Foraminiferal assemblage indices: A comparison of sediment and reef rubble samples from Conch Reef, Florida, USA

• Published in: Ecological indicators 2015-01, Vol.48, p.1-7
• Main Authors: Stephenson, Christy McNey, Hallock, Pamela, Kelmo, Francisco
• Format: Article
• Language: English
• Subjects: Assessments; Biodiversity; Coastal environments; Coral reefs; Diversity indices; Environmental indicators; FORAM Index; Foraminifera; Indicators; Mathematical analysis; Reefs; Sediments; Shells; Standard deviation
• ISSN: 1470-160X; 1872-7034
• DOI: 10.1016/j.ecolind.2014.07.004

•Most reef-dwelling foraminifers live on firm substrata such as reef or phytal surfaces.•Case study quantified differences between sediment and phytal/rubble samples from same sites.•The same taxa were found in both sample sets, but in different proportions.•Larger-benthic and some agglutinated taxa were concentrated about 1.5–3 fold in sediments.•Shells of smaller foraminifers were more abundant in phytal/rubble samples. Benthic foraminiferal assemblages are increasingly utilized as indicators of water and sediment quality in coastal-marine environments. Most reef-dwelling foraminifers live on firm substrata such as reef or phytal surfaces, while most assessments have examined assemblages from sediments. This case study compared relative abundances of total foraminiferal-shell assemblages between sediment and phytal/rubble samples collected from one reef within one week. A total of 117 species within 72 genera were identified, with the same taxa in both sample sets in different proportions. Larger benthic foraminifers and some agglutinated taxa were concentrated about 1.5–3 fold in sediment samples, while nearly two-thirds of small, fragile shells were lost. Several common indices were compared, including Taxonomic Richness (number of genera), Shannon (H), Simpson's (D) and Fisher (α) diversity indices, Evenness (E), and the FORAM Index (FI). Highly significant differences (p