Population structure and physiological plasticity of Favia gravida with differences in terrestrial influence

Terrestrial runoff is a source of sediments and nutrients to coral reefs. Due to runoff, Brazilian reefs are typically turbid, and have coral species that are naturally turbidity-resistant. This study investigated how terrestrial input influences population and physiology for the coral Favia gravida on two reefs with differences in river mouth proximity in eastern Brazil. The population structure and physiological traits of F. gravida colonies were assessed on both reefs, then some colonies selected for a subsequent transplantation experiment. The reef less impacted by terrestrial influence showed higher population density and lower recruitment. At this site, the coral colonies displayed higher calcification and larger larvae. The reproductive effort between coral populations at the two sites showed no significant difference. The transplantation experiment confirmed the high physiological plasticity of F. gravida colonies at the more turbid reef site. Despite being regarded as a more challenging environment, where F. gravida has a lower population density, the reef closer to the river mouth appears to secure more nutrients, which may heterotrophically compensate its coral colonies

Specific plasmid patterns and high rates of bacterial co-occurrence within the coral holobiont

Despite the importance of coral microbiomes for holobiont persistence, the interactions among these arenot well understood. In particular, knowledge of the co-occurrence and taxonomic importance of specific members of the microbial core, as well as patterns of specific mobile genetic elements (MGEs), is lacking. We used seawater and mucus samples collected from Mussismilia hispida colonies on two reefs located in Bahia, Brazil, to disentangle their associated bacterial communities, intertaxa correlations, and plasmid patterns. Proxies for two broad-host-range (BHR) plasmid groups, IncP-1 and PromA, were screened. Both groups were significantly (up to 252 and 100%, respectively) more abundant in coral mucus than in seawater. Notably, the PromA plasmid group was detected only in coral mucus samples. The core bacteriome of M.hispidamucus was composed primarily of members of the Proteobacteria, followed by those of Firmicutes. Significant host specificity and co-occurrences among different groups of the dominant phyla (e.g., Bacillaceae and Pseudoalteromonadaceae and the genera Pseudomonas, Bacillus, and Vibrio) were detected. These relationships were observed for both the most abundant phyla and the bacteriome core, in which most of the operational taxonomic units showed intertaxa correlations. The observed evidence of host-specific bacteriome and co-occurrence (and potential symbioses or niche space co-dominance) among the most dominant members indicates a taxonomic selection of members of the stable bacterial community. In parallel, host-specific plasmid patterns could also be, independently, related to the assembly of members of the coral microbiome

O ouriço Echinometra lucunter (Echinodermata, Echinoidea) como refúgio para o gobiídeo Elacatinus figaro (Perciformes, Gobiidae)

