A multi-disciplinary study of sediment core records from the Mingulay Reef Complex, a cold-water coral reefs system off western Scotland, highlights the potential of cold-water corals from which detailed centennial-scale palaeo-environmental reconstructions can be derived. This study provides a new insight on the mechanisms controlling Lophelia pertusa reef build-up, shifts in biodiversity, the physical/chemical/biological processes and the sedimentary regime. A detailed record of Mingulay Complex growth history shows unprecedented high average accumulation rates of 3 – 4 mm a-1. Marine radiocarbon reconstruction derived from paired 14C and U-series dated fossil corals revealed substantial abrupt oceanic shifts during the Holocene that have repetitively affected cold-water coral growth, eventually causing local disappearance. These periods of reduced accumulation rates are synchronous with other coral structures from the NE Atlantic illustrating basin wide events. Finally, trace/minor element ratios reproducibility within coral skeleton was investigated to test if palaeo-environmental reconstructions could be made from cold-water corals.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-04-04T11:10:45Z No. of bitstreams: 1 2013 - Vin?cius da Rocha Miranda.pdf: 4210864 bytes, checksum: 3c37254eedb367413a77718eae172a75 (MD5) / Made available in DSpace on 2017-04-04T11:10:45Z (GMT). No. of bitstreams: 1 2013 - Vin?cius da Rocha Miranda.pdf: 4210864 bytes, checksum: 3c37254eedb367413a77718eae172a75 (MD5) Previous issue date: 2013-06-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Cold-water coral reefs are of great ecological importance, they can support a great diversity associated with. They can offer a sheltered, three-dimensional, micro-habitat to many species. Studies involving the Brazilian deep-sea coral reefs, and the fauna which composes it, are recent and still scarce. These reefs were studied only in terms of the species of coral which composes it and their distribution in our coast, as the benthic fauna which are associated with this environment. Two projects, CAP-BC and ECOPROF, coordinated by CENPES/PETROBRAS, surveyed the Campos Basin (located at the northeast of Rio de Janeiro) with the objective of studying this environment and the associated fauna. On each project samples of the reef-building corals were collected with a ROV, at depths from 245 to 1100m. Five species of coral were surveyed: Solenosmilia variabilis Duncan, 1873, Lophelia pertusa (Linnaeus, 1758), Enallopsammia rostrata (Portual?s, 1758), Madrepora oculata Linnaeus, 1758 and Errina sp.,and fixed in formalin 10% and sorted at the laboratory. Here in, we present the first, qualitative, results from the polychaetes found in association with the coral reefs in Campos BasinThe specie of Eunice prognatha McIntosh, 1885 were the most abundant, followed by Harmothoe gilchristi (Day, 1960) and Nicon maculata Kimberg, 1866. The majority of polychaetes were found associated to the coral S. variabilis, followed by E. profunda and L. pertusa, both M. oculata and Errina sp. were the corals with less associated polychaetes. Five new species of Polychaeta are reported: Harmothoe sp. (Polynoidae), Pholoides sp. (Sigalionidae), Leocratides sp. (Hesionidae), Euchone sp. (Sabellidae) and Ophryotrocha sp. (Dorvilleidae).Specimens identified as Glycerella magellanica (McIntosh, 1885), Harmothoe gilchristi (Day, 1960), Eunice gracilicirrata (Treadwell, 1922), Eunice prognatha McIntosh, 1885, Pionosyllis procera Hartman, 1965, Haplosyllis ohma (Imajima & Hartman, 1964) and Nicon maculata Kimberg, 1866, are new occurrence for the Brazilian coast. Two other species, Filogranula revizee Nogueira & Abbud, 2009 and Notopygos crinita Grube, 1855had their range of occurrence extended. This is the first study aiming on the polychaetes associated with deep sea corals in the Brazilian waters, further studies should be conducted to better understand the distribution of species described here in, as well as to better understand the polychaete assemblage associated with each species of coral. / Recifes de corais de profundidade possuem uma grande import?ncia ecol?gica, uma vez que podem abrigar uma grande diversidade de esp?cies associadas. Isso ? poss?vel gra?as ? sua conforma??o tridimensional que proporciona uma alta hetereogenidade espacial, criando um ambiente protegido para muitas esp?cies. No Brasil, estudos sobre corais. de profundidade, s?o escassos e recentes. Muitos destes se limitam a descrever as esp?cies de corais encontradas e a sua distribui??o pela costa brasileira assim como organismos