Thesis (M.S.)--University of Iowa, 2005. / Includes bibliographical references (leaves 86-87).

Future climate change has been the subject of considerable speculation with scientists called upon to predict timing, magnitude, and impact of these changes. The Pliocene Warm Period serves as the best-available, pre-modern analog to predicted climate changes, and Pliocene climate anomalies are examined as possible scenarios for future climate change. Comparing modern conditions to the mean climate state of the Pliocene is essential for better constrained predictions of future climate change, and seasonal paleoenvironmental records provide a data set more analogous to instrumental observations and thereby reducing the uncertainty in modeled climate changes. This study first examines the potential of large gastropod shells as a paleoclimate proxy. Specimens of Busycon sinistrum, active in winter, and Fasciolaria tulipa , active in the summer, were collected alive from Tampa Bay and St. Joseph Bay in the hope of establishing a multi-year record of seasonality. The δ18O time series of each shell were compared with predicted δ18O, based on local marine temperature variations, and both species cease shell growth during the winter months, despite opposing seasons of feeding activity. As none of the profiles provide information on winter environmental parameters, this sclerochronological system was replaced by work on pristine specimens of the scleractinian coral Siderastrea spp.  Seasonal δ18O and Sr/Ca time series from two Pliocene corals, collected from the Lower Pinecrest Member of the Tamiami Formation in southwest Florida, were used to calculate seawater δ18O variations. Inferred salinity in the Pliocene has a reversed seasonal pattern from that of modern annual salinity variations, and is interpreted to be a response to an increase in winter precipitation, a teleconnection of the Pliocene “Super El Niño.” Concentrations of variance in the typical ENSO frequency band are not apparent above the 95% confidence interval, suggesting that the Pliocene was dominated by a perennial, rather than an intermittent, El Niño-like state.  Further geochemical analyses from both Pliocene and Pleistocene Siderastrea spp. corals indicate a high nutrient nearshore marine environment in south Florida. Marine phosphates, inferred from P/Ca analyses, were significantly higher in the Pliocene Tamiami Fm. than in the Early Pleistocene Caloosahatchee and Bermont Fms, and the decline in nutrients preceded local extinction by > 0.5 Ma. Additionally, high-resolution P/Ca analyses of an individual coral reveal no evidence of seasonality required by a previously hypothesized upwelling-based nutrient delivery mechanism The Pliocene nearshore marine environment in southwest Florida was characterized by higher nutrients than in the Pleistocene and precipitation patterns similar to modern El Niño teleconnections.

Submitted by Everaldo Pereira (pereira.evera@gmail.com) on 2017-02-21T01:16:25Z No. of bitstreams: 1 Lucas Rocha (2015) - mestrado.pdf: 14637707 bytes, checksum: 996b70d370a5333486ee80bf8542477b (MD5) / Made available in DSpace on 2017-02-21T01:16:25Z (GMT). No. of bitstreams: 1 Lucas Rocha (2015) - mestrado.pdf: 14637707 bytes, checksum: 996b70d370a5333486ee80bf8542477b (MD5) / Considerando a indisponibilidade de longas séries temporais para registros instrumentais, torna-se imprescindível a utilização de proxies capazes de fornecerem medidas precisas do clima e de ambientes pretéritos. As bandas alternadas de densidade nos esqueletos de corais permitem quantificar e datar características relacionadas ao seu crescimento. Este padrão anual está diretamente relacionado às variações sazonais de parâmetros ambientais que caracterizam a água do mar. A calibração entre o proxy utilizado e o comportamento da variável ambiental investigada é fundamental para estabelecer a relação entre o estímulo ambiental e sua resposta no organismo. Deste modo, o objetivo