Elacatinus are small bright colored reef fish that have the habit of cleaning fishes and invertebrates. Elacatinus figaro are often found near the sea urchin Echinometra lucunter, suggesting a possible relationship between them. The addressed questions of this study are: (1) is the territory occupied by E. figaro related to the proximity of E. lucunter?; (2) does E. figaro show a refuge preference for E. lucunter spines?; and (3) are the densities of the two organisms correlated in the studied rocky reefs? Quadrats (1.0m2) were randomly sampled in three rocky reefs in Arraial do Cabo, RJ, Brazil. Before placing each quadrat on the substrate, the distances between each of the 89 E. figaro individuals observed and their nearest urchins were registered. While placing each quadrat, the escape behavior and the chosen refuge were observed. Furthermore, the densities of E. lucunter and E. figaro in each quadrat were quantified. From all observed E. figaro, around 57% were inside the perimeter of the urchins’ spines, 21% were less than 10cm far from them, 17% were between 10cm and 20cm away from them and less than 5% were more than 20cm away from the urchins. Most of the E. figaro (around 95%) that were out of the urchins spines’ perimeter promptly moved to the nearest urchin during the quadrat location. A positive correlation was observed between the densities of E. lucunter and E. figaro, suggesting a strict association between them, probably due to the use of the spines of the sea urchin as a refuge by this goby.Elacatinus são pequenos peixes recifais de colorido brilhante que possuem hábito de limpar peixes e invertebrados. Elacatinus figaro são freqüentemente encontrados junto aos ouriços Echinometra lucunter, sugerindo uma possível relação entre eles. As questões abordadas no presente estudo são: (1) o território ocupado por E. figaro está relacionado à proximidade com E. lucunter?; (2) E. figaro mostra preferência de refúgio pelos espinhos de E. lucunter?; e (3) as densidades dos dois organismos estão correlacionadas nos recifes estudados? Quadrados (1.0m2) foram aleatoriamente amostrados em três costões rochosos em Arraial do Cabo, RJ, Brasil. Antes do posicionamento de cada quadrado no substrato, a distância entre cada um dos 89 indivíduos de E. figaro observados e o ouriço mais próximo foi registrada. Durante a colocação de cada quadrado, o comportamento de fuga e o refúgio escolhido foram observados. Além disso, foram quantificadas as densidades de E. lucunter e de E. figaro em cada quadrado. Do total de E. figaro observados, aproximadamente 57% estavam dentro do perímetro dos espinhos do ouriço, 21% estavam a menos de 10cm de distância, 17% estavam entre 10cm e 20cm de distância, e menos de 5% a mais de 20cm de distância dos ouriços. A maioria dos E. figaro (aproximadamente 95%) que não se encontravam no perímetro dos espinhos do ouriço se deslocaram rapidamente para o ouriço mais próximo durante a colocação do quadrado. Uma correlação positiva foi observada entre as densidades de E. lucunter e E. figaro, sugerindo uma associação entre eles, provavelmente devido à utilização dos espinhos do ouriço como refúgio por este gobiídeo

AMPLIANDO A DISCUSSÃO SOBRE ECOLOGIA NEOTROPICAL

In face of the Brazilian megadiversity, the contribution of Brazilian researchers to the conception of new hypotheses and theories in ecology can still be considered as shy, and this may be one of the main reasons why we have advanced less than we potentially could. In consequence of this reality, the 1st Symposium on Ecological Theory (I SET) took place at the Federal University of Minas Gerais in 2004, aiming to stimulate the concept of new theories by  Brazilian ecologists. In 2006, the 2 nd Symposium on Ecological Theory (II SET) took place at the Federal University of Rio de Janeiro, organized by the Pos Graduation Program in Ecology (PPGE/UFRJ), aiming to give continuity to the fist event, through the discussion of various hypotheses and theories that compose the mosaic of traditional ecology, with emphasis on tropical systems. This article presents a historical perspective of this event and the themes discussed during the event written in a resumed form.Frente à megadiversidade brasileira, pode-se qualificar como ainda tímida a contribuição de pesquisadores do país na geração de novas hipóteses e teorias ecológicas, o que talvez seja uma das principais razões pela qual tenhamos avançado menos do que potencialmente poderíamos. Em face a esta realidade, o I Simpósio de Ecologia Teórica (I SET) foi realizado em 2004, na Universidade Federal de Minas Gerais, com o intuito de incentivar o avanço dos ecólogos brasileiros na elaboração de novas teorias. Em 2006, o Programa de Pós-Graduação em Ecologia da Universidade Federal do Rio de Janeiro (PPGE/UFRJ) organizou o II Simpósio de Ecologia Teórica (II SET) com o objetivo de dar continuidade ao primeiro evento através da discussão das diversas hipóteses e teorias que compõem o mosaico da ecologia tradicional, com enfoque nos sistemas tropicais. Este manuscrito faz um breve apanhado do evento e apresenta resumidamente os demais artigos que constam desta publicação e que foram base para as palestras e mesas redondas

Coral Bacterial-Core Abundance and Network Complexity as Proxies for Anthropogenic Pollution

