Shallow-water Habitat Change Detection of Kaledupa Island, Wakatobi National Park (Wnp) for 14 Years

Metode penginderaan jauh sangat membantu dalam pemetaan kondisi habitat perairan dangkal secara spasial pada cakupan area yang luas. Penelitian ini bertujuan untuk menganalisis Perubahan habitat perairan dangkal Pulau Kaledupa, Taman Nasional Wakatobi (TNW), selama 14 tahun, dari tahun 2002 hingga 2016. Data citra yang digunakan dalam penelitian ini adalah Landsat 8 OLI (2016), Landsat 5TM (2009), dan Landsat 7ETM+ (2002), yang dikombinasikan dengan data in-situ dan TNW. Klasifikasi Mahalanobis dimanfaatkan untuk memproduksi peta habitat perairan dangkal (karang hidup, karang mati, lamun, dan pasir) dan mendeteksi Perubahannya. Hasil yang diperoleh bahwa Perubahan yang terjadi dari tahun 2002 sampai 2016 adalah tutupan karang hidup menurun dari 2217 ha menjadi 2039 ha, tutupan karang mati juga menurun dari 3327 ha menjadi 2108 ha, luas pasir meningkat dari 1201 ha menjadi 1346 ha, area lamun naik dari 4130 ha menjadi 5294 ha. Metode ini merupakan alat analisis yang baik untuk menilai efektivitas upaya perlindungan ekosistem terumbu karang dan lamun di perairan Pulau Kaledupa, serta dapat diterapkan pada 3 pulau utama lainnya di TNW dan pulau-pulau kecil di Indonesia

SHALLOW-WATER HABITAT CHANGE DETECTION OF KALEDUPA ISLAND, WAKATOBI NATIONAL PARK (WNP) FOR 14 YEARS

Metode penginderaan jauh sangat membantu dalam pemetaan kondisi habitat perairan dangkal secara spasial pada cakupan area yang luas. Penelitian ini bertujuan untuk menganalisis perubahan habitat perairan dangkal Pulau Kaledupa, Taman Nasional Wakatobi (TNW), selama 14 tahun, dari tahun 2002 hingga 2016. Data citra yang digunakan dalam penelitian ini adalah Landsat 8 OLI (2016), Landsat 5TM (2009), dan Landsat 7ETM+ (2002), yang dikombinasikan dengan data in-situ dan TNW. Klasifikasi Mahalanobis dimanfaatkan untuk memproduksi peta habitat perairan dangkal (karang hidup, karang mati, lamun, dan pasir) dan mendeteksi perubahannya. Hasil yang diperoleh bahwa perubahan yang terjadi dari tahun 2002 sampai 2016 adalah tutupan karang hidup menurun dari 2217 ha menjadi 2039 ha, tutupan karang mati juga menurun dari 3327 ha menjadi 2108 ha, luas pasir meningkat dari 1201 ha menjadi 1346 ha, area lamun naik dari 4130 ha menjadi 5294 ha. Metode ini merupakan alat analisis yang baik untuk menilai efektivitas upaya perlindungan ekosistem terumbu karang dan lamun di perairan Pulau Kaledupa, serta dapat diterapkan pada 3 pulau utama lainnya di TNW dan pulau-pulau kecil di Indonesia

Contrasting Light Spectra Constrain the Macro and Microstructures of Scleractinian Corals

The morphological plasticity of scleractinian corals can be influenced by numerous factors in their natural environment. However, it is difficult to identify in situ the relative influence of a single biotic or abiotic factor, due to potential interactions between them. Light is considered as a major factor affecting coral skeleton morphology, due to their symbiotic relation with photosynthetic zooxanthellae. Nonetheless, most studies addressing the importance of light on coral morphological plasticity have focused on photosynthetically active radiation (PAR) intensity, with the effect of light spectra remaining largely unknown. The present study evaluated how different light spectra affect the skeleton macro- and microstructures in two coral species (Acropora formosa sensu Veron (2000) and Stylophora pistillata) maintained under controlled laboratory conditions. We tested the effect of three light treatments with the same PAR but with a distinct spectral emission: 1) T5 fluorescent lamps with blue emission; 2) Light Emitting Diodes (LED) with predominantly blue emission; and 3) Light Emitting Plasma (LEP) with full spectra emission. To exclude potential bias generated by genetic variability, the experiment was performed with clonal fragments for both species. After 6 months of experiment, it was possible to detect in coral fragments of both species exposed to different light spectra significant differences in morphometry (e.g., distance among corallites, corallite diameter, and theca thickness), as well as in the organization of their skeleton microstructure. The variability found in the skeleton macro- and microstructures of clonal organisms points to the potential pitfalls associated with the exclusive use of morphometry on coral taxonomy. Moreover, the identification of a single factor influencing the morphology of coral skeletons is relevant for coral aquaculture and can allow the optimization of reef restoration efforts

