimates of gross growth efficiency (GGEZ 30e40%), such impacts imply that sec...

Mixotrophs are important components of the bacterioplankton, phytoplankton, microzooplankton, and (sometimes) zooplankton in coastal and oceanic waters. Bacterivory among the phytoplankton may be important for alleviating inorganic nutrient stress and may increase primary production in oligotrophic waters. Mixotrophic phytoflagellates and dinoflagellates are often dominant components of the pla...

The hypothesis was tested that zooplankton community size structure shifts toward an increased relative biomass of microzooplankton with increased lake trophy at 12 sites in Quebec, The seasonal mean abundance and biomass of ciliates, rotifers, nauplii, cladocerans, and cyclopoid copepods were significantly (P < 0.1) related to lake trophy, but Calanoid copepod abundance and biomass varied inde...

The qualitative composition, numerical abundance and seasonal distribution of microzooplankton in the São Sebastião Channel were studied in different seasonal periods. Data are presented for 43 Protozoa, 4 rotifer and 30 copepod nauplii specimens. Tintinnids represented the most abundant group within the microzooplankton community, with 31 species recorded, among which Amphorellopsis acuta, Cod...

Impacts of ocean acidification (OA) on marine biota have been observed in a wide range of marine systems. We used a mesocosm approach to study the response of a high Arctic coastal microzooplankton community during the post-bloom period in Kongsfjorden (Svalbard) to direct and indirect effects of high pCO2/low pH. We found almost no direct effects of OA on microzooplankton composition and diver...

Using the seawater dilution technique, we measured phytoplankton growth and microzooplankton grazing rates within and outside of the 1999 Bering Sea coccolithophorid bloom. We found that reduced microzooplankton grazing mortality is a key component in the formation and temporal persistence of the Emiliania huxleyi bloom that continues to proliferate in the southeast Bering Sea. Total chlorophyl...

 Phytoplankton growth and microzooplankton grazing were investigated at one station in the Homa Lagoon from February to January in 2006-2007. Our results showed significant seasonal variations in phytoplankton dynamics. Microzooplankton was mainly composed of dinoflagellates and tintinnid ciliates and nauplii. Microzooplankton grazing increased with increasing of temperature. Grazing rate was ma...