Paulo Antunes Horta

Federal University of Santa Catarina | UFSC · Departamento de Botânica

Global marine conservation remains fractured by an imbalance in research efforts and policy actions, limiting progression towards sustainability. Rhodolith beds represent a prime example, as they have ecological importance on a global scale, provide a wealth of ecosystem functions and services, including biodiversity provision and potential climate...

The transport of passively dispersed organisms across tropical margins remains poorly understood. Hypotheses of oceanographic transportation potential lack testing with large scale empirical data. To address this gap, we used the seagrass species, Halodule wrightii, which is unique in spanning the entire tropical Atlantic. We tested the hypothesis...

In this review we highlight the relevance of biodiversity that inhabit coastal lagoons, emphasizing how species functions foster processes and services associated with this ecosystem. We identified 26 ecosystem services underpinned by ecological functions performed by bacteria and other microbial organisms, zooplankton, polychaetae worms, mollusks,...

Despite global needs regarding the mitigation of the climatic and biodiversity crisis, Brazilian federal government signalized the bidding of 92 blocks of oil and gas exploitation. The potential production in these marine areas will add to the pre-salt reserves already contracted, multiplying by eight the Brazilian annual fossil fuel emissions by 2...

Rhodolith beds harbor a highly diverse associated biota. The Brazilian coast encompasses the world’s largest rhodolith beds of the world that occur along a wide latitudinal expanse, from off the Amazon River mouth in northern Brazil (5°N/49°W) to Santa Catarina State in southern Brazil (27°S/48°W). Although recent studies revealed diverse fish comm...

We seek to shed light on the recent controversy regarding the existence, vitality and extent of the Great Amazon Reef System (GARS; see Francini-Filho et al., 2018). This elucidation is critical considering the plans for large-scale oil and gas exploration in the region and the ongoing legal disputes between oil companies and the Brazilian Environm...

Aim Over the past 50 years, anthropogenic activities have led to the disappearance of approximately one‐third of the world's mangrove forests and their associated ecosystem services. The synergetic combined effect of projected climate change is likely to further impact mangroves in the years to come, whether by range expansions associated with warm...

Marine connectivity studies are essential to provide a framework for analyzing long-term source sink dynamics, as well as determining how species dispersal affects population genetic diversity and structure on large and regional scales. Here we present the first large-scale genetic population and connectivity study of the widespread seagrass specie...

Coralline algae are important components in a large variety of ecosystems. Among them, rhodoliths are a group of free-living coralline red algae that cover extensive coastal areas, from tropical to polar regions. In contrast to other ecosystem engineers, limited research efforts preclude our understanding of their physiology, underlying mechanisms,...

Radiation induces different processes in photosynthetic organisms through photosynthetic pigments and photoreceptors. This study evaluated the performance of the red alga Gracilaria cornea cultivated under different radiation treatments. The objective was to identify responses associated with the treatments and mediated by photoreceptors. For this,...

Humankind, by a particular set of social systems driving the exploitation of nature, has been taking ravaging actions causing enough biogeophysical damage to the planet so that a new geological era has been discussed. Among all environmental threats, climate change has the potential to alter the planet in ecological and evolutionary ways through di...

Sea urchins play a key role in shallow rocky shores, acting as modulators of abundance, density and species composition of macroalgae. In communities that host more than one species, understanding how trophic resources are used and partitioned is a key aspect of understanding the ecosystem’s dynamics in which they are inserted. In Southern Brazil,...

Phenotypic plasticity and local adaptation can adjust individual responses to environmental changes across species’ ranges. Studies addressing the implications of such traits have been underrepresented in the marine environment. Sargassum cymosum represents an ideal model to test phenotypic plasticity, as populations along the southwestern Atlantic...

Functional redundancy can stabilize ecological functions as asynchronous fluctuations among functionally similar species may buffer environmental changes. We investigated the temporal dynamics of a subtidal macroalgal community in the warm temperate Southwestern Atlantic coast (SWA) to evaluate whether functional redundancy stabilize ecosystems fun...