Efeito da iluminação no cultivo ex situ de corais simbióticos

Doutoramento em BiologiaThe increasing interest in coral culture for biotechnological applications, to supply the marine aquarium trade, or for reef restoration programs, has prompted researchers to optimize coral culture protocols, with emphasis to ex situ production. When cultured ex situ, the growth performance of corals can be influenced by several physical, chemical and biological parameters. For corals harbouring zooxanthellae, light is one of such key factors, as it can influence the photosynthetic performance of these endosymbionts, as well as coral physiology, survival and growth. The economic feasibility of ex situ coral aquaculture is strongly dependent on production costs, namely those associated with the energetic needs directly resulting from the use of artificial lighting systems. In the present study we developed a versatile modular culture system for experimental coral production ex situ, assembled solely using materials and equipment readily available from suppliers all over the world; this approach allows researchers from different institutions to perform truly replicated experimental set-ups, with the possibility to directly compare experimental results. Afterwards, we aimed to evaluate the effect of contrasting Photosynthetically Active Radiation (PAR) levels, and light spectra emission on zooxanthellae photochemical performance, through the evaluation of the maximum quantum yield of PSII (Fv/Fm) (monitored non-invasively and non-destructively through Pulse Amplitude Modulation fluorometry, PAM), chlorophyll a content (also determined non-destructively by using the spectral reflectance index Normalized Difference Vegetation Index, NDVI), photosynthetic and accessory pigments, number of zooxanthellae, coral survival and growth. We studied two soft coral species, Sarcophyton cf. glaucum and Sinularia flexibilis, as they are good representatives of two of the most specious genera in family Alcyoniidae, which include several species with interest for biotechnological applications, as well as for the marine aquarium trade; we also studied two commercially important scleractinian corals: Acropora formosa and Stylophora pistillata. We used different light sources: hydrargyrum quartz iodide (HQI) lamps with different light color temperatures, T5 fluorescent lamps, Light Emitting Plasma (LEP) and Light Emitting Diode (LED). The results achieved revealed that keeping S. flexibilis fragments under the same light conditions as their mother colonies seems to be photobiologically acceptable for a short-term husbandry, notwithstanding the fact that they can be successfully stocked at lower PAR intensities. We also proved that low PAR intensities are suitable to support the ex situ culture S. cf. glaucum in captivity at lower production costs, since the survival recorded during the experiment was 100%, the physiological wellness of coral fragments was evidenced, and we did not detect significant differences in coral growth. Finally, we concluded that blue light sources, such as LED lighting, allow a higher growth for A. formosa and S. pistillata, and promote significant differences on microstructure organization and macrostructure morphometry in coral skeletons; these findings may have potential applications as bone graft substitutes for veterinary and/or other medical uses. Thus, LED technology seems to be a promising option for scleractinian corals aquaculture ex situ.O potencial dos corais como espécies emergentes com interesse para a aquacultura evidencia-se pela sua possível comercialização em três segmentos de mercado: a) aplicações biotecnológicas para pesquisa e exploração de novos compostos bioativos, b) aquariofilia marinha, e c) restauração de recifes de coral. Deste modo, o crescente interesse na aquacultura de corais conduziu a um esforço da comunidade científica para otimizar protocolos de cultivo, nomeadamente cultivo ex situ. O desempenho dos corais cultivados ex situ, em sistemas fechados com recirculação, pode ser afetado por diversos fatores físicos, químicos e biológicos. A iluminação