The formation and subsequent detachment of these structures from the islands stimulate the vertical ascent of nutrients up to the euphotic
zone, promoting phytoplankton bloom and/or the passive advection of subsurface phytoplankton maximums towards the surface (Hasegawa et al., 2009).
Channel Mean Min-Max Temperature ([degrees]C) 26.5 20.4-22.5 Dissolved oxygen (mg [L.sup.-1]) 4.8 0-11.5 Salinity (psu) 7 0-16.8 Maximum euphotic
zone (m) depth 1.2-depth Depth (m) 1 0.8-1.5 Lagoon Mean Min-Max Temperature ([degrees]C) 27.8 21.4-31.5 Dissolved oxygen (mg [L.sup.-1]) 8.4 4.9-13.9 Salinity (psu) 12.5 7.2-17.2 Maximum euphotic
zone (m) 1.8 1.5-2.7 Depth (m) 3.9 3-4 Table 2.
As result of this interaction, a horizontal/vertical deformation (narrowing/expansion) of the eddy favoring the isolines eddy elevations within the euphotic
Values of precipitation--Pre (mm); wind speed--Win (m.[s.sup.-1]), depth--Dep (m), euphotic
zone--[Z.sub.cu] (m), euphotic
zone:maximum zone ratio--[Z.sub.cu]:[Z.sub.max], air temperature--[T.sub.a] ([degrees]C), water temperature--[T.sub.w] ([degrees]C), dissolved oxygen--DO (mg.[l.sup.-1], turbidity--Turb (NTU), soluble reactive phosphorus--P-SRP ([micro]g.[l.sup.-1]), dissolved total phosphorus--P-DTP ([micro]g.[l.sup.-1]) and dissolved inorganic nitrogen--N-DIN ([micro]g.[l.sup.-1]) recorded in the four sampling stations in the two arms of Salto Caxias reservoir, from September 2010 to July 2011.
1c) during which the euphotic
zone encompassed almost the whole water column (Goncalves et al., 2007).
The rainfall data indicated the existence of clearly distinct periods in terms of rainfall, i.e., a rainy period extending from November 2006 (spring) to March 2007, which was also characterized by higher temperatures and decrease of the extent of the euphotic
Photosynthetic production and exoenzymatic degradation of organic matter in the euphotic
zone of a eutrophic lake.
0.2 m), middle and immediately below the euphotic
zone and near to the bottom (ca.
Here, it was used the Lalli & Parsons' criterion (2006) who define z as the limit of the euphotic
Near-surface stratification is an important parameter for the supply of nutrients to the euphotic
zone by turbulent mixing processes, with increased stratification during austral summer acting to suppress mixing.
As a result, nutrient supply in the euphotic
zone is reduced which leads to dwindling phytoplankton productivity and an increase in water transparency in deep lakes such as lakes Tanganyika and Kivu (Plisnier, 2000; O'Reilly et al., 2003; Verburg et al., 2003; Lorke, Tietze, Halbwachs, & Wuest, 2004) whereas in the shallow Lake Victoria, an increase in productivity has been observed since the lake does not stratify (Hecky et al., 1994).
The prominence of calcareous algae implies that the seafloor was in the euphotic