Acclimatization via changes in the stable (core) or the variable microbial diversity and/or abundance is an important element in the adaptation of coral species to environmental changes. Here, we explored the spatial-temporal dynamics, diversity and interactions of variable and core bacterial populations associated with the coral Mussismilia hispida and the surrounding water. This survey was performed on five reefs along a transect from the coast (Reef 1) to offshore (Reef 5), representing a gradient of influence of the river mouth, for almost 12 months (4 sampling times), in the dry and rainy seasons. A clear increasing gradient of organic-pollution proxies (nitrogen content and fecal coliforms) was observed from Reef 1 to Reef 5, during both seasons, and was highest at the Buranhém River mouth (Reef 1). Conversely, a clear inverse gradient of the network analysis of the whole bacterial communities also revealed more-complex network relationships at Reef 5. Our data also indicated a higher relative abundance of members of the bacterial core, dominated by Acinetobacter sp., at Reef 5, and higher diversity of site-stable bacterial populations, likely related to the higher abundance of total coliforms and N content (proxies of sewage or organic pollution) at Reef 1, during the rainy season. Thus, the less “polluted” areas may show a more-complex network and a high relative abundance of members of the bacterial core (almost 97% in some cases), resulting in a more-homogeneous and well-established bacteriome among sites/samples, when the influence of the river is stronger (rainy seasons)

Expression of a symbiosis-specific gene in Symbiodinium type A1 associated with coral, nudibranch and giant clam larvae

Symbiodinium are responsible for the majority of primary production in coral reefs and found in a mutualistic symbiosis with multiple animal phyla. However, little is known about the molecular signals involved in the establishment of this symbiosis and whether it initiates during host larval development. To address this question, we monitored the expression of a putative symbiosis-specific gene (H+-ATPase) in Symbiodinium A1 ex hospite and in association with larvae of a scleractinian coral (Mussismilia hispida), a nudibranch (Berghia stephanieae) and a giant clam (Tridacna crocea). We acquired broodstock for each host, induced spawning and cultured the larvae. Symbiodinium cells were offered and larval samples taken for each host during the first 72 h after symbiont addition. In addition, control samples including free-living Symbiodinium and broodstock tissue containing symbionts for each host were collected. RNA extraction and RT-PCR were performed and amplified products cloned and sequenced. Our results show that H+-ATPase was expressed in Symbiodinium associated with coral and giant clam larvae, but not with nudibranch larvae, which digested the symbionts. Broodstock tissue for coral and giant clam also expressed H+-ATPase, but not the nudibranch tissue sample. Our results of the expression of H+-ATPase as a marker gene suggest that symbiosis between Symbiodinium and M. hispida and T. crocea is established during host larval development. Conversely, in the case of B. stephanieae larvae, evidence does not support a mutualistic relationship. Our study supports the utilization of H+-ATPase expression as a marker for assessing Symbiodinium-invertebrate relationships with applications for the differentiation of symbiotic and non-symbiotic associations. At the same time, insights from a single marker gene approach are limited and future studies should direct the identification of additional symbiosis-specific genes, ideally from both symbiont and host.publishe

Coral Bacterial-Core Abundance and Network Complexity as Proxies for Anthropogenic Pollution

Acclimatization via changes in the stable (core) or the variable microbial diversity and/or abundance is an important element in the adaptation of coral species to environmental changes. Here, we explored the spatial-temporal dynamics, diversity and interactions of variable and core bacterial populations associated with the coral Mussismilia hispida and the surrounding water. This survey was performed on five reefs along a transect from the coast (Reef 1) to offshore (Reef 5), representing a gradient of influence of the river mouth, for almost 12 months (4 sampling times), in the dry and rainy seasons. A clear increasing gradient of organic-pollution proxies (nitrogen content and fecal coliforms) was observed from Reef 1 to Reef 5, during both seasons, and was highest at the Buranhem River mouth (Reef 1). Conversely, a clear inverse gradient of the network analysis of the whole bacterial communities also revealed more-complex network relationships at Reef 5. Our data also indicated a higher relative abundance of members of the bacterial core, dominated by Acinetobacter sp., at Reef 5, and higher diversity of site-stable bacterial populations, likely related to the higher abundance of total coliforms and N content (proxies of sewage or organic pollution) at Reef 1, during the rainy season. Thus, the less "polluted" areas may show a more-complex network and a high relative abundance of members of the bacterial core (almost 97% in some cases), resulting in a more-homogeneous and well-established bacteriome among sites/samples, when the influence of the river is stronger (rainy seasons)