bent?nicos associados a eles. Recentemente foram realizados dois projetos coordenados pela CENPES/PETROBRAS, CAP-BC e ECOPROF com objetivo de realizar um levantamento dos recifes de corais de profundidade, bem como das esp?cies associadas a estes, na regi?o da Bacia de Campos (noroeste do estado do Rio de Janeiro). Em cada um desses projetos foi utilizado um ROV para coletar amostras nas profundidades entre 300 e 1100 metros. Cinco esp?cies de corais formadores desse ecossistema foram coletadas: Solenosmilia variabilis Duncan, 1873, Lophelia pertusa (Linnaeus, 1758), Enallopsammia rostrata (Portual?s, 1758), Madrepora oculata Linnaeus, 1758 and Errina sp., cada amostra foi fixada em uma mistura tamponada de formalina (10%), para posterior triagem em laborat?rio. Aqui apresentamos o estudo dos poliquetas associados a estes corais na Bacia de Campos. A esp?cie Eunice prognatha McIntosh, 1885 foi a mais abundante, seguida por Harmothoe gilchristi (Day, 1960) e Nicon maculata Kimberg, 1866. O coral S. variabilis foi o que apresentou o maior n?mero de esp?cies associadas, seguida dos corais E. rostrata e L. pertusa, j? as esp?cies M. oculata e Errina sp. foram os corais com menos esp?cies de poliquetas encontrados. Foram reportadas cinco novas esp?cies de poliquetas Harmothoe sp. (Polynoidae), Pholoides sp. (Sigalionidae), Leocratides sp. (Hesionidae), Euchone sp. (Sabellidae), e Ophryotrocha sp. (Dorvilleidae). O total de oito esp?cies foram registradas pela primeira vez para a costa brasileira: Glycerella magellanica (McIntosh, 1885), Harmothoe gilchristi (Day, 1960), Eunice gracilicirrata (Treadwell, 1922), Eunice prognatha McIntosh, 1885, Pionosyllis procera Hartman, 1965, Haplosyllis ohma (Imajima & Hartman, 1964), e Nicon maculata Kimberg, 1866. Duas outras esp?cies, viii Filogranula revizee Nogueira & Abbud, 2009 e Notopygos crinita Grube, 1855, tiveram suas ?reas de ocorr?ncia ampliadas. Este ? o primeiro estudo focando nos poliquetas associados aos corais de profundidade da costa brasileira. Novos estudos devem ser realizados para melhor compreender a distribui??o das esp?cies descritas neste trabalho, assim como entender as poss?veis associa??es destas com as esp?cies de coral desse ecossistema

Scleractinian cold-water corals are widely distributed in seaways and basins of the North Atlantic Ocean, including the Straits of Florida. These corals can form extensive biogenic mounds, which are biodiversity hotspots in the deep ocean. The processes that lead to the genesis of such cold-water coral mounds and control their distribution and morphology are poorly understood. This work uses an innovative mapping approach that combines 130 km2 of high resolution geophysical and oceanographic data collected using an Autonomous Underwater Vehicle (AUV) from five cold-water coral habitats in the Straits of Florida. These AUV data, together with ground-truthing observations from eleven submersible dives, are used to investigate fine-scale mound parameters and their relationships with environmental factors. Based on these datasets, automated methods are developed for extracting and analyzing mound morphometrics and coral cover. These analyses reveal that mound density is 14 mound/km2 for the three surveyed sites on the toe-of-slope of Great Bahama Bank (GBB); this density is higher than previously documented (0.3 mound/km2) in nearby mound fields. Morphometric analyses further indicate that mounds vary significantly in size, from a meter to up to 110 m in relief, and 81 to 600,000 m2 in footprint area. In addition to individual mounds, cold-water corals also develop in some areas as elongated low-relief ridges that are up to 25 m high and 2000 m long. These ridges cover approximately 60 and 70% of the mapped seafloor from the sites at the center of the Straits and at the base of the Miami Terrace, respectively. Morphometrics and current data analyses across the five surveyed fields indicate that mounds and ridges are not in alignment with the dominant current directions. These findings contradict previous studies that described streamlined mounds parallel to the northward Florida Current. In contrast, this study shows that the sites dominated by coral ridges are influenced by unidirectional flowing current, whereas the mounds on the GBB slope are influenced by tidal current regime. The GBB mounds also experience higher sedimentation rates relative to the sites away from the GBB slope. Sub-surface data document partially or completely buried mounds on the GBB sites. The sediments burying mounds are off-bank material transported downslope by mass gravity flow. Mass