1 Bq kg− 1 d.w.) was only slightly higher than the value found in the core surface sediment, whereas the 214Bi activity concentration was identical. Moreover, the activities of 137Cs in both materials were also very similar, indicating that both the isotopic and the in situ methods yield comparable results. The rate of sediment deposition calculated from sediment trap measurements (1.67 mm year− 1) is comparable with the rate established by the Ku-0059436 isotopic method (1.61 mm year− 1). This results from the fact that the trapped sediment cannot be redeposited, which is contrary to natural
conditions, where strong hydrodynamic regimes can give rise to seabed erosion. “
“Coastal oceanic environments are sites of dynamic physical and biogeochemical processes. Over the last few decades, eutrophication-related algal bloom events have been on the rise in coastal areas. Such events alter the colour of the water as a result of selleck inhibitor the transient proliferation of phytoplankton. The absorption of light by phytoplankton is a major factor contributing to the optical variability of waters both in coastal regions and the open ocean. The shape and magnitude of the phytoplankton absorption spectrum reflect the pigment composition and its concentration in the water. Factors contributing to the
variability in a*ph(λ) include pigment packaging ( Duysens 1956) and concentrations of non-photosynthetic pigments ( Allali et al., 1997 and Vijayan et al., 2009). The latter contribute significantly to absorption
in the 460–640 nm region of the photosynthetically active radiation (Bidigare 1989b), particularly in coastal waters ( Bricaud et al., 1995 and Cleveland, 1995). The study area, Manila Bay, is a highly eutrophic coastal water body located between latitudes 14°23′ –14°87′N and longitudes 120°53′–121°03′E and is reported to be a pollution hot spot in East Asia (Maria et al. 2009). There have been many reports of the repeated occurrence of algal bloom events caused by Pyrodinium in the 1980s and 1990s ( Gonzales, 1989 and Furio and Gonzales, 2002); more recently, the blooming species changed to green Noctiluca ( Furuya et al. 2006). The bay is subject to multifarious biogeophysical conditions, which have created a complex biooptical Miconazole environment within the bay. Most of the studies conducted in Manila Bay have focused on the physico-chemical parameters ( Prudente et al., 1994, Velasquez and Jacinto, 1995, Velasquez et al., 1997 and Jacinto et al., 2011) and taxonomic aspects of phytoplankton ( Azanza and Miranda, 2001 and Siringan et al., 2008), algal photophysiology ( Hansen et al. 2004), modelling the physical characteristics of the environment ( De las Alas and Sodusta, 1985 and Fuji-ie et al., 2002), heavy metal pollution ( Hosono et al. 2010 and references therein) and the bloom dynamics of Pyrodinium ( Villanoy et al., 1996 and Villanoy et al., 2006). The bio-optical properties of seawater in Manila Bay are poorly documented.