Reef Communities Research Articles

Spatio-temporal variation in the growth of coral fragments of opportunity in the Eastern Tropical Pacific: implications for coral reef restoration

Introduction: Coral- reef communities are considered one of the most biodiverse, but also most threatened, marine ecosystems, and the accelerating loss of habitat over the past decades warrants active intervention. 
 Objective: The present study demonstrates the successful implementation of a low-impact restoration technique in three Central Mexican Pacific degraded coral communities, using a protocol based on natural fragmentation (“fragments of opportunity”) of the branching coral Pocillopora spp., considered the most abundant and primary carbonate-producing coral species of the Eastern Tropical Pacific. 
 Methods: The restoration program was implemented in two offshore and one inshore coraline areas. The relationships between seawater temperature and coral survival, growth, and attachment rate were assessed over one year, with 183 fragments monitored each month. 
 Results: The mean coral growth rate was 3.3 ± 0.1 mm mo-1, with annual growth rates in length and width of 39.9 ± 14.2 and 36.5 ± 19.5 mm yr-1, respectively. Self-attachment efficiency was 78 % and the survival rate was high (84 %). The growth rate differed significantly among reefs. 
 Conclusions: Upon monitoring directly fragmented corals over a year, growth rates were deemed high enough to merit active restoration in the region. However, our data show that structural and abiotic differences and seasonal variability must be considered overall in successful long-term coral community restoration initiatives in the eastern Pacific region.

Stability analysis of reef fish communities based on symbiotic graph model

The community stability of coral reefs and fish is the focus of ecological monitoring of coral reefs. Among them, the realization of effective metrics of variations in reef fish communities (i.e., the combined communities of coral reefs and fish) is important for analyzing the stability of communities as well as maintaining the ecological balance of coral reefs. Based on coral reef and fish data collected at St. John's Island from 2004 to 2010, this study proposes a symbiotic graph modeling method to express the biological relationships of reef fish communities, and a Pyramid Match graph kernel method for fusing Attributes (PMA) to quantify community fluctuations to measure interannual variability of communities. The results showed that the community similarity was low in 2006, 2007, and 2008. The total coral cover rate in the study area decreased by 32.04% from 2006 to 2007 and increased by 24% in 2008. The total number of fish fell from 3780 in 2006 to 2596 in 2007 and rose to 6249 in 2008. Among them, the proportion of herbivorous fish decreased to 30.84% in 2007. Furthermore, we have combined the Louvain algorithm with the proposed PMA method to effectively identify the regions that should be prioritized for protection. Experiments were conducted on real datasets with good results, demonstrating the potential of the proposed method to assist in the analysis of community stability and identification of priority conservation areas.

Current condition of shallow-water benthic foraminifera in Manado bay, Indonesia

Coral reef community in Manado Bay is under pressure due to human activities in areas in and around Manado. In order to be able to wisely manage the bay area and the coral reefs in it, information about present conditions is needed. The use of marine organisms as bioindicators is one way to find information about the condition, and organisms such as foraminifera have the potential to be used as some species share the same requirement for water quality as the corals. Sampling for the foraminifera was carried out at 10 locations, and the depth of water ranged from 2.5 m to 7.0 m. The samples obtained were washed through a 63 μm sieve and dried. The separation of foraminifera tests from other sediments was done under a stereomicroscope and they were then identified to genus level. A total of 40 genera was identified among 3194 specimens. To get the FoRAM Index value, the foraminifera was categorized into three functional groups. 8 genera were categorized as symbiont-bearing group, 8 as opportunistic group, and 29 as heterotrophic group. FoRAM Index was found to be varied from 2.06 to 9.19 which indicated that Manado Bay water condition is also varied among the sampling area. In general based on the data obtained, it is assumed that water in Manado Bay is conducive for coral reef growth.

Effects of sponge-to-sponge contact on the microbiomes of three spatially competing Caribbean coral reef species.

