These events led barrier layers to form between the base of the upper isohaline
layer and the base of the isothermal layer.
position as a habitat indicator for estuarine populations.
Ichthyoplankton distributions, concentrations, and sizes were evaluated with respect to the salt front and site of intersection of the 2.0 isohaline
with the bottom (referred to as [X.sub.2] by Jassby et al., 1995).
The structures are operated to maintain salinities within the project along two isohaline
lines (5ppt and 12ppt), while allowing as much ingress and egress of marine organisms as possible.
The highest squid abundance or optimum habitat were concentrated around the 19-20[degrees]C SST isotherm, the 33.3-33.4 psu SSS isohaline
, and the 0.3mg/[m.sup.3] chl-a isopleth in August; 16-17[degrees]C SST, 33.3-33.4 psu SSS, and 0.4-0.5 mg/[m.sup.3] chl a in September; and 15-16[degrees]C SST, 33.3-33.4 psu SSS, and 0.3-0.4 mg/[m.sup.3] chl a in October.
A recent fit to measurements taken within eight under-ice plumes (CSSA, 1993; Anctil et al., 1996) yields the following empirical relationship for the area A (in km2) encompassed by the isohaline
of salinity S of a plume arising from a volume discharge rate Q0 (m3/s) spreading over water of salinity Sb (measured at a depth of 3 m below the pycnocline; Sb ranges from 22 to 27 over the eight rivers examined):
of 30, considered the boundary of estuarine waters (Guerrero, 1998), showed a south-eastward extension indicating a river discharge in this direction whose influence reaches 37[degrees]50'S.
Due to difficulties in creating continuous salinity and temperature contour maps in GIS, these variables were classified as follows: salinity was classified by one of the five isohaline
zones described previously and analyzed as such to determine its influence on brown shrimp distribution; and water temperature was classified by season determined by cluster analysis and analyzed to examine possible temporal effects of brown shrimp distribution.
7i,j, in which both isotherm and isohaline
spacing represent equal contributions to density.
Similar results were observed for Chesapeake and Delaware bays (Bulger et al, 1993; Able et al, 1997), who identified the 25-27 isohaline
as the edge of the brackish water for strictly marine species.
Farther south along the 34.6 isohaline
, higher salinity relative to the long-term mean was found.
In (a) only isotherm contours mostly outside the thermocline are shown, and in (b) only isohalines
mostly associated with the high-salinity Subtropical Underwater (STUW) are shown.