gravity transport creates complex slope architecture on the toe-of-slope of GBB, with canyons, slump scars, and gravity flow deposits. Cold-water corals use all three of these features as location for colonization. Coral mounds growing on such pre-existing topography keep up with off-bank sedimentation. In contrast, away from the GBB slope, off-bank sedimentation is absent and coral ridges grow independently of antecedent topography. In the sediment-starved Miami Terrace site, coral ridge initiation is related to a cemented mid-Miocene unconformity. In the center of the Straits, coral ridges and knobs develop over an unconsolidated sand sheet at the tail of the Pourtales drift. Coral features at the Miami Terrace and center of the Straits have intricate morphologies, including waveform and chevron-like ridges, which result from asymmetrical coral growth. Dense coral frameworks and living coral colonies grow preferentially on the current-facing ridge sides in order to optimize food particle capture, whereas coral rubble and mud-sized sediments accumulate in the ridge leesides. Finally, this study provides a method using solely acoustic data for discriminating habitats in which cold-water corals are actively growing. Results from this method can guide future research on and management of cold-water coral ecosystems. Taken together, spatial quantitative analyses of the large-scale, high-resolution integrated surveys indicate that cold-water coral habitats in the Straits of Florida: (1) are significantly more diverse and abundant than previously thought, and (2) can be influenced in their distribution and development by current regime, sedimentation, and/or antecedent topography.

The distribution of biodiversity on the planet faces dramatic spatial reorganization from climate change. This is especially true in the marine realm, where species often live near their physiological limits. Thus, effective conservation agendas for marine biodiversity must be predicated upon robust multi-scenario projections of climate-driven changes in oceanographic conditions. However, much of the theory and empirical work on distributional changes in marine biodiversity comes from shallow-water ecosystems. The deep seafloor (> 200 m) has received comparably little attention despite mounting evidence of the accrual of climatic changes within this largest habitable area of the planet. Here, I present a number of case studies predicting the effects of climate change on the distributions of cold-water coral (CWC) reef habitats and their associated fauna, using both modelling approaches and empirical data collected on multiple oceanographic cruises to the CWC reefs of the southeast USA (SEUS) in 2018-2019. These reefs are persistent features of continental margins (~200 – 4000 m ) around the globe, important biodiversity and biogeochemical cycling hotspots, and sentinels of marine climate change. In Chapter 2, I fit global habitat suitability models (HSMs) using publicly available oceanographic and biogeographic products to predict the occurrence of reef-forming CWC species and the reef habitat they form, testing for taxonomic and regional differences in their ecological niches. I then use an ensemble of global climate model outputs as inputs for ensemble HSMs projecting the distributions of these same taxa to 2100 in a range of climate scenarios, and test for differences in distribution changes across species and bioregions. In Chapter 3, I use higher-resolution regional and global climate products and data from multiple oceanographic cruises to the SEUS to build HSMs for this region; this data collation revealed the largest known, essentially continuous CWC reef province on the planet. The models located pivotal climate refugia primarily at deeper (> 600 m) eastward reef sites – notably including those outside of areas designated to protect coral from bottom-contact fisheries – that may remain suitable to 2100 while shallower sites are projected to experience catastrophic declines. In Chapters 4 and 5 I present community ecological work based from research expeditions to CWC reefs of the SEUS described in Chapter 2. In Chapter 4, I use video imagery and in situ collections of intact seafloor communities to test how the abundance, taxonomic and functional diversity, and community structure of invertebrate communities in hard-substratum ecosystems along the SEUS margin, including CWC reefs and submarine canyons change along biocomplexity (e.g. the percentage of live coral cover), bathymetric, and oceanographic gradients. In Chapter 5, I synthesize invertebrate and fish data