Sponges perform important ecosystem functions, host diverse microbial symbiont communities (microbiomes), and have been increasing in density on Caribbean coral reefs over the last decade. Sponges compete for space in coral reef communities through both morphological and allelopathic strategies, but no studies of microbiome impacts during these interactions have been conducted. Microbiome alterations mediate spatial competition in other coral reef invertebrates and may similarly impact competitive outcomes for sponges. In this study, we characterized the microbiomes of three common Caribbean sponges (Agelas tubulata, Iotrochota birotulata, and Xestospongia muta) observed to naturally interact spatially in Key Largo, Florida (USA). For each species, replicate samples were collected from sponges in contact with neighbors at the site of contact (contact) and distant from the site of contact (no contact), and from sponges spatially isolated from neighbors (control). Next-generation amplicon sequencing (V4 region of 16S rRNA) revealed significant differences in microbial community structure and diversity among sponge species, but no significant effects were observed within sponge species across all contact states and competitor pairings, indicating no large community shifts in response to direct contact. At a finer scale, particular symbiont taxa (operational taxonomic units at 97% sequence identity, OTUs) were shown to decrease significantly in some interaction pairings, suggesting localized effects for specific sponge competitors. Overall, these results revealed that direct contact during spatial competition does not significantly alter microbial community composition or structure of interacting sponges, suggesting that allelopathic interactions and competitive outcomes are not mediated by microbiome damage or destabilization.

Culturing for conservation: the need for timely investments in reef aquaculture

Temperate oyster and tropical coral reefs are analogous systems that create habitat for economically, ecologically, and culturally important species, and they provide countless ecosystem services to human coastal communities. Globally, reefs are imperiled by multiple anthropogenic stressors, particularly climate impacts. Using aquaculture to support conservation goals - known as conservation aquaculture - is a relatively new approach for many reef building species, but it shows great promise for promoting species recovery and bolstering resilience to stressors. Concerns about aquaculture-associated risks, both known and potential, have often restricted the implementation of this tool to an emergency intervention following dramatic declines on reefs, when species or systems were unlikely to recover. Here, we combine expertise from coral and oyster reef ecosystems to consider the role of aquaculture as a conservation intervention for reefs, and provide recommendations for its timely development and targeted implementation. We highlight the importance of evaluating reef systems - alongside local stakeholders and Indigenous communities - to determine where and when the benefits of using aquaculture are most likely to outweigh the risks. We spotlight the importance of proactive monitoring to detect reef population declines, and the value of early aquaculture interventions to increase efficacy. Novel aquaculture approaches and technologies specifically designed for reef builders are considered, including techniques for building complex, multi-generational and multi-species reefs. We address the need for scaling up aquaculture-assisted reef recovery, particularly of corals, using high volume methods like those that have been successfully employed for oysters. We also recommend the immediate assessment and development of techniques to increase climate resilience of reef builders and we identify the challenges and trade-offs of these approaches. We highlight the use of proof-of-concept projects to test these promising methods, and we advise tracking of all interventions over time to determine their long-term efficacy. Finally, we outline opportunities to leverage novel partnerships among conservation, industry, and community interests that utilize aquaculture to facilitate the conservation of reefs. Developing conservation aquaculture approaches now is critical to position managers, scientists, and restoration practitioners to implement this intervention in timely and effective ways to support resilient reef and human communities worldwide.

SCUBA noise alters community structure and cooperation at Pederson’s cleaner shrimp cleaning stations

Recreational SCUBA diving is widespread and increasing on coral reefs worldwide. Standard open-circuit SCUBA equipment is inherently noisy and, by seeking out areas of high biodiversity, divers inadvertently expose reef communities to an intrusive source of anthropogenic noise. Currently, little is known about SCUBA noise as an acoustic stressor, and there is a general lack of empirical evidence on community-level impacts of anthropogenic noise on coral reefs. Here, we conducted a playback experiment on Caribbean reefs to investigate impacts of SCUBA noise on fish communities and interspecific cooperation at ecologically important cleaning stations of the Pederson’s cleaner shrimp Ancylomenes pedersoni. When exposed to SCUBA-noise playback, the total occurrence of fishes at the cleaning stations decreased by 7%, and the community and cleaning clientele compositions were significantly altered, with 27% and 25% of monitored species being affected, respectively. Compared with ambient-sound playback, SCUBA-noise playback resulted in clients having to wait 29% longer for cleaning initiation and receiving 43% less cleaning; however, cheating, signalling, posing and time spent cleaning were not affected by SCUBA-noise playback. Our study is the first to demonstrate experimentally that SCUBA noise can have at least some negative impacts on reef organisms, confirming it as an ecologically relevant pollutant. Moreover, by establishing acoustic disturbance as a likely mechanism for known impacts of diver presence on reef animals, we also identify a potential avenue for mitigation in these valuable ecosystems.

