photic zone

(redirected from Euphotic depth)

photic zone

[′fōd·ik]
(ecology)
The uppermost layer of a body of water (approximately the upper 330 feet or 100 meters) that receives enough sunlight to permit the occurrence of photosynthesis.
References in periodicals archive ?
9 between Secchi depth and euphotic depth was assumed based on Kalff's (2002) review of the relationship for clear water lakes, such as Bonilla, in order to estimate the relationship between mixing and euphotic depths.
That means that mixing depth is greater than euphotic layer in this lake, and the ratio of euphotic depth to mixing depth varied between 0.
In Vortsjarv the general long-term dynamics of the euphotic depth followed the water level changes (r = 0.
d,PAR]) based on regressions with optically active substances or their proxies offers a good approach for calculating the euphotic depth ([z.
The calculation of euphotic depth using the equation given above assumes that light reduction conforms, approximately, to a single average vertical extinction coeffcient, [K.
Euphotic depths (the depth at which 1% of the surface irradiance is detected) estimated using vertical extinction coeffcients calculated from Secchi depths seem to indicate that the vertical extent of the euphotic zone was always shallower than 2 m.
Phytoplankton growth has been found to be negative when the depth of the mixture is more than four times greater than the euphotic depth (Talling, 1986).
The euphotic depth exceeded the mixing depth only during summer and was not significantly different between seasons (p>0.
Water transparency was determined with a Secchi disk and euphotic depth with a submarine photometer.
Several investigators have used the concept of a euphotic depth to calculate phytoplankton carrying capacities under light-limited conditions (e.
Although the question of depth scaling for aquatic productivity has not been directly addressed previously, there is indirect evidence that under steady-state, nutrient-rich conditions, phytoplankton growth and biomass often adjust such that euphotic depth corresponds with mixed-layer depth (Wofsy 1983).