Sampling of the 10 paired
tributary and river sites confirmed a pattern that we had previously reported (Gilliam et al.
The fall of the Roman Empire therefore did not impact on the East; the
tributary mode survived this "event' just as it would the Islamization-Arabization of the East.
In each
tributary site, one transect was placed 5 m from the stream edge (mean high-water mark) on one side of the stream and sampling encompassed both sides of the stream.
During the 4-mo pre-stocking period, we left the experimental tributaries unscreened to verify that Rivulus could ascend the waterfall of each
tributary. By the end of this period, Rivulus were found in each
tributary, indicating that each was accessible to Rivulus.
Agency officers, who were at the scene during the afternoon believe that low water levels in the
tributary stream at the time of the pollution caused levels of dissolved oxygen in the water to drop significantly.
Ten acres of riparian forest buffer was planted along a highly visible
tributary of the Patapsco River.
``With additional funding, active support and guidance from Environment Agency Wales, the whole of this valuable
tributary has been made accessible to migrating fish, which shows clearly how much more can be achieved by working in partnership,'' said Mr O'Reilly.
The most likely explanation for the abrupt appearance of these fossils, Young says, is that a west-flowing
tributary of the ancestral lower Colorado River began to carve a small valley eastward into the edge of the Colorado Plateau.
Following each
tributary and subtributary of a stream upstream to its divide yields a series of terminal points corresponding in pattern to the twig tips of a tree (this watershed form is termed dendritic" due to its treelike form).
"Oysters used to be present almost completely from one end of the bay to the other, in every
tributary." Over the last 30 years, however, the oyster population has declined precipitously.