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The aim of the present study was to propose a biotic index (North Adriatic Mesophotic BiogEnic Reefs, NAMBER) suitable for assessing the ecological quality of the mesophotic biogenic reefs of the northern Adriatic continental shelf based on photographic sampling.At each of the 20 study sites, the degree of bioconstruction (expressed as percentage cover of crustose coralline algae), the α‐diversity (expressed as the mean number of taxa), and the degree of sensitivity to human disturbance and climate change (based on literature data and expert judgement) of the benthic assemblages were selected as descriptors and combined in the NAMBER index, using the best values that the three metrics can currently achieve in the studied region as a reference.The study highlighted that there was large spatial heterogeneity among reefs and high variability in the ecological quality values obtained by NAMBER, ranging from bad to high. The index indicates that reefs lying furthest from the coast, under substantially lower anthropogenic pressure, have a generally higher status of environmental quality. However, a clear geographical pattern did not emerge, as reefs close together often had different ecological qualities.The NAMBER index, which combines three ecological descriptors, in accordance with the requirements of the European Marine Strategy Framework Directive, represents a specific adaptation to the northern Adriatic Sea of a multimetric index previously developed for the north‐western Mediterranean Sea, capitalizing on previous knowledge and research efforts.This multimetric biotic index provides an effective standardized tool for monitoring programmes and environmental impact assessments in the northern Adriatic mesophotic biogenic reefs and lays the foundation for ecosystem‐based management and conservation in this basin. [ABSTRACT FROM AUTHOR]

A non‐geniculate coralline alga, Lithophyllum nagaokaense Min‐Khant‐Kyaw, A. Kato, M. Baba sp. nov., described by Min‐Khant‐Kyaw et al. in this issue. In situ view of encrusting thalli attached on boulders at the shore of Nagaoka City, Niigata Prefecture, Japan (left, photo taken by Masasuke Baba). Dried rhodolith‐shaped specimen (upper right) showing nucleated core (lower right, both photos taken by Min‐Khant‐Kyaw). [ABSTRACT FROM AUTHOR]

Coralline algae play important ecological roles throughout the photic zone of the world’s oceans. Recent studies have shown that attached-living coralline algae can contain records of past climate variability. So far, algal-based paleo-reconstructions are mainly available from mid- to high-latitudes, while in low latitude and temperate regions only few examples exist. Here, we investigate samples from the attached-living encrusting coralline algal species Neogoniolithon hauckii (Rothpletz) R.A Townsend & Huisman [= Neogoniolithon mamillosum (Hauck) Setchell & L.R. Mason, nom illeg.] from a temperate site in the Mediterranean Sea to assess its potential as an environmental recorder. The specimens were collected at different water depths (20 and 40 m) in the Columbretes Islands (Spain). Sclerochronological analysis of sectioned samples revealed seasonal growth patterns. Mg/Ca, Li/Ca, and Ba/Ca ratios were measured in the algal skeletons using laser ablation inductively coupled mass spectrometry (LA-ICP-MS) in ultra-high resolution. We report a mean vertical extension rate of 1.1 to 1.2 mm/year (based on analysis of Mg/Ca cycles in 40 m and 20 m samples), representing the first growth rate measurement for this species. In addition, subannual banding patterns were mapped, measured, and could be linked to high frequency variability in laser-analyzed Mg/Ca ratios. Elemental ratios analyzed in Neogoniolithon hauckii were compared to in situ water temperatures measured at the water depth of sample collection. Our results show significant positive relationships between algal Mg/Ca (R=0.55) as well as Li/Ca ratios (R=0.46) and in situ measured temperature data (40 m specimen). Ba/Ca ratios show no significant correlation to temperature and may be influenced by other factors. These data suggest potential of this species for climate reconstructions in warm-temperate regions as Neogoniolithon hauckii is not only widely distributed in the Mediterranean, but also one of the few species that may be used as a temperature archive for mesophotic coralligenous assemblages that are strongly affected by the recent anthropogenic temperature rise. Further calibration studies are needed to test the element-temperature relationships on samples with longer growth records and in different settings and water depths.

In this work, a review of petrographic studies in recent decades on 50 sandy beach samples of the eastern Canary Islands (La Graciosa, Lanzarote, Fuerteventura and Gran Canaria) has been carried out in order to know the composition and provenance of the sand grains. The sandy samples are intertidal and most are related to beach-dune systems with coastal desert and arid climates. Thus, these samples contain different proportions of calcareous bioclast, intraclast and volcaniclast grains, with the latter coming from different source areas associated with the building stages of the islands (shield, decline, erosive and rejuvenation). In general, the calcareous bioclasts are mostly fragments of red coralline algae and molluscs, with the appearance of occasional grains of echinoderms, foraminifera and bryozoans. The lithoclasts are essentially fragments of ultramafic and mafic alkaline rocks (basanite and basalt) from the shield and rejuvenation stages and to a lesser extent trachytic-phonolitic felsic rocks from the decline stage, while there are few mafic (olivine, clinopyroxene, Fe-Ti oxide, and amphibole) and felsic (feldspar) mineral grains. The intraclasts are fragments of coastal sedimentary rocks such as beachrocks, eolianites, and paleosols. The abundance percentages depend on geographic and geological factors in each coastal zone. In general, the beaches studied in La Graciosa, Lanzarote and Fuerteventura contain higher percentages of bioclasts than lithoclasts. However, volcaniclasts are more abundant than bioclasts in Gran Canaria, and sand grains of trachytic-phonolitic composition appear only on this island. Finally, urban and semi-urban beaches were found to have fewer bioclasts than natural ones. [ABSTRACT FROM AUTHOR]

Partial rbcL sequences from type specimens of three of the earliest described Corallina species showed that C. arbuscula (type locality: Unalaska Island, Alaska, USA) and C. pilulifera (type locality: Okhotsk Sea, Russia) are synonymous, with C. pilulifera as the taxonomically accepted name and that C. vancouveriensis (type locality: Botanical Beach, Vancouver Island, Canada) is a distinct species. To identify molecular species limits and clarify descriptions and distributions of C. pilulifera and C. vancouveriensis, we sequenced and analyzed portions of one mitochondrial and two plastid genes from historical and recent collections. The single‐gene phylogenetic reconstructions support the recognition of both species as distinct, as well as two additional species, C. hakodatensis sp. nov. and C. parva sp. nov., which are sister to, and often morphologically indistinguishable from C. pilulifera and C. vancouveriensis, respectively. DNA sequence data currently illustrate that C. pilulifera is found in the cold northern Pacific waters from the Okhotsk Sea of Russia to Hokkaido, Japan, eastward across the Aleutian Islands to Knoll Head, Alaska, and as far south as Nanaimo, British Columbia. Corallina vancouveriensis is distributed as far west as Attu Island in the Aleutian Islands to Sitka, Alaska, and southeasterly at numerous sites from British Columbia to the north of Point Conception, California, USA. The cryptic species C. hakodatensis and C. parva occur sympatrically with their sister species but with narrower ranges. The complex phylogenetic relationships shown by the single gene trees recommend Corallina as a model genus to explore coralline algal biogeography, evolution, and patterns of speciation. [ABSTRACT FROM AUTHOR]

Crustose coralline algae (CCA) are one of the most important benthic substrate consolidators on coral reefs through their ability to deposit calcium carbonate on an organic matrix in their cell walls. Discrete polysaccharides have been recognized for their role in biomineralization, yet little is known about the carbohydrate composition of organic matrices across CCA taxa and whether they have the capacity to modulate their organic matrix constituents amidst environmental change, particularly the threats of ocean acidification (OA) and warming. We simulated elevated pCO2 and temperature (IPCC RCP 8.5) and subjected four mid‐shelf Great Barrier Reef species of CCA to 2 months of experimentation. To assess the variability in surficial monosaccharide composition and biomineralization across species and treatments, we determined the monosaccharide composition of the polysaccharides present in the cell walls of surficial algal tissue and quantified calcification. Our results revealed dissimilarity among species' monosaccharide constituents, which suggests that organic matrices are composed of different polysaccharides across CCA taxa. We also observed that species differentially modulate composition in response to ocean acidification and warming. Our findings suggest that both variability in composition and ability to modulate monosaccharide abundance may play a crucial role in surficial biomineralization dynamics under the stress of OA and global warming. [ABSTRACT FROM AUTHOR]

