scholarly journals Modelling the linkage between coral assemblage structure and pattern of environmental forcing

2020 ◽  
Vol 7 (10) ◽  
pp. 200565
Author(s):  
Stuart A. Sandin ◽  
Yoan Eynaud ◽  
Gareth J. Williams ◽  
Clinton B. Edwards ◽  
Dylan E. McNamara
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Reef Coral ◽  
Assemblage Structure ◽  
Benthic Assemblages ◽  
Environmental Forcing ◽  
Temporal Variance ◽  
Coral Communities ◽  
Colony Loss ◽  
Coral Assemblage

Geographical comparisons suggest that coral reef communities can vary as a function of their environmental context, differing not just in terms of total coral cover but also in terms of relative abundance (or coverage) of coral taxa. While much work has considered how shifts in benthic reef dynamics can shift dominance of stony corals relative to algal and other benthic competitors, the relative performance of coral types under differing patterns of environmental disturbance has received less attention. We construct an empirically-grounded numerical model to simulate coral assemblage dynamics under a spectrum of disturbance regimes, contrasting hydrodynamic disturbances (which cause morphology-specific, whole-colony mortality) with disturbances that cause mortality independently of colony morphology. We demonstrate that the relative representation of morphological types within a coral assemblage shows limited connection to the intensity, and essentially no connection to the frequency, of hydrodynamic disturbances. Morphological types of corals that are more vulnerable to mortality owing to hydrodynamic disturbance tend to grow faster, with rates sufficiently high to recover benthic coverage during inter-disturbance intervals. By contrast, we show that factors causing mortality without linkage to morphology, including those that cause only partial colony loss, more dramatically shift coral assemblage structure, disproportionately favouring fast-growing tabular morphologies. Furthermore, when intensity and likelihood of such disturbances increases, assemblages do not adapt smoothly and instead reveal a heightened level of temporal variance, beyond which reefs demonstrate drastically reduced coral coverage. Our findings highlight that adaptation of coral reef benthic assemblages depends on the nature of disturbances, with hydrodynamic disturbances having little to no effect on the capacity of reef coral communities to resist and recover with sustained coral dominance.

scholarly journals 3D HABITAT COMPLEXITY OF CORAL REEFS IN THE NORTHWESTERN HAWAIIAN ISLANDS IS DRIVEN BY CORAL ASSEMBLAGE STRUCTURE

2019 ◽  
Vol XLII-2/W10 ◽  
pp. 61-67 ◽  
Author(s):  
J. H. R. Burns ◽  
A. Fukunaga ◽  
K. H. Pascoe ◽  
A. Runyan ◽  
B. K. Craig ◽  
...  
Keyword(s):  
Coral Reef ◽  
Habitat Complexity ◽  
Coral Cover ◽  
Light Availability ◽  
Structural Complexity ◽  
Assemblage Structure ◽  
Natural Environments ◽  
Live Coral ◽  
Ecological Processes ◽  
Coral Assemblage

<p><strong>Abstract.</strong> Corals act as ecosystem engineers by secreting structurally complex calcium carbonate skeletons on the benthic substrate that provide habitat for a diverse array of associated reef organisms. Communities of living corals create large and dynamic benthic structures that directly affect ecological parameters such as habitat provisioning and light availability, thus influencing overall ecosystem function. Despite the important role 3D structural complexity plays in ecosystem biodiversity and productivity, the field of coral ecology has lacked accessibility to practical technology capable of quantifying 3D characteristics of underwater habitats. Advancements in the field of computer vision has led to Structure-from-Motion (SfM) photogrammetry, which provides a simple and cost-effective method for creating high-resolution and spatially accurate 3D reconstructions of natural environments. Integrating SfM approaches into coral reef research and monitoring has provided useful insight into the relationship between 3D habitat complexity and ecological processes. In this study, we examined the relationships among 2D estimates of live coral cover and several metrics of 3D habitat structural complexity among eleven long-term monitoring sites at French Frigate Shoals. Our findings show that coral assemblage structure acts as a significant driver of 3D structural complexity of coral reef habitats at this atoll. This study highlights the importance of diverse and abundant coral assemblages in supporting structurally complex coral reef habitats and provides a framework for future investigations into the ecological role of various coral morphotypes.</p>

Hawai'i Coral Reef Assessment and Monitoring Program: Spatial Patterns and Temporal Dynamics in Reef Coral Communities

