We conducted ship-, shore- and laboratory-based crude oil exposure experiments to investigate (1) the effects of crude oil (Louisiana light sweet oil) on survival and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in mesozooplankton communities, (2) the lethal effects of dispersant (Corexit 9500A) and dispersant-treated oil on mesozooplankton, (3) the influence of UVB radiation/sunl...

Copepods play a critical role in the marine food webs, being source for organisms. In this study, we investigated toxic effects of Water Accommodated Fractions (WAFs) from three types oil: Naphthenic North Sea crude oil (NNS), Intermediate Fuel Oil (IFO 180) and commercial Marine Gas (MGO). The WAFs were prepared at 10 °C 30 PSU (practical salinity unit), tested on copepod Acartia tonsa differe...

Fine-scale water column structure was mimicked in a laboratory plane jet flume to examine responses of the calanoid copepods Temora longicornis and Acartia tonsa to layers consisting of a velocity gradient, density gradient, phytoplankton exudates and food (phytoplankton). Copepods were exposed to isolated layers and combinations of cues as defined by in situ conditions. Behaviors elicited by t...

Among the thousands of unicellular phytoplankton species described in the sea, some frequently occurring and bloom-forming marine dinoflagellates are known to produce the potent neurotoxins causing paralytic shellfish poisoning. The natural function of these toxins is not clear, although they have been hypothesized to act as a chemical defence towards grazers. Here, we show that waterborne cues...

The heterotrophic dinoflagellate Protopemdinium cf. divergens, known as prey for adult copepods, itself feeds on copepod eggs and early naupliar stages. One to several P. cf. divergens can attack an egg or nauplius larger than themselves. The time for an egg to be digested was proportional to the number of P. cf. divergens attacking it. Ingestion rates of P, cf. djvergens on Acartia tonsa eggs ...

The association of Vibrio cholerae with zooplankton has been suggested as an important factor in transmission of human epidemic cholera, and the ability to colonize zooplankton surfaces may play a role in the temporal variation and predominance of the two different serogroups (V. cholerae O1 El Tor and O139) in the aquatic environment. To date, interactions between specific serogroups and speci...

The estuarine copepod Acartia tonsa naturally carried diverse strains of bacteria on its body. The bacterial community composition (BCC) remained very conservative even when the copepod was fed different axenic algal species, indicating that the food per se did not much affect BCC associated with the copepod. In xenic algal treatments, however, copepod-associated BCC differed with each alga fed...

Peritrich ciliates are commonly found as epibionts, colonizing living organisms, or attached to non-living substrates in freshwater, estuarine and marine environments. Several species of peritrich epibionts are obligate, which means that they are able to only colonize other organisms, while others are facultative attaching to living or non-living substrates. The peritrich Zoothamnium intermediu...

When different growth phases (exponential or stationary) or forms (solitary cells or colonies) of a single clone of Phaeocystis globosa were fed to three copepods, grazing, measured indirectly by fecal-pellet production, on different types of P. globosa differed by nearly two orders of magnitude, with differences on this clone sometimes exceeding differences between different phytoplankton spec...

It is commonly accepted that summer cyanobacterial blooms cannot be efficiently utilized by grazers due to low nutritional quality and production of toxins; however the evidence for such effects in situ is often contradictory. Using field and experimental observations on Baltic copepods and bloom-forming diazotrophic filamentous cyanobacteria, we show that cyanobacteria may in fact support zoop...