International Journal of Marine Science 2015, Vol.5, No.19, 1-10
8
Theophane (3) areas have intermediate indicators of
pollution and the most exposed of household water
pollution Bay Round (area 1). Sevastopol bay in
which sampled Chuhchin (1961a, b) is even more
disadvantaged in terms of environmentally
contaminated areas than the Round bay. Regardless of
the degree of chemical contamination in any of our
areas of research were not found imposex females. It
does not speak in favor of dependence the presence
imposex females in
R. venosa
from contamination.
Judging by the fact that the Turkish researchers
(Saglam and Duzgunes, 2014) divided
R. venosa
for
males and females without mentioning imposex
females one can assume that this category was
missing from collections in the area. No reported
observations of imposex in rapa whelks from native
populations in Korea (Chung et al. 1993) also could
be evidence of their absence.
It is believed that the lack of imposex signs in females
could be interpreted as a symptom of a healthy population
or a signal that this population had not been exposed
enough time to TBT to develop signs of imposex
Uruguayan Rio de la Plata coastal zone (Lanfrankoni
et al, 2009). It is possible that Korean, Turkish and
Uruguayan waters are cleaner than the waters of
Chesapeake Bay (USA) and Romania coast but it
hardly applies to the waters adjacent to Sevastopol.
The health of the population can be judged by the
physiological condition of the individual that
indicators are the weight and size of individuals.
Table 1 shows the weight and size of individuals
from different areas. It is easy to notice that the
size-weight characteristics of individuals from areas
where registered imposex females exceed the
corresponding parameters in most areas where such
individuals were not found. And in the Chesapeake
Bay area which the preponderance of imposex
females were over ‘normal’ females by at least a 2:1
ratio (Mann et al, 2006) size-weight indicators are
higher significantly (Table 1).
Table 1 Some comparative characteristics for
R. venosa
mature specimens of the investigated areas (according Figure 1) and other
regions after the following authors:
Black Sea,
Turkey [Saglam and Duzgunes, 2014], Agigea coast, Romania
[
Micu et al., 2009],
Uruguayan Rio de la Plata
coastal zone [Lanfranconi et al, 2009],
Chesapeake Bay, USA [Mann et al., 2006]
. SL – shell length (mm),
W – whelk total wet weight (g), TW - whelk wet tissue weight (g), Imposex, (% of total specimens), ND – no data
Region (No)
Depth (m)
SL (mm)
W (g)
TW (g)
Imposex, %
Round bay (1)
3–6
43–77.5
12–126.9
2.5–31.5
0
Blue Bay (2)
4–6
42.5–79.5
8.0–69.0
2.0–20
0
Theophan cap (3)
4–6
55–82.5
29–106
9–44
0
Laspi Bay (4)
4–6
43–66.5
15–40
2.0–10
0
Turkey
20
? –95.8
? –122.8
? –50.22
0
Uruguay
1.5
57.3–81.2
41.1–91.1
ND
0
Romania
4–5
58.69–96.88
ND
ND
11.19
Chesapeake Bay
ND
71–174
ND
>150 (average)
26
The fact that shell lengths and wet tissue weights (g)
of both imposex females and males were
approximately the same when the true female rapa
whelks had lower wet tissue weights than either
imposex females or males (Mann et al., 2006) not
talking about the suppression of physiological
functions but the appearance of excess reserves.
At the same time analysis of data on Muricidae
Hexaplex trunculus
(L., 1758)
from two fishing
harbours showed that in the first site, the concentration
of TBT was quite low, but imposex indices were high.
On the contrary, TBT concentrations in the second site
were high, but imposex indices were low. Besides this,
an initial development of imposex in
H. trunculus
specimens from museum collections collected in the
period between 1845 and 1930, i.e. 30–115 years
before the use of TBT have found. These observations
suggest that factors other than TBT could be
implicated on the development of imposex (Lahbib et
al, 2009).
The correlation of various indicators is not always the
result of a cause-effect relationship. As regards
pollutants, among them may be present simultaneously
as inhibitors or stimulators of organisms.
Eutrophication of waters caused by human activities
can sometimes stimulate the development of