2004 ◽  
Vol 58 (2) ◽  
pp. 159-174 ◽  
Author(s):  
P. L. (Paul L.) Jokiel ◽  
Eric K. Brown ◽  
Alan Friedlander ◽  
S. Ku'ulei Rodgers ◽  
William R. Smith
Keyword(s):  
Coral Reef ◽  
Spatial Patterns ◽  
Temporal Dynamics ◽  
Monitoring Program ◽  
Reef Coral ◽  
Coral Communities ◽  
Assessment And Monitoring

scholarly journals Beyond coral-algal regimes: high taxonomic resolution surveys and trait-based analyses reveal multiple benthic regimes

2021 ◽  
Author(s):  
Miriam Reverter ◽  
Matthew Jackson ◽  
Sven Rohde ◽  
Mareen Moeller ◽  
Robert Bara ◽  
...  
Keyword(s):  
Coral Reef ◽  
Taxonomic Resolution ◽  
Marine Biodiversity ◽  
Soft Corals ◽  
Benthic Assemblages ◽  
North Sulawesi ◽  
Reef Communities ◽  
Coral Communities ◽  
Specific Species ◽  
Coral Reef Communities

As coral reef communities change and reorganise in response to anthropogenic and climate disturbances, there is a growing need of detecting and understanding the different emerging species regimes and their contribution to key ecosystem processes. Using a case study on coral reefs at the epicentre of tropical marine biodiversity (North Sulawesi), we explored how application of different biodiversity approaches (i.e. use of major taxonomic categories, high taxonomic resolution categories and trait-based approaches) affects the detection of distinct fish and benthic community assemblages. Our results show that using major categories (family level or above) to study coral reef communities fails to identify distinct regimes. We also show that for detection of different benthic regimes, especially communities dominated by non-coral organisms, monitoring of only scleractinian coral communities is insufficient, and that all types of benthic organisms (e.g. sponges, ascidians, soft corals, algae etc.) need to be considered. We have implemented for the first time, the use of a trait-based approach to study the functional diversity of whole coral reef benthic assemblages, which allowed us to detect five different community regimes, only one of which was dominated by scleractinian corals. We circumvented the challenge that for some benthic groups (e.g. sponges, ascidians or some soft corals) visual identification up to the species level is not possible, by identifying and categorising traits that can be applied to groups of similar organisms instead of specific species. Furthermore, by the parallel study of benthic and fish communities we provide new insights into key processes and functions that might dominate or be compromised in the different community regimes.

scholarly journals Evolution and connectivity influence the persistence and recovery of coral reefs under climate change in the Caribbean, Southwest Pacific, and Coral Triangle

2021 ◽  
Author(s):  
Lisa C. McManus ◽  
Daniel L. Forrest ◽  
Edward W. Tekwa ◽  
Daniel E. Schindler ◽  
Madhavi A. Colton ◽  
...  
Keyword(s):  
Climate Change ◽  
Coral Reef ◽  
Coral Cover ◽  
Larval Settlement ◽  
Network Size ◽  
Coral Triangle ◽  
Southwest Pacific ◽  
Network Characteristics ◽  
Coral Communities ◽  
The Caribbean

AbstractCorals are experiencing unprecedented decline from climate change-induced mass bleaching events. Dispersal not only contributes to coral reef persistence through demographic rescue but can also hinder or facilitate evolutionary adaptation. Locations of reefs that are likely to survive future warming therefore remain largely unknown, particularly within the context of both ecological and evolutionary processes across complex seascapes that differ in temperature range, strength of connectivity, network size, and other characteristics. Here, we used eco-evolutionary simulations to examine coral adaptation to warming across reef networks in the Caribbean, the Southwest Pacific, and the Coral Triangle. We assessed the factors associated with coral persistence in multiple reef systems to understand which results are general and which are sensitive to particular geographic contexts. We found that evolution can be critical in preventing extinction and facilitating the long-term recovery of coral communities in all regions. Furthermore, the strength of immigration to a reef (destination strength) and current sea surface temperature robustly predicted reef persistence across all reef networks and across temperature projections. However, we found higher initial coral cover, slower recovery, and more evolutionary lag in the Coral Triangle, which has a greater number of reefs and more larval settlement than the other regions. We also found the lowest projected future coral cover in the Caribbean. These findings suggest that coral reef persistence depends on ecology, evolution, and habitat network characteristics, and that, under an emissions stabilization scenario (RCP 4.5), recovery may be possible over multiple centuries.

