Variables a predicting the diversity of macroinvertebrates associated with the largest rhodolith bed bank in the world: Abrolhos Bank

Abstract

This proposal is related with the project "XXX" supported by Fapesp process 2016/14017-0. Rhodolith beds are sea bottoms covered by nodules composed of more than 50% of encrusting coralline algae. The ecosystem formed by these sea bottoms have been neglected in actions related to the brazilian marine conservation. Studying the composition and functionality of rhodolith beds and understand which variables are indicative of the associated biodiversity are fundamental issues in the process of proposal and implementation of management and conservation strategies. In order to test the main predictor variables of the diversity associated with nodules, we will sample rhodoliths in nine areas distributed in a latitudinal and depth gradient of the Abrolhos Bank. Rhodoliths will be carefully sampled and individualized in plastic bags. Besides identification and quantification of associated fauna, we will measure the diameters, volume and dry weight of macroalgae and sediment associated with each nodule. For determination of the mineralogical sediment trapped in rhodolith we will use the technique of X-ray diffraction. We expect to produce enough data to propose variables that can be used in the classification of areas covered by rhodolith beds associated with greater or lesser diversity of vagile macroinvertebrates and, thus, support actions for the conservation of these ecosystems. (AU)