Light limitation and coral mortality in urbanised reef communities due to sea-level rise

Sea-level rise (SLR) is expected to elevate the depth of seawater above shallow coral reefs, reducing light availability to the benthic environment, and impacting the survival and growth of corals especially on turbid reefs. However, the extent of impact at the deepest reef zones remains unknown. Coral growth could continue to keep pace above light thresholds as sea level rises, but mortality due to light limitation could vary between localities and local conditions. Here, we examine possible outcomes of corals inhabiting Singapore's turbid reefs in the years 2050 and 2100 by characterising their depth distributions and predicting potential mortality rates based on SLR projections. Our results reveal that in 2050, under both RCP4.5 and RCP8.5 sea level projections, up to 6.24% of colonies could face mortality if their growth is not considered. In 2100, up to 7.68% mortality under RCP4.5 and up to 10.7% mortality under RCP8.5 are predicted. When coral linear extension is considered, in 2050, under both RCP4.5 and RCP8.5 sea level projections, up to 1.03% of colonies could face mortality. In 2100, up to 0.87% mortality under RCP4.5 and up to 1.84% mortality under RCP8.5 are predicted. Species-specific losses could amount to 20% of colonies primarily at the deepest zones. The most vulnerable species exhibit a depth distribution with most colonies situated at the deeper parts of their depth ranges. Our findings suggest that sea-level rise may potentially result in the loss of coral cover for some species, but overall mortality could be low.

Preliminary observations on the coral reef communities in Angria Bank, an isolated carbonate bank in the Northern Indian Ocean

Submerged carbonate banks are of significant geological and biological importance and relatively little is known about the biodiversity of these deeper and less accessible habitats. This study provides pilot information on the biodiversity and spatial distribution of the coral reef communities in Angria Bank, a submerged carbonate platform along the central west coast of India. An exploratory survey was carried out in January 2014 to document the habitat characteristics and biodiversity of different reef communities across a gradient from the western to the eastern edge of the Angria Bank. The western zone of the bank comprises rocky and coralline substrates in contrast to the eastern zone which is sandy with calcareous deposits. The overall biodiversity includes 16 genera of corals from 10 families and 82 species of reef fish from 26 families, comparatively lower than the other major reef formations in the Indian Ocean. The study sites between the depths of 25–29 m along the eastern edge of the bank host abundant and diverse coral communities. The macroalgae was equally abundant in three of the five dive sites along the east zone reflecting the homogeneous distribution of reef communities in the Angria bank. Other invertebrates including members of the phylum Porifera, Mollusca, Annelida, Arthropoda, Echinodermata, and Cnidaria account for 28 species. Angria Bank signifies a biodiversity hotspot and these remote habitats hold the potential to serve as a refugium for the shallow reef communities for a range of environmental disturbances. Further research to understand the effect of climate-associated stress on the reef communities of Angria bank is vital to evolve a conservation strategy to sustain the biodiversity and resilience of these communities.

Setting the stones to restore and monitor European flat oyster reefs in the German North Sea

Abstract Ecological restoration includes specific technical phases over the course of an ecosystem recovery process. In the marine environment and for oyster reef restoration, the installation and implementation of pilot reefs close the gap between feasibility studies with small‐scale experiments and designated upscaling for marine conservation measures. Against this background, this study presents the design, planning and installation of the first pilot oyster reef in offshore sublittoral regions of the North Sea. The work was conducted as part of marine protected area management in the Natura 2000 site Borkum Reef Ground in the German Bight, in the area of historical offshore oyster grounds. It includes logistical considerations, material selection, methodology for reef base construction and deployment of European flat oysters Ostrea edulis as spat‐on‐shell, young and adult single seed oysters, and spat‐on‐reef, as well as the development of an efficient monitoring approach for reef‐associated biodiversity. Native Oyster Restoration Alliance monitoring methodologies, such as underwater visual census and seabed images were selected, tested and successfully adapted for the pilot oyster reef and study site. The evaluation and optimization of offshore sublittoral oyster reef monitoring are presented here, and biodiversity metrics are put into perspective with data from recent and historical studies. Results show a few mobile fauna species (e.g., fish and decapods) as first colonizers after reef construction. One year later, biodiversity increased due to a larger number of invertebrate and fish species. However, the pilot oyster reef community still represents an early recolonization stage, with lower biodiversity than historical records. This study presents a proof of concept for the design, planning and construction of an offshore oyster reef and indicates stages in the recovery process. Strategies to optimize and to complement reef‐monitoring in challenging environments are discussed, emphasizing additional molecular and functional analyses for future assessments.