Molecular studies have revealed cryptic diversity and polyphyly in the genus Lithothamnion. In this study we aimed to investigate the diversity and phylogeny of specimens that are morphologically described as Lithothamnion based on extensive collections along the Brazilian coast and an integrative taxonomic approach. Our results led to the proposal...

Marine pollution caused a growing trend of aesthetic and functional disturbances in coastal ecosystems with environmental, social and economic impairment, with abrupt acceleration in the 1970s. Within these last 50 years, the over-enrichment of continental runoff by nutrients has emerged as one of the leading causes of water quality impairment, wit...

Coralline red algae (CRA) are key players in the construction and maintenance of biogenic reefs, and they have important functional roles in ecological systems in the Southwestern Atlantic (SWA). Like many other marine organisms, CRA are currently affected by global and local stressors, but little is known about their biodiversity and the environme...

Beta-1,3-glucanases are enzymes that hydrolyze beta-1,3-glucans, and they are essential for the metabolism of seaweed, plants and fungi. These enzymes also participate in the digestion of herbivore and fungivore animals. Because of the importance of these enzymes in insects, beta-1,3-glucanase inhibitors may be used for the development of new contr...

An increase in the use of macroalgal biomass for different applications is required in development of efficient cultivation systems and low-cost culture media. With this in mind, the present work proposes modifications to the Algal Turf Scrubber (ATS) system inducing the establishment of a monospecific culture of Ulva ohnoi through a seeding proces...

The feasibility of strain selection using tetraspore and carpospore progeny from wild fronds of Chondracanthus teedei to obtain strains with high growth rates, tolerance to temperature, and high yield of native carrageenan was investigated. A total of 34 strains were isolated, 14 from gametophytic progenitors and 20 from tetrasporophytic progenitor...

Calcified coralline algae are ecologically important in rocky habitats in the marine photic zone worldwide and there is growing concern that ocean acidification will severely impact them. Laboratory studies of these algae in simulated ocean acidification conditions have revealed wide variability in growth, photosynthesis and calcification responses...

Given the ecological and biogeochemical importance of rhodolith beds, it is necessary to investigate how future environmental conditions will affect these organisms. We investigated the impacts of increased nutrient concentrations, acidification, and marine heatwaves on the performance of the rhodolith-forming species Lithothamnion crispatum in a s...

Rhodolith beds built by free-living coralline algae are important ecosystems for marine biodiversity and carbonate production. Yet, our mechanistic understanding regarding rhodolith physiology and its drivers is still limited. Using three rhodolith species with different branching morphologies, we investigated the role of morphology in species’ phy...

KEYNOTE POINTS 1. Innovations in technology and engineering regarding sensors and autonomous observation platforms have substantially increased observations of the ocean and allowed for those observations to be collected at finer temporal and spatial resolutions. 2.The networking and coordination of regional observation programmes has been promote...

The Southwestern Atlantic harbors unique reef environments with high proportions of endemic species. The most prominent reefs are located in the Abrolhos Bank, a 46,000 km 2 extension of the South American continental shelf. However, just 100 km north of Abrolhos is the Royal Charlotte Bank (RCB), an area still poorly investigated. From a biologica...

Kelps are canopy-forming brown seaweed sustaining critical ecosystem services in coastal habitats, including shelter and nursery grounds, and providing food resources to a myriad of associated species. This study modeled the fundamental niche of Laminaria abyssalis along the Brazilian continental margin, an endemic species of the South Atlantic, to...

The Parcel de Manuel Luís (PML) is located at the southern end of the Amazon Reef System, which comprises the northernmost reef formations of the Brazilian biogeographical province. Its unique position and singular seascape make the PML an important stepping-stone for marine organisms between the Brazilian and Caribbean provinces. Yet, due to its d...