representa um fator chave para o cultivo de corais que se caraterizem por um modo de vida em simbiose com dinoflagelados fotossintéticos (zooxantelas), uma vez que este fator influencia diretamente o desempenho destes endossimbiontes e, consequentemente, a fisiologia e crescimento do coral hospedeiro. A viabilidade económica de uma exploração aquícola está dependente do equilíbrio entre receitas e custos de produção, sendo que no caso do cultivo ex situ de corais, o custo relacionado com a utilização de sistemas de iluminação artificial influencia de forma preponderante o custo total de produção. No presente trabalho foi desenvolvido um sistema modular e versátil para o cultivo experimental de corais, recorrendo unicamente a materiais e equipamentos disponíveis no mercado á escala global; a utilização generalizada deste sistema permitirá a execução de desenhos experimentais estatisticamente robustos, bem como comparar de forma direta os resultados obtidos por diferentes equipas de investigação. Posteriormente foi avaliado o efeito de diferentes níveis de radiação fotossintética ativa (PAR – “Photosynthetically Active Radiation”), bem como diferentes espetros de emissão (comprimento de onda), na atividade fotossintética dos endossimbiontes (zooxantelas) de corais, recorrendo ao métodos não invasivo e não destrutivo designado como Fluorometria de Pulso Modulado (PAM – “Pulse Amplitude Modulation fluorometry”), para avaliar a eficiência fotoquímica do fotossistema II (Fv/Fm). Avaliou-se a concentração de clorofila a de forma indireta, através do cálculo do índice NDVI (“Normalized Difference Vegetation Index”) que resulta da reflectância espectral obtida de forma não invasiva e não destrutiva; para além do método mencionado realizaram-se análises para obtenção da concentração de pigmentos fotossintéticos e acessórios. Por fim, avaliou-se o efeito da luz na taxa de crescimento e percentagem de sobrevivência das espécies de corais estudadas. As variáveis independentes estudadas foram as diferentes fontes de iluminação artificial utilizadas para cultivo ex situ de corais, nomeadamente: lâmpadas de halogeneto metálico (HQI – “hydrargyrum quartz iodide”) com diferentes temperaturas de cor, lâmpadas T5 fluorescentes, lâmpadas de plasma (LEP – “Light Emitting Plasma”) e lâmpadas de LED (“Light Emitting Diode”). Estudaram-se duas espécies de corais moles, Sarcophyton cf. glaucum e Sinularia flexibilis, que representam dois dos géneros com mais espécies na família Alcyoniidae, onde se incluem numerosas espécies com interesse para a biotecnologia marinha e para o mercado da aquariofilia marinha; foram igualmente estudadas duas espécies de corais duros, Acropora formosa e Stylophora pistillata, comercialmente importantes para o mercado da aquariofilia marinha, e relevantes para ações de repovoamento nos recifes de coral. Demonstrámos através dos resultados das diferentes experiências realizadas, que a cicatrização e recuperação de fragmentos de S. flexibilis mantidos após fragmentação nas mesmas condições luminosas das colónias mãe dos fragmentos são aceitáveis, embora possam igualmente ser mantidos com sucesso em regimes luminosos com uma menor intensidade do valor de PAR. Ficou também demonstrado que o cultivo do coral S. cf. glaucum em regimes luminosos com uma baixa intensidade do valor de PAR é biologicamente viável, o que permite uma redução acentuada nos custos de produção associados á iluminação artificial. Finalmente, concluiu-se que a utilização de sistemas de iluminação que emitam nos comprimentos de onda na faixa de radiação azul proporciona taxas de crescimento mais elevadas aos corais A. formosa e S. pistillata, para além de promover alterações ao nível da organização das micro e macroestruturas que integram os exosqueletos destes corais, referidos como um biomaterial com potencial para aplicação biomédica em implantes ósseos ou reconstrução maxilo-facial. Ficou também provado neste estudo, que as novas tecnologias de iluminação (LED) são bastante promissoras para o cultivo ex situ de corais

Beyond bilateral symmetry: geometric morphometric methods for any type of symmetry