First occurrence in life position of two Triassic brachiopod species (Thecideida) from NE Italy: Paleoecological considerations

The San Cassiano Formation from the Dolomites, NE Italy, is a Ladinian–Carnian (Middle – Upper Triassic) lithostratigraphic unit belonging to the Western Tethys domain. In this formation numerous groups of marine invertebrates from reef communities have been reported. In particular, brachiopods are represented by different orders. Thecideids are the most abundant and diverse, with different species of the genus Thecospira. Despite the apparent abundance, only one report exists of a thecideid of the genus preserved in life position: Thecospira tyrolensis. In this study, we describe and discuss the first finding of Thecospira semseyi and Thecospira tenuistriata in life position based on the study of thin sections of Cipit boulders. Seemingly, the Th. semseyi shells were not firmly attached to the substrate by a small cementation surface; therefore, they could have lived embedded into the biogenic matrix. By contrast, Th. tenuistriata displays an umbonal region modified in a cementation area, allowing the attachment to the bio-builder. Most samples don’t show any signal of transport since all specimens are articulated and are still attached to the substrate. Besides, the commissures are partially opened, free of any encrustation of sponge or bryozoan growing. The preservation of brachiopods suggests that the samples of both species were fossilized in life position. Moreover, Th. semseyi and Th. tenuistriata continued to live although the host’s fabric was imbibing the brachiopods’ ventral valve. This shows that thecideids were important components of Tethys reef communities.

Hydrodynamic and atmospheric drivers create distinct thermal environments within a coral reef atoll

Within coral reefs, different thermal environments can be found at locations separated by less than 100 s of meters and can generate fine-scale patterns of thermal stress and subsequent bleaching. In this study, we use an 11-month record of in situ temperature measurements, coupled with oceanographic and atmospheric data to examine the role of surface and advective heat fluxes in driving spatial patterns of temperature variability across several reef zones (i.e., fore-reef, reef flat, channel and lagoon) within an individual coral reef atoll. We show that advection of heat (driven by a combination of wave and tidal flows) was dominant across all sites and surface heating was more important across shallow areas or areas of low net exchange (i.e., reef flat and lagoon zones). Tidal flows were important in driving short term variability in the transport of heat across the atoll, but their contribution to the net transport of heat (cooling vs heating) was less significant over the longer timescales (days to weeks) that are typically used to assess thermal stress experienced by coral reef communities (e.g., Degree Heating Weeks). Conversely, although the wave-driven advection of heat contributed minimally to reef temperature changes over short timescales, the net transport of heat over daily to weekly timescales had a significant influence on persistent temperature anomalies. By parameterising the mechanisms driving temperature variability across the reef flat and lagoon zones, we demonstrate how satellite measurements of sea surface temperatures can be corrected to provide robust temperature estimates at the reef scale.

Bleaching, mortality and lengthy recovery on the coral reefs of Lord Howe Island. The 2019 marine heatwave suggests an uncertain future for high-latitude ecosystems