deste trabalho foi realizar a calibração dos indicadores proxy de temperatura e turbidez da água do mar nos corais da espécie Siderastrea stellata Verril, 1868, para duas regiões específicas: Baía de Todos os Santos (Salvador, Bahia) e Arquipélago de Tinharé (Cairu, Bahia). Para isto, foram geradas placas de aproximadamente 5 mm de espessura do esqueleto de oito colônias de coral, posteriormente radiografadas e analisadas esclerocronologicamente no software Coral XDS®. A partir desta análise, pôde-se estimar as taxas de extensão linear, densidade e taxas de calcificação médias anuais e mensais para cada uma das colônias. As séries mensais da temperatura da superfície do mar (TSM) foram obtidas através do sistema operacional OSTIA. As séries mensais das variáveis ambientais Radiação Fotossinteticamente Ativa (PAR), Coeficiente de Atenuação Difusa da Luz (K490) e Concentração de Clorofila Superficial (CHLO) foram obtidas dos sensores MODIS e SeaWiFS. A comparação realizada entre os dois sítios de amostragem evidenciou uma diferença estatisticamente significativa para os três parâmetros esclerocronológicos analisados, enfatizando a influência dos fatores locais sobre os padrões de crescimento desta espécie de coral. As taxas de calcificação obtidas para as duas sub-áreas mostraram-se principalmente determinadas pela variabilidade da extensão linear, com a densidade exercendo um papel secundário. Colônias de S. stellata no sitio de amostragem Comunidade coralina do Yatch Clube da Bahia mostraram-se mais sensíveis a possíveis alterações nas variáveis ambientais. TSM e PAR exerceram maior influência sobre o padrão de densidade dos esqueletos desta espécie de coral em comparação às outras variáveis analisadas. / ABSTRACT - Considering the unavailability of long time series for instrumental records, mainly in the South Atlantic Ocean, it is essential to use indirect or proxy indicators to provide accurate measures of past climates and environments. The alternating density bands in coral skeletons allows dating and quantify characteristics related to its growth. This annual pattern is directly related to seasonal changes in environmental parameters that characterize the seawater. The calibration between the proxy used and the behavior of the investigated environmental variables is critical in establishing the relationship between the environmental stimulus and the organism response. Thus, the aim of this work was to perform the calibration of proxy indicators of temperature and turbidity of sea water in the coral specie Siderastrea stellata Verril, 1868, for two specific regions: Todos os Santos Bay (Salvador, Bahia) and Archipelago of Tinharé (Cairu, Bahia). For this, plates of approximately 5 mm were generated from skeletons of eight coral colonies, then x-rayed and analyzed sclerochronologically in the XDS® Coral Software. From this analysis, it was possible to estimate the annual and monthly averages of densities, linear extent and calcification rates for each colony. Sea surface temperature (SST) monthly series were obtained through the operating system OSTIA. The monthly series of environmental variables Photosynthetically Active Radiation (PAR), Diffuse Attenuation Coefficient (K490) and Superficial Chlorophyll Concentration (CHLO) was obtained from the MODIS and SeaWiFS sensors. The comparison between the two sampling sites showed a statistically significant difference for the three sclerochronological parameters analyzed, emphasizing the influence of local factors on the growth patterns of this species of coral. Calcification rates obtained for the two sub-areas were shown to be mainly determined by the variability of the linear extension, with the density as a secondary factor. Colonies of S. stellata in YCB sampling site were more sensitive to possible changes in environmental variables. TSM and PAR had the greatest influence on the pattern density of the skeletons of this species of coral compared to other variables.