Abstract Background Studies of symmetric structures have made important contributions to evolutionary biology, for example, by using fluctuating asymmetry as a measure of developmental instability or for investigating the mechanisms of morphological integration. Most analyses of symmetry and asymmetry have focused on organisms or parts with bilateral symmetry. This is not the only type of symmetry in biological shapes, however, because a multitude of other types of symmetry exists in plants and animals. For instance, some organisms have two axes of reflection symmetry (biradial symmetry; e.g. many algae, corals and flowers) or rotational symmetry (e.g. sea urchins and many flowers). So far, there is no general method for the shape analysis of these types of symmetry. Results We generalize the morphometric methods currently used for the shape analysis of bilaterally symmetric objects so that they can be used for analyzing any type of symmetry. Our framework uses a mathematical definition of symmetry based on the theory of symmetry groups. This approach can be used to divide shape variation into a component of symmetric variation among individuals and one or more components of asymmetry. We illustrate this approach with data from a colonial coral that has ambiguous symmetry and thus can be analyzed in multiple ways. Our results demonstrate that asymmetric variation predominates in this dataset and that its amount depends on the type of symmetry considered in the analysis. Conclusions The framework for analyzing symmetry and asymmetry is suitable for studying structures with any type of symmetry in two or three dimensions. Studies of complex symmetries are promising for many contexts in evolutionary biology, such as fluctuating asymmetry, because these structures can potentially provide more information than structures with bilateral symmetry.</p

The Future of Coral Reefs

This volume contains a series of papers prepared for presentation at the 14th International Coral Reef Symposium, originally planned for July 2020 in Bremen, Germany, but postponed until 2021 (online) and 2022 (in person) because of the COVID-19 pandemic. It contains a series of papers illustrating the breadth of modern studies on coral reefs and the response of the reef science community to the threats that coral reefs now face, above all from climate change. The first group of papers focus on the biology of a selection of reef organisms, ranging from sea fans to coral dwelling crabs. The next group describe studies of coral communities and ecological interactions in regions as diverse as Florida, Kenya, Colombia, and Norway. Further papers describe investigations into the effects of global warming (in the Maldives and in Timor-Leste) and of other impacts (UV blockers, ocean acidification). The final two papers describe the latest applications of satellite and camera technology to the challenge of mapping and monitoring reefs

The influence of light and water flow on the growth and physiology of the scleractinian coral Galaxea fascicularis