from SEUS CWC reefs to fit Bayesian community-level joint HSMs predicting the occurrence and abundance of these faunas as functions of their ecological traits. These models reveal strong distinctions fish and invertebrates in their climate and habitat preferences at CWC reefs, suggesting opposing responses to climate change. Overall, Chapters 3-5 expand upon baseline descriptions of reef habitats and coral-associated fauna in the SEUS, testing for mechanisms driving observed ecological patterns across large environmental gradients. Together, this volume improves our understanding of the ecological drivers of vulnerable marine ecosystem occurrence and biodiversity, augmenting conservation efforts for these critical components of the global ocean. / Biology

As the largest and most poorly environment on Earth, the deep-sea is facing global threats from climate change and anthropogenic disturbance further compounded by the lack of critical baseline data on seafloor species composition and community structure. Many data-deficient regions include those in geographically-isolated offshore environments, like low-latitude seamounts, where sampling and surveys have been limited, resulting in critical knowledge gaps that do not allow for effective conservation measures to be realized. This work seeks to characterize the coral fauna of tropical seamount environments greater than 150 m depth and understand the environmental controls on species distribution and community assembly for long-lived, ecologically-important species, primarily from the Octocorallia, Antipatharia, Stylasteridae, and Scleractinia. Methodologies for accomplishing this research have included analysis of remotely operated vehicle (ROV) video surveys and identification of collected voucher specimens to understand biogeographic patterns within coral communities on seamounts and other rugged seafloor features in 3 different regions: the tropical western Atlantic (Anegada Passage), the equatorial central Pacific (Phoenix Islands), and the tropical eastern Pacific (Costa Rica). These regions represent vastly different oceanographic regimes in terms of biological productivity and water column structure resulting in differential effects on deep-sea coral communities. Evidence from these three regions has shown significant effects of the role that oceanic water masses have on structuring deep-water coral biodiversity and suggests that these features, along with other abiotic environmental variables, are important indicators for understanding species distribution patterns, community structure, and global biogeographic patterns. More broadly, the results of this work have demonstrated the capabilities of exploratory ROV surveys, across multiple platforms, to add practical knowledge to coral species inventories and identify bathyal biogeographic patterns in remote regions of the deep sea. The results of this work, serving as baseline coral biodiversity surveys for each area, are also germane to evaluating the effects of human-mediated disturbance and global climate change in the deep ocean. These disturbances also include ocean acidification, ocean deoxygenation, deep-sea mining, and bottom-contact fishing, all of which have been identified as threats to the seamount benthos. / Biology

Cold-water corals act as critical foundation species in the deep sea by creating extensive three-dimensional habitat structures that support biodiversity hotspots. There is currently a paucity of data concerning the environmental requirements and physiology of cold-water corals, severely limiting our ability to predict how resilient they will be to future environmental change. Cold-water corals are expected to be particularly vulnerable to the effects of ocean acidification, the reduction in seawater pH and associated changes to the carbonate system caused by anthropogenic CO2 emissions. Here, the ecological niche and physiology of the cold-water coral Lophelia pertusa is explored to predict its sensitivity to ocean acidification. Species distribution models were generated in order to quantify L. pertusa’s niche in the Gulf of Mexico with regard to parameters including seafloor topography, the carbonate system, and the availability of hard substrate. A robust oceanographic assessment of the Gulf of Mexico was conducted in order to characterize the current environmental conditions at benthic sites, with a focus on establishing the baseline carbonate system in L. pertusa habitats. Finally, an experimental approach was used to test the physiological response of biogeographically separated L. pertusa populations from the Gulf of Mexico and the Norwegian coast to ocean acidification. Based on my findings, it appears that L. pertusa already persists near the edge of its viable niche space in some locations, and therefore may be highly vulnerable to environmental change. However, experimental results suggest that some populations may be surprisingly resilient to ocean acidification, yielding broad implications for the continued persistence of cold-water corals in future oceans. / Biology

