Coastal Marine Environment Sustainability - Sustainable Practices in Geoenvironmental Engineering - page 278

Site 5
Site 13
Average of 16 sites
Site 10

0.5

0.4

0.3

0.2

0.1

0

1999 2001 2003 2005 2007 2009

Year (October)

FIGURE 8.4
Annual changes in sulide content for the Harima-nada sediments. (Data from Ministry of Land, Infrastructure,
Transport and Tourism, Japan. Available at http://www.pa.cgr.mlit.go.jp/chiki/suishitu/download/input.htm.)

potential versus pH values for the period between October 1993 and June 1994 for various
sites in the Seto Inland Sea.
Figure 8.4 shows the changes in sulide concentration obtained from Harima-nada in
the month of October between 2000 and 2008. The concentration and its luctuation are
unpredictable. The data for site 10 were obtained from ine sand, which had a relatively
low level (less than 0.1 mg/g) of sulide (between 2000 and 2006) and a rapid increase to
0.2 mg/g after that.

8.4.3.2 Guidelines for Sulide for Surface Water and Sediments

The Quality Criteria for Water (USEPA, 1976) concluded that the hazard from hydrogen
sulide to aquatic life is often localized and transient. Available data indicate that water
containing concentrations of 2.0 μg/L undissociated H 2 S would not be hazardous to most
ish and other aquatic wild life, but concentrations in excess of 2.0 μg/L would constitute
a long-term hazard.
Hydrogen sulide has an adverse impact on aquatic life, especially to crustacea. The stan-
dard level provided by the Japanese sediment guideline for ish is 0.2 mg/g. Herein, the
sulide content is deined by the percentage of sulide/dry weight of sediment. If the pore
space of sand is the habitat of marine life, the conventional deinition of sulide should be
modiied for an aestivating ish such as sand lance.
The comparison between both the guidelines for water and sediments mentioned above
indicates that the value of the criterion for sediments will be somewhat higher than that of
water, even if the difference between the densities of sediments and water is considered.

8.4.4 Connecting Problems of Geoenvironment and Bioenvironment

It is well understood that the marine geoenvironment is directly connected to the bioenvi-
ronment through the food chain. Eutrophication of marine geoenvironment often results