Dalian Island is located in the sea area near Pingtan County, Fujian, Southeast China. The sea area used to be the junction of the eastern and western ship routes on the Maritime Silk Road, and is also an important region for underwater archaeology in China. This study focused on a sauce-glazed ware of the Song Dynasty, with serious degradation, which was salvaged out of the water at the Dalian Island Wharf. Optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and micro-Raman spectroscopy were used to comprehensively analyze the composition, phase attributes and microstructure of the ware and the surface-attached coagula. The findings revealed that the sea wave-borne debris scoured the surface of the ware, causing mechanical damage to varying degrees and a significant decrease in its degradation resistance. This was the primary factor accounting for the poor preservation state of the salvaged ceramic ware, and the precondition for the subsequent attachment of marine organisms and the deposition of inorganic pollutants. The calcareous skeletons formed on the surface induced by the bio-mineralization of coralline algae (a type of marine plant) could resist the mechanical action caused by the motion of sea waves, thereby slowing down the ware's degradation process. In other words, the calcareous skeletons played a 'bio-protective' role to a certain degree. In addition, inorganic pollutants represented by iron rusts also participated in the corrosion of the glaze. Some pollutants were directly deposited on the pits and cracks on the surface of the ware, which brought stress to the glaze and glaze/body interface, causing the glaze to further crack and spall. Moreover, iron rusts reacted with the glaze, leading to chemical alteration, accompanied by the formation of iron silicate as the alteration product. Anorthite crystals in the interlayer did not participate in the reaction but remained at the original position. The alteration product gradually replaced the original glass phase of the glaze and entered into the body via pores and cracks. In conclusion, the complex degradation morphology of the salvaged sauce-glazed ware could be attributed to the combined action of mechanical damage, marine bio-fouling, and chemical alteration. [ABSTRACT FROM AUTHOR]

Crustose coralline algae (CCA) occur from the tropics to the poles in photic benthic environments. Here, we report on some of the world's southernmost and coldest CCA sites in Terra Nova, Ross Sea, Antarctica at 74°41′ S. The recently described red alga Tethysphytum antarticum is investigated for its skeletal architecture, its mineralogical and geochemical composition, as well as for its taxonomic classification. A phylogenetic analysis based on molecular genetics and the sequencing of the photosystem II protein D1 (psbA) gave a perfect match with T. antarcticum. Histological sections and micro-CT-scans provide new diagnostic details for the conceptacles (the reproductive organs of the alga). X-ray diffractometry and electron-microprobe measurements yielded a clear high-Mg calcite (~8 mol%) composition of the skeletal parts. Detailed back-scattered electron imaging of polished petrographic thin sections revealed a two-layered thallus (vegetative plant tissue), comprising an organic-rich irregularly calcified basal layer with rectangular cells, overlain by the main thallus. Elemental maps show relatively increased sulphur in the basal layer, clearly tied to organic cell walls. MgCO3 and SrCO3 were targeted with semiquantitative elemental mappings and in an ontogenetic quantitative spot transect. Compared with temperature (−1.95 °C to +1.08 °C), the MgCO3 (mol%) reflects this world's coldest CCA site temperature with the lowest MgCO3 content of 7.9 ± 1.6 mol%. The along transect variability, however, shows with ~6 mol% a larger MgCO3 variability than expected for the 3 °C intra-annual temperature amplitude in Terra Nova Bay. This implies that in low amplitude settings the biomineralisation control on Mg/Ca ratios can outcompete its temperature sensitivity. Mark-recapture studies, next to the environmental logger station La Zecca are suggested, to perform a detailed growth rate and biomineralisation quantification. [ABSTRACT FROM AUTHOR]

The lower and middle Miocene sediments of the North Croatian Basin belong to the south-western margin of the Central Paratethys. The timing of the first marine transgression is of great importance for understanding the palaeogeography of the Paratethys. Based on micropalaeontological analyses (calcareous nannoplankton, planktonic and benthic foraminifera, ostracods and palynomorphs), we determined the local-to-regional palaeoecological characteristics of Miocene deposits from south-eastern Medvednica Mt., as well as identifying global-to-regional events. Marine index fossils point to calcareous nannofossil Zones NN4 and NN5 (equivalent to the Mediterranean MNN4 and MNN5) and planktonic foraminiferal Zones M5 and M6 (Mediterranean MMi4). The lowermost part of the investigated marls was generally deposited on a mid-outer shelf––which received an input of fine-grained clastic material––in a sedimentary basin that had a restricted connection with the Mediterranean during the Mi2 climatic event. In addition, an important nannofossil bioevent––the paracme of Sphenolithus heteromorphus––in the Mediterranean was recorded in the lower part of the section, close to the Karpatian/Badenian boundary (identified based on the Coccolithus pelagicus/Reticulofenestra minuta shift), which supports other evidence for a shift in global climate change. Warm-water ostracods (Paijenborchella iocosa) and benthic foraminifera (Glabratella and Pararotalia) in the middle part of the sequence indicate a warmer climate, an open connection with the Mediterranean Sea (and, indirectly, with the Indian Ocean), associated with the third-order TB 2.3 relative sea-level cycle of the early Badenian transgression. The upper part of the sequence (in the Plaz outcrop) contains coarsening–upwards cycles, consisting of silty and sandy sediments, sandstones and calcarenites, indicating a regional regressive phase close to the M5/M6 planktonic foraminifera zonal boundary (15.1 Ma). Infaunal benthic foraminifera species were replaced by shallow, warm-water benthic foraminifera (Elphidium, Biasterigerina, Ammonia, Amphistegina) and ostracods with ornamented shells, which occurred in tandem with shallow, warm-water R. minuta, more proximal dinocysts, coralline red algae, echinoids and bryozoans, all indicating the Middle Miocene Climatic Optimum (MMCO), with sedimentation taking place in a middle- to inner-shelf environment. A tuff layer is present at the top of the sequence; it contains planktonic foraminifera (Globigerina tarchanensis, G. subcretacea, Globigerinita uvula), suggesting a redeepening and influence of the TB 2.4 sea-level cycle. [ABSTRACT FROM AUTHOR]

The Yamama Formation is characterized by a wide geographic extension of southern Iraq. Microfacies analysis of this formation was studied in six wells distributed in six fields: Fayhaa, Sindbad, Siba, Zubair, Ratawi and West Qurna. This research aims to determine paleoenvironments by diagnosing biofacies and lithofacies. Miscellaneous marine fauna of foraminifera and calcareous algae, mainly green algae (dasycladacean.) and skeletal bioclasts from gastropods, pelecypods, bryozoans, sponge spicules, and echinoderms were found. Petrographic studies and well logs interpretations led to the identification of five main Microfacies ( Mudstone, Wackestone, Packestone, Grainestone and Rudstone and twelve submicrofacies (Foraminiferal-Lime mudstone submicrofacies, Argillaceous Lime Mudstone submicrofacies, Planktonic foraminiferal – Lime Wackestone submicrofacies, piculites/ Calcisphers – Lime Wackstone submicrofacies, Benthonic Foraminiferal -Lime wackestone/packestone submicrofacies, Algal (desycladecan) Lime wackestone submicrofacies, Algal-Lime packestone submicrofacies, Bioclastic/ Algal-Lime packestone submicrofacies, Algal/ Foraminiferal- Algal -Lime packstone submicrofacies, Peloidal poorly sorted grainstone with bioclasts submicrofacies, Intraclastic grainstone submicrofacies, Pesudo oolitic-Lithocodium aggregatum grainstone submicrofacies and finally Peloidal-intraclastic, and bioclastic grainstone submicrofacies). Microfacies are deposited in the lagoon, shoal, rudist biostrome and open marine gradient to middle and outer ramp environments. Vertical changes in microfacies with depth were reflected by lateral changes in marine depositional systems and the thickness of the formation. Shoal environments' microfacies are characterized by high thickness, while low thickness characterizes the open marine microfacies. The Yamama Formation was deposited on the low-angle homoclinic carbonate ramp, mainly in the inner and middle ramp, with outer ramp conditions in some parts of the formation. [ABSTRACT FROM AUTHOR]

Ocean warming and population irruptions of crown-of-thorns starfish (CoTS; Acanthaster cf. solaris) are two of the greatest threats to coral reefs. As such, there is significant interest in understanding how CoTS may be directly impacted by rising ocean temperatures. Settlement of planktonic larvae and subsequent metamorphosis is purported to be a major population bottleneck in marine invertebrates, yet it is unknown how ocean warming will impact these processes in CoTS. Herein, the effect of temperature (28 °C ambient, 30 °C, 32 °C, 34 °C) on the settlement success, metamorphic success, and post-settlement survival of this corallivore was explored. While larval settlement was robust to elevated temperature, with at least 94% of larvae settling after 48 h across all temperatures, it was observed that settlement success was lower on substrate that had been pre-treated ≥ 32 °C. Metamorphic success was also significantly constrained at temperatures ≥ 32 °C. At 32 °C and 34 °C metamorphic success was 16% and 63% lower than at ambient temperature, respectively. Significant adverse effects of warming on post-settlement survival were observed at even cooler temperatures, with 10% lower survival at 30 °C compared to at ambient temperature, and at 34 °C, survival was 34% lower. Substantial reductions in metamorphic success and early post-settlement survival at elevated temperatures, as well as negative impacts of warming on the settlement substrate and its capacity to induce settlement, may present a bottleneck for recruitment in a warmer ocean. [ABSTRACT FROM AUTHOR]

