Briguglio, A.

Eder, W.

Hohenegger, J.

Torres Silva, A. I.

English

Archivio istituzionale della ricerca - Università di Genova

ICRS 13TH INTERNATIONAL CORAL REEF SYMPOSIUM92event. NOAA’s Coral Reef  Watch is coordinating global data collection and analysis of  this event to make sure key scientific information is not lost. This presentation discusses the latest satellite and field data on the ongoing global bleaching event and its impacts on coral reefs worldwide.http://coralreefwatch.noaa.govEasson, C. G., Nova Southeastern University, Halmos College of  Natural Sci. and Oceanogra-phy, USA, cgeasson86@gmail.comSPATIAL AND HOST-GENETIC FORCES STRUCTURE THE MICROBIOME OF THE SPONGE CLIONA DELITRIX (Abstract ID: 29669)Sponges are important members of  benthic communities throughout the world. They host diverse symbiont communities with compositions that are largely species-specific and structured by host evolutionary history. However, little is known about how microbi-omes vary among spatially distributed populations within a species. In the current study, we investigated how the microbiome of  the coral-excavating sponge C. delitrixvaried in relation to genetic differentiation and habitat location. Sponge samples from four distinct populations in the Caribbean were collected, and 16S rRNA amplicons were Illumina-based sequenced as part of  the Earth Microbiome Project (EMP). Our analysis revealed that microbial diversity was consistent among all locations and populations, while both genetic and environmental forces influenced the microbial composition of  sponges. Additionally, we found that C. delitrix maintains a “core” community across all sites in the Caribbean, with 62 microbial taxa found in at least 85% of  all samples. Most of  these microbial taxa were unique to C. delitrix or were only additionally found in the congener C. celata . Interestingly, all of  the genera- and species-specific taxa were rare in the host microbiome. Our results indicate that C. delitrix microbiomes are a complex consortia of  microbial taxa structured by both host-genetic and environmental forces, while maintain-ing a core group of  microbial symbiont taxa reflective of  broader host evolution.East, H. K., University of  Exeter, United Kingdom, h.k.east@exeter.ac.ukPerry, C. T., University of  Exeter, United Kingdom, c.perry@exeter.ac.ukKench, P. S., University of  Auckland, New Zealand, p.kench@auckland.ac.nzBeetham, E. P., University of  Auckland, New Zealand, e.beetham@auckland.ac.nzLiang, Y., University of  Auckland, New Zealand, christine.liang@auckland.ac.nzREEF ECOLOGY – REEF ISLAND CONNECTIVITY ON HUVADHU ATOLL RIM, MALDIVES (Abstract ID: 28321)Coral reef  islands are low-lying (typically <3 m above MSL) accumulations of  bioclastic sediment produced by the surrounding coral reefs. Given their low elevations and reli-ance upon locally generated sediment, they are regarded among the most vulnerable environments to sea-level rise. Understanding the linkages between reef  ecology and reef  islands is thus crucial for assessing future island resilience. Here, we present a holistic study of  reef  ecology-reef  island linkages within a section of  Huvadhu Atoll rim. This is the first detailed study of  marine-island connectivity to be undertaken in an atoll rim setting in the Maldives. Sediment production rates were quantified using ecological survey data of  sediment producers. Connectivity was assessed through comparisons of  marine, beach, and island (from a series of  cores) sediment samples (n = 157). Estimated annual sediment production was 382,000 kg across an area of  1.3 km2. Sediment production rates ranged from 0.05 kg m-2 yr-1 in the oceanward sand zone to 0.84 kg m-2 yr-1 on the lagoonward reef  crest. Excavating parrotfish were identified as the dominant sediment producers, accounting for 79.4% of  production. Marine, beach and island sediments were dominated by sand-grade coral (63%, 61%, 74% respectively). As parrotfish are the most likely source of  sand-grade coral, this reflects the reliance of  rim island systems on a limited range of  sediment producers. Hence, ecological shifts associated with environmental change may have a critical impact upon future reef  island vulnerability in the face of  sea-level rise.Eder, W., University of  Vienna, Austria, wolfgang.eder@univie.ac.atHohenegger, J., University of  Vienna, Austria, johann.hohenegger@univie.ac.atTorres Silva, A. I., University of  Vienna, Austria, ana_ivist@hotmail.comBriguglio, A., University Brunei Darussalam, Brunei Darussalam, antonio.briguglio@ubd.edu.bnPALEO-GEOGRAPHIC DIVERSIFICATION AND ENVIRONMENTAL DEPEN-DENCE OF THE LARGER FORAMINIFER HETEROSTEGINA (Abstract ID: 27868)The worldwide distributed larger benthic foraminifer (LBF) Heterostegina prefers oligo-trophic environments in tropic and warm temperate seas. Harboring diatoms enables the broadest distribution along the illumination gradient within LBF. Down to the fair weather wave base Heterostegina protects entrainment by living in holes of  structured boulders. The dependence on light intensities is managed by increasing surface/volume ratios correlated with decreasing light. The dependence on hydrodynamics leads to a shift in proportions between schizonts (smaller proloculi) and gamonts (larger proluculi) along the hydrodynamic gradient. The dominance of  schizonts in high energetic environ-ments, the mixture between schizogony and gametogony and the dominance of  gamonts in low energetic environments leads to an apparently gradual increase of  proloculus size with decreasing hydrodynamics. Additionally, the negatively correlated number of  oper-culinid chambers apparently changes along the