Submitted by Everaldo Pereira (pereira.evera@gmail.com) on 2017-04-11T18:42:18Z No. of bitstreams: 1 Carolina Poggio_2007.pdf: 3194005 bytes, checksum: 7f81951f726dc7c80658ce8d39015099 (MD5) / Made available in DSpace on 2017-04-11T18:42:18Z (GMT). No. of bitstreams: 1 Carolina Poggio_2007.pdf: 3194005 bytes, checksum: 7f81951f726dc7c80658ce8d39015099 (MD5) / O fenômeno do branqueamento é caracterizado pela despigmentação do coral em conseqüência da desestabilização da relação existente entre o coral e suas zooxantelas simbiontes, resultando em perda de zooxantelas e/ou dos seus pigmentos fotossintetizantes. As causas e conseqüências desse fenômeno, no ecossistema recifal, vêm sendo discutidas no meio científico, apesar de não serem, ainda, totalmente esclarecidas. Diante disso o presente trabalho tem como objetivo avaliar se o branqueamento das colônias de Siderastrea spp., presentes nas poças intermareais do topo do recife de Guarajuba, ocorre em função das variações sazonais dos parâmetros da água do mar: temperatura, salinidade, pH e nutrientes. Essa avaliação foi realizada com base nas medidas da densidade das algas zooxantelas em amostras do coral, as quais foram coletadas nas poças de maré do topo recifal durante as marés baixas de sizígia, no início de cada uma das quatro estações, considerando o período de março de 2005 à março de 2006. Os parâmetros físicoquímicos da água foram medidos a cada 15 dias, nesse mesmo espaço de tempo e, também, durante as marés baixas de sizígia. Dentre os parâmetros analisados, a temperatura da água das poças foi o que variou mais significativamente, enquanto os outros parâmetros praticamente não sofreram alteração. Em relação à densidade das zooxantelas simbiontes, os resultados obtidos indicaram que esta foi menor nas colônias coletadas na estação mais quente (verão), do que naquelas coletadas na estação mais fria (inverno), quando a temperatura da água das poças esteve mais baixa, caracterizando, assim, uma influencia sazonal no branqueamento das colônias. Pode-se concluir, dessa forma, que o branqueamento registrado entre as amostras de Siderastrea spp., ao longo de um ano (2005/2006), esteve associado às variações sazonais da temperatura da água das poças do topo do recife de Guarajuba. / ABSTRACT The phenomenon of coral bleaching is characterized by the lack of pigmentation in the coral tissue in consequence of loss of the existing relationship between the coral and their symbiotic zooxanthellae, resulting in loss of zooxanthellae and/or its photosynthetic pigments. The causes and consequences of this phenomenon, in the reef ecosystem, have been argued scientifically, although not totally clarified. The objective of the present work is evaluate if bleaching of the colonies of Siderastrea spp. from the tidal pools of the Guarajuba Reef top occur in function of seasonal variations of the sea water parameters: temperature, salinity, pH and nutrients. This evaluation was based upon measurement of the density of the zooxanthellae in coral samples, which were collected in the tidal pools during low spring tides, at the beginning of each of the four seasons, from March 2005 to March 2006. The sea water parameters were measured fortnightly, also during low spring tides. Amongst the analyzed parameters, sea water temperature varied more significantly. Considering the density of the symbiotic zooxanthellae, the results indicated that it was lower in the coral colonies collected during summer and higher in samples collected during winter, when seawater temperature was lower, thus characterizing a seasonal influence in the coral bleaching colonies. Therefore, it can be concluded that the bleaching event registered among samples of Siderastrea (colonies), from the Guarajuba reef top (north Bahia) may be attributed to seasonal variations of seawater temperature observed from 2005 through 2006.

No description available.

