Distribution and ecology of recent benthic Foraminifera from Tarut Bay, Arabian Gulf, Saudi Arabia
Samples from 121 stations in Tarut Bay, on the
Arabian Gulf coastline of Saudi Arabiat were examined
for their foraminiferal content. 109 of these contained
Foraminifera. The environment is hypersaline (45ýwl up to
75%4) and sampling stations included bare sediment substrates
as well as vegetated substrates. Depth of waterl
temperature, salinity and substrate were recorded. 43
foraminiferal taxa. were recognizedp 14 of which constituted
9Wo of the dead population and 93% of the living.
These 14 taxa are regarded as the common taxa and their
distribution plotted on maps. Living and dead specimens
of most of these taxa, have a similar distribution. The
distribution is patchy because it is controlled by the
type of substrate and to a less extent by water depth.
3 assemblage zones have been recognized: Intertidall
Shallow Subtidal (0-3 m) and Deeper Subtidal (3-13 m).
These are recognized by the relative abundance of the
different common taxa.
The fauna has a low diversity for both living
(CV, = 1-4) and dead (cx-'= 1-5)9 and is dominated by
Miliolina (c. 55%) of which the most abundant are
Quinqueloculina spp. p Triloculina spp. 9
spp. 9 Spirolina arietina and Peneroplis planatuS. The
suborder Rotaliina (c. 39%) is next in abundance with
Ammonia beccarii varieties and Elphidium spp. The
Textulariina (c. 67o) are represented by Textularia spp.
and Eggerella scabra.
Living/Dead ratios have been examined and taken to
indicate no relationship between this ratio and rate of
The fauna of Tarut Bay is compared with that of
other hypersaline environments in the Arabian Gulf and
in the Red Sea. These faunas have certain characteristics
which can be regarded as typifying the hypersaline
environment: low diversity# dominance of Miliolinat
and rarity of Textularina.