Oceanic thermal anomalies are increasing in both frequency and strength, causing detrimental impacts to coral reef communities. Water temperatures beyond the corals optimum threshold causeing coral bleaching and mass mortality, impacting our global coral reef ecosystems, including marginal high-latitude reefs. Coral bleaching and mortality were observed at the southernmost coral reef, Lord Howe Island Marine Park, during the summer of 2019, coinciding with anomalously high sea surface temperatures across the reef system from January-April. Here we document the extent of coral impacts within the Lord Howe Island lagoonal reef and the recovery from bleaching eight-months later. Significant differences in bleaching prevalence were observed across the lagoonal coral reef, ranging from 16 to 83% across offshore and inshore reef regions and with variable onset timing. Coral mortality of up to 40% was recorded in the reef’s most severely impacted near-shore area. The four most dominant species, Stylophora pistillata, Pocillopora damicornis, Porites spp. and Seriatopora hystrix, were the most susceptible to bleaching, with all coral colonies found either bleached or dead at the most affected inshore site during and following peak heat stress. Interestingly, during the eight-months following bleaching, there was no evidence of bleaching recovery (i.e., re-establishment of symbiosis) at the offshore lagoonal site. However, there was a significant increase in the abundance of healthy coral colonies at the inshore site, suggesting the recovery of the surviving bleached corals at this site. Importantly, we found no evidence for bleaching or mortality in the Acropora spp. and minimal bleaching and no mortality in Isopora cuneata during the study period, typically highly susceptible species. Given the isolation of high-latitude reefs such as Lord Howe Island, our results highlight the importance of understanding the impacts of bleaching, mortality and bleaching recovery on coral population structure and resilience of high-latitude coral reefs.

Benthic source dominance in temperate rocky reefs revealed by stable isotopes

Rocky reefs are heavily impacted by anthropogenic activity and since they are important breeding, nursery and feeding areas, their protection is imperative. To improve conservation methods, it is necessary to understand the structure and processes of rocky reef communities. Trophic relationships are one of the examples of species connection, with food webs representing the flow of matter and energy from producers to consumers and from prey to predators. Stable isotope analysis (δ13C and δ15N) was used to characterize the food web of the rocky reefs of Arrábida Marine Protected Area (Portugal) and to explore habitat complexity – niche diversification relationships. Results showed a complex food web with high trophic richness supported by a wide range of basal resources. As a result of the wide range of basal resources and primary consumers the food web was characterized by a high degree of omnivory which led to a relatively short food web. Furthermore, consumers displayed diverse diets and feeding strategies, exploiting different sources of organic matter, of both benthic (macroalgae and benthic POM) and pelagic origin (phytoplankton and pelagic POM). However, the benthic pathway was more important with more than half of the diet of most secondary and tertiary consumers following this route, hinting at the importance held by macroalgae and benthic production in this ecosystem. Overall, the high habitat complexity allied to the shallow and sheltered location of the reefs increased niche diversification (wide range of basal resources) supporting a diversity of omnivore species which improved the connectance among taxa and thus the complexity of the food web. This study is an essential step to better understand shallow temperate rocky reefs and, as such, provide additional support for conservation measures and management decisions.

Influence of upwelling on coral reef benthic communities: a systematic review and meta-analysis.

Highly competitive coral reef benthic communities are acutely sensitive to changes in environmental parameters such as temperature and nutrient concentrations. Physical oceanographic processes that induce upwelling therefore act as drivers of community structure on tropical reefs. How upwelling impacts coral communities, however, is not fully understood; upwelling may provide a natural buffer against climate impacts and could potentially enhance the efficacy of spatial management and reef conservation efforts. This study employed a systematic review to assess existing literature linking upwelling with reef community structure, and a meta-analysis to quantify upwelling impact on the percentage cover of coral reef benthic groups. We show that upwelling has context-dependant effects on the cover of hard coral and fleshy macroalgae, with effect size and direction varying with depth, region and remoteness. Fleshy macroalgae were found to increase by 110% on inhabited reefs yet decrease by 56% around one well-studied remote island in response to upwelling. Hard coral cover was not significantly impacted by upwelling on inhabited reefs but increased by 150% when direct local human pressures were absent. By synthesizing existing evidence, this review facilitates adaptive and nuanced reef management which considers the influence of upwelling on reef assemblages.

A persistent green macroalgal mat shifts ecological functioning and composition of associated species on an Eastern Tropical Pacific coral reef

Global evidence of phase shifts to alternate community types is of particular concern because these new communities can provide fundamentally different and often novel ecosystem functions and services compared to the original community. Shifts of a diverse range of marine communities to dominance by green macroalgal mats have occurred worldwide, making it critical to understand their emerging functions and roles. We observed a green algal mat on two reefs in the Eastern Tropical Pacific, with one persisting for >10 years on a reef with stable herbivore populations and no known sources of anthropogenic nutrients. These mats supported a more speciose macroalgal community with fewer taxa present in the adjacent coral community and facilitated growth of an associated understory macroalgal species by reducing herbivory pressure and possibly enhancing nutrient supplies within the mat community state. These results demonstrate a weakening in the processes controlling reef community structure as a result of the shift in composition associated with the macroalgal mat, creating a positive feedback supporting mat persistence. These novel ecosystem functions generated by this alternate community state illustrate the importance of further research on community shifts, which will become increasingly common in the Anthropocene.