Epiphytes on Posidonia oceanica play a crucial role for determination of the ecological status of marine environment in time and space besides the seagrasses alone. The study was aimed to estimate the spatiotemporal ecological status linked to variation in biometry of an epiphytic micro-calcareous red alga, Hydrolithon boreale, found on leaves of the meadow with the exclusive environmental parameters along the entire Turkish coast of the Mediterranean Sea. Collection of Posidonia oceanica samples was conducted at 64 stations in winter (December 2018–January 2019) and 112 stations in summer (June–July 2019) by SCUBA (0.4 × 0.4 m of a quadrate frame) in the infralittoral zone along the entire Turkish Mediterranean coast surrounded by the siliciclastic Taurus Mountain Range which favor growth of epiphytic micro-calcareous red algae. Percent occurrence of the epiphyte changed seasonally—lower in winter (25%) than in summer (44%). The epiphyte which is an indicator and sensitive to undisturbed marine area grew up well to 5 mm in diameter, 0.35 mm in thickness of the crust size, and was populated up to 1006 ind/m2 in summer owing to the increased utilization of the carbonate by the epiphyte with the increased water temperature. The size was contrasted to the density (abundance and biomass) in space. The biometry was significantly dependent on the siliciclastic-carbonate deposition as inferred from SiO4–Si of the water in relation to the leaf area index (LAI) of P. oceanica. Therefore, this deposition induced specimens to grow in size, followed by the reduced density concerning the N-based nutrient of the water. Further major environmental parameters which negatively affected the biometry were pH and total suspended matter of the water, analogous to turbidity. Of the trace elements, Ni was negatively correlated with the biometry, whereas the LAI was however positively correlated with all the anthropogenic-sourced trace elements (V, Cu, Zn, As, Cd, and Pb) in the leaves. Of the bottom types, the calcite rock had a higher density than the other soft bottoms in contrast to the size of the epiphyte. Future studies could be based on the present study for determination of the ecological status regarding two dominant epiphytes on leaves of two seagrasses (H. boreale on P. oceanica and partly Pneophyllum fragile on Cymodocea nodosa) found in the different environments and substrates in space and time. [ABSTRACT FROM AUTHOR]

The Eocene Large Benthic Foraminiferal limestones of the Tethyan margins are proven hydrocarbon reservoirs. This study examines the controls on porosity and permeability development of the producing Middle Eocene Pirkoh Member of the Eastern Tethys using well core data from Well Zx-01 from the Punjab Platform area, Central Indus Basin, Pakistan. The standard petrographic and core analysis techniques were adopted to determine these controls. Petrographic studies revealed three microfacies comprising bioclastic packstone to floatstone, bioclastic wackestone and mud-wackestone microfacies. The allochems belong to benthic foraminifera including Nummulites sp., Discocyclinids sp.., Coralline algae, Assilina sp., Lockhartia sp., Coralline algae and Gastropods along with the other bioclastic debris. These allochems were found embedded in the micritic matrix with extensive cementation of calcite. The diagenetic events included cementation, compaction, dolomitization, fracture filling and neomorphism. Based on microfacies, the environment of deposition is interpreted to be a high-energy zone of the middle ramp in shallow marine environment. Subsurface core indicates that the porosity of the reservoir is low to high ranging between 6 to 27.47% and permeability is found low to fair ranging between 0.03 to 7.73 mD, found closely related to microfacies and diagenetic modifications. This study is a first attempt to document the reservoir facies of the non-reefal carbonates of the Pirkoh limestone that would help to exploit the reservoir's potential of the carbonate platforms developed in similar settings worldwide. [ABSTRACT FROM AUTHOR]

This study was realized to evaluate the efficacy of dietary supplementation of sodium bicarbonate plus magnesium oxide “MgO”, calcareous marine algae (AcidBuf) and essential oils (Actifor®Boost) on the animal performance and prevention of ruminal acidosis in goats moreover, evaluation the diagnostic accuracy of some biochemical parameters including blood pH, total antioxidant capacity (TAC), bicarbonate (HCO3 - ), partial pressure of carbon dioxide (pCO2), beta-hydroxybutyric acid (βHBA) and plasma L-lactate versus ruminal pH in diagnosis of ruminal acidosis. A total of 30 goats were divided into five equal groups (G1-5) according to the type of dietary treatment. G1 served as a control group and fed the concentrate diet only, G2 fed the concentrate diet supplemented with 10 g Na bicarbonate plus 4g MgO, G3 supplemented with 4g AcidBuf, G4 supplemented with 10 g Na bicarbonate plus 4g MgO plus 4g AcidBuf and G5 supplemented with 1g Actifor® boost/head/day for five days. Tachycardia, tachypnea and decreased ruminal motility were recorded in G1 only. The ruminal pH tended to return to its toward normal for G3 and G4 with a mean of (6.3±0.03 and 6.3±0.01, respectively) which significantly higher than those of G1 and G2 (6.19±0.01 and 6.17±0.02 respectively). A significant increase in plasma L-lactate and a significant decrease in blood pH, HCO3 -, pCO2, TAC, and βHBA were recorded in G1 when compared with other groups. Calcareous marine algae with or without adding other compounds found to be a promising rumen buffer agent, moreover TAC and plasma L-lactate showed better diagnostic performance versus rumen pH in the diagnosis of ruminal acidosis. [ABSTRACT FROM AUTHOR]

Introduction: Populations of the coral Orbicella annularis have shown low recruitment in the Caribbean. One of the demographic bottlenecks is the high mortality in the early stages of development. Detailed knowledge of the cycle and survival rates of these phases will allow us to assist in population recovery and reef restoration. Objective: To describe the embryogenesis and larval stages obtained by assisted fertilization and measure the settlement and survival rates of larvae on artificial substrates, before being outplanted to the reef. Methods: Six days after the full moon in September 2021, gamete bundles were collected from eight O. annularis colonies in Los Corales del Rosario and San Bernardo National Natural Park, Colombia and brought to the laboratory. Cross fertilization was carried out and embryonic and larval development were followed until larval settlement and survival was recorded until day 41. The larvae were kept in three tanks with filtered sea water with 126 tagged substrates, previously conditioned with crustose coralline algae. The substrates were then outplanted to the reef. Results: The onset of embryonic development occurred 1.11 hAF (hours after fertilization), when cells showed signs of the first cleavage, and lasted until 104.59 hAF when they began to metamorphose. Larvae settlement was observed on the sixth day AF. Twenty-one days after fertilization, zooxanthellae were found. Post-settlement larval survival was 27.5 %. Conclusions: In this first sexual propagation effort using O. annularis in Colombia, 1.4 % of competent larvae completed the entire development process. Although low survival rate, these results add to coral restoration efforts in the Caribbean in which species are assisted to increase the survival of corals in their early stages of development. [ABSTRACT FROM AUTHOR]

Non-geniculate coralline algal specimens were collected in 2013 during the XXVIII Italian Expedition to Antarctica in Adélie Cove (Terra Nova Bay; Ross Sea) and deposited in the collections of the Italian National Antarctic Museum (MNAIT, Section of Genoa). Specimens were characterized through a polyphasic approach combining DNA sequence data obtained for four genes (psbA, rbcL, 18S rDNA and cox1) with morpho-anatomical observations. DNA sequences revealed that all specimens belonged to the same species. Phylogenetic reconstructions unambiguously recovered this alga as a member of the order Hapalidiales, but without any close relationship to a genus of this order currently recognized on a molecular phylogenetic basis. Instead, it formed a well-supported lineage with specimens named 'Hapalidiales sp. ZH-Twist-2019', collected in New Zealand, for which no formal assignment at genus level has been proposed. Species delimitation methods (ABGD, PTP, GMYC) applied to the psbA dataset indicated that the Adélie Cove coralline alga is a distinct species from all other known hapalidialean species for which such sequences are available. A new genus, Thalassolithon gen. nov., is proposed for T. adeliense sp. nov. [ABSTRACT FROM AUTHOR]

With rubble predicted to increase on coral reefs worldwide, we review the physical, biological, and ecological dynamics of rubble beds, with a focus on how rubble generation, mobilization, binding, and coral recruitment is expected to change on future reefs. Major disturbances, including storms and coral bleaching, are predicted to increase in intensity and frequency, and—like localized impacts including blast fishing and ship groundings—generate large quantities of coral rubble. Reefs will have increasingly smaller recovery windows between successive disturbances, leading to persistence of unstable rubble beds on reefs. With more severe storms and increased bioerosion on future reefs, rubble mobilization thresholds will be met more often as smaller, less complex rubble pieces are generated. If rubble remains stable for adequate time, it can be bound by organisms including sponges and coralline algae, and eventually be cemented. However, increasing rubble mobilization frequencies will reduce the time available for binding, while changing ocean chemistry could reduce the efficacy of calcifying binders. Ultimately, increased rubble cover will negatively impact coral recruitment into rubble beds. Rubble mobilization abrades and smothers corals, and rubble beds typically experience altered environmental and ecological conditions to the coral frameworks that precede them. Several knowledge gaps exist in relation to improved rubble mobilization thresholds, binding rates and strengths, and coral survival in varying rubble bed types and hydrodynamic regimes. Addressing these knowledge gaps will improve our ability to predict the recovery trajectory of rubble beds and assess the need for stabilization interventions. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Featured Application: Aqueous extracts from selected red seaweeds collected from central Portugal present antioxidant and antimicrobial activity, and therefore may be considered potential natural resources in a biotechnological context. Throughout the ages, macroalgae have provided humankind with elements beneficial to human health, and often with bioactive abilities. Yet, while today we fully acknowledge such potential, especially that of the most widely known species, an even greater number of species remain unaknowledged. This holds particularly true for the highly diverse phylum Rhodophyta (red seaweeds) and, therefore, the present study aims to unveil the antioxidant and the antimicrobial potential of twelve red seaweed species collected in central Portugal. Results obtained from the antioxidant assays ABTS and TPC highlighted the high scavenging capacity of the coralline algae Corallina officinalis, Ellisolandia elongata and Amphiroa rigida, and the high phenolic content of Porphyra umbilicalis, whereas the antimicrobial analyses through MIC determination emphasized the activities of Sphaerococcus coronopifolius and Mesophyllum lichenoides against, respectively, Bacillus subtilis and Saccharomyces cerevisiae. This study raised awareness of the bioactive potential waiting to be discovered regarding less known Rhodophyta species, such as Amphiroa rigida and Mesophyllum lichenoides. Therefore, we believe this study provides extra steps in pinpointing Rhodophyta species with bioactive potential, encouraging further studies tailored toward a biotechnological perspective, and, ultimately, influencing current perspectives regarding the exploration of seaweeds. [ABSTRACT FROM AUTHOR]