Kokeellinen tutkimus jarosiitin termisestä prosessoinnista

In hydrometallurgical production of zinc, the leaching stage produces 0.5‒0.9 tons of jarosite leach residue for every ton of zinc produced. Jarosite leach residue contains several potentially recoverable metals that can be critical (In, Ga, Ge, and Sb), precious and valuable (Ag and Au), heavy metals of concern (Cd, As, Pb, and Hg), or unrecovered Zn. The residues are classified as hazardous waste due to the aforementioned heavy metals. Currently, the metals present in the jarosite leach residue are not recovered or utilized, but disposed into the ponds. Therefore, metallurgical treatment of these residues has become more attractive. The purpose of this thesis was to investigate experimentally the thermal processing of jarosite residue. The treatment is divided into two steps (oxidizing and reducing). In the oxidizing step, jarosite is decomposed, sulfates and OH-groups are released, metals are oxidized into their highest oxidation states and an oxide melt is formed. In the reduction step, the melt is reduced, volatile elements are removed to gas phase and a clean slag and a metal phase (speiss) are formed. The aim was to determine the optimal processing times for these steps and study the distribution of elements between the phases. The experiments were carried out in a vertical tube furnace at 1350 °C. Two sets of oxidation experiments were carried out. The first set was conducted under air atmosphere with 65 ml/min air flow rate. The chemical analyses showed that the material had not been efficiently oxidized as even after the longest experiment (256 min), the sulfur content was 21.3 wt.-% when the target is below 1 wt.-%. The air flow rate was quadrupled for the second set to oxidize the material more efficiently. However, this did not show any significant improvement. It was observed that the material was not completely melted during the experiments. SEM backscattered images showed that there were large sulfur precipitates left in the material. The XRD analyses showed that the material consisted mainly of wurtzite (ZnS) and troilite (FeS). In addition, there were magnetite (Fe2+Fe3+2O4), galena (PbS) and sulfur. As the material was not efficiently oxidized in the experimental set up, only one reduction experiment was carried out. The material was first oxidized under O2 atmosphere (65 ml/min, 120 min) and then reduced (CO-CO2, 50:50, 260 ml/min in total, 120 min). The chemical analyses showed that the oxidation was significantly more efficient as O2 was used instead of air, as the sulfur content of the resulting material was 11.7 wt.-%. The removal of Zn and Pb into the gas phase was not sufficient enough as there were 4.6 wt.-% of Zn and 2.1 wt.-% of Pb when the targets are Zn < 1 wt.-% and Pb < 0.3 wt.-%. In further research, it is essential to figure out how the oxidation should be carried out so that the material would be melted completely and, thus, the sulfur content to be decreased to < 1 wt.