Abnormal test growth in Larger Benthic Foraminifera from hypersaline coastal ponds of the United Arab Emirates

Abstract

The larger benthic foraminifera (LBF) assemblage from shallow hypersaline coastal ponds located in the intertidal area of theUnitedArab EmirateWestern Region was investigated. The studied coastal ponds are located between a lagoonal areawith carbonate sedimentation, and a supratidal, evaporite-dominated, sabkha. Epiphytic larger benthic foraminifera, mostly belonging to the genus Peneroplis, dominate the benthic foraminifera assemblage. At all the sampled locations, the larger benthic foraminifera assemblage is characterised by high percentages of tests with abnormal growth. Dissolution and microboring are also common on the majority of LBF tests. The high percentage of abnormal tests reflects natural environmental stress caused by the instability of physical parameters (particularly high and variable salinity and temperature) in this transitional marine environment. The unique presence of epiphytic species in some of the ponds suggests that epiphytic foraminifera are transported into the ponds attached to floating seagrass and subsequently continue to live in the stressed pond environment.