Morphological deformities of benthic foraminiferal tests in response to pollution by heavy metals: implications for pollution monitoring
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1998
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Анотація
Live foraminiferal assemblages were studied along the
Mediterranean coast of northern Israel. Two hundred
seventeen benthic foraminiferal species were identified,
30% of which (65 species from 20 calcareous families
and one agglutinated family) exhibited 11 distinct types
of morphological deformities of their tests. These include:
wrong coiling, aberrant chamber shape and size,
poor development of the last whorl, twisted chamber arrangement,
additional chambers, protuberances, multiple
apertures, irregular keel, twinning, lateral asymmetry,
and lack of sculpture. Morphological deformities are
independent of latitude, taxonomic position, mode of life
and feeding strategy of foraminifera. In small numbers
(up to 1% of total live population) they can occur within
the range of natural variability of a given species in given
environmental conditions. However, several species
display an increase in the proportion of deformed foraminifera
in live assemblages that can be caused by low
salinity (e.g., for Adelosina cliarensis) or by an increase
in concentrations of heavy metals within the sediment.
For example, an increase in deformed Amphistegina lobifera
indicates an increase in Cd, Cibicides advenum -
Cr, Pseudotriloculina subgranulata - Ti concentrations
in sediments. The highest concentrations of Cd are attributed
to coarse carbonate substrates adjacent to hard
grounds, while Cr and Ti have a strong affinity to muddy-
clay substrates enriched with organic matter. Test deformities
of benthic foraminifera appear to be sensitive
in situ monitors of marine pollution by heavy metals.
However, the biochemical and crystallographic mechanisms
controlling the development of test deformities remain
to be studied by culture experiments under controlled
conditions.
Опис
Ключові слова
foraminiferal, pollution monitoring
Бібліографічний опис
Journal of Foraminiferal Research