-%. By adding an oxygen lance to the experimental arrangement the oxidizing gas could be blown directly into the material and, hereby, the oxidation is believed to be more efficient. By adding silica to the material the melting of the material could be promoted. After these problems are solved the optimal processing times for both oxidation and reduction can be investigated more closely.Hydrometallurgisen sinkinvalmistuksen liuotusvaiheessa sivutuotteena tuotetaan 0,5‒0,9 tonnia jarosiittijätettä jokaista tuotettua sinkkitonnia kohden. Jarosiittijäte sisältää kriittisiä metalleja (In, Ga, Ge ja Sb), arvokkaita jalometalleja (Au ja Ag), raskasmetalleja (Cd, As, Pb ja Hg) ja hukattua Zn. Jarosiittijätteen sisältämien raskasmetallien vuoksi se luokitellaan vaaralliseksi jätteeksi. Tällä hetkellä sen sisältämiä metalleja ei oteta talteen tai hyödynnetä, vaan ne päätyvät läjitysalueille. Viime aikoina jarosiittijätteen metallurginen käsittely onkin alkanut herättää kiinnostusta myös ympäristönäkökulman vuoksi. Diplomityössä tarkoituksena oli tutkia kokeellisesti jarosiittijätteen termistä käsittelyä kahdessa vaiheessa, joista ensimmäisessä materiaali sulatetaan ja hapetetaan, ja toisessa vaiheessa sula pelkistetään. Tavoitteena oli selvittää optimaaliset ajat näille kahdelle vaiheelle sekä tutkia, miten eri alkuaineet jakautuvat muodostuvien faasien välillä. Hapetusvaiheessa metallit hapettuvat korkeimpiin hapetustiloihinsa ja oksidisula muodostuu. Pelkistysvaiheessa sula pelkistetään niin, että tuloksena saadaan speissiksi kutsuttu metallifaasi sekä puhdas kuona höyrystyvien aineiden poistuessa kaasufaasiin. Kokeet suoritettiin pystyputkiuunissa 1350 °C lämpötilassa. Hapetuskokeita tehtiin kaksi koesarjaa. Ensimmäinen sarja suoritettiin ilma-atmosfäärissä tilavuusvirtauksella 65 ml/min. Kemiallisen analyysin perusteella materiaali ei ollut hapettunut kokeissa riittävästi, sillä pisimmänkin kokeen (256 min) jälkeen materiaalissa oli rikkiä 21,3 m-% tavoitteen ollessa alle 1 m-%. Toisessa koesarjassa hapetuskokeita tehtiin nelinkertaisella ilman tilavuusvirtauksella, jotta materiaali saataisiin hapettumaan tehokkaammin. Tämä muutos ei kuitenkaan laskenut rikin määrää. Hapetusvaihekokeissa havaittiin myös, ettei materiaali ollut sulanut täydellisesti. Mikrorakennekuvat näyttivät, että materiaaliin oli jäänyt melko suuriakin rikkipitoisia sulkeumia. XRD-analyysin mukaan näytteet koostuivat pääosin wurtsiitista (ZnS) sekä troiliitista (FeS). Lisäksi niissä oli magnetiittia (Fe2+Fe3+2O4), lyijyhohdetta (PbS) ja rikkiä. Koska materiaalia ei saatu hapetusvaihekokeissa hapetettua riittävästi, tehtiin vain yksi pelkistyskoe. Materiaalia hapetettiin O2-atmosfäärissä (65 ml/min, 120 min), minkä jälkeen sitä pelkistettiin CO-CO2 kaasuseoksella (50:50, yht. 260 ml/min, 120 min). Kemiallisen analyysin perusteella hapetus oli huomattavasti tehokkaampi käytettäessä ilman sijasta happea, sillä näytteen rikkipitoisuus oli 11,7 m-%. Zn ja Pb höyrystyminen kaasufaasiin ei ollut riittävää, sillä niiden pitoisuudet materiaalissa olivat Zn 4,6 m-% ja Pb 2,1 m-% tavoitteiden ollessa Zn < 1 m-% ja Pb < 0,3 m-%. Jatkotutkimuksissa oleellista on selvittää, miten hapetusvaiheessa materiaali saadaan sulamaan täysin ja rikkipitoisuus alle 1 m-% tavoitteen. Piidioksidin lisäämisellä saadaan materiaalin sulamista tehostettua. Tulevissa kokeissa happipillin lisääminen koejärjestelyyn mahdollistaa paremman kontaktin kaasun sekä materiaalin välillä. Näiden ongelmien ratkaisemisen jälkeen tulee selvittää optimaalinen aika sekä olosuhteet hapetukselle sekä siirtyä tutkimaan pelkistysvaiheen toteuttamista