scholarly journals Comparison of Live Coral Cover in Central and South Bangka

2018 ◽  
Vol 21 (1) ◽  
pp. 37
Author(s):  
Mu'alimah Hudatwi ◽  
Umroh Umroh
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Reef Coral ◽  
Live Coral ◽  
Dead Coral ◽  
Live Coral Cover ◽  
Anthropogenic Stressor ◽  
High Turbidity ◽  
The Universe ◽  
Runoff And Sedimentation

Abstract Coral reef ecosystem has many biological, ecological, and economical functions to the universe. This ecosystem provides shelter, food, and home for many marine organisms and together they perform diverse and rich ecosystem. However, this diverse ecosystem is very susceptible to environmental change, such as climate change, ocean acidification, and other anthropogenic impact. When reef-building coral could not stand with harsh condition they will eventually die. We assume that anthropogenic stressor such as turbidity, terrestrial runoff, and sedimentation is the main problem here, because of high number of tin mining activities. Bangka and Belitung Islands are huge tin producer and has been exploited heavily by the legal and illegal miner company. The purpose of this study is to investigate the live coral cover in Central and South Bangka by using the line intercept transect to calculate the live coral, died coral, and algae in each stations. The results showed that the coral cover in Central Bangka and South Bangka has fair condition (25-40% of live stony coral). Value of live and dead coral cover was 40% with Semujur and Ketawai represent the coral cover in Central Bangka. While South Bangka has slight (1-2%) difference of live coral, dead coral, and algae cover. High number of dead coral mainly composed by dead coral overgrown by algae, allegedly caused by high turbidity and sedimentation from the anthropogenic stressor. Keywords: coral reef, coral cover, died coral, sedimentation Abstrak Perbandingan Tutupan Karang Hidup di Bangka Tengah dan SelatanEkosistem terumbu karang mempunyai fungsi biologi, ekologi, dan ekonomi yang bermanfaat bagi manusia. Ekosistem ini menyediakan tempat berlindung, makanan, dan rumah bagi organisme laut dan membentuk suatu ekosistem yang kaya dan beragam. Namun, ekosistem ini sangat rentan terhadap perubahan lingkungan, sepertiiklim, asidifikasi, dan dampak lain yang dilakukan manusia. Ketika terumbu karang tidak mampu bertahan dengan perubahan lingkungan yang ekstrim mereka akan mati. Kami menduga bahwa dampak antropogenik seperti turbiditas, runoff dari darat, dan sedimentasi merupakan penyebab utama kerusakan terumbu karang, karena banyaknya aktivitas penambangan. Kepulauan Bangka belitung adalah penghasil timah terbesar dan telah dieksploitasi oleh penambang timah legal maupun ilegal. Tujuan dari penelitian ini adalah untuk mengetahui tutupan karang hidup di Provinsi Bangka Tengah dan Bangka Selatan dengan menggunakan metode traksek garis. Hasil menunjukkan bahwa terumbu karang di Bangka Tengah dan Selatan termasuk kategori sedang (25- 40% tutupan karang). Tutupan karang hidup dan karang mati di Bnagka Tengah sebesar 40% dari hasill pengamatan di Semujur dan Ketawai. Sedangkan nilai tutupan karang hidup, karang mati, dan alga di Bangka Selatan mempunyai angka perbedaan yang rendah (1-2%). Tingginya tutupan karang mati tersusun oleh karang mati yyang ditumbuhi alga yang disebabkan oleh turbiditas dan sedimentasi.Kata Kunci: karang mati, terumbu karang, tutupan karang, sedimentasi

scholarly journals Effects of the Stony Coral Tissue Loss Disease Outbreak on Coral Communities and the Benthic Composition of Cozumel Reefs

2021 ◽  
Vol 8 ◽  
Author(s):  
Nuria Estrada-Saldívar ◽  
Blanca A. Quiroga-García ◽  
Esmeralda Pérez-Cervantes ◽  
Omar O. Rivera-Garibay ◽  
Lorenzo Alvarez-Filip
Keyword(s):  
Coral Cover ◽  
Coastal Development ◽  
Tissue Loss ◽  
Coral Tissue ◽  
Coral Mortality ◽  
Benthic Assemblages ◽  
Stony Coral ◽  
Coral Communities ◽  
The Caribbean ◽  
Benthic Composition

