ABSTRACT

Brizalina lowmani was found to be the most abundant living foraminiferan of the south Texas outer continental shelf, both in the sediment and in the water column. Brizalina lowmani, considered a nearshore benthonic foraminifer evidently possesses a meroplanktonic stage which allows it to take advantage of the pelagic and benthonic environments. Our study indicates that standing crops of B. lowmani in the water column can be used to determine provenance and direction of shallow and deep shelf currents.

Standing crops of B. lowmani in the sediment can be used as indicators of bottom shelf current and direction, depth and area of winter water column mixing, and degree of eutrophism of bottom and overlying waters.

The meroplanktonic nature of B. lowmani allows a wide dispersal of the form, suggesting why similar forms can be utilized as biostratigraphically useful index fossils. The form, B. lowmani, may be reminiscent of the early evolution of planktonic foraminiferans.