Relationship between the bloom of Noctiluca scintillans and environmental factors in the coastal waters of Sagami Bay, Japan

Seasonal variability of the red tide-forming heterotrophic dinoflagellate Noctiluca scintillans in the neritic area of Sagami Bay, Japan: its role in the nutrient-environment and aquatic ecosystem

“…exact duration of occurrence, abundance, distribution) differed depending on the year, overall variation patterns were essentially similar during all five years, and these were similar to those reported for other temperate coastal waters (e.g. Uhlig & Sahling 1990, Pithakpol et al 2000a, b, Tada et al 2004, Miyaguchi et al 2006). For Noctiluca, such seasonal variations occur commonly in temperate seas, being explainable by local abiotic/biotic variables (i.e.…”

“…Kuroda & Saga 1978, Schaumann et al 1988, Elbrächter & Qi 1998, Tada et al 2004. In littoral waters, after ascent to the upper layer caused by seasonal stratification, the passive accumulation of Noctiluca cells due to wind and/or tidal currents has been reported as an important mechanism for the formation of Noctiluca blooms or aggregations (Le Fèvre & Grall 1970, Huang & Qi 1997, Dela-Cruz et al 2003, Miyaguchi et al 2006.…”

“…Seasonal, year-on-year and/or spatial variations in abundance of Noctiluca have been extensively studied in temperate and subtropical estuarine and coastal waters (e.g. Kuroda & Saga 1978, Uhlig & Sahling 1990, Huang & Qi 1997, Tada et al 2004, Miyaguchi et al 2006. These studies found distinct seasonal variations with considerable peaks (i.e.…”

“…Although chemical oxygen demand (COD), dissolved inorganic nutrient and chlorophyll a (Chl-a) concentrations in Sagami Bay have maintained much lower levels than in neighboring Tokyo Bay (Saitou 1992, Ara & Hiromi 2008, Ara et al 2011b, since the 1980s some signs of eutrophication (i.e. gradual rise in COD and Chl-a concentration, decline in transparency, red tide outbreaks) have occurred, partly in the coastal waters of Sagami Bay (Yamada & Iwata 1992, Yamada 1997, Machida et al 1999, Yamada & Matsushita 2005, Miyaguchi et al 2006, Ara & Hiromi 2008, Ara et al 2011a). The neritic waters in the innermost open area of Sagami Bay, especially the upper layer around Enoshima Island, have higher phytoplankton standing crops (Chl-a) and primary production than those in any other open area in the bay (Ara & Hiromi 2007, 2008, Ara et al 2011a.…”

“…Studies on Noctiluca in the coastal waters of Sagami Bay have dealt with aspects of red tides and/or red coloration phenomena, sometimes having originated in expanded from neighboring Tokyo Bay (Tanaka 1985, Yamada 1997, Kamataki 2005, predominance in the microphytoplankton assemblages (Tatara & Kikuchi 2003, Baek et al 2009, and seasonal and interannual variations in abundance in relation to environmental factors (Miyaguchi et al 2006). However, in these waters as well as other waters of the world, there has been no attempt to investigate the availability of nutrients regenerated by Noctiluca for phytoplankton growth or to evaluate the contribution of nutrient (N and P) supply by Noctiluca excretion to phytoplankton primary production.…”