In the Caribbean, disease outbreaks have emerged as significant drivers of coral mortality. Stony Coral Tissue Loss Disease (SCTLD) is a novel white plague-type disease that was first reported off the Florida coast in 2014. This disease affects &gt;20 coral species and is spreading rapidly throughout the Caribbean. In December 2018, SCTLD reached southwestern (SW) Cozumel, one of the healthiest reef systems in the Caribbean. In this study, we integrate data from multiple survey protocols conducted between July 2018 and April 2020 to track the progression of the outbreak in SW Cozumel and to quantify the impacts of SCTLD on coral communities and the benthic composition of reefs. Given that the SCTLD outbreak coincided with a period of prolonged thermal stress that concluded in widespread coral bleaching in autumn 2019, we also investigated whether this event further exacerbated coral mortality. Our findings show that SCTLD spread throughout SW Cozumel in only 2 months and reached a peak after only 5 months. By the summer of 2019, most of the afflicted corals were already dead. Species of the families Meandrinidae, Faviinae, and Montastraeidae showed 33–95% mortality. The widespread coral die-off caused an overall loss of 46% in coral cover followed by a rapid increase of algae cover across all surveyed reefs that persisted until at least April 2020. In November 2019, more than 15% of surveyed coral colonies were bleached. However, we did not find that bleaching further increased coral mortality at either the colony or the community level, which suggests that the coral communities were able to recover from this event despite still being affected by the disease. In conclusion, SCTLD is radically changing the ecology of coral reefs by decimating the populations of several key reef-builders and reconfiguring the benthic assemblages. The actions needed to restore coral populations have to be accompanied by stringent controls related to the effects of climate change, coastal development, and wastewater treatment to improve coral conditions and ecosystem resilience.

scholarly journals Rapid increase in coral cover on an isolated coral reef, the Ashmore Reef National Nature Reserve, north-western Australia

2011 ◽  
Vol 62 (10) ◽  
pp. 1214 ◽  
Author(s):  
D. M. Ceccarelli ◽  
Z. T. Richards ◽  
M. S. Pratchett ◽  
C. Cvitanovic
Keyword(s):  
Coral Reef ◽  
Western Australia ◽  
Coral Cover ◽  
Taxonomic Composition ◽  
Coastal Pollution ◽  
Percent Cover ◽  
Community Recovery ◽  
Coral Communities ◽  
Coral Recovery ◽  
North Western

Against a background of coral reef ecosystem decline, understanding the propensity for coral communities to recover after acute disturbances is fundamental to forecasting and maintaining resilience. It may be expected that offshore reef ecosystems are less affected by anthropogenic disturbances compared with reefs closer to population centres, but that recovery may be slower on isolated reefs following disturbances. To test the hypothesis that community recovery is slow in isolated locations, we measured changes in coral cover and relative abundance of coral genera over a 4 year period (2005–09) at Ashmore Reef, north Western Australia, following severe bleaching. The percent cover of hard coral tripled, from 10.2% (±1.46 s.e.) in 2005 to 29.4% (±1.83 s.e.) in 2009 in all habitats (exposed and lagoonal) and depth zones (2–5 and 8–10 m), and the percent cover of soft corals doubled, from 4.5% (+0.63 s.e.) in 2005 to 8.3% (+1.4 s.e.) in 2009. Significant shifts in the taxonomic composition of hard corals were detected. Our results imply that coral recovery in isolated locations can occur rapidly after an initial delay in recruitment, presumably through the interacting effects of self-recruitment and reduced exposure to additive impacts such as coastal pollution.

scholarly journals Cross shelf gradients of scleractinian corals in the Spermonde Islands, South Sulawesi, Indonesia

2021 ◽  
Vol 22 (3) ◽  
Author(s):  
SYAFYUDIN YUSUF ◽  
MARIA BEGER ◽  
Asmi Citra Malina A.R. Tassakka ◽  
MAARTEN DE BRAUWER ◽  
AMANDA PRICELLA ◽  
...  
Keyword(s):  
Species Richness ◽  
Coral Reef ◽  
Coral Cover ◽  
Outer Shelf ◽  
Shelf Zone ◽  
Live Coral ◽  
Hard Coral ◽  
Coral Colony ◽  
South Sulawesi ◽  
Coral Communities

