| 1 |
|
Louisiana Marsh Management Plan 1995
|
We sampled experimental research areas in the Barataria Basin of Louisiana during
March and May, 1995, to examine the effects of structural marsh management on habitat
use by small nekton (100 mm total length TL or carapace width CW). The research areas
consisted of two control (unmanaged) marshes and two impounded (managed) marshes managed
areas were surrounded by levees with water-control structures constructed by the U.S.
Department of Interior, National Biological Survey. We conclude that the restricted
water exchange in marshes under structural marsh management diminishes recruitment
and standing stocks of species that must migrate from coastal spawning sites to marsh
nurseries. Even when water-control structures were open, the densities of these transient
species were low inside managed areas. In contrast to the negative effect of management
on transient species, the resident fish and crustacean populations seemed to flourish
in the managed areas when a drawdown was not in effect. Following two months of a
drawdown, however, the populations of residents appeared similar inside and outside
managed areas. Increases in submerged aquatic vegetation (SAV) within ponds occurred
outside the managed areas during the study period, but not inside managed areas. Because
many resident species were closely associated with the SAV, the effect of management
on SAV may have been responsible for the distribution patterns of resident species.
|