Hudson T. Pinheiro

Baseline Assessment of Mesophotic Reefs of the Vitória-Trindade Seamount Chain Based on Water Quality, Microbial Diversity, Benthic Cover and Fish Biomass Data

Seamounts are considered important sources of biodiversity and minerals. However, their biodiversity and health status are not well understood; therefore, potential conservation problems are unknown. The mesophotic reefs of the Vitória-Trindade Seamount Chain (VTC) were investigated via benthic community and fish surveys, metagenomic and water chemistry analyses, and water microbial abundance estimations. The VTC is a mosaic of reef systems and includes fleshy algae dominated rhodolith beds, crustose coralline algae (CCA) reefs, and turf algae dominated rocky reefs of varying health levels. Macro-carnivores and larger fish presented higher biomass at the CCA reefs (4.4 kg per frame) than in the rhodolith beds and rocky reefs (0.0 to 0.1 kg per frame). A larger number of metagenomic sequences identified as primary producers (e.g., Chlorophyta and Streptophyta) were found at the CCA reefs. However, the rocky reefs contained more diseased corals (>90%) than the CCA reefs (~40%) and rhodolith beds (~10%). Metagenomic analyses indicated a heterotrophic and fast-growing microbiome in rocky reef corals that may possibly lead to unhealthy conditions possibly enhanced by environmental features (e.g. light stress and high loads of labile dissolved organic carbon). VTC mounts represent important hotspots of biodiversity that deserve further conservation actions.

Brazilian aquatic biodiversity in peril

The ongoing fiscal and political crisis in Brazil has already caused deep cuts to science and education (“Fiscal crisis has Brazilian scientists scrambling,” H. Escobar, In Depth, 28 August, p. [909][1]), and now the environment is in the crosshairs. On 2 October, the Federal Government

Island biogeography of marine organisms

Studies on the distribution and evolution of organisms on oceanic islands have advanced towards a dynamic perspective, where terrestrial endemicity results from island geographical aspects and geological history intertwined with sea-level fluctuations. Diversification on these islands may follow neutral models, decreasing over time as niches are filled, or disequilibrium states and progression rules, where richness and endemism rise with the age of the archipelago owing to the splitting of ancestral lineages (cladogenesis). However, marine organisms have received comparatively little scientific attention. Therefore, island and seamount evolutionary processes in the aquatic environment remain unclear. Here we analyse the evolutionary history of reef fishes that are endemic to a volcanic ridge of seamounts and islands to understand their relations to island evolution and sea-level fluctuations. We also test how this evolutionary history fits island biogeography theory. We found that most endemic species have evolved recently (Pleistocene epoch), during a period of recurrent sea-level changes and intermittent connectivity caused by repeated aerial exposure of seamounts, a finding that is consistent with an ephemeral ecological speciation process. Similar to findings for terrestrial biodiversity, our data suggest that the marine speciation rate on islands is negatively correlated with immigration rate. However, because marine species disperse better than terrestrial species, most niches are filled by immigration: speciation increases with the random accumulation of species with low dispersal ability, with few opportunities for in situ cladogenesis and adaptive radiation. Moreover, we confirm that sea-level fluctuations and seamount location play a critical role in marine evolution, mainly by intermittently providing stepping stones for island colonization.

The anti-predator role of within-nest emergence synchrony in sea turtle hatchlings

Group formation is a common behaviour among prey species. In egg-laying animals, despite the various factors that promote intra-clutch variation leading to asynchronous hatching and emergence from nests, synchronous hatching and emergence occurs in many taxa. This synchrony may be adaptive by reducing predation risk, but few data are available in any natural system, even for iconic examples of the anti-predator function of group formation. Here, we show for the first time that increased group size (number of hatchlings emerging together from a nest) reduces green turtle (Chelonia mydas) hatchling predation. This effect was only observed earlier in the night when predation pressure was greatest, indicated by the greatest predator abundance and a small proportion of predators preoccupied with consuming captured prey. Further analysis revealed that the effect of time of day was due to the number of hatchlings already killed in an evening; this, along with the apparent lack of other anti-predatory mechanisms for grouping, suggests that synchronous emergence from a nest appears to swamp predators, resulting in an attack abatement effect. Using a system with relatively pristine conditions for turtle hatchlings and their predators provides a more realistic environmental context within which intra-nest synchronous emergence has evolved.

Expansion of an invasive coral species over Abrolhos Bank, Southwestern Atlantic

Invasive coral species of the genus Tubastraea have been increasingly recorded in Southwestern Atlantic waters since the 1980s. Their invasion and infestation are mainly related to port and oil exploration activities. For the first time the presence of Tubastraea tagusensis colonies is reported in Espírito Santo State, colonizing a port shore area, and incrusting oil/gas platform structures situated in the southern Abrolhos Bank, which is part of the most important coral reef system of the South Atlantic Ocean. Tubastraea colonies exhibit fast growth and high recruitment rates, and colonized 40% of the analyzed structures in just four years. The projection of port and oil/gas industry growth for the Espírito Santo State (more than 300%) highlights an alert to the dispersal of this alien species to natural areas.