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the mechanisms that allow the permanence of coral reefs and the constancy of their characteristics is necessary to alleviate the effects of chronic environmental changes. After a disturbance, healthy coral reefs display trajectories that allow regaining coral cover and the establishment of framework building corals. Through a comparative approach, in a patch reef partially affected by a ship grounding, we analyzed the successional trajectories in affected and unaffected sectors. Fleshy algae (which do not promote the recruitment of corals) dominated the reef surface irrespective of the impact of the ship grounding incident. Acropora species had near-zero contributions to community structure, whereas non-framework building corals like Porites sp. had a slightly higher recruitment. Cover of coral and calcareous crustose algae decreased over time, and neither the latter nor adult coral colonies had any effect on the occurrence probabilities of small corals. Sea urchin (Diadema antillarum) densities were generally low, and thus unlikely to contribute to reverting algal dominance. The successional trajectories of the community in the impacted and non-impacted sectors of the coral patch reef agree with the inhibition successional model, leading to the development of a degraded state dominated by fleshy algae. It is probable that the stability and resilience of this degraded state are high due to the ability of fleshy algae to monopolize space, along with low coral recovery potential. [ABSTRACT FROM AUTHOR]

The limestones of the Upper Jurassic to lowermost Cretaceous from the Hăghimaş Mountains were studied in two sections from the upper part of the Fagu Oltului valley, a tributary of the Olt River. The lower part of the succession is remarkable for the rich brachiopod fauna contained in a red limestone buildup, documented previously as a stromatactis mud-mound. The mound consists of bioclastic wackestones and packstones with numerous brachiopods, crinoids, and sponges. The mud-mound is covered with intraclastic grainstones and fine-grained limestones with pelagic bivalves. The following lithological units pass into shallow water limestone with nerineid gastropods, calcareous algae and foraminifera, in a regressive sequence. The micropaleontological association identified in the Upper Jurassic to lowermost Cretaceous limestones from Fagul Oltului includes calcareous algae, foraminifera, saccocomid crinoid fragments, annelid worm tubes, sponge fragments, rare calpionellids and microorganisms with an uncertain systematic position. The identified microfossils have a wide stratigraphic distribution. The most important stratigraphic landmarks are Trocholina conica (which does not extend younger than Kimmeridgian) and Calpionella alpina (which does not appear before the upper Tithonian). Based on the whole micropaleontological assemblage, the lower part of the succession (the skeletal mud-mound) can be ascribed to the Kimmeridgian - lower-middle Tithonian, and the upper part to the upper Tithonian - Berriasian. [ABSTRACT FROM AUTHOR]

The Big Seaweed Search invites people to survey UK seashores for 14 conspicuous seaweeds. The science investigates: (i) impact of sea temperature rise; (ii) spread of non‐native species; and (iii) impact of ocean acidification. Survey data submitted between June 2016 and May 2020 were analysed to evaluate and explore project directions in relation to citizen science project development.Of the 378 surveys submitted, 1,414 people participated, contributing 1,531 person hours. Surveys were undertaken around the UK, with the highest proportion (46.7%) in the south west and the lowest (3.7%) in the north east.After data verification, 1,007 (54%) records were accepted. Fucus serratus had the highest number of entries correctly identified (66%) and Undaria pinnatifida the lowest (5%), inferring that at least some seaweeds can be difficult to identify, although the overall misidentification rate was relatively low (c. 15%).Apart from Alaria esculenta, U. pinnatifida and Saccharina latissima, the large brown seaweeds were abundant on at least some shores. Non‐natives Sargassum muticum and Asparagopsis armata, were band‐forming but in low numbers. Coralline algae, whilst band‐forming on some shores, were most commonly patchy or sparse in abundance. Revisits, i.e. repeat surveys, at the same site with an interval of at least 1 year, are relatively low, with 18 sites revisited once and three sites revisited twice. Currently, data are insufficient to determine whether any changes in abundance could be detected.This study highlights areas where project developments can enhance data quality and quantity, e.g. better identification resources, training programmes for dedicated volunteers, and an annual focus week of activities. The project framed around climate change impacts, aims to raise awareness of the ecological importance of, and threats faced by, this understudied habitat and introduce conservation concepts including the need to protect common species showing signs of decline. [ABSTRACT FROM AUTHOR]

Background: Despite a global prevalence of photosynthetic organisms in the ocean's mesophotic zone (30–200+ m depth), the mechanisms that enable photosynthesis to proceed in this low light environment are poorly defined. Red coralline algae are the deepest known marine benthic macroalgae — here we investigated the light harvesting mechanism and mesophotic acclimatory response of the red coralline alga Lithothamnion glaciale. Results: Following initial absorption by phycourobilin and phycoerythrobilin in phycoerythrin, energy was transferred from the phycobilisome to photosystems I and II within 120 ps. This enabled delivery of 94% of excitations to reaction centres. Low light intensity, and to a lesser extent a mesophotic spectrum, caused significant acclimatory change in chromophores and biliproteins, including a 10% increase in phycoerythrin light harvesting capacity and a 20% reduction in chlorophyll-a concentration and photon requirements for photosystems I and II. The rate of energy transfer remained consistent across experimental treatments, indicating an acclimatory response that maintains energy transfer. Conclusions: Our results demonstrate that responsive light harvesting by phycobilisomes and photosystem functional acclimation are key to red algal success in the mesophotic zone. [ABSTRACT FROM AUTHOR]

In the area of Bad Deutsch-Altenburg (Hainburg Mountains, Lower Austria) a Middle Miocene transgression over Mesozoic basement was explored in the course of the Danube power plant project "Hainburg". The Mesozoic basement forms a narrow ridge dipping to the northeast towards the Vienna Basin, covered by various Miocene sediments. The ridge represents a specific paleotopography that required a detailed study with 78 shallow, fully cored drill holes in an area of c. 0.5 km2. Ten drillings were selected for this study based on sedimentary composition and position relative to the Mesozoic ridge. These 10 cores, ranging in drilling depth from 26.5 to 96.4 m, were studied in respect to sedimentology, corallinacean algae, calcareous nannoplankton, foraminifers and ostracodes to reconstruct sediment distribution and paleoenvironment. Sediment distribution clearly shows that the Mesozoic ridge formed a physical barrier with siliciclastics dominating in the SW of the ridge and carbonate sediments prevailing in the NE. Based on biostratigraphy (calcareous nannoplankton, foraminifera, ostracodes, dinoflagellates) the majority of the sediments can be dated to the late Badenian (early Serravallian) only in some drillholes lower Sarmatian (upper Serravallian) sediments were detected. In terms of sequence stratigraphy, the Badenian sediments represent the transgressive and highstand systems tract of 3rd order sequence TB 2.5 (bound by the lowstands Ser 2 and Ser 3), the lower Sarmatian sediments can be correlated to sequence TB 2.6. Carbonate sediments show a wide spectrum of 13 facies which are mostly dominated by coralline algae. According to the relative positions of the drill holes a water depth between 0 and about 50 m can be reconstructed what is supported by the occurrence of the benthic biota. This biota indicates that the sedimentary succession started from the very beginning under full marine conditions. Except of basal conglomerates/breccias water energy conditions were low and turbidity high. Close to the Sarmatian boundary a reduction in salinity and depth may have occurred which is also observed in the Sarmatian sediments. Carbonate sediments and, in particular, larger benthic foraminifers indicate tropical to warm-temperate conditions for the late Badenian of the studied sections. The siliciclastic sediments NW of the Mesozoic ridge reflect riverine input indicated by the occurrence of freshwater ostracodes and characean oogonias. Calcareous nannoplankton and dinoflagellates show a high share of reworking from Upper Cretaceaous and Paleogene sediments. [ABSTRACT FROM AUTHOR]

