Phytoplankton pigments, group composition and absorption coefficients: The following diagnostic pigments were used to identify seven phytoplankton groups: fucoxanthin (Fuco), peridinin (Peri), alloxanthin (Allo), 19 ́-hexanoyloxyfucoxanthin (19HF), 19 ́-butanoyloxyfucoxanthin (19BF), zeaxanthin (Zea), and total chlorophyll-b (TChlb, i.e. the sum of monovinylchl-b, chl-b, and divinylchl-b (div-b))...

We analyzed the cellular content of C, N, P, S, K, Mg, Ca, Sr, Fe, Mn, Zn, Cu, Co, Cd, and Mo in 15 marine eukaryotic phytoplankton species in culture representing the major marine phyla. All the organisms were grown under identical culture conditions, in a medium designed to allow rapid growth while minimizing precipitation of iron hydroxide. The cellular concentrations of all metals, phosphor...

Characterisation of phytoplankton communities in aquatic ecosystems is a costly task in terms of time, material and human resources. The general objective of this paper is not to replace microscopic counts but to complement them, by fine-tuning a technique using absorption spectra measurements that reduces the above-mentioned costs. Therefore, the objective proposed in this paper is to assess t...

Phytoplankton extracellular release of organic substances was studied in the Southern Bight of the North Sea in relation to changes in growth conditions (light intensity and inorganic nitrogen concentration) and in taxonomic phytoplankton composition. Light intensity had no effect on percent extracellular release (PER). A high negative correlation between PER and mineral nltrogen concentration ...

Estuarine and coastal systems represent a challenge when it comes to determining the causes of ecological change because human and natural perturbations often interact. Phytoplankton biomass (chlorophyll a) and group-specific photopigment indicators were examined from 1994 to 2007 to assess community responses to nutrient and climatic perturbations in the Neuse River Estuary, NC. This system ex...

Aquatic organisms produce compounds that deter consumers, alter prey behavior, suppress or kill target and nontarget species, and dramatically affect food-web structure, community composition, and the rates and pathways of biogeochemical cycles. Toxins from marine and freshwater phytoplankton create health hazards for both aquatic and terrestrial species and can significantly affect human activ...

Phytoplankton size class variation is a good indicator of water dynamics changes, alga blooms or ecosystem change, for it usually corresponds to different phytoplankton group composition. Remote sensing technique is a very effective method for studying phytoplankton at large scale by virtue of synoptic view and large area cover. Here we detected seasonal and annual phytoplankton size class vari...

Phytoplankton diagnostic photopigments in near-surface waters (<0.5 m) were identified and quantified by high-performance liquid chromatography beginning in April 1994 in the Neuse River Estuary and in October 1999 in the Pamlico Sound, North Carolina. Photopigment concentrations were analyzed using ChemTax to determine the class-specific biomass of the dominant phytoplankton groups. Long-term ...

Mesozoic and Early Cenozoic marine animals across multiple phyla record secular trends in morphology, environmental distribution, and inferred behaviour that are parsimoniously explained in terms of increased selection pressure from durophagous predators. Another systemic change in Mesozoic marine ecosystems, less widely appreciated than the first, may help to explain the observed animal record...

Atrazine is a common agricultural herbicide that is readily transported into estuaries through surface water runoff. In this study, we determined the short-term (24-48 h) sublethal effects of atrazine on estuarine phytoplankton biomass and community composition. Phytoplankton group-specific responses to atrazine exposure (25 microgh(-1)) were measured using natural water samples collected from ...