Background Zooxanthellate scleractinian corals are sessile colonial animals that live in symbiosis with photosynthetic algae, the zooxanthellae. They can feed both phototrophically and heterotrophically and produce an external skeleton of calcium carbonate, which process is enhanced by light. They are the key organisms of tropical coral reefs and responsible for building the large carbonate structures. Tropical coral reefs are increasingly threatened by both natural and anthropogenic stresses. Concurrently with the gradual decline of coral reefs, a growing interest in keeping this delicate ecosystem in aquaria has emerged. To reduce harvest from the wild, increasing effort is put in developing cost-effective coral aquaculture culture. The objective of this thesis was to study the influence of light (irradiance and photoperiod) and flow on coral growth and physiology. Furthermore, the interaction between light and water flow was studied. Methods The effect of flow (Chapter 2), light (Chapter 3), photoperiod (Chapter 4) and the interaction between light and flow (Chapter 5) on coral growth were studied in long-term experiments monitoring several growth parameters such as buoyant weight (i.e. skeletal mass), surface area and polyp number. Physiological parameters such as photosynthesis and respiration were measured in respirometric flowcells to provide an explanation for the observed differences in growth. Moreover, an overview was given of different factors controlling coral growth and how such knowledge can be translated to aquaculture practice (Chapter 6). Results In the absence of water flow, coral growth was significantly lower and corals appeared unhealthy. In the presence of water flow (10, 20 and 25 cm s-1, at 90 µE m-2 s-1), growth rates were significantly increased. However, growth was not significantly different between 10 cm s-1 and 20 cm s-1, but again significantly increased at 25 cm s-1. Differences in growth could not be explained by net photosynthetic rate and Scope for Growth based on phototrophic carbon, since these parameters decreased with increasing water flow (Chapter 2). Increasing irradiance significantly increased the specific exponential growth rate of Galaxea fascicularis. The relation between skeletal growth and net photosynthesis was not directly proportional, but distorted at high irradiance levels (Chapter 3). Increasing photoperiod did not increase the specific exponential growth rate of Galaxea fascicularis. However, since growth neither increased with increasing irradiance, it is suggested that growth was limited by another factor and light was therefore saturating. The corals in the 24 hour light treatment were not able to adapt to prolonged light duration. However, the corals in the 16 hour light treatment probably photo-acclimated to prolonged photoperiod under light-saturating conditions by reducing their hourly photosynthetic rates (16 hour vs. 8 hour light) As a result, daily net photosynthetic was not significantly different, just as their growth rates (Chapter 4). The interaction between light and water flow for coral growth was significant. Water flow stimulated coral growth more at 600 µE m-2 s-1 than at 300 µE m-2 s-1 and the highest growth rates were attained at high irradiance (600 µE m-2 s-1) in combination with high flow rates (15-25 cm s-1). Nevertheless, enhancement of coral growth with either increasing irradiance or increasing water flow could not be explained by net photosynthetic rates (Chapter 5). There are many factors (both environmental and genetical) that can potentially limit or inhibit coral growth. Optimization of coral aquaculture therefore requires close fine-tuning of factors. Growth models can be used as a tool to determine the best culture strategy (Chapter 6). Conclusion Increasing water flow has a positive effect on coral growth at a wide range of irradiance levels (90, 300 and 600 µE/m2/s). Increasing irradiance also has a positive effect on coral growth. However, the positive relation between irradiance and coral growth is disturbed when other factors are limiting. Corals were able to retain their growth rates upon photoperiod extension under light-saturating conditions, presumably by means of reducing their hourly photosynthetic rate. At high irradiance levels, the enhancement of coral growth was not proportionally related to net photosynthesis, suggesting that other factors become limiting. Since the interaction between irradiance and water flow is significant, this indicates that water flow can remove some of those limitations at high irradiance levels. The mechanism of enhancement did not seem related to differences in net photosynthetic rate, but is possibly related to reduced energy allocation toward costly photo-protective mechanisms at high irradiance and high flow. The information in this thesis should not be used as a blueprint for coral aquaculture, however, its value lies in providing a blueprint for targeted optimization studies of coral aquaculture. Since the magnitude of effect of one factor often depends on the other, it is of importance for the future to perform multi-factorial experiments to provide insight in the interactions between factors. Under light-saturating conditions, further increases in irradiance or extension of photoperiod do not result in more growth. [ Increasing irradiance has a positive relation with both coral growth and net photosynthesis. At high irradiance levels, the enhancement of coral growth was not proportionally related to net photosynthesis, suggesting that other factors become limiting. Since the interaction between irradiance and water flow is significant, this indicates that water flow can remove some of those limitations at high irradiance levels. The mechanism did not seem related to differences in net photosynthetic rate, but is possibly related to reduced energy allocation toward costly photo-protective mechanisms at high irradiance and high flow. Under light-saturating conditions, further increases in irradiance or extension of photoperiod do not result in more growth. [ Both increasing irradiance and water flow enhance coral growth. Enhancement of coral growth by light was not proportionally related to net photosynthesis at higher irradiance levels, suggesting that other factors become limiting. Since the interaction between irradiance and water flow is