We found that upper photic zone
coccolithophore communities in southern Tyrrhenian Sea water and Levante Bay were very similar in areas unaffected by elevated C[O.
The species Encyonema silesiacum (Bleish) Mann (ENSY), Eolimna minima (Gru) Lange-Bertalot (EOMI), Sellaphora seminulum (Gru) Mann (SSEM), Navicula cryptotenella Lange-Bertalot (NCRY), Lemnicola hungarica (Gru) Round and Basson (LHUN), and Achnanthidium minutissimum (Kut) Czamecki (AMIN) formed an assemblage that was associated with the February 2009 sampling period (C4), with increased water temperature, high rainfall, and a deeper photic zone
(see Figure 3).
All of these are carbonate sites, probably because most terrigenous sites are not in the photic zone
Secchi disk measurements taken outside the mesocosms indicated that the exposures were always within the photic zone
(as estimated by 1.
While strong upwelling provides increased nutrients to the photic zone
, excess turbulence can be detrimental to primary producers by decreasing light penetration, and to grazers by increased dispersal of available food (Ware, 1992).
Heteropods are found in the upper photic zone
(within 100 m of the surface) but are not typically a neustonic or floating species.
Bioclasts are generally broken and perforated indicating their reworking in the photic zone
One can calculate the velocity of ascent of deeper water and the quantity of nutrients it brings to the photic zone
, as well as the kinetic energy obtained from the hydrosphere-atmosphere system to carry out the local mechanical work that supports this continuous high primary production.
We studied the gametogenic development and gonadal index in two populations of sea cucumbers, one found in the photic zone
(10 m depth, a depth at which light penetrates all year long) and the other in the aphotic zone (110 m, a depth at which no light penetrates all year long; Babin et al.
Micritization is caused by endolithic algae and usually occur within the photic zone
of the shallow marine setting (Tucker and Wright 1990).
This region is considered a biologically rich zone because of the upwelling phenomenon that carries up deep nutrient-rich waters to the photic zone
(Matsuura, 1986; Chaves, 2006).
The condition of this environment is shallow, with medium to low energy and presence in the photic zone
below the fair-weather wave base.