Eight years of community structure monitoring through recreational citizen science at the "SS Thistlegorm" wreck (Red Sea).

Large artificial coral reef communities, such as those thriving on sunken shipwrecks, tend to mirror those of nearby natural coral reefs and their long-term dynamics may help future reef resilience to environmental change. We examined the community structure of the world-renown "SS Thistlegorm" wreck in the northern Red Sea from 2007 through 2014, analyzing data collected during the recreational citizen science Red Sea monitoring project "Scuba Tourism for the Environment". Volunteer divers collected data on 6 different diving parameters which included the date of the dive, maximum depth, average depth, temperature, dive time, hour of dive, and gave an abundance estimation of sighted taxa from a list of 72 target taxa. Although yearly variations in community structure were significant, there was no clear temporal trend, and 71 of all 72 target taxa were sighted throughout the 8 years. The 5 main taxa driving variations among year clusters in taxa presence/absence (Soft Tree Coral-Dendronephthya spp., Giant Moray-Gymnothorax javanicus, Squirrel Fish-Sargocentron spp., Humpback Batfish-Platax spp., and Caranxes-Carangidae) and taxa abundance (Soft Tree Coral, Giant Moray, Red Sea Clownfish-Amphiprion bicinctus, Napoleon Wrasse-Cheilinus undulatus, and Caranxes) data were determined. The "SS Thistlegorm" provides a compelling example of how artificial coral reefs can sustain a well-established community structure similar to those of their natural counterparts.

Pectoral fin swimmers turn to save energy in coral reef waves

It takes all sorts to make a coral reef community. From elegant shimmering Hawaiian flagtails (Kuhlia xenura) to vivid kole tangs (Ctenochaetus strigosus) and stripy sergeant major fish (Abudefduf vaigiensis), these creatures all make their homes in the perpetual swell of the coral reef waters off Hawaii. ‘The waves over shallow reefs create constantly changing water flows that may help explain the great variety of fish body shapes and types of swimming we see among reef fishes’, says Keith Korsmeyer from Hawaii Pacific University, USA. Some fish swim sinuously, gently beating their tails from side to side, while others manoeuvre and hover deftly by wiggling their wing-like pectoral fins. But all must be able to withstand strong surges and remain in place, even when the turbulence of the strongest storms blows through. Yet it wasn't clear just how much of an effort it takes for fish with different builds and swimming styles to hold their own in turbulent coral reef waters. Korsmeyer teamed up with Mathias Schakmann (Hawaii Pacific University) and the pair recreated the wavey conditions on a reef to find how much effort it takes fish to stay in place and how much swimming style affects their exertions.‘I went fishing at the local pier and was lucky to catch fish with interesting differences in body shape and how they swim’, says Schakmann, who came back with Hawaiian flagtails, kole tangs, sergeant major fish and saddle wrasse (Thalassoma duperrey). He then set up a fish ‘treadmill’ in the lab with water flowing through a tube, where he could measure the fish's oxygen consumption to calculate the energy they used as they swam at different steady speeds, in addition to how hard they had to swim when the water washed to and fro as he simulated coral reef waves. ‘All the fish quickly adjusted to each wave surge and kept swimming into the flow’, says Korsmeyer.It was quickly clear that the fish switched direction each time a simulated wave washed through, speeding up and slowing down to remain in place as the waves surged past. Although all of the fish swam harder to stay put in the wavey conditions, when Schakmann compared the fish's swimming styles, it was evident that the pectoral fin wiggling swimmers were far more efficient than the tail-beating Hawaiian flagtails. The flagtail's energy use increasing 2.5-fold as the waves increased from one every 10 s to one every 3.3 s, while the fin-flapping saddle wrasse only increased their exertions by 1.5-fold and the disc-shaped fin-wiggling sergeant major fish barely made any additional effort (0.5-fold increase). ‘The fish that swam with flapping pectoral fins could deal with the increasing wave motion more easily, which would save energy while living in these wave-swept habitats’, says Korsmeyer.However, when Schakmann compared the exertions of the three pectoral fin swimmers, the deepest-bodied kole tangs and sergeant major fish swam more efficiently than the slimmer saddle wrasse as they switched back and forth. ‘Our results suggest that more rounded disc-shaped bodies seem to be the most efficient for dealing with staying put in a wave surge water flow’, says Schakmann.So disc-like fish that depend on their pectoral fins for manoeuvrability are best suited for life on wave-swept coral reefs, turning on a dime as each wave washes through, and it takes all sorts to make a community, although some are better suited to steady swimming in the calmer deep waters off coral reefs.