Made available in DSpace on 2015-04-01T14:16:02Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1597259 bytes, checksum: eaba4f2d4108bede1b543c3806717952 (MD5) Previous issue date: 2013-05-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Bacteria play a fundamental role in the health of corals. The interest in the study of microorganisms associated with corals has increased since the confirmation that they can be pathogenic or mutualistic. In the coastal reefs of the State of Paraiba the cases of the pigmentation changes of scleractinian Siderastrea stellata, that probably occurs in the process of coral bleaching, are observed. The aim of this work was to analyze the density and diversity of culturable bacteria associated with healthy and with pattern pigmentation altered (pink) colonies of coral S. stellata of coral reefs of Cabo Branco, João Pessoa - PB, as well as the physico-chemical and microbiological parameters of seawater in the study area over one year. Among the environmental variables (temperature, salinity, pH, dissolved oxygen, turbidity) of the reefs and beach water of Cabo Branco, only turbidity showed higher differences among the sites studied. The thermotolerant fecal coliforms, enterococci and Escherichia coli of seawater at the study sites were within the limits recommended for saline water class I (CONAMA 274/00). In general, the values of density of total heterotrophic bacteria and Vibrio spp. were significantly higher in the seawater during the months of December, January and February. According to the results of the partial sequencing of the 16S rRNA gene was found that bacteria isolated from healthy and pink S. stellata belonged to the classes Alpha-Proteobacteria and Gamma-Proteobacteria, and the variety of genera of bacteria were very different among the isolates from the two colonies. The high percentage of Vibrio spp., bacteria that are usually related to the diseases of corals, were observed among the isolates from pink colony. / Bactérias desempenham um papel fundamental na saúde dos corais. Devido à confirmação de que elas podem ser patogênicas ou mutualistas, aumentou o interesse no estudo de microrganismos associados aos corais. Nos recifes costeiros do Estado da Paraíba observam-se casos de alteração de pigmentação no escleractíneo Siderastrea stellata, que provavelmente ocorre no processo de branqueamento de corais. Neste trabalho objetivou-se analisar a quantidade e diversidade de bactérias cultiváveis associadas ao coral S. stellata sadio e com coloração alterada (roxo) dos recifes de corais de Cabo Branco, João Pessoa PB, bem como os parâmetros físico-químicos e microbiológicos de água do mar da área estudada durante um ano. Entre as variáveis ambientais (temperatura, salinidade, pH, oxigênio dissolvido, turbidez) da água dos recifes e da praia de Cabo Branco apenas a turbidez apresentou maiores diferenças entre os locais estudados. Na base das análises de coliformes termotolerantes, Escherichia coli e enterococos foi constatado que a água dos locais analisados se enquadra dentro dos parâmetros para águas salinas de classe I (CONAMA 274/00). Em geral, os valores da densidade de bactérias totais e Vibrio spp. foram significativamente maiores em água do mar nos meses de dezembro, janeiro e fevereiro. Na base de dados de sequenciamento parcial do gene RNAr 16S foi constatado que as bactérias isoladas de S. stellata sadia e roxa pertenceram ás classes de Alfa-proteobactéria e Gama-proteobactéria, sendo que a variedade dos gêneros de bactérias foi bastante distinta entre os isolados das duas colônias. Os isolados da colônia roxa apresentaram um alto percentual de Vibrio spp., que são bactérias geralmente relacionadas com as doenças de corais.

Submitted by Everaldo Pereira (pereira.evera@gmail.com) on 2017-02-19T20:25:16Z No. of bitstreams: 1 Dissertação_Carlos_Filho_2012.pdf: 2253334 bytes, checksum: bb9ff26de80271736ca73e37fb291dff (MD5) / Made available in DSpace on 2017-02-19T20:25:16Z (GMT). No. of bitstreams: 1 Dissertação_Carlos_Filho_2012.pdf: 2253334 bytes, checksum: bb9ff26de80271736ca73e37fb291dff (MD5) / A utilização do esqueleto de coral como indicador paleo-oceanográfico tem sido pouco explorada no Brasil. Neste trabalho, investigou-se o potencial do coral Siderastrea stellata como registro paleo-oceanográfico de alta resolução, da ocupação antrópica da Baía de Todos os Santos – BTS – (BA – Brasil), através das razões isotópicas do Pb incorporado nos esqueletos coralíneos coletados em recifes internos e externos à baía. Para uma melhor compreensão da distribuição espacial, além das possíveis fontes do Pb da BTS, foram igualmente analisadas amostras de sedimentos recifais e estuarinos de diversas localidades da baía. Os resultados mostraram que, de modo geral, no início dos registros coralíneos (1993 – 1997), dos recifes internos à baía, havia empobrecimento em 206Pb, indicando uma maior influencia do Pb proveniente do minério arqueano da mina de Boquira (BA) e beneficiado na antiga metalúrgica Plumbum, extinta em 1993 e localizada na cidade de Santo Amaro – BA, à NO da BTS. As razões isotópicas de Pb das amostras de sedimento mostraram que mesmo extinta, a região da antiga metalúrgica ainda é uma importante