Euendolithic, or true‐boring, cyanobacteria actively erode carbonate‐containing substrata in a wide range of environments and pose significant risks to calcareous marine fauna. Their boring activities cause structural damage and increase susceptibility to disease and are projected to only intensify with global climate change. Most research has, however, focused on tropical coral systems, and limited information exists on the global distribution, diversity, and substratum specificity of euendoliths. This metastudy aimed to collate existing 16S rRNA gene surveys along with novel data from the south coast of South Africa to investigate the global distribution and genetic diversity of endoliths to identify a "core endolithic cyanobacterial microbiome" and assess global diversification of euendolithic cyanobacteria. The cyanobacterial families Phormidesmiaceae, Nodosilineaceae, Nostocaceae, and Xenococcaceae were the most prevalent, found in >92% of categories surveyed. All four known euendolith clusters were detected in both intertidal and subtidal habitats, in the North Atlantic, Mediterranean, and South Pacific oceans, across temperate latitudes, and within rock, travertine tiles, coral, shell, and coralline algae substrata. Analysis of the genetic variation within clusters revealed many organisms to be unique to substratum type and location, suggesting high diversity and niche specificity. Euendoliths are known to have important effects on their hosts. This is particularly important when hosts are globally significant ecological engineers or habitat‐forming species. The findings of this study indicate high ubiquity and diversity of euendolithic cyanobacteria, suggesting high adaptability, which may lead to increased community and ecosystem‐level effects with changing climatic conditions favoring the biochemical mechanisms of cyanobacterial bioerosion. [ABSTRACT FROM AUTHOR]

The mesophotic zone is a relatively poorly studied area of the Mediterranean Sea, drawing great interest by the scientific community in the last years. This zone represents a connection between the shallow water and the deep-sea communities, in which photophilic framework builders (e.g. coralline red algae) are gradually replaced by heterotrophic ones, such as ahermatypic corals and the bivalve Neopycnodonte cochlear. In this habitat the framework-forming organisms produce a hard substrate with a high topographic complexity, hosting a great biodiversity of secondary structuring taxa like bryozoans. During a survey on coralligenous banks in the mesophotic zone in c. 60 m depth off Gallipoli (southern Apulia), epibiotic aggregations of N. cochlear were found on the fans of the hexacoral Savalia savaglia. In the present paper the diversity of cheilostomatid bryozoans hosted by these bivalve aggregations is described and compared with published information on similar nearby habitats. A total of 48 taxa were found, six of which are newly described: Crassimarginatella matildae sp. nov., Micropora biopesiula sp. nov., Haplopoma celeste sp. nov., Schizomavella (Schizomavella) cerranoi sp. nov., Schizomavella (Calvetomavella) biancae sp. nov., and Schizoporella adelaide sp. nov. The species richness known from the southern Apulian shelf at this depth (47 species) is hereby raised to 83 cheilostomatid bryozoans. Moreover, only 12 species are shared with the other localities studied previously, while 36 are restricted to Gallipoli, supporting the hypothesis of a high rate of exclusivity among Apulian sites in terms of species composition. The differences in faunal composition, and particularly the presence of several new species discovered at Gallipoli, show once more that our knowledge of the bryozoan fauna in certain Mediterranean habitats is still incomplete and warrants further studies. [ABSTRACT FROM AUTHOR]

The once abundant black abalone, Haliotis cracherodii , is a large, long-lived grazing marine mollusk that inhabits the rocky intertidal along the coast of California. The species has experienced dramatic declines since the mid-1980s largely due to the fatal bacterial disease called withering syndrome, leading to the collapse of an economically important fishery and to its inclusion into the IUCN listing as a critically endangered species. In some places impacted by the disease, populations of black abalone have declined by more than 90%, prompting population crashes associated with very little recruitment of new individuals and changes to intertidal communities. Habitats that were dominated by crustose coralline algae and bare rock have become dominated instead by fleshy algae and sessile invertebrates. Here, we present the first high-quality black abalone reference genome, assembled with PacBio HiFi long-reads and assembled with Dovetail Omni-C data to generate a scaffold-level assembly. The black abalone reference genome will be an essential resource in understanding the evolutionary history of this species as well as for exploring its current levels of genetic diversity and establishing future management and restoration plans. [ABSTRACT FROM AUTHOR]

Widespread mortality of reef‐building coral substantially reduces the capacity for reef growth and makes available extensive bare substrate areas that in the absence of coral recovery will be eroded by a variety of external and internal bioeroders. Here, we analyze rates of external erosion on six different types of carbonate substrates under in situ conditions over a 2‐yr period. We measure vertical changes in the surface elevation of four species of recently dead corals afflicted by the stony coral tissue loss disease outbreak, and other two common types of calcareous substrates, long‐dead Acropora palmata fronds and bare calcareous hardground, as a reference for "bare" carbonate substrates that occur widely in Caribbean reefs. The surface of the recently dead colonies experienced significant erosion after 2 yr of exposure, but at different rates depending on the species. Dead skeletons of Orbicella faveolata experienced the greatest rates of erosion after 2 yr at −9.9 mm (±3.2 mm); Dendrogyra cylindrus eroded −3.6 mm (±2.8 mm), Pseudodiploria strigosa −3.3 mm (±3.7 mm), and Siderastrea siderea −1.2 mm (±0.9 mm), while long‐dead substrates remained unchanged. There was significant erosion in the presence of parrotfish grazing scars and of short algal turf mats, while crustose coralline algae cover and sand‐and‐high turf mats were not associated with significant changes in elevation, arguably indicating a protective effect. This study provides new insights into how and at what rates external carbonate erosion is shaping contemporary reefs at fine spatial and temporal scales. [ABSTRACT FROM AUTHOR]

This study was designed to evaluate the therapeutic efficacy of calcareous marine algae (AcidBuf), sodium bicarbonate and magnesium oxide mixture for the treatment of lactic acidosis in goats. In this study, a total of 57 goats were diagnosed with lactic acidosis and subjected to a therapeutic trial of 4g AcidBuf plus 10 g Na-bicarbonate plus 4g magnesium oxide/head once daily for three days. Before and 72 h after treatment, a clinical examination and blood and ruminal fluid samples were taken. Within 72 h of the therapeutic trial, the clinical signs of lactic acidosis gradually improved and resolved, and the rumen pH increased significantly from 5.16±0.460 to 6.54±0.246. Rumen contraction, rumen fluid physical properties (color, odor and consistency), protozoal motility and ruminal microflora differed significantly toward the normal of healthy goats. Regarding haemgasometry and hematobiochemical parameters, a highly significant decrease in Hb, HCT%, TLC, ALT, AST, creatinine and lactate values and a highly significant increase in blood pH, HCO3-, pCO2, serum urea, total antioxidant capacity (TAC) and β-hydroxybutyric acid (βHBA) were recorded compared to the pre-treatment values. The current study concluded that calcareous marine algae, sodium bicarbonate and magnesium oxide mixture is very helpful in minimizing the severity of ruminal lactic acidosis in goats and could be used as the therapy of choice. [ABSTRACT FROM AUTHOR]

Halysites catenularius Linnaeus is reported from the Silurian strata that form outcrop in the Rancho Placeritos (San Antonio dolostone) located west of Hermosillo, capital of Sonora, Mexico. In this region, a sequence of Paleozoic sedimentary rocks of ages ranging from the Upper Ordovician to the Lower Mississippian is exposed. Halysites catenularius is identified as a reef buildings tabulate coral associated with calcareous algae, sponges, rugose corals, other tabulate corals, bryozoans, brachiopods and, pelmatozoans. The biota developed in shallow tropical seas from southwest of the North American craton, which was located near the paleoecuatorial line. The Silurian platform deposits of Sonora correlate with localities in the southern United States of America and northern Mexico (Sonora and Chihuahua) that were part of the margin of the North American craton. The description of Halysites catenularius contributes to the knowledge of the biota of the lower Paleozoic of Mexico, particularly the Silurian. • Halysites catenularius is reported from the Silurian, Sonora, Mexico. • Halysites catenularius is a tabulated reef coral associated with diverse Early Paleozoic marine taxa. • The biota developed in shallow tropical seas from southwest of the North American craton. [ABSTRACT FROM AUTHOR]

• The δ11B of coralline algae skeleton offer a means to reconstruct coastal pH. • 2D maps of trace element content and δ11B were collected on Boreolithothamniom cf. soriferum. • These images were aligned using correlated multimodal imaging techniques. • We reconstruct an ocean acidification trend of −0.018 pH units yr-1 in Loch Sween. • Loch Sween switched from being a substantial sink of CO 2 to a source in ∼2008. Ocean Acidification (OA) arises from the increase in atmospheric carbon dioxide concentration following the industrial revolution. The ecological and socio-economic consequences of OA were first identified around 10–15 years ago but remain poorly understood. This is particularly true in coastal regions where local processes can have dramatic consequences on pH trends through time, obscuring and compounding the long-term effects from rising atmospheric CO 2. Here we explore the possibility of generating long records of coastal ocean pH using the skeletons of widely distributed coralline algae (CA). The skeletons of these slow growing (<1 mm/year) taxa often contain micron-scale heterogeneities, making sampling for high-resolution climate reconstructions using bulk sampling techniques difficult. Here we use laser ablation coupled to inductively coupled plasma mass spectrometers to generate high-resolution 2D images of the element/calcium ratios and boron isotope composition (δ11B) of a sample of Boreolithothamniom cf. soriferum from Loch Sween in Scotland, UK where we have been monitoring temperature since 2004 and pH during 2014. By carefully correlating the geochemical images with a scanning electron microscopy image we can segment them to remove the marginal portions of the skeleton, isolating the central growth axis to generate an age model and growth rate. The δ11B-pH is significantly elevated above the seawater pH in Loch Sween (8.4 to 8.9 vs. 7.9 to 8.1) consistent with other CA that show internal pH elevation. On a seasonal scale, internal pH is negatively correlated with temperature and also exhibits a long-term decline. By removing this temperature effect, internal pH can be correlated to seawater pH during the 2014 monitoring period allowing us to reconstruct a seawater acidification trend from 2004 to 2018 of -0.018 pH units per year, 10x higher than open ocean trends but consistent with contemporaneous monitoring efforts of UK coastal waters. Reconstructed aqueous CO 2 suggests that prior to ∼2008 Loch Sween was a sink of CO 2 but after this date, particularly during the early summer, it was a substantial CO 2 source. Comparison of reconstructed aqueous CO 2 with a record of calcification rate of our sample of Boreolithothamniom cf. soriferum suggests this acidification and associated rise in local seawater pCO 2 may have freed this sample from carbon limitation leading to a recent increase in calcification. [ABSTRACT FROM AUTHOR]