Utilizing the Autonomous Reef Monitoring Structure (ARMS) to study the temporal variation of benthic community on coral reef ecosystems in Pemuteran, Bali, Indonesia

Tracking changes in community composition in the coral reef ecosystem is essential, mainly to understand the complexities of the ecosystem and its long-term response to environmental and anthropogenic threats. A standardized method sensitive to changes and comparable across sites is needed to provide robust data helpfully. We used a standardized monitoring protocol Autonomous Reef Monitoring Structure (ARMS), to investigate the growth of marine sessile communities and observe variations in motile taxa (decapods) composition through time. Eighteen units of ARMS were deployed at a depth of ∼10–15 m in the coral reef ecosystem in Pemuteran, Bali, Indonesia; three units were then recovered every two months for one year. The sessile community in each ARMS plate was then photographed and annotated using a web-based annotation tool called CoralNet, while the motile decapods were identified using their morphological characteristics. We observed twenty-four benthic categories of sessile communities and three infraorder of decapods across the sampling duration. The sessile community was contributed mainly by Encrusting Sponge, Brown Flesh Algae, and Bryozoan in almost every sampling duration. The ANOVA result shows that the composition is significantly different over time, showing apparent changes in composition. However, the NMDS result indicated similar structure composition during the ARMS’s time retrieval. Future research on temporal changes in benthic diversity can be used to understand the dynamic more about relationship between motile and sessile and how their interaction can affect the coral reef community.

Assessment of macroalgae coverage in a scarcely studied deep rocky reef in the tropical eastern Mexican Pacific

The biodiversity of epibenthic communities in rocky reefs in the Mexican tropical Pacific has been studied minimally during the past three decades. This study describes the abundance and distribution of algae and invertebrates in a deep rocky reef from this region. Samples were taken at 20 m depth in 2012 by randomly placing 50×50 cm quadrats. Also, photographs were taken of each quadrat to quantify the coverage of organisms. Throughout the study, the algae were the most abundant group (17748.5 cm m-2), of which encrusting calcified (6350.9 cm m-2), turf (3040.3 cm m-2), and larger-sized articulated corallines (2700.9 cm m-2) had the highest coverage. Regarding invertebrates, zoanthids (1153.3 cm m-2) and corals (746.7 cm m-2) had high coverage. All of the algal groups were found on vertical and horizontal substrates. The detrended correspondence analysis showed that larger-sized articulated corallines and encrusting not calcified groups were prevalent on the horizontal substrate and corals on the vertical substrate. These abundance and distribution patterns represent the first quantitative study of rocky reefs from the region. Considering the rapid influence of human activities in this coastal zone and the fact that rocky reefs have been minimally studied, there is a clear need for long-term monitoring programs to establish reef communities' patterns and processes, which are useful in conservation programs.

Last Fish, Phantom Islands, and Reef Ruins: Unsettling Logics of Permanence

At the core of this contribution are reflections about catastrophe in the context of the coral reef communities of eastern Sulawesi, and about modes of thinking, imagining, understanding, and being-in-relation. To that end, the writing unsettles and challenges expectations of a stable point of view from which catastrophic events, which are inseparable from how they are conceived, might be overseen. Local sayings and transregional scholarship regarding those say-ings offer a vital repository of knowledge and ways of knowing that is integral to this work. A proverb, Sama tales, and multiple narratives of the volcanic eruptions on the island of Una-Una foreground the navigation of change and impermanence by the communities and creatures of land and sea that inhabit the surrounding waters. The author, a philosopher, poet, and diver, begins the composition gazing upward from within the currents, as the reef awakens just before dawn. Keywords: reef communities; Sulawesi; proverb; volcanic eruption; living-through