Description: Coral recruitment was assessed in highly diverse and economically important Spermonde Archipelago, a reef system subjected to land-based sources of siltation/pollution and destructive fishing, over a period of 2 years. Recruitment on settlement tiles reached up to 705 spat m−2 yr−1 and was strongest in the dry season (July–October), except off-shore, where larvae settled earlier. Pocilloporidae dominated near-shore, while a more diverse community of Acroporidae, Poritidae and others settled in the less polluted mid-shelf and off-shore reefs. Non-coral fouling community appeared to hardly influence initial coral settlement on the tiles, although, this does not necessarily infer low coral post-settlement mortality, which may be enhanced at the near- and off-shore reefs as indicated by increased abundances of potential space competitors on natural substrate. Blast fishing showed no local reduction in coral recruitment and live hard coral cover increased in oligotrophic reefs, indicating potential for coral recovery, if managed effectively.

Description: In situ incubation experiments, complemented by tissue analyses, were conducted with the coral Porites lutea at four sites featuring contrasting environmental conditions: two shallow (3m) reefs in Spermonde Archi-pelago (Indonesia) subjected to coastal pollution (Lae Lae, LL) and oligotrophic waters (Bonebatang, BBA), respectively; a deep (20m, KR-D) and a shallow (7m, KR-S) reef at off-shore Ko Racha (KR) in the Andaman Sea (Thailand) subjected to pulsed upwelling. Mean tem-perature varied only little (29-30°C). While most tis-sue parameters responded to light and nutrient changes as ex-pected, metabolic rates revealed surprising patterns: 3-fold elevated calcification occurred at KR-S compared to all other sites despite reduced gross photosynthesis. Fur-ther-more, equal photosynthesis occurred in 7 and 20m depth at KR, despite a 5-fold reduction in light intensity, which could not be solely ascribed to photo-acclimation processes, such as increased cell-specific chlorophyll a in 20m depth. These findings support the notion of a highly flexible species and indicate that this might partly be ascribed to a strong variation in the internal turnover of oxygen and nutrients between coral host and zooxanthellae, meaning a strong variation in the rates of energy ac-quisition. Those differences are particularly difficult to determine in situ, but require greater attention in the future in order to enhance our understanding of metabolic pro-cesses and acclimatization abilities.

Description: Together with Coral reefs and mangrove forests, seagrass meadows rank amongst the most important ecosystem components of tropical coastlines. The highly productive seagrasses support large biomasses of fishes and invertebrates, and are the preferred food item of iconic endangered species like green turtles and dugongs. Southeast Asia has the greatest diversity of seagrasses worldwide, and a substantial part of the global seagrass area. In spite of that, seagrasses in the region remain poorly studied. Research conducted in the Spermonde archipelago by scientists of the AWI in collaboration with representatives of Hasanuddin University Makassar aimed to fill some of the knowledge gaps on Southeast Asian seagrass ecosystems. In the first phase of the project the impact of seaweed farming on the productivity of the seagrass meadow below was adressed. The second focus was on the ecological role of synaptid holothurians, burrowing axiid shrimp and siganid fishes in the meadows. The biodiversity of gobiid fishes and plankton was also studied. In the second phase the main focus was on seagrass distribution, the impact of water motion and water depth on the composition of multispecies meadows, the controlling effect of callianassid shrimp and the diversity and diet of fish communities. Pinnid bivalves, macrobenthos diversity and plankton processes were the subject of further studies. In the third phase an in-situ carbon dioxide enrichment experiment was conducted, and the magnitude and fate of river inputs into the Spermonde lagoon was measured. In all three phases, capacity building was done through jointly supervised final theses and lectures in the “Marine Ecology Special Training Course”. Seventeen German and ten Indonesian students wrote their thesis within the project. A total of four PhD, 15 master and eight bachelor theses were completed.

