Recent Benthic Foraminifers from the Coast of Susa Area, North East Libya: Taxonomic Notes and Environmental Implications

Abstract

This study deals with the taxonomy and environmental implications of recent benthic foraminifers from the coast on the Susa area in northeast Libya. Six recent sediment samples were collected from the beach of the Susa area at a depth of less than 1 m. Twenty grams of each sample were weighed and processed with standard methods to extract the foraminifera. Thirty-nine species of benthic foraminifera belonging to twenty genera under the Textularina, Rotalina, Spirillinina, and Miliolina suborders were identified and systematically described. The most common genera are Amphiseigina and Textularia, which form 49.7% and 20.25% of the recorded fauna, respectively. Followed by Peneroplis (i.e., symbiont-bearing taxa) (11.6%), Quinqueloculina (4.2%), Elphidium (3.1%), Sorites (2.5%), Adelosina (1.3%), Spiroloculina (1%), and Rosalina (0.9%). Amphistegina lessonii is the most dominant species (49.7%) of the total assemblage. Textularia bocki and Peneroplis pertusus are also dominant species (13.8% and 7.8%, respectively). Environmentally, the analysis of benthic foraminifers in this study shows the effect of pollution and abnormal environmental conditions. Various diversity indices, including species richness (S), the Shannon index, the Simpson index, the Fisher alpha index, and dominance, have been investigated, and foraminiferal test abnormalities as well. The foraminifera display very low to moderate density and low diversity and frequent occurrence of abnormal specimens have been recorded. Eleven test abnormalities are described and illustrated, including (1) double apertures, (2) reduction in the size of the chambers, (3) extra chambers, (4) complex forms, (5) enlarged and deformed apertures, (6) aberrant chamber shapes, (7) twinned forms, (8) loose milliolid coiling (9) wrong coiling, (10) twisted tests and (11) corroded tests. The ecological quality status EcoQS has been evaluated for the studied stations using the Shannon-Wiener H’ (log2) indices, where station 3 has a poor EcoQS, stations 1, 2, 4, and 6 have a moderate EcoQS, and station 5 has a good EcoQS. Three types of pollutants are recognized in the study area, which are sewage, desalination plants wastewater discharge and patches of oil accumulation along the beach. The present findings are essential for enhancing Susa coast habitat conservation and management in the coming years.