21(0.79 – 1.59); calculation of this ratio using the data from the floating spectroradiometer for the same stations gave a value of 1.04(0.77 – 1.51). More data from simultaneous field and satellite measurements are needed to refine these algorithms.
The MODIS-Aqua data used in this study were obtained from the Goddard Distributed Active Archive Centre. The authors thank the two anonymous reviewers for their very helpful comments. “
“Phytoplankton communities are the basis of many marine and freshwater food webs (Huertas et al. 2011). Their composition fluctuates depending on hydrological conditions, such as light, temperature, salinity, pH, nutrients and turbulence (Legendre & Demers 1984, Smayda 1990, Leterme et al. 2005, 2006). PD332991 Typically, diatoms dominate coastal marine communities. However, other groups of phytoplankton can dominate depending on the combination of hydrological conditions and climatic variability (Margalef 1975, Leterme et al. 2006). Changes in dominant base groups/species often propagate up the food chain, impacting on fish, marine mammals and birds (Donnelly et al. 2007). Phytoplankton are known to exhibit rapid responses to changes in environmental conditions (Furnas 1990) and are therefore commonly acknowledged as excellent bio-indicators of the impact of
natural and seasonal changes in coastal ecosystems (Harris 1986, Rimet & Bouchez 2012). Their susceptibility to environmental change is usually expressed by morphological and/or behavioural changes as well as by persistent or seasonally www.selleckchem.com/products/BIBW2992.html atypical differences in abundance and distribution (Margalef 1975, Leterme et al. 2010, 2013). Where mono- or class-specific blooms are
observed on an annual basis, they often vary significantly in magnitude and/or duration between years (Ji et al. 2006). These seasonal fluctuations in biomass can be explained by (i) a generally positive correlation between phytoplankton biomass, day length and temperature, (ii) the patterns of upwelling/downwelling-favourable conditions impacting on nutrient ratios and (iii) the ability of phytoplankton to rapidly metabolise nutrients (Lips & Lips 2010). In coastal ecosystems, the capacity of phytoplankton populations and biomass to fluctuate in response to changing environmental conditions is often highly amplified when compared to the open ocean (Cloern Thiamine-diphosphate kinase 1996, Carter et al. 2005). These changes range from temperature changes, over naturally occurring nutrient fluctuations caused by upwelling/downwelling-favourable conditions, to biochemical input from natural and anthropogenic land run-off (Justic et al. 1995). The oceanography of Gulf St Vincent (GSV) has recently been described by Pattiaratchi et al. (2006) and Bye & Kämpf (2008). They showed that the key processes affecting the currents and mixing of the GSV are (1) astronomical tides with a strong spring neap cycle, (2) wind-driven flows (i.e.