Foraminiferal assemblage and reef check census in coral reef health monitoring of East Brazilian margin

Assessing coral reef health in the North Ari Atoll (Maldives) using the FoRAM Index

“…Although larger foraminifera can be abundant in coarse sediments, Hallock et al (2003) and Ramirez et al (2008) demonstrated that, in ecosystems where environmental conditions are conducive for higher abundances of smaller foraminifera, they are not overwhelmed by the shells of larger species even in coarse sediments. However, as noted above, Barbosa et al (2009) showed that along the coast of Brazil, the distribution of symbiont-bearing foraminifers can be controlled by the sedimentation regime where corals form extensive canopies at the sea surface. Barbosa et al also demonstrated that some coral species can thrive in muddy sediments that are not tolerated by symbiont-bearing foraminifera.…”

“…FI values < 2 indicate ecological conditions unfavorable for calcifying organisms that host algal endosymbionts (and therefore not conducive to reef growth), values between 2 and 4 indicate marginal conditions, and values > 4 indicate ecological conditions generally favorable for calcifying organisms that host algal endosymbionts, and therefore that support reef growth. During specimen counting, the degree of bioclast preservation was also evaluated (Barbosa et al, 2009;Hallock, 2012). For example bioclasts corroded or rounded may indicate prolonged reworking by currents (e.g., heavily broken specimens and missing or eroded tubulospines in calcarinids).…”

“…The calibration was performed daily. These parameters were chosen to facilitate comparison with previous studies on the FI (e.g., Hallock et al, 2003;Ramirez et al, 2008;Barbosa et al, 2009). Averages for each island are in Table 2 and the complete data set in Supplementary Material-3.…”

“…This limitation can be overcome by excluding calcarinids from the symbiont-bearing category. Another exception is for Brazilian reefs that are characterized by unique canopy structures, where the FI appears to be more dependent on sediment texture (Barbosa et al, 2009(Barbosa et al, , 2012). An additional limitation of this index is in higher energy environments where larger foraminifera have been major sediment producers in the past.…”

“…Although the FI can vary with parameters such as distance from the coast (Narayan and Pandolfi, 2010), sediment texture, hydrodynamic regime and light penetration (Barbosa et al, 2009), several studies have demonstrated that the FI is primarily related to water quality (Uthicke and Nobes, 2008;Uthicke et al, 2010;Koukousioura et al, 2011;Velásquez et al, 2011;Reymond et al, 2012;Oliver et al, 2014).…”