hydrodynamic gradient. Both characters were used as the most significant metric characters in the evolution of  Heterostegina. Beside the environmental dependence, proloculus size can differ between biogeographi-cally different populations (e.g., Okinawa, Hawaii) taken under similar hydrodynamic conditions. Therefore, paleogeographical differences leading to subspecies together with transport, reworking and time-averaging possibly lead to erroneous interpretations of  evolutionary lineages. Using growth-independent and growth-invariant characters describing the internal test morphology completely allows a much better interpretation of  evolutionary tendencies separated from paleogeographic diversification.http://www.univie.ac.at/Palaeontologie/Edward Patterson, J. K., Suganthi Devadason Marine Research Institute, India, edwardjkpat-terson@sdmri.inMathews, G., Suganthi Devadason Marine Research Institute, India, mathews.gilbert@gmail.comRaj, K. D., Suganthi Devadason Marine Research Institute, India, diraviyam_raj@yahoo.co.inDeepak Bilgi, S., Gulf  of  Mannar Marine National Park, India, deepakbilgi@gmail.comWilhelmsson, D., Swedish Research Council , Sweden, dan.wilhelmsson@telia.comMalleshappa, H., Department of  Environment, Government of  Tamil Nadu, India, h.malleshappa@yahoo.co.inDECADAL TRANSITION IN CORAL REEF STATUS, DISTRIBUTION, ISSUES AND CONSERVATION INITIATIVES IN GULF OF MANNAR, SOUTHEASTERN INDIA (Abstract ID: 29196)The coral reefs of  Gulf  of  Mannar are distributed around 21 islands and show resilience after complete halt of  mining in 2005 and other conservation initiatives. Considerable awareness and capacity building, coral rehabilitation, protection and livelihood support has been provided to coastal communities after the major Indian Ocean coral bleaching event in 1998, and live coral cover increased from 37% in 2005 to 43% in 2009. Though there was loss of  10% live coral in 2010 due to prolonged elevated sea surface tem-perature (32oC) resulting bleaching and mortality, the reefs showed resilience to reach 39% live coral cover in 2015. Coral recruitment density increased significantly from 0.65 to 0.86 no/m2 between 2005 and 2015 and more recruits dominated by genera like Acropora, Montipora, Pocillopora, Porites, and Turbinaria. Recruits are occupying the nearby sandy and seagrass areas, and in Vaan Island, live coral cover area increased from 2.75 to 3.5 km2. The coral communities shifted from dominance, for example from P. damicornis to Acropora and Montipora in Shingle Island. However, issues like invasion of  exotic seaweed, diseases, poaching reef  associated ornamental fishes and elevated temperature pose challenge to reef  managers. Over 1.2 Km2 reef  area was affected by exotic seaweed invasion. Tissue loss disease (white syndrome) and growth anomalies along with several types of  lesions was noted in 9% of  the corals in 2015. The intensity of  2016 coral bleaching is alarming. To address the issues and to maintain reef  health, regular monitoring, coral rehabilitation, capacity building, and community involvement programmes are implemented.http://sdmri.inEdwards, C. B., Scripps Institution of  Oceanography, University of  California San Diego, USA, clint@ucsd.eduEynaud, Y. X., Scripps Institution of  Oceanography, University of  California San Diego, USA, yenaud@ucsd.eduWilliams, G. J., School of  Ocean Sciences, Bangor University, USA, g.j.williams@bangor.ac.ukZgliczynski, B. J., Scripps Institution of  Oceanography, University of  California San Diego, USA, bzgliczy@ucsd.eduGleason, A. C., University of  Miami, USA, University of  MiamiSmith, J. E., Scripps Institution of  Oceanography, University of  California San Diego, USA, jes013@ucsd.eduSandin, S. A., Scripps Institution of  Oceanography, University of  California San Diego, USA, ssandin@ucsd.eduA CHARACTERIZATION OF THE SPATIAL PATTERNS OF SCLERACTINIAN COR-ALS AT PALMYRA ATOLL (Abstract ID: 29922 | Poster ID: 552)Coral reefs are spatially complex habitats, yet our understanding of  their non-equilibrium dynamics is largely based upon percent cover data using imagery of  limited scale (< 1 m2). However, ecological processes leading to differences in the spatial patterns of  indi-vidual coral colonies cannot be detected from percent cover based analyses. As a result, we lack a robust and highly taxonomically resolved appreciation of  landscape-scale patterning in coral reef  environments. Here we investigate the spatial patterns of  hard coral assemblages at Palmyra Atoll using large scale photomosaic images, each covering 100 m2 of  benthic habitat. All individual coral colonies were mapped and identified to the lowest taxonomic level possible, and using spatial-analytical techniques we investigated departures from spatial randomness. While patterns of  dispersion were variable, all taxa showed some degree of  clustering. Despite this, the distributions of  a number of  taxa did not significantly depart from randomness. We did not observe over-dispersion in any of  the observed taxa. Further for many taxa, the level of  clustering was linearly related to abundance, suggesting density dependence in dispersion. These patterns, at least partially, 

Paleo-geographic diversification and environmental depen­dence of the larger foraminifer Heterostegina

https://iris.unige.it/bitstream/11567/921386/5/Paleo-geographic%20diversification%20and%20environmental%20depen%c2%addence%20of%20the%20larger%20foraminifer%20Heterostegina..pdf

Paleo-geographic diversification and environmental depen\uaddence of the larger foraminifer Heterostegina

Abstract

Similar works

Full text

Available Versions

Archivio istituzionale della ricerca - Università di Genova