Large marine protected areas (MPAs) will likely multiply worldwide to address accelerating biodiversity loss. Coral reefs are an especially at-risk ecosystem, but our understanding of whether and how large MPAs will benefit reef recovery from disturbances remains limited. Here, we evaluate how fishes influence coral reef recovery and if there are cascading trophic interactions in the fish community that influence recovery. We combine i) a meta-analysis of previous research evaluating how fishes affect coral reef succession, ii) field surveys of sharks, fishes, and benthic cover, and iii) a 2.5-year coral recruitment experiment of caged, uncaged, and partially caged settlement tiles in a remote and large MPA, in the Chagos Archipelago. In both our meta-analysis and field experiment, we found variable effects of fishes on coral recruitment with no overall significant effect, but strong control by fishes on the developing benthic communities, where fishes promote crustose coralline algae and reduce macroalgae. Within the Chagos, fishes had a positive effect on corals in protected microhabitats but a negative effect on exposed surfaces, leading to an overall neutral effect from fishes. Although mesopredatory fish abundance was negatively correlated with shark abundance, these top-down effects did not cascade down the food web through herbivores and corallivores to coral recruitment and benthic succession. Thus, our results suggest that within this large MPA, herbivores are important in limiting algae during recovery and there are compensatory responses to the loss of benthic feeding fishes and sharks, with implications for coral reef persistence in the face of global change. [ABSTRACT FROM AUTHOR]

[Display omitted] • Global Lithophylloideae revealed an unexpected cryptic diversity. • Genetic diversity of Lithophylloideae showing geographical isolation patterns. • TTE barrier playing a role in differentiation of Lithophylloideae. • Controversial cryptic genus Titanoderma , should be separated from Lithophyllum. • Multiscale analysis supported Lithophyllum a regional rather than a global taxon. Cryptic diversity abounds in many biological species, posing challenges to our understanding of biological diversity, conservation and management. Taking the common coralline algae, the subfamily Lithophylloideae as an illustration, this study delved into the implications of cryptic diversity through global-level phylogenetic and geographical analysis based upon Lithophylloideae molecular data worldwide, as well as a multi-locus time-calibrated phylogeny to elucidate their possible evolutionary process. The multiscale analysis revealed the polyphyly in current concept of the genus Lithophyllum. Geographic isolation resulting from the Tethys terminal event (TTE) has led to two distinct distribution regions for this so-called cosmopolitan genus: one regionally distributed along European coasts/Mediterranean that should include the taxonomical Lithophyllum ; others widely distributed, particularly among pan-tropic waters, suggesting at least five groups to be rediscovered within the subfamily Lithophylloideae. Meanwhile, the cryptic genus Titanoderma , lacking morphological identification features with Lithophyllum , exhibited differences in distribution and evolutionary patterns consistent with their ecological habits, thus supporting their separation. This study provided useful hints for cryptic diversity, which advocated an integrative thinking to investigating global cryptic diversity and exploring the broad linkages between phylogenetic relationships and evolutionary origin, biogeography, morphological and ecological traits to achieve a more comprehensive understanding of biodiversity. [ABSTRACT FROM AUTHOR]

1. There is an increased need for habitat models of coral reefs to aid active interventions and restoration efforts rather than just map reef habitat extent. Habitat models provide the base layer for connectivity estimates among coral populations, to identify sites with likely increased coral survival and reduced project costs. We present a spatial modelling method to better identify coral reef habitats for coral recruitment and survival. 2. We demonstrate these methods for an offshore reef cluster in North Western Australia that has lost live coral as a result of successive bleaching events. This isolated set of reefs has high levels of coral self-recruitment, which makes them a good test for methods that underpin spatial optimisation of coral restoration locations. 3. Our method uses satellite derived, multiscale depth and rugosity metrics to model habitat classes, and applies randomForest cross-validated variable importance to optimally select a subset of these metrics that best model each habitat. Our approach produces improved models compared to existing object-based segmentation methods by overcoming a bias toward larger single-scale homogenous reef features. 4. Our method produces robust models of target reef recruitment habitats with encrusting and juvenile corals with crustose coralline algae but also models of habitats that are not desirable as recruitment habitat such as turf algae, sand, and rubble. All these models meet or exceed accepted accuracy benchmarks (accuracy and AUC values >0.8 on blind hold-out data used for validation and kappa values >0.6). 5. These models are specifically designed to support coral restoration including prime coral recruitment habitats with a mixture of crustose coralline encrusting and juvenile corals. 6. We demonstrate how spatially explicit model validation can identify locations within the target area where models are most and least supported, providing valuable additional insights into planning targeted survey efforts to reduce spatial uncertainty, and targeted restoration interventions that have the highest probability of success. 7. Our method has broad utility due to the widely and freely available Sentinel 2 remote sensing data cover for most reef systems globally, and field data collected with a simple drop camera system and classified with via the ReefCloud open access image classification system. It also has potential for adaption and refinement using other finer scale commercial remote sensing satellite data that can be used to drive digital elevation models including Planet Labs Skysat and Worldview 3 data. • Remote sensing model identifies coral recruitment habitats for reef conservation. • Uses machine learning to map habitats using depth, rugosity, and band values. • Maps desirable (e.g., CCA, juvenile corals) and undesirable (e.g., sand) habitats. • Spatial validation accuracy guides field surveys and restoration sites. • Applicable globally using open Sentinel 2 data and simple camera setups. [ABSTRACT FROM AUTHOR]

Non-geniculate coralline algae (NGCA), Corallinophycidae - Rhodophyta, are characterized by prominent calcified vegetative thalli. They exhibit broad phenotypic plasticity, and morphoanatomical convergences due to the simplicity of their thalli. These characteristics makes their taxonomy one of the most complex within Rhodophyta. The nomenclature and taxonomy of the NGCA have been controversial and subject to intensive debate even after the advent of molecular techniques. Until the mid-19th century, all calcareous organisms were classified as animals. Still, the algal nature of the NCG became evident with advances in microscopy and anatomical techniques, based on anatomical and reproductive attributes rather than thallus form. This review provides a comprehensive historical overview of significant milestones in the NGCA taxonomy. From 1890–1910, Mikael Foslie described about 400 species of NGCA. Since then, and after the advances in microscopy in the mid-20th century, the taxonomy of this algal group, traditionally based on morphological aspects, has been replaced by anatomical features. Paraffin and historesin-embedded microtomy and sectioning techniques allowed access to taxonomically relevant microanatomical features, while scanning and transmission electron microscopy allowed access to ultrastructural aspects. The subsequent use of molecular markers promoted a real revolution, by disclosing phylogenetic relationships between taxa. As perspectives, high-resolution confocal microscopy images can provide information on intricate three-dimensional structures and reveal unexplored aspects of NGCA morphoanatomy. Meanwhile, whole-genome sequencing and comparative genomics can uncover the genetic underpinnings of taxonomic variations, helping to elucidate the mechanisms driving the diversification of NGCA species. We envision that the recent expansion of sampling expeditions to previously unknown geographic and bathymetric regions along with the convergence of advanced morphoanatomy imaging, genomics, and bioinformatics, would clarify the complex tapestry of NGCA taxonomy and safeguard (e.g., through conservation action-plans) these ecologically important marine organisms. • Rhodolith are marine nodule with species of non-geniculate coralline algae (NGCA). • Historically, the identification of NGCA has been and still is a very complex task. • We provide a historical review about the controversial development of taxonomy of NGCA. • NGCA taxonomy needs to use imaging, genomics, bioinformatics and their distribution. [ABSTRACT FROM AUTHOR]