Description: It has been postulated that mound-building callianassid shrimp and seagrass have mutually negative effects on each other. On reef flats in the Spermonde Archipelago, Indonesia, sediment mounds of callianassid shrimp are rare in wave exposed seagrass meadows, occur frequently in sheltered seagrass meadows, and reach their highest densities (4.2 mounds m− 2) in unvegetated subtidal areas. There sediment turnover is high at an estimated 3408 g DW m− 2 ∗ d− 1. Based on collected specimens and burrow casts, the most important bioturbators are Glypturus armatus within seagrass beds and Neocallichirus vigilax in unvegetated subtidal areas. Six shrimp exclusion, six control and six zero treatment plots were set up in an unvegetated subtidal N. vigilax bed. Half of the plots for each treatment were ca. 1.5 m (“shallow”) and the other half ca. 2 m or slightly more (“deep”) below spring low tide level. The survival of transplanted shoots of the six seagrass species Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Halodule uninervis, Syringodium isoetifolium and Halophila ovalis was monitored over 27 months. At the end, E. acoroides had survived in about half of the plots with no obvious relation to either treatment or water depth. C. rotundata and H. uninervis had successfully established themselves on the shallowest exclusion plot only, and had disappeared from all other plots. T. hemprichii and S. isoetifolium had disappeared from all plots. H. ovalis expanded rapidly in the dry seasons, but wet seasons caused a temporary decline in shoot numbers. At the end, the highest shoot numbers were counted in shallow exclusion plots, some shoots survived in deep exclusion plots and the species disappeared from all deep control and zero treatment plots. H. ovalis shoot numbers were significantly influenced by water depth (ANOVA p 〈 0.01) and, to a lesser extent, by treatment (ANOVA p 〈 0.05) but there was no interaction between the two factors. It is concluded that seagrasses are only controlled by shrimp bioturbation at the lower limit of their distribution in sheltered subtidal areas. Here they are already under considerable stress from a combination of factors such as light limitation and sedimentation. However, the distribution pattern of seagrasses vs. shrimp elsewhere on the islands suggests that seagrasses are equal competitors in sheltered intertidal areas, where they may even profit from the abundant small tidal pools between mounds created by the shrimp, and dominant competitors in exposed intertidal and subtidal areas.

Description: Coral recruitment was assessed in highly diverse and economically important Spermonde Archipelago, a reef system subjected to land-based sources of siltation/pollution and destructive fishing, over a period of 2 years. Recruitment on settlement tiles reached up to 705 spat m�2 yr�1 and was strongest in the dry season (July–October), except off-shore, where larvae settled earlier. Pocilloporidae dominated nearshore, while a more diverse community of Acroporidae, Poritidae and others settled in the less polluted mid-shelf and off-shore reefs. Non-coral fouling community appeared to hardly influence initial coral settlement on the tiles, although, this does not necessarily infer low coral post-settlement mortality, which may be enhanced at the near- and off-shore reefs as indicated by increased abundances of potential space competitors on natural substrate. Blast fishing showed no local reduction in coral recruitment and live hard coral cover increased in oligotrophic reefs, indicating potential for coral recovery, if managed effectively.

Description: Early‐diagenetic cementation of tropical carbonates results from the combination of numerous physico‐chemical and biological processes. In the marine phreatic environment it represents an essential mechanism for the development and stabilization of carbonate platforms. However, diagenetic cements that developed early in the marine phreatic environment are likely to become obliterated during later stages of meteoric or burial diagenesis. When lithified sediment samples are studied, this complicates the recognition of processes involved in early cementation, and their geological implications. In this contribution, a petrographic microfacies analysis of Holocene Halimeda segments collected on a coral island in the Spermonde Archipelago, Indonesia, is presented. Through electron microscopical analyses of polished samples, this study shows that segments are characterized by intragranular cementation of fibrous aragonite, equant High‐Mg calcite (3.9 to 7.2 Mol% Mg), bladed Low‐Mg calcite (0.4 to 1.0 Mol% Mg) and mini‐micritic Low‐Mg calcite (3.2 to 3.3 Mol% Mg). The co‐existence and consecutive development of fibrous aragonite and equant High‐Mg calcite results initially from the flow of oversaturated seawater along the aragonite template of the Halimeda skeleton, followed by an adjustment of cement mineralogy towards High‐Mg calcite as a result of reduced permeability and fluid flow rates in the pores. Growth of bladed Low‐Mg calcite cements on top of etched substrates of equant High‐Mg calcite is explained by shifts in pore water pH and alkalinity through microbial sulphate reduction. Microbial activity appears to be the main trigger for the precipitation of mini‐micritic Low‐Mg calcite as well, based on the presumable detection of an extracellular polymeric matrix during an early stage of mini‐micrite Low‐Mg calcite cement precipitation. Radiocarbon analyses of five Halimeda segments furthermore indicate that virtually complete intragranular cementation in the marine phreatic environment with thermodynamically/kinetically controlled aragonite and High‐Mg calcite takes place in about 100 years. Collectively, this study shows that early‐diagenetic cements are highly diverse and provides new quantitative constraints on the rate of diagenetic cementation in tropical carbonate factories.