fonte contemporânea deste metal para o ambiente da baía. Contudo, a tendência de enriquecimento em 206Pb entre os anos de 1997 e 2007, nas amostras coralíneas dos recifes internos, juntamente com a sincronicidade do comportamento da composição isotópica do Pb das amostras coralíneas coletadas no recife externo à BTS com o desenvolvimento da indústria baiana, mostraram que durante esta última década, o Pb proveniente das industrias Químicas e Petroquímicas configura-se como uma das fontes principais para os recifes e, consequentemente, para a BTS. / ABSTRACT - In Brazil the use of coral skeleton as paleo-oceanographic index is been underexplored. On this paper, the coral Siderastrea stellata potential as a high resolution paleo-oceanographic proxy of antropic occupation of Baía de Todos os Santos – BTS – (BA – Brazil) was investigated through the Pb isotopic ratios incorporated on coral skeletons collected on inner and outer bay reefs. Reef and estuarine sediment samples of several location in the bay had been analyzed for a better special distribution and Pb source understanding. The results showed that at the first inner bay reef coral records (1993 – 1997) there was an 206Pb depleted, indicating a major influence of the Boquira’s mine (BA) archean ore, which was processed at the Plumbum metallurgical, located in NW BTS, Santo Amaro city and closed in 1993. The sediment samples Pb isotopics ratios showed that, even extinguished, the metallurgical industry still is an important source of Pb to the bay. However, the 206Pb enrichment on the inner bay reef coral samples between 1997 and 2007, with the outer bay reef coral samples isotopic composition behavior synchronicity, and Bahia’s industry development showed that during the last decade, the chemical and petrochemical industries are the most important source of Pb to the BTS coral reef environment.

With increasing coastal development along southeastern Florida, nearshore coral reef communities are at an increased risk from anthropogenic impacts. Impact minimization and mitigation efforts associated with permitted coastal construction activities generally exclude nearshore small (< 10 cm diameter) Siderastrea siderea colonies from required coral transplantation due to an assumed high colony mortality associated with transplanting small stony corals. This study evaluated the efficacy of transplanting these small colonies by monitoring survival, growth, and zooxanthellae density post transplantation to an offshore reef area. Unexpected observations of parrotfish predation on the newly transplanted corals were made within the first 24 hours. Within 2 weeks, 94% of the transplants were affected and exhibited recent parrotfish grazing scars. A duplicate transplantation attempt was made at an alternate offshore reef area; however similar results were produced. Due to the high extent of colony tissue loss caused by parrotfish, the initial transplantation effort was repeated with the addition of partial cages to exclude large parrotfish. Zooxanthellae density analysis of the caged colonies revealed an adaptive capability of S. siderea to transplantation as one year post-transplantation, algal densities of the transplanted colonies reflected those of surrounding in situ colonies. A second component of this study investigated if transplantation alone was a direct cause for high predation by examining predation intensity and long-term survival for both transplanted and undisturbed small S. siderea colonies, as well as transplanted Dichocoenia stokesii and Porites porites colonies. Siderastrea siderea colonies were collected from areas surrounding the offshore transplant site and given various stress levels prior to being attached into the transplant grid inter-mixed with colonies transplanted from the shallow nearshore site. All colonies in the transplant grid were placed randomly to eliminate spatial bias. Some nearshore S. siderea transplants were partially caged for 80 days to provide a moderate acclimation period. Many non-caged transplanted colonies suffered some degree of parrotfish predation within 1 week post-transplantation, suggesting that transplantation alone did increase corals susceptibility to predation. However, predation intensity was significantly higher on S. siderea transplanted from nearshore than all in-site transplanted and undisturbed S. siderea colonies from the offshore transplant area. Despite minor parrotfish predation on the offshore in-site transplanted colonies, many displayed long term growth and survival. Partial cages were successful in excluding large parrotfish; however once removed, predation intensity was similar to the non-caged nearshore transplants. Predation on the transplants was selective across both species and place of origin. These results suggest that parrotfish differentiated between transplanted colonies and preferred nearshore S. siderea and P. porites transplants. Findings in this study may aid southeastern Florida resource managers as transplantation activities are frequently utilized due to coastal construction and vessel groundings. The impact of parrotfish corallivory on coral growth and survival should be of higher regard in the light of increasing threats to coral reefs.