The last interglacial (MIS 5) transgressive-regressive deposits of the Capo Colonna marine terrace provide a good fossil example of a Central Mediterranean infra/circa-littoral setting, characterized by both calcareous coralline algae-dominated low-relief bioherms and biostromes, equivalent respectively to the modern coralligenous and mäerl habitats. The skeletal primary framework of the bioherms, consists of laminar to massive encrusting coralline red algae acting as main bioconstructors, with minor bryozoans, encrusting foraminifera, and serpulids as secondary frame-builders. Whereas, the autochthonous mäerl tabular beds are mainly composed of free-branched coralline red algae rudstone. A variable amount of sandy bioclastic sediment is laterally interbedded with the bioconstructions and tends to be entrapped in their cavities and pockets. All sedimentary sub-facies of the bioconstructions and associated sediment are rich in autochthonous syn-sedimentary microbial-mediated micrite, forming aphanitic, peloidal, clotted peloidal, and filamentous fabrics. Microbial micrite can also trap and bind a variable amount of grains, or be a secondary component of the sandy sediment as micritic rims surrounding the clasts. All these early-lithified micrites show the typical nanostructure of the primary microbial-mediated carbonates, rather than a detrital mud particles accumulation, as they consist of nanospheres coalescing into subhedral microcrystals that replace both microbial cells (present with several morphological types) and extracellular substances. This in turn implies the original widespread presence of benthic lithifying microbial biofilms which colonized both the cavities of the skeletal framework of the bioconstructions, and the intergranular space of the associated sediment. These microbial communities, thanks to the metabolic processes of the microorganisms that induced the carbonate precipitation, significantly contributed to the early cementation of all the studied deposits. • Capo Colonna MIS 5 bioconstructions are typified by calcareous red algae, metazoans, and autochthonous microbial mediated micrites. • Lithifying microbial biofilms are found on the seabed, within bioconstruction skeletal framework and associated sediment. • The early hardening of microbial micritefavored the bioconstructions strength and growth and the sediment stabilization. • All micritic fabrics derive from the mineralization of organic substrates by submicron calcite nanospheres. • Microbial communities were dominated by heterotrophs taking advantage of organic matter deriving from dead organisms. [ABSTRACT FROM AUTHOR]

Coastal benthic communities in temperate regions have been influenced by climate change, including increasing sea-surface temperature. Nevertheless, scleractinian coral Alveopora japonica Eguchi, 1968, is thriving in shallow subtidal hard bottoms around Jeju Island, off the southern coast of Korea. The presence of this corals has negatively impacted subtidal kelp populations in Jeju Island. However, there is no study to document how the presence or absence of this coral relates to other benthic communities. This study investigated the benthos in three shallow subtidal sites (Shinheung (SH), Bukchon (BC), and Seongsan (SS)) in northern Jeju using underwater photography. Macro-benthic organisms appearing on a 1 × 20 m line transect installed at depths of 5, 10, and 15 m at each site were analyzed. Results showed that of the three sites investigated, A. japonica colonies were most abundant at BC, accounting for 45.9% and 72.8% of the total transect area at 10 m and 15 m, respectively. At SS, A. japonica occupied 15.3% of the total area at 15 m and less than 1% at 5 m and 10 m. The same at SH accounted for 10% of the total area at 5 m, and less than 1% at 10 m and 15 m. Dead and bleached colonies accounted for 1.2–11.5% and 1.8–5.7%, respectively, at 5, 10, and 15 m at three sites. At SS, canopy-forming brown algae Ecklonia cava and Sargassum spp. accounted for 20.2 and 24.3% of the total transect area, respectively, at 5 m depth. In contrast, the percent cover of E. cava and Sargassum spp. at SH and BC ranged from 0.1 to 1.8%, respectively. Moreover, non-geniculate coralline algae dominated the subtidal substrate at SH, ranging between 60.2 and 69% at 15 and 10 m. The low cover of A. japonica in SS (at 5 m) coincided with a high percent cover of canopy-forming brown algae. However, canopy-forming brown algae were rare at all depths at SH and BC and were dominated instead by coralline algae and the scleractinian corals. This study, by utilizing a non-destructive method, provides a baseline qualitative and quantitative information for understanding the site and depth-dependent distribution of A. japonica and algal populations, which is important to understand climate change related changes in benthic communities in Jeju and elsewhere. [ABSTRACT FROM AUTHOR]

• South African Chamberlainium , an exemplar for the study of coralline algal systematics • Description of Chamberlainium tenue, a new cryptic/pseudocryptic species of coralline algae • Integrated taxonomic approach using DNA sequences from historical and field specimens • Keys to all Chamberlainium species in South Africa • Biogeographic considerations Based on plastid encoded DNA sequences from psb A and rbc L markers, a new non-geniculate coralline algal species, Chamberlainium tenue , is described from South Africa that was previously passing under the misapplied name, Spongites yendoi. DNA sequences, supported by the morpho-anatomical character of tetrasporangial conceptacle roof development, placed C. tenue in Chamberlainium , subfamily Chamberlainoideae. Instead of one species, Spongites yendoi , widely distributed across the entire coastline of South Africa, seven molecularly distinct species were present under that name and all belong in Chamberlainium. Three occur in the cooler water Benguela Marine Province, C. capense, C. glebosum , and C. occidentale, the last extending into the Benguela-Agulhas Transition Zone; three occur in the warmer water Agulhas Marine Province, C. tenue, C. cochleare and C. natalense , with the latter two extending into the Benguela-Agulhas Transition Zone; two occur only in the Benguela-Agulhas Transition Zone, C. agulhense and the historically recognized, C. impar. Both the rbc L and psb A phylograms indicate that ancestral taxa gave rise to species found in both warmer and cooler water habitats. Keys to species of South African Chamberlainium are provided for use in both the field and the laboratory. The methodology used to study these Chamberlainium species, that included: 1) DNA sequencing of type specimens to correctly apply names; 2) DNA sequencing of numerous field-collected specimens; and 3) morpho-anatomical observations on these same DNA sequenced specimens, can be an exemplar for resolving the systematics and biogeography of the many unresolved and unstudied species of South African coralline algae. [ABSTRACT FROM AUTHOR]

The non-geniculate coralline alga Lithophyllum okamurae includes two infraspecific taxa, L. okamurae f. trincomaliense and L. okamurae f. validum (currently regarded as an independent species, L. validum), which were described from Sri Lanka solely on the basis of morpho-anatomical features. We investigated the taxonomic status of these two taxa using comparable DNA sequence data (psbA, rbcL, partial LSU rDNA, and COI) and complementary morpho-anatomical features from type material and from specimens whose sequences were linked to type material. Our molecular analyses showed that both taxa are well-defined and are adequately treated as independent species, and that they are distantly related to L. okamurae. Morpho-anatomically, L. trincomaliense and L. validum were nearly indistinguishable, both possessing well-developed fruticose thalli and lacking trichocytes, the only distinguishable features being the shapes of the branch tips (round for L. trincomaliense vs flattened for L. validum). The present study confirmed two Lithophyllum species from the Indian Ocean. Seven infraspecific taxa have been ascribed to L. okamurae; one was shown to be conspecific and four are now confirmed to be distinct species, including the two infraspecific taxa investigated in the current study. [ABSTRACT FROM AUTHOR]

Calcium carbonate precipitation associated with biotic activity is first recorded in Archaean rocks. The oldest putative fossils related to hydrothermal vents have been dated at ~3.77 Ga (possibly 4.29 Ga). Stromatolites, the oldest dated at 3.70 Ga, have since occurred through Earth history, despite dramatic changes in physical and chemical conditions in aquatic environments. A key question is: what advantages do photosynthesizing aquatic prokaryotes and algae gain by precipitating carbonates? We propose the Phosphate Extraction Mechanism (PEM) to explain the benefits of biomineralization in warm, oligotrophic, alkaline, euphotic environments. Carbonate precipitation enhances access to otherwise limited carbon dioxide and phosphate in such environments. This mechanism also provides an explanation for prolific production of carbonates during times of elevated atmospheric carbon dioxide at intervals in the Phanerozoic. [ABSTRACT FROM AUTHOR]

Marine forests are shrinking globally due to several anthropogenic impacts including climate change. Forest-forming macroalgae, such as Cystoseiras.l. species, can be particularly sensitive to environmental conditions (e.g. temperature increase, pollution or sedimentation), especially during early life stages. However, not much is known about their response to the interactive effects of ocean warming (OW) and acidification (OA). These drivers can also affect the performance and survival of crustose coralline algae, which are associated understory species likely playing a role in the recruitment of later successional species such as forest-forming macroalgae. We tested the interactive effects of elevated temperature, low pH and species facilitation on the recruitment of Cystoseira compressa. We demonstrate that the interactive effects of OW and OA negatively affect the recruitment of C. compressa and its associated coralline algae Neogoniolithon brassica-florida. The density of recruits was lower under the combinations OW and OA, while the size was negatively affected by the temperature increase but positively affected by the low pH. The results from this study show that the interactive effects of climate change and the presence of crustose coralline algae can have a negative impact on the recruitment of Cystoseira s.l. species. While new restoration techniques recently opened the door to marine forest restoration, our results show that the interactions of multiple drivers and species interactions have to be considered to achieve long-term population sustainability. [ABSTRACT FROM AUTHOR]

