Brazilian coral reefs in a period of global change: A synthesis

Abstract

Brazilian coral reefs form structures significantly different from the well-known reef models, as follows: (i) they have a growth form of mushroomshaped coral pinnacles called "chapeirões", (ii) they are built by a low diversity coral fauna rich in endemic species, most of them relic forms dating back to the Tertiary, and (iii) the nearshore bank reefs are surrounded by siliciclastic sediments. The reefs are distributed in the following four major sectors along the Brazilian coast: the northern, the northeastern and the eastern regions, and the oceanic islands, but certain isolated coral species can be found in warmer waters in embayments of the southern region. There are different types of bank reefs, fringing reefs, isolated "chapeirões" and an atoll present along the Brazilian coast. Corals, milleporids and coralline algae build the rigid frame of the reefs. The areas in which the major coral reefs occur correspond to regions in which nearby urban centers are experiencing accelerated growth, and tourism development is rapidly increasing. The major human effects on the reef ecosystem are mostly associated with the increased sedimentation due to the removal of the Atlantic rainforest and the discharge of industrial and urban effluents. The effects of the warming of oceanic waters that had previously affected several reef areas with high intensity coral bleaching had not shown, by the time of the 2010 event, any episodes of mass coral mortality on Brazilian reefs. AbstrActDescriptors: Coral reefs, Global changes, Coral bleaching, Endemic fauna.Os recifes de coral do Brasil formam estruturas significativamente diferentes dos modelos conhecidos: (i) possuem uma forma de crescimento de pináculos coralíneos em forma de cogumelo, chamados "chapeirões", (ii) são construídos por uma fauna coralínea com baixa diversidade e rica em espécies endêmicas, sendo grande parte destas formas relíquias do período Terciário e (iii) os recifes costeiros estão num ambiente dominado por sedimentos siliciclásticos. Os recifes estão distribuídos em quatro áreas ao longo da costa brasileira: regiões norte, nordeste, leste, e nas ilhas oceânicas, mas espécies isoladas de coral podem ser encontradas em águas mais quentes nas enseadas da região sul. Diferentes tipos de banco recifais, recifes em franja, "chapeirões" isolados e um atol estão presentes ao longo da costa brasileira. Corais, milleporídeos e algas coralinas incrustantes constroem a estrutura rígida dos recifes. As áreas em que ocorrem os maiores recifes de coral correspondem às regiões nas proximidades de centros urbanos que estão experimentando crescimento acelerado e rápido desenvolvimento do turismo. Os principais efeitos antropogênicos sobre o ecossistema recifal estão associados, essencialmente ao aumento da sedimentação devido à remoção da mata atlântica e as descargas de efluentes industriais e urbanos. Os efeitos do aquecimento das águas oceânicas que vem afetando várias áreas de recifes, com alta intensidade de branqueamento de coral, não causaram mortalidade em massa ...

Limited potential of deep reefs to serve as refuges for tropical Southwestern Atlantic corals

“…, Leão et al. ). Its physiological and morphological adaptations to tolerate greater depths have been documented as well (Esser et al.…”

“…The shallow reefs of this and other tracts of the Northeastern Brazil ecoregion are relatively well studied; some reefs are attached to the coast, and others are several kilometers offshore, generally lying parallel to the coast at depths of approximately 5–10 m (Leão et al. ). The deep reefs of the region, on the other hand, are virtually unknown.…”

“…, Leão et al. ). The Brazilian coral fauna is low compared to the Caribbean reefs, being currently represented by 23 scleractinian species, five hydrocorals, and 22 species of octocorals (Castro et al.…”

“…, Leão et al. ). In contrast to the shallow reefs, the mesophotic coral ecosystems of the Southern Atlantic are still poorly studied (Oliveira Soares et al.…”

Physical contact interactions with scleractinian corals in hard substrate communities

“…Eastern areas (TSB and ABR) are characterized as coral reefs, with biogenic carbonates composing their structure, and they contain the richest reefs in the South Atlantic as well as all Brazilian reef‐building coral species (Leão et al., ). Southern areas (ARC and SAP), in contrast, present a rocky framework and a less diverse hermatypic coral fauna (Leão et al., , ). Although corals interacted with more categories of neighboring organisms in the eastern study areas than in the southern areas, in all four areas each coral species interacted more with few, but abundant, neighboring organisms than with rarer ones.…”