Drivers of change in the epifaunal assemblages associated with intertidal macro-algae at the Mangrove site South Safaga, Egypt, Red Sea

Abstract

The present study aimed to study the effects of intertidal habitat complexion on algae-epifaunal communities in the poly-zoned coastal mangrove site south Safaga on the Egyptian Red Sea coast. The study focuses on the effects of main intertidal primary habitats along with the facilitation of habitat cascades on the focal/inhabited organisms, which represented here by algae-epifaunal organisms. The intertidal main primary zones (habitats) in the study area including 1-outer mangrove tree zone, 2-inner flat back reef area, and 3-A sand lagoon in between the previous two zones. However, different algae species that either stand-alone or mixed by other algae species in patches were considered here as secondary habitat-formers. Results indicated that a total of 64 epifaunal species were recorded in different intertidal macro-algae habitats and such faunal diversity and abundance affected mainly by the primary habitat in which approximately 50% of the current epifaunal species showed specificity to only one primary habitat. Results also detected that habitat facilitation was strongest when the secondary habitat-former was most functional for the epifaunal organisms in feeding and hiding from predators. The present study suggested that such effects of secondary habitat formers on the algae-epifaunal diversity are depending essentially on the primary habitat construction and its zone characteristics. In consistence, the results suggested that predation effort is the main factor controlling the distribution of algae-associated organisms depending on how far such organisms can benefit from the special shape and construction of each algae habitat-unit in protection and hiding from predators.