Raphidiopsis raciborskii (formerly Cylindrospermopsis raciborskii) is a freshwater cyanobacterium potentially producing saxitoxins (STX) and cylindrospermopsin. Its ecophysiological versatility enables it to form blooms in the most diverse types of environments, from tropical to temperate, and from relatively pristine to polluted. In Peri Lake, loc...

Climate driven range shifts are driving the redistribution of marine species and threatening the functioning and stability of marine ecosystems. For species that are the structural basis of marine ecosystems, such effects can be magnified into drastic loss of ecosystem functioning and resilience. Rhodoliths are unattached calcareous red algae that...

The coastal zone, where most of the Brazilian population lives, plays a central role for discussing vulnerability and adaptation strategies to climate change. Besides saltmarshes, mangroves and coral reefs, this region also presents seagrass beds, macroalgae and rhodolith beds, forming underwater forests, which are key habitats for services such as...

Marine heatwaves (MHWs) are a major concern worldwide due to their increasing impacts in recent years, and these extreme events may trigger deoxygenation of coastal waters affected by sewage and eutrophication. Here we investigate the combined effects of MHWs and nutrient enrichment on the water quality and biodiversity of the Bay of Santa Catarina...

Aim As a step towards providing support for an ecological approach to strengthening marine protected areas (MPAs) and meeting international commitments, this study combines cumulative impact assessment and conservation planning approach to undertake a large‐scale spatial prioritization. Location Exclusive Economic Zone (EEZ) of Brazil, Southwest A...

This study presents a systematic review to assess the main similarities and gaps in efforts to evaluate the impacts of heavy metals on benthic marine seaweeds. A total of 91 studies were compiled, the main parameters (abiotic, biological, ecotoxicological, and heavy metals) and descriptors of which were evaluated by quantitative and qualitative ana...

Light, or visible radiation, serves as a source of energy for photosynthesis of plants and most algae. In addition, light and ultraviolet radiation (UV-A and UV-B) act as a biological signal, triggering several cellular processes that are mediated by photoreceptors. The aim of this study was to evaluate the physiological and biochemical responses o...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Coralline algae have come to the forefront of current research efforts due to their expected susceptibility to global climate change-induced ocean acidification, and more recently, due to their use as paleo-ecological proxies and potentially large contribution to carbon sequestration. Yet, our understanding of coralline algae remains limited, partl...

New drugs development for lymphoid neoplasms treatment is an urgent necessity. The aim of this study was to evaluate the cytotoxic effect of the marine plastoquinone, 9’-hydroxysargaquinone (9’-HSQ), focusing on the investigation of its death mechanisms on lymphoid neoplastic cells. This particular plastoquinone reduced cell viability of different...

This study presents two years of characterization of a warm temperate rhodolith bed in order to analyse how certain environmental changes influence the community ecology. The biomass of rhodoliths and associated species were analysed during this period and in situ experiments were conducted to evaluate the primary production, calcification and resp...

Marine climate change mitigation initiatives have recently attracted a great deal of interest in the role of natural carbon sinks, particularly on coastal systems. Brown seaweeds of the genus Sargassum are the largest canopy-forming algae in tropical and subtropical environments, with a wide global distribution on rocky reefs and as floating stands...

In early September 2019, dense crude oil began to wash the beaches of Brazil's tropical coast. Four months after the first report, the crude oil has already been found along >3000 km of the Brazilian coastline on >980 beaches and was recently observed along the Amazon coast, making this oil spill the most extensive and severe environmental disaster...

The impact of invasive species has been increasing in recent decades due to globalization, threatening marine biodiversity. Tubastraea spp. (sun corals) have been spreading worldwide, showing rapid increases in abundance and/or spatial occupancy and adverse effects on recipient native ecosystems. In Brazil, they have become major invaders, extendin...

Physical attack through mesenterial filaments of the zoanthid Palythoa caribaeorum by the sun coral Tubastraea coccinea. In this case the attacks were ineffective, but have been shown to induce necrosis in the endemic Brazilian coral Mussismilia hispida (Santos et al. 2013) and moratility in the corallimorph Ricordea florida and the rock flower ane...