Description: Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

Description: https://doi.pangaea.de/10.1594/PANGAEA.923980

Description: Abstract Ecological and social processes of the Spermonde Archipelago, South Sulawesi, Indonesia, have been intensively studied during the Science for the Protection of Indonesian Coastal Ecosystems (SPICE) program. The archipelago is of specific interest to better understand how intensive exploitation of marine resources results in the degradation of reef systems. The projects specifically targeted (1) ecological processes in coral reefs, (2) genetic structure of populations, and (3) social–ecological dynamics relating to resource use, social networks, and governance structures. A modeling component emphasized (4) the integration of different ecological, social, and environmental components. Results indicated that reef resources in the Spermonde Archipelago are intensively exploited and further stressed by pollution effluents from hinterland processes. The lack of alternative livelihoods perpetuates dependencies within the patron–client system of the artisanal fisheries and supports high exploitation and also destructive resource uses. Greater inclusion of local stakeholders in the governance may result in better conservation practices, sustainable resource use, and improved livelihoods for the people. Abstrak Selama proyek SPICE, aspek ekologis dan sosial di perairan Kepulauan Spermonde, Sulawesi Selatan, Indonesia, dipelajari secara intensif. Kepulauan dan perairan ini mengundang banyak perhatian untuk lebih memahami bagaimana tingkat pemanfaatan sumber daya laut yang intensif berakibat pada degradasi sistem terumbu karang. Kerangka kerja proyek penelitian SPICE, secara khusus, menargetkan kajian-kajian mengenai (a) proses ekologis dalam sistem terumbu karang, (b) struktur genetik populasi untuk menentukan konektifitasnya, dan (c) dinamika sosial-ekologi yang berkaitan dengan penggunaan sumber daya, jejaring sosial dan struktur tata kelola. Komponen pemodelan juga dimasukkan kedalam kajian mengenai (d) integrasi berbagai komponen ekologi, sosial dan lingkungan dalam karakterisasi sistem sosial-ekologis. Hasil-hasil penelitian menunjukkan bahwa sumber daya terumbu karang di Kepulauan Spermonde sangat tereksploitasi dan terancam juga oleh limbah polusi dari proses di daratan. Kurangnya mata pencaharian alternatif memperkuat ketergantungan para nelayan tradisional pada sistem patron-klien dan meningkatkan penggunaan sumber daya yang tidak berkelanjutan dan merusak. Keikutsertaan pemangku kepentingan lokal yang lebih erat dalam tata kelola sumber daya alam Kepulauan Spermonde sangat memungkinkan hasil praktik konservasi yang lebih baik, penggunaan sumber daya berkelanjutan, dan peningkatan mata pencaharian bagi masyarakat.

Description: Foraminifera are a group of mostly marine protists with high taxonomic diversity. Species identification is often complex, as both morphological and molecular approaches can be challenging due to a lack of unique characters and reference sequences. An integrative approach combining state of the art morphological and molecular tools is therefore promising. In this study, we analysed large benthic Foraminifera of the genus Amphisorus from Western Australia and Indonesia. Based on previous findings on high morphological variability observed in the Soritidae and the discontinuous distribution of Amphisorus along the coast of western Australia, we expected to find multiple morphologically and genetically unique Amphisorus types. In order to gain detailed insights into the diversity of Amphisorus, we applied micro CT scanning and shotgun metagenomic sequencing. We identified four distinct morphotypes of Amphisorus, two each in Australia and Indonesia, and showed that each morphotype is a distinct genotype. Furthermore, metagenomics revealed the presence of three dinoflagellate symbiont clades. The most common symbiont was Fugacium Fr5, and we could show that its genotypes were mostly specific to Amphisorus morphotypes. Finally, we assembled the microbial taxa associated with the two Western Australian morphotypes, and analysed their microbial community composition. Even though each Amphisorus morphotype harboured distinct bacterial communities, sampling location had a stronger influence on bacterial community composition, and we infer that the prokaryotic community is primarily shaped by the microhabitat rather than host identity. The integrated approach combining analyses of host morphology and genetics, dinoflagellate symbionts, and associated microbes leads to the conclusion that we identified distinct, yet undescribed taxa of Amphisorus. We argue that the combination of morphological and molecular methods provides unprecedented insights into the diversity of foraminifera, which paves the way for a deeper understanding of their biodiversity, and facilitates future taxonomic and ecological work.