Mesophotic fishes of the Abrolhos Shelf, the largest reef ecosystem in the South Atlantic.

Fishes inhabiting rhodolith beds and reefs at mesophotic depths on the Abrolhos Shelf, which encompasses the largest and richest coral reef formation in the South Atlantic Ocean, were assessed through technical diving and remotely operated vehicles (ROVs). A total of 74 fish species were recorded, including at least one new species, one new record for the south-western Atlantic and six new records for the Abrolhos region. Overfishing, mining and port activities are already threatening many endangered and commercially important species recorded on the mesophotic reefs of Abrolhos Shelf, and the establishment of marine protected areas and off-reserve fisheries regulations are urgently needed.

Reef oases in a seamount chain in the southwestern Atlantic

The Vitória-Trindade Chain (VTC) is a line of seamounts extending 1,200 km eastwards from the central Brazilian coast (20 S) to the Trindade and Martin Vaz islands (Fig. 1a). These seamounts present mesophotic summits (60–55 m depths) that are predominantly flat and covered by soft sediments and rhodolith beds (Pereira-Filho et al. 2011; Fig. 1b). High-relief biogenic reefs (Fig. 1c) were only recently found in the VTC, during two expeditions in 2011. These singular structures are mostly built by crustose coralline algae and sparse corals and hydrocorals (Fig. 1d), reaching up to 35–17 m (Vitória and Davis seamounts) and 62–84 m depths (Jaseur and Columbia seamounts). Structural reefs shelter a richer and more abundant fauna than the surrounding flat beds, including large, endangered, and commercially important reef fishes (Fig. 1e). Although being small and sparse, reef patches represent a critical habitat in the VTC, functioning as connectivity stepping-stones for several reef organisms that reach and maintain permanent populations in the isolated islands (Floeter and Gasparini 2000). As fishing effort is largely unregulated and mining of carbonates is already taking place at the VTC, the region urgently needs increased scientific and conservation efforts.

Fish diversity of a southwestern Atlantic coastal island: aspects of distribution and conservation in a marine zoogeographical boundary

Despite the increase of knowledge about the southwestern Atlantic ichthyofauna, there is still a lack of information along extensive marine areas. The Espirito Santo state (ES) coast, considered a zoogeographic boundary and a transitional zone between tropical and subtropical realms, is still largely unknown. Here is provided a checklist containing 221 fish species at Franceses Island (south coast of ES), which was attained with data from 2000 to 2010 by means of underwater observations, specimen collections and fisheries monitoring. Abundance, habitats and threat risks of each species are shown and discussed. The number of reef fish species found at Franceses Island corresponds approximately to 35% of all fishes present in the Brazilian Province. The conservation of the Franceses Island and surrounding areas would protect a mosaic of environments that can support a high diversity of fish species.

Mesophotic coral ecosystems are threatened and ecologically distinct from shallow water reefs

Deep coral reefs are different Coral reefs are under intense pressure from anthropogenically induced climate warming and habitat destruction. It has been suggested that coral reefs in deeper waters may provide a refuge less affected by human development and climate change. Rocha et al., however, show that shallow and deep reefs are biologically different. Furthermore, deep (or mesophotic) reefs are also suffering from human impacts. Thus, deep reefs do not represent a potential refuge for other reef ecosystems. Indeed, they too are threatened and need protection. Science, this issue p. 281 Deep water reefs will not provide a refuge for shallow reef ecosystems. The rapid degradation of coral reefs is one of the most serious biodiversity problems facing our generation. Mesophotic coral reefs (at depths of 30 to 150 meters) have been widely hypothesized to provide refuge from natural and anthropogenic impacts, a promise for the survival of shallow reefs. The potential role of mesophotic reefs as universal refuges is often highlighted in reef conservation research. This hypothesis rests on two assumptions: (i) that there is considerable overlap in species composition and connectivity between shallow and deep populations and (ii) that deep reefs are less susceptible to anthropogenic and natural impacts than their shallower counterparts. Here we present evidence contradicting these assumptions and argue that mesophotic reefs are distinct, impacted, and in as much need of protection as shallow coral reefs.

Roa rumsfeldi, a new butterflyfish (Teleostei, Chaetodontidae) from mesophotic coral ecosystems of the Philippines

Abstract A new species of the butterflyfish genus Roa is herein described from the Verde Island Passage in the Philippines, West Pacific Ocean. Roa rumsfeldi sp. n. was found on mesophotic coral ecosystems at Puerto Galera and Batangas, and sampled through technical mixed-gas rebreather diving at 100–130 m depth. This represents the fifth known species of Roa. The main differences between Roa rumsfeldi sp. n. and its congeners are the lower number of pored scales in the lateral line, longer snout, longer caudal peduncle, shorter caudal fin, pelvic fin color (dark first spine vs. white in all other Roa), and genetics (8.4% divergence from its closest relative Roa modesta in the mitochondrial COI gene). Roa spp. are usually seen in pairs, but the two specimens we collected were solitary individuals. We have kept one of the specimens alive in the California Academy of Sciences’ Twilight Zone exhibit for more than one year, where it thrives and is feeding on a variety of dried and fresh food.