Marine bioinvasions are increasing worldwide by a number of factors related to the anthroposphere, such as higher ship traffic, climate change and biotic communities' alterations. Generating information about species with high invasive potential is necessary to inform management decisions aiming to prevent their arrival and spread. Grateloupia turu...

In his News In Depth story “Mystery oil spill threatens marine sanctuary in Brazil” (8 November 2019, p. 672), H. Escobar highlights important ecosystems that have been affected by the spill. However, he did not mention the Brazilian rhodolith beds—the most extensive, abundant, and diverse biogenic carbonate habitats in the South Atlantic. The oil...

The damages of Mariana’s mining mud in the physiology of the brown algae Sargassum cymosum and its main epiphytic, the red algae Hypnea pseudomusciformis, were evaluated by controlled essays. Seaweeds were exposed to presence or absence of mud, isolated or in biological association, for 5 and 15 days. Measured parameters were growth rates, biochemi...

The loss of canopy‐forming seaweeds from urbanised coasts has intensified in response to warming seas and non‐climatic pressures such as population growth and declining water quality. Surprisingly, there has been little information on the extent of historical losses in the South‐western Atlantic, which limits our ability to place this large marine...

Although the global macroalgae production has increased in the last decades, the contribution of green macroalgae to this scenario is little motivated, mainly, by technical limitations in obtaining a reliable and constant source of germlings. Ulva ohnoi (Chrolophyta) is a widely distributed species that exhibit rapid growth and high rates of nitrog...

Resumo: A Ulva lactuca Linnaeus é uma alga marinha verde encontrada na região costeira. Esta alga apresenta capacidade de se proliferar rapidamente em águas eutróficas e forma uma "maré verde" que leva à morte de organismos aquáticos por hipóxia. A Ulva lactuca é constituída principalmente de uma classe de heteropolissacarídeos sulfatados, denomina...

Environmental conditions shape the occurrence and abundance of habitat-building organisms at global scales. Rhodolith beds structure important hard substrate habitats for a large number of marine benthic organisms. These organisms can benefit local biodiversity levels, but also compete with rhodoliths for essential resources. Therefore, understandi...

The Southwest Atlantic is notable for having extensive reef areas cemented by non‐geniculate coralline red algae. Based on an analysis of four genetic markers and morpho‐anatomical features, we clarify the species of Harveylithon in the tropical and warm temperate Southwest Atlantic. Species delimitation methods (mBGD, ABGD, SPN and PTP) using thre...

As seagrasses decline worldwide, determining their phenotypic variability in response to human altered environmental factors becomes important to better understand their acclimation strategies. Many studies have reported seagrass responses to environmental gradients of single parameters, using either single or multiple metrics. However, studies of...

The direct and indirect effects of mining tailing on macroalgae were evaluated in vitro to determine the relationship between heavy metals toxicity and pH alterations caused by the presence of pollutants. The marine brown seaweed Sargassum cymosum (C. Hagard 1820) and its main epiphytic alga, the red seaweed Hypnea pseudomusciformis (Nauer, Cassano...

Ulva ohnoi is a green macroalga with fast growth and high rates of nitrogen and phosphorus absorption. Recently, this species has been recorded in several places with record green tide formation in some of them. Using molecular tools, we herein report the first occurrence of this species in Brazil and demonstrate its potential for phytoremediation...

Rhodolith beds, like many other marine ecosystems, are affected by climate change that is causing an increase in the magnitude and frequency of extreme high temperature events (heat waves). Unfortunately, this does not represent the sole peril for these communities, as coastal urbanization in conjunction with altered precipitation patterns can incr...

The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions betwe...

Presence of toxic compounds in marine coastal waters has increased exponentially since Industrial Revolution. In this way, we aimed to evaluate biochemical and physiological changes occurring within Hypnea musciformis after short-term exposure to gasoline. Hypnea musciformis was cultivated without gasoline and then exposed to various concentrations...