104
R. Capelli et al.
samples were collected show the presence of two
different water masses:
1. Surface water of Atlantic origin (MAW,
Modified Atlantic Water) usually extending
from the surface to a depth of 200 metres.
2. Intermediate water of levantine origin (LIW,
Levantine Intermediate Water) warmer and
saltier than the Atlantic water, usually found
down to a 700 metres depth.
A comparison between MAW (mean 0.21
ng/I) and LIW (mean 0.23 ng/I) was made for the
first three samplings (Dec. 93-Dec. 94) but no significant differences have been detected. Data collected in July 97 show significantly higher reactive mercury concentrations (mean 0.41 ngll,
range 0.27-0.61 ng/I). No explication was found
for such difference, and July 97 data have been
excluded from the comparison. No relationship
was found between the concentration of reactive
mercury, salinity. temperature and depth.
It is difficult to compare these data with
those found in the literature. because there are
few data available for the Mediterranean Sea and
especially for reactive mercury at great depth.
Ferrara and Maserti (1986) reported reactive
mercury concentrations of 3.5 ng/I in the
Tyhrrenian Sea (range 2.0-5.9 ng/I) in off-shore
waters and concentrations of 2.0 ng/I (range 0.52.5 ng/I) in samples of coastal waters.
Significantly lower values recently found by
Cossa et al. (1997), who recorded reactive mercury values below 0.14 ngll, are in agreement
with data found in this work.
Data referred to surface water samples in the
Ligurian Sea show reactive values of 0.3±0.2 ngfl
(n=33. range 0.2-0.8 ng/l, Minganti et al. 1993).
The use of reactive mercury concentrations,
from data reported in this work, seems to be
unable to differentiate water masses of different
origin.
Acknowledgements. The authors thank Dr. Marco Orsi for his help
in acquiring the oceanographic data and the crew of the MN
Urania for their assistance during sampling. This research was
carried out in the framework of the project "ODAS ItaHa1"
(Istituto per l'Automazione Navale. Genova, Consiglio Nazionale
delle Ricerche).
References
Capelli R, Chiarini C, De Pellegrini R, Minganti V (1998) A new
sampler (Marikiki) for deep water for the determination of
mercury at ng L-lleveLAnn Chim 88: 413-417
Copin-Montegut G, Coureau P, Laumont F (1986) Occurrence of
mercury in the atmosphere and waters of the
Mediterranean. in: Pap FAO/UNEP/WHOnOCllAEA Meet
Biogeochem Cycle Mercury Mediterr, Siena, Italy. 27-31
August 1984, FAO Fish Rep (325) Suppl, pp 51-75
Cossa D,Martin JM, Takayanagi K, Sanjuan J (1997) The distribution and cycling of mercury species in the western
Mediterranean. Deep-Sea Res II 44: 721-740
Ferrara R, Maserli B (1986) Mercury in the Mediterranean Basin.
Mar Pollut Bull 1]: 533-534
Ferrara R, Maserti BE (1988) Mercury exchange between outflowing and i.nflowing water in the Strait of Gibraltar. Mar Pollut
Bull 19: 387-388
Gill GA, Fitzgerald WF (1985) Mercury sampling of open ocean
waters at the picomolar level. Deep-Sea Res 32: 287-297
Minganti V. Fiorentino F. De Pellegrini R. Capelli R (1993) Mercury
concentrations in coastal and offshore waters of the Ligurian
Sea (Mediterranean). Fresenenius Environ Bull 2: 65-69
R. Capelli et al.
samples were collected show the presence of two
different water masses:
1. Surface water of Atlantic origin (MAW,
Modified Atlantic Water) usually extending
from the surface to a depth of 200 metres.
2. Intermediate water of levantine origin (LIW,
Levantine Intermediate Water) warmer and
saltier than the Atlantic water, usually found
down to a 700 metres depth.
A comparison between MAW (mean 0.21
ng/I) and LIW (mean 0.23 ng/I) was made for the
first three samplings (Dec. 93-Dec. 94) but no significant differences have been detected. Data collected in July 97 show significantly higher reactive mercury concentrations (mean 0.41 ngll,
range 0.27-0.61 ng/I). No explication was found
for such difference, and July 97 data have been
excluded from the comparison. No relationship
was found between the concentration of reactive
mercury, salinity. temperature and depth.
It is difficult to compare these data with
those found in the literature. because there are
few data available for the Mediterranean Sea and
especially for reactive mercury at great depth.
Ferrara and Maserti (1986) reported reactive
mercury concentrations of 3.5 ng/I in the
Tyhrrenian Sea (range 2.0-5.9 ng/I) in off-shore
waters and concentrations of 2.0 ng/I (range 0.52.5 ng/I) in samples of coastal waters.
Significantly lower values recently found by
Cossa et al. (1997), who recorded reactive mercury values below 0.14 ngll, are in agreement
with data found in this work.
Data referred to surface water samples in the
Ligurian Sea show reactive values of 0.3±0.2 ngfl
(n=33. range 0.2-0.8 ng/l, Minganti et al. 1993).
The use of reactive mercury concentrations,
from data reported in this work, seems to be
unable to differentiate water masses of different
origin.
Acknowledgements. The authors thank Dr. Marco Orsi for his help
in acquiring the oceanographic data and the crew of the MN
Urania for their assistance during sampling. This research was
carried out in the framework of the project "ODAS ItaHa1"
(Istituto per l'Automazione Navale. Genova, Consiglio Nazionale
delle Ricerche).
References
Capelli R, Chiarini C, De Pellegrini R, Minganti V (1998) A new
sampler (Marikiki) for deep water for the determination of
mercury at ng L-lleveLAnn Chim 88: 413-417
Copin-Montegut G, Coureau P, Laumont F (1986) Occurrence of
mercury in the atmosphere and waters of the
Mediterranean. in: Pap FAO/UNEP/WHOnOCllAEA Meet
Biogeochem Cycle Mercury Mediterr, Siena, Italy. 27-31
August 1984, FAO Fish Rep (325) Suppl, pp 51-75
Cossa D,Martin JM, Takayanagi K, Sanjuan J (1997) The distribution and cycling of mercury species in the western
Mediterranean. Deep-Sea Res II 44: 721-740
Ferrara R, Maserli B (1986) Mercury in the Mediterranean Basin.
Mar Pollut Bull 1]: 533-534
Ferrara R, Maserti BE (1988) Mercury exchange between outflowing and i.nflowing water in the Strait of Gibraltar. Mar Pollut
Bull 19: 387-388
Gill GA, Fitzgerald WF (1985) Mercury sampling of open ocean
waters at the picomolar level. Deep-Sea Res 32: 287-297
Minganti V. Fiorentino F. De Pellegrini R. Capelli R (1993) Mercury
concentrations in coastal and offshore waters of the Ligurian
Sea (Mediterranean). Fresenenius Environ Bull 2: 65-69