Deep-water or cold-water corals are abundant and highly diverse, greatly increase habitat heterogeneity and species richness, thereby forming one of the most significant ecosystems in the deep sea. Despite this remote location, they are not removed from the different anthropogenic disturbances that commonly impact their shallow-water counterparts. The global decrease in seawater pH due to increases in atmospheric CO2 are changing the chemical properties of the seawater, decreasing the concentration of carbonate ions that are important elements for different physiological and ecological processes. Predictive models forecast a shoaling of the carbonate saturation in the water column due to OA, and suggest that cold-water corals are at high risk, since large areas of suitable habitat will experience suboptimal conditions by the end of the century. The main objective of this study was to explore the fate of the deep-water coral community in time of environmental change. To better understand the impact of climate change this study focused in two of the most important elements of deep-sea coral habitat, the reef forming coral Lophelia pertusa and the octocoral community, particularly the gorgonian Callogorgia delta. By means of controlled experiments, I examined the effects of long- and short-term exposures to seawater simulating future scenarios of ocean acidification on calcification and feeding efficiency. Finally In order to understand how the environment influences the community assembly, and ultimately how species cope with particular ecological filters, I integrated different aspects of biology such functional diversity and ecology into a more evolutionary context in the face of changing environment. My results suggest that I) deep-water corals responds negatively to future OA by lowering the calcification rates, II) not all individuals respond in the same way to OA with high intra-specific variability providing a potential for adaptation in the long-term III) there is a disruption in the balance between accretion and dissolution that in the long term can shift from net accretion to net dissolution, and IV) there is an evolutionary implication for certain morphological features in the coral community that can give an advantage under stresfull conditions. Nevertheless, the suboptimal conditions that deep-water corals will experience by the end of the century could potentially threaten their persistence, with potentially negative consequences for the future stability of this already fragile ecosystem. / Biology

Ocean acidification is the reduction in seawater pH due to the absorption of anthropogenic carbon dioxide by the oceans. Reductions in seawater pH can inhibit the precipitation of aragonite, a calcium carbonate mineral used by marine calcifiers such as corals. Lophelia pertusa is a cold-water coral that forms large reef structures which enhance local biodiversity on the seafloor, and is found commonly from 300-600 meters on hard substrata in the Gulf of Mexico. The present study sought to investigate the potential impacts of ocean acidification on L. pertusa in the Gulf of Mexico through combined field and laboratory analyses. A field component characterized the carbonate chemistry of L. pertusa habitats in the Gulf of Mexico, an important step in establishing a baseline from which future changes in seawater pH can be measured, in addition to collecting in situ data for the design and execution of perturbation experiments in the laboratory. A series of recirculating aquaria were designed and constructed for the present study, and support the maintenance and experimentation of live L. pertusa in the laboratory. Finally, experiments testing L. pertusa's mortality and growth responses to ocean acidification were conducted in the laboratory, which identified thresholds for calcification and a range of sensitivities to ocean acidification by individual genotype. The results of this study permit the monitoring of ongoing ocean acidification in the deep Gulf of Mexico, and show that ocean acidfication's impacts may not be consistent across individuals within populations of L. pertusa. / Biology