significant, this indicates that water flow can remove some of those limitations at high irradiance levels. The mechanism did not seem related to differences in net photosynthetic rate, but is possibly related to reduced energy allocation toward costly photo-protective mechanisms at high irradiance and high flow. Under light-saturating conditions, further increases in irradiance or extension of photoperiod do not result in more growth. [ Increasing water flow has a positive effect on coral growth at a wide range of irradiance levels (90, 300 and 600 µE/m2/s). In our studies, differences in growth could not be explained with differences in net photosynthetic rate. Rather differences in growth could be related to algal competition and sedimentation or other physiological parameters such as (in)organic nutrient uptake, relief of photo-oxidative stress and dark respiration that are influenced by water flow. Increasing irradiance also has a positive effect on coral growth. Enhancement of coral growth by light was not proportionally related to net photosynthesis at higher irradiance levels, suggesting that other factors become limiting. The significant interaction between light and water flow indicates that water flow can remove some limitations and that the presence of water flow is very important for optimal light use for coral growth. The mechanism did not seem related to differences in net photosynthetic rate, but is possibly related to reduced energy allocation toward costly photo-protective mechanisms at high irradiance and high flow. The effect of increasing photoperiod under light-limiting conditions still needs to be established. Since enhancement of coral growth did not seem to be d… by photosynthesis at higher irradiance levels [WEL, maar niet proportional], it suggested limited.. One of such factors that can remove limitations is water flow. A significant interaction between light and water flow is detected, … but this effect is dependent on water flow. The interaction between light and water flow indicates that water flow is very important for optimal light use for coral growth. The mechanism is still unclear, but is possibly related to reduced energy allocation toward costly photo-protective mechanisms at high irradiance and high flow. Both increasing irradiance and water flow have a positive effect on coral growth, and a significant interaction is found between light and water flow. The positive effect of increasing water flow on coral growth was found to be significant both at an irradiance of 90 µE/m2/s (Chapter 2), 300 µE/m2/s and 600 µE/m2/s (Chapter 5). Neither of these differences in growth were supported by a significant increase in net photosynthetic rate, in contrast to our expectations. The positive effect of increasing water flow on coral growth is probably a consequence of both external (algal competition and sedimentation) and internal mechanisms( (in)organic nutrient uptake, relief of photo-oxidative stress, respiration). Different at different irradiance levels. External at 90, internal at 300 and 600 The positive effect of irradiance on skeletal growth was demonstrated in both Chapter 3 and 5. The relationship with photosynthesis irradiance curve not proportional. - mediation by P not clear. - The relation between skeletal growth and net photosynthesis was not proportional, In contrast, no positive effect of irradiance on skeletal growth was found in Chapter 4. Both specific growth rate and net photosynthesis increased with irradiance, however, this relationship was not proportional. It is suggested that .at high irradiance levels, skeletal growth (i.e. calcification and organic matrix synthesis) is not limited by light or photosynthesis. At high irradiance, other factor (e.g. availability of bicarbonate (i.e. aragonite saturation state), heterotrophic feeding and/or water flow) may become limiting. Water flow and light… Photoperiod… still needs to be established. .. offset limitations . optimize balance between factors At an irradiance of 90 µE m-2 s-1, water flow enhanced coral growth Increased water flow enhanced coral growth at a wide range of irradiances: 90 µE m-2 s-1 (Chapter 2), 300 and 600 µE m-2 s-1 (Chapter 5). AT 90 µE m-2 s-1, no The mechanism of enhancement is however not clear. Flow enhanced growth.. absence of flow detrimental.. did… however.. P, algae.. Light… relation growth and photosynthesis distorted.. light enhanced calcificcaiotn. Photoperiod… no effect .. light not limiting.. photoacclimation.. 24 not able to adapt, but 16 hours well, probably by reducing hourly P. Light x flow… Interaction between light and water flow (chapter 5).. … no diff chapter 4… Review factors (chapter 6) .. examined… chapter.. Furthermore… In addition.. different mechanisms at different irradiance levels. No relation with P. At 90… reduce disturbance of coral growth by competing algae. at 300 and 600 …. Reduce photo-protective mechanisms <br/

11th International Coral Reef Symposium Proceedings

A defining theme of the 11th International Coral Reef Symposium was that the news for coral reef ecosystems are far from encouraging. Climate change happens now much faster than in an ice-age transition, and coral reefs continue to suffer fever-high temperatures as well as sour ocean conditions. Corals may be falling behind, and there appears to be no special silver bullet remedy. Nevertheless, there are hopeful signs that we should not despair. Reef ecosystems respond vigorously to protective measures and alleviation of stress. For concerned scientists, managers, conservationists, stakeholders, students, and citizens, there is a great role to play in continuing to report on the extreme threat that climate change represents to earth’s natural systems. Urgent action is needed to reduce CO2 emissions. In the interim, we can and must buy time for coral reefs through increased protection from sewage, sediment, pollutants, overfishing, development, and other stressors, all of which we know can damage coral health. The time to act is now. The canary in the coral-coal mine is dead, but we still have time to save the miners. We need effective management rooted in solid interdisciplinary science and coupled with stakeholder buy in, working at local, regional, and international scales alongside global efforts to give reefs a chance.https://nsuworks.nova.edu/occ_icrs/1000/thumbnail.jp