Background: Crustose coralline algae (CCA) are calcifying red macroalgae that play important ecological roles including stabilisation of reef frameworks and provision of settlement cues for a range of marine invertebrates. Previous research into the responses of CCA to ocean warming (OW) and ocean acidification (OA) have found magnitude of effect to be species-specific. Response to OW and OA could be linked to divergent underlying molecular processes across species. Results: Here we show Sporolithon durum, a species that exhibits low sensitivity to climate stressors, had little change in metabolic performance and did not significantly alter the expression of any genes when exposed to temperature and pH perturbations. In contrast, Porolithon onkodes, a major coral reef builder, reduced photosynthetic rates and had a labile transcriptomic response with over 400 significantly differentially expressed genes, with differential regulation of genes relating to physiological processes such as carbon acquisition and metabolism. The differential gene expression detected in P. onkodes implicates possible key metabolic pathways, including the pentose phosphate pathway, in the stress response of this species. Conclusions: We suggest S. durum is more resistant to OW and OA than P. onkodes, which demonstrated a high sensitivity to climate stressors and may have limited ability for acclimatisation. Understanding changes in gene expression in relation to physiological processes of CCA could help us understand and predict how different species will respond to, and persist in, future ocean conditions predicted for 2100. [ABSTRACT FROM AUTHOR]

Madagascar is a major hotspot of biodiversity in the Western Indian Ocean, but, as in many other regions, coral reefs surrounding the island confront large-scale disturbances and human-induced local stressors. Conservation actions have been implemented with encouraging results for fisheries, though their benefit on coral assemblages has never been rigorously addressed. In this context, we analyzed the multiscale spatial variation of the composition, generic richness, abundance, life history strategies, and cover of coral assemblages among 18 stations placed at three regions around the island. The potential influences of marine protected areas (MPAs), algal cover, substrate rugosity, herbivorous fish biomass, and geographic location were also analyzed. Our results highlight the marked spatial variability, with variation at either or both regional and local scales for all coral descriptors. The northeast coastal region of Masoala was characterized by the high abundance of coral colonies, most notably of the competitive Acropora and Pocillopora genera and stress-tolerant taxa at several stations. The southwest station of Salary Nord was distinguished by lower abundances, with depauperate populations of competitive taxa. On the northwest coast, Nosy-Be was characterized by higher diversity and abundance as well as by high coral cover (~42–70%) recorded at unfished stations. Results clearly underline the positive effects of MPAs on all but one of the coral descriptors, particularly at Nosy-Be where the highest contrast between fished and unfished stations was observed. Biomass of herbivorous fishes, crustose coralline algae cover, and substrate rugosity were also positively related to several coral descriptors. The occurrence of reefs with high diversity, abundance, and cover of corals, including the competitive Acropora, is a major finding of this study. Our results strongly support the implementation of locally managed marine areas with strong involvement by primary users, particularly to assist in management in countries with reduced logistic and human resources such as Madagascar. [ABSTRACT FROM AUTHOR]

Calcareous red algae are foundation species and ecosystem engineers with a global distribution. The principles governing their calcification pathways are still debated and the morphological characters are frequently unreliable for species segregation, as shown by molecular genetics. The recent description of the new species Lithophyllum pseudoracemus, previously undetected and morphologically confused with Lithophyllum racemus, offered a challenging opportunity to test the effectiveness of microanatomy and ultrastructural calcification traits as tools for the identification of these two species, for integrative taxonomy. High resolution SEM images of molecularly identified samples showed that the different size of the perithallial cells and the features of the asexual conceptacle chambers may contribute to the separation of the two species. The two species share the same crystallite morphology in the primary and secondary cell-wall calcification, as previously described in other species belonging to the same clade. However, the perithallial secondary calcification was significantly thicker in L. racemus than in L. pseudoracemus. We described a granular calcified layer in the innermost part of the cell wall, as a putative precursor phase in the biomineralization and formation of the secondary calcification. The hypothesis of different pathways for the formation of the primary and secondary calcification is supported by the observed cell elongation associated with thicker and higher Mg/Ca primary calcification, the inverse correlation of primary and secondary calcification thickness, and the absence of primary calcification in the newly formed wall cutting off an epithallial cell from the meristem. [ABSTRACT FROM AUTHOR]

Niche differentiation is a key stabilizing mechanism in the maintenance of biodiversity and species coexistence. Recent work shows that trophic niche partitioning between parrotfishes (Labridae: Scarini) is more extensive than previously described. One Indo-Pacific species, Scarus spinus, appears highly specialized, scraping crustose coralline algae (CCA) with powerful oral jaws. CCA are of low nutritional value, suggesting that the dietary targets of this parrotfish are protein-rich microphotoautotrophs associated with CCA, particularly filamentous cyanobacteria. We collected feeding substrata samples at mid-shelf and outer-shelf sites near Lizard Island, Great Barrier Reef, Australia, in 2018 and 2019, respectively. Scarus spinus were followed on snorkel. When biting was observed, bite substrata were photographed and then a 22-mm-diameter core extracted around the bite site. Density of biota including filamentous cyanobacteria and diatoms was quantified microscopically on photographs of the bite cores (up to 630 × magnification). The taxonomy of cyanobacteria and CCA was refined using next-generation sequencing of 16S and 18S rRNA genes, respectively. CCA and filamentous cyanobacteria were present on all bite cores and the density of filamentous cyanobacteria where S. spinus fed did not vary between mid-shelf and outer-reef samples. Epiphytic and shallow endophytic cyanobacteria were consistently associated with the CCA where S. spinus fed, including Calothrix spp., Mastigocoleus testarum, Leptolyngbya spp., Hyella patelloides and Oscillatoriales. Our results emphasize the importance of high-resolution species-specific dietary data for parrotfishes. We conclude that polyphasic methods are essential both for diet tracing and to develop our understanding of the cyanobacteria that are integral to coral reef functioning. [ABSTRACT FROM AUTHOR]

Sea cucumbers are important ecological engineers in marine ecosystems. However, the fishery demand of some species, especially large-epifaunal and commercially used (LEC) sea cucumbers, has risen drastically, resulting in serious depletion of local populations for many species. Despite this problem, basic ecological data on sea cucumbers, such as population densities and preferred habitats, are often still insufficient. Here, we report on the population densities of multiple LEC sea cucumber species, and their ambient benthic communities at eight sites around Okinawa Islands. Further, we discuss the correspondence between sea cucumber densities and the surrounding coral communities. Our results show two sites within national or quasi-national parks, Aka and Manza, where stricter rules have been placed on fisheries and land reclamation compared to other areas, had the highest and third highest sea cucumber population densities among sites, respectively. Holothuria atra was observed at all survey sites and made up the majority of sea cucumber populations at all sites except for Chatan and Sesoko, where Holothuria leucospilota and Stichopus chloronotus were most abundant, respectively. Regarding the relationships between benthic composition and LEC sea cucumber species, S. chloronotus was significantly correlated with dead corals, scleractinian corals, and coralline algae. As well, H. leucospilota had significant correlations with rubble. Although there were no significant correlations between any specific scleractinian coral genus and sea cucumber densities, S. chloronotus was marginally insignificant with Platygyra and Psammocora. Notably, medium- to highly valued species were sparse in our surveys, and most of them appeared at only one site. Additionally, at one site (Odo), only three LEC sea cucumber individuals were observed. Combining these facts with relatively low population densities around the Okinawa Islands compared to densities reported in previous research from the Indo-West Pacific Ocean region, we conclude that Okinawan LEC sea cucumber populations have been and are being impacted by high levels of direct (e.g., overexploitation, as well as coastal development) and indirect anthropogenic pressure (e.g., decreasing water quality). To address the current situation, repeated monitoring and more detailed investigations to reveal the drivers that determine LEC sea cucumber species aggregations and population densities are urgently needed, along with more robust management of remaining LEC sea cucumber populations. [ABSTRACT FROM AUTHOR]

The article discusses a study which examined the global predictions of the productivity of seaweed habitats. Results show that seaweed net primary production (NPP) is a strong driver of production in the coastal ocean and call for its integration in the oceanic carbon cycle. Topics covered include the patterns of observed seaweed NPP across groups, taxa and methodology, how the productivity of seaweed forests and algal turfs were modeled and the NPP patterns across primary producers.

Despite the notoriety of the corallivorous crown of thorns starfish (COTS, Acanthaster sp.), with population outbreaks that decimate reefs throughout the Indo‐Pacific, the physiology of the juvenile stage remains poorly understood. We determined the feeding rate and metabolic rate of juvenile COTS during their initial algae‐eating stage. The metabolic rate of juveniles after their ontogenetic diet transition from a diet of coralline algae to coral was also investigated. We found that the weight‐specific metabolic rate of both the herbivorous (mean = 0.052 mg O2 g−1 h−1) and corallivorous (mean = 0.034 mg O2 g−1 h−1) juveniles increased exponentially with juvenile size. Juveniles consumed ~4 mm2 of algae (Amphiroa sp.) in 1 day, and consumption rate also increased with juvenile size. Juveniles may impact the distribution of coralline algae for other herbivores on coral reefs and the settlement habitat for many invertebrate larvae. Increased metabolism of both herbivorous and corallivorous juveniles with size is indicative of their increasing ecological impact as they grow, highlighting the importance of understanding the juvenile physiology of influential species such as COTS. [ABSTRACT FROM AUTHOR]