Knowledge of effective reef restoration techniques are necessary in this age of worldwide coral reef decline. Coral transplantation is a restoration technique employed after natural (i.e. hurricanes) and anthropogenic (i.e. vessel groundings) physical disturbance events. The study was conducted to compare the efficacy of propagating small colony fragments in laboratory and field conditions in terms of survival and growth. Fragment growth and survival were assessed for six scleractinian boulder corals common to Florida and Caribbean reefs: Montastraea annularis, M. cavernosa, Diploria clivosa, Siderastrea siderea, S. radians and Dichocoenia stokesii. Broken coral colonies were salvaged from vessel grounding sites and marine debris, fragmented into pucks and secured to travertine tiles. One hundred and fifty-three coral colony fragments were cultivated in an ex situ laboratory nursery and 133 coral colony fragments were cultivated in an in situ field nursery and monitored for 13 months. Survival of all colonies was 94%, with 98% survival in the laboratory treatment and 89% survival in the field treatment. Complete colony mortality was documented in three S. radians colonies, all in the laboratory treatment. All colony loss in the field treatment was due to colony pucks being detached from the tiles. Overall mean percent change in colony tissue area from initial to final monitoring events was calculated to determine growth. Across species, growth was greater in the laboratory treatment (76 ± 4 % SEM) in comparison to the field treatment (27 ± 5 % SEM). Positive growth was observed in D. clivosa, D. stokesii, M. annularis, M. cavernosa and S. siderea in the laboratory treatment. In the field treatment, D. clivosa, M. annularis and M. cavernosa were the only species that exhibited positive growth. Negative growth was observed in both the laboratory and field treatments for S. radians. In conclusion, colonies propagated in the ex situ nursery (laboratory treatment) had higher growth and survival than colonies propagated in the in situ nursery (field treatment). A critical acclimation period accomplished through the use of stable laboratory conditions will produce healthier, more secure coral colonies that may be used to repopulate disturbed reef sites.

Restoration efforts are being implemented in many of the world’s coral reefs due to damages from anthropogenic sources such as ship groundings and anchor damage. One restoration technique involves attempts to save dislodged and fragmented coral colonies by transplanting them back to damage sites. Research has shown that survivorship and growth of transplanted colonies is comparable to that of natural, control colonies. What remains unknown is to what extent transplantation affects the ecological success and reproduction of dislodged and fragmented coral colonies. The purpose of this study was twofold. Reproduction and spawning information is sparse for S. intersepta and Solenastrea bournoni, so the first purpose was to describe gamete development of these two species and assess correlations between environmental dynamics and spawning of each species. Tissue samples were collected throughout Broward County, Florida and processed for histological examination. Gametes were counted, and development was assessed. For S. intersepta and S. bournoni, late stage oocyte abundance was compared with environmental factors of mean daily water temperatures at depth, lunar phase, semidiurnal tides and solar insolation for correlative evidence to predict future spawning events. Findings indicated that both S. bournoni and S. intersepta are gonochoric broadcast spawners. Solenastrea bournoni spawns annually after the full moon in September when sea temperatures are at a maximum. Stephanocoenia intersepta spawns annually after the full moon of August or September, depending on the timing of the full moon. The second purpose was to determine if previously transplanted Porites astreoides, Montastraea cavernosa, Siderastrea siderea and Stephanocoenia intersepta corals produce gametes and spawn similarly to naturally occurring colonies and to address the issue of transplantation as a suitable resource management tool to aid in reef recovery for future coral generations. Results indicated no significant difference in fecundity between transplants and controls of M. cavernosa, S. siderea or S. intersepta. A significant difference was found in fecundity between P. astreoides transplants and controls, but it is thought that it is due to a difference in depth of collected samples. Overall, this study shows that transplantation of coral colonies after damage and fragmentation events does not have adverse effects on the long-term fecundity of coral colonies.