In:
Canadian Journal of Fisheries and Aquatic Sciences, Canadian Science Publishing, Vol. 56, No. 11 ( 1999-11-01), p. 2136-2147
Abstract:
Several million tons of sediments and various debris were transported to the north arm of the Saguenay Fjord and the Baie des Ha! Ha! following the torrential rains and accompanying flash flood of July 1996 in the Saguenay region (Québec). The flood deposits covered the indigenous sediments and buried the benthic community. The objective of this work is to determine the best chemical and biological indicators of the changes that occurred in the benthic habitat of the fjord. The new sediment layer is poor in organic matter but rich in detrital carbonates and contains low mercury and lead concentrations reflecting the absence of industrial contamination. Ongoing geological processes leading to the re-establishment of steady-state conditions were evidenced by measurements of porosity, redox potential (Eh), and salinity of interstitial waters taken a few weeks and a few months after the events. The meiofauna were severely affected with a massive reduction of the average density of organisms relative to values recorded before the flood, but recolonisation was already in progress 1 year after the flood. Important losses of macrobenthic species were recorded in 1997 relative to 1996. However, the abundance and the diversity of the polycheate taxa were higher in 1997, indicating a recolonisation of the new sediment layer by pioneer species.
Type of Medium:
Online Resource
ISSN:
0706-652X
,
1205-7533
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
1999
detail.hit.zdb_id:
7966-2
detail.hit.zdb_id:
1473089-3
SSG:
21,3
SSG:
12
Permalink