Abstract. Yusuf S, Beger M, Tassakka ACMAR, Brauwer MD, Pricella A, Rahmi, Umar W, Limmon GV, Moore AM, Jompa J. 2021. Cross shelf gradients of scleractinian corals in the Spermonde Islands, South Sulawesi, Indonesia. Biodiversitas 22: 1415-1423. Coral reef ecosystems around the world have suffered extensive degradation, including the reefs of the Wallacea region within the Coral Triangle global biodiversity hotspot. Anthropogenic and natural threats can reduce the level of coral reef biodiversity differentially across environmental or impact gradients. The purpose of this study was to evaluate the changes in hard coral (Scleractinia) diversity and community structure across an inshore-offshore zonation gradient in the Spermonde Islands, South Sulawesi, Indonesia. Data on coral colony species and abundance as well as live coral cover were collected from 10 m2 belt transects at a depth of 6 to 8 m. A total of 72 transects were placed around the 12 island stations in three zones: the inner mid-shelf zone, outer mid-shelf zone and outer shelf zone. Data were analyzed to determine the species richness, and three ecological indices for the hard coral communities were calculated: the Shannon Diversity Index (H'), Similarity Index (E), and Dominance Index (C). A total of 310 hard coral species belonging to 62 genera were recorded. The coral communities were dominated by the genera Fungia, Montipora and Porites, and coral cover was in the 'moderate' category. The number of species was directly proportional to the number of colonies within each zone. Live coral cover was higher in the inner mid-shelf zone and outer shelf zone than the outer mid-shelf zone; conversely, the species richness and coral colony abundance were higher in the outer mid-shelf zone. However, the differences were not statistically significant. The indices H’, C, and E did not differ significantly between the zones. However, Tambakulu Island in Zone 4 had the lowest values of E and H’ and the highest value of C. Findings suggest that most-hard coral communities in the cross-shelf zones of the Spermonde Islands are stable communities characterized by relatively high diversity and low dominance indices.

scholarly journals High taxonomic resolution surveys and trait-based analyses reveal multiple benthic regimes in North Sulawesi (Indonesia)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Miriam Reverter ◽  
Matthew Jackson ◽  
Sven Rohde ◽  
Mareen Moeller ◽  
Robert Bara ◽  
...  
Keyword(s):  
Coral Reef ◽  
Benthic Communities ◽  
Taxonomic Resolution ◽  
Marine Biodiversity ◽  
Benthic Organisms ◽  
Benthic Assemblages ◽  
North Sulawesi ◽  
Coral Communities ◽  
Taxonomic Categories

AbstractAs coral reef communities change and reorganise in response to increasing disturbances, there is a growing need for understanding species regimes and their contribution to ecosystem processes. Using a case study on coral reefs at the epicentre of tropical marine biodiversity (North Sulawesi, Indonesia), we explored how application of different biodiversity approaches (i.e., use of major taxonomic categories, high taxonomic resolution categories and trait-based approaches) affects the detection of distinct fish and benthic communities. Our results show that using major categories fails to identify distinct coral reef regimes. We also show that monitoring of only scleractinian coral communities is insufficient to detect different benthic regimes, especially communities dominated by non-coral organisms, and that all types of benthic organisms need to be considered. We have implemented the use of a trait-based approach to study the functional diversity of whole coral reef benthic assemblages, which allowed us to detect five different community regimes, only one of which was dominated by scleractinian corals. Furthermore, by the parallel study of benthic and fish communities we provide new insights into key processes and functions that might dominate or be compromised in the different community regimes.

scholarly journals Prevalence of Stony Coral Tissue Loss Disease at El Seco, a Mesophotic Reef System off Vieques Island, Puerto Rico

2021 ◽  
Vol 8 ◽  
Author(s):  
Stacey M. Williams ◽  
Jorge García-Sais ◽  
Jorge Sabater-Clavell
Keyword(s):  
Puerto Rico ◽  
Coral Reef ◽  
Coral Cover ◽  
Coral Disease ◽  
Tissue Loss ◽  
Coral Tissue ◽  
Stony Coral ◽  
Reef System ◽  
Coral Communities ◽  
Mesophotic Reef

Mesophotic coral ecosystems (MCEs) are ecologically and functionally vital, as they are Essential Fish Habitats that function as refugia for corals and sponges of shallow-water reefs. Stony Coral Tissue Loss Disease (SCTLD) is a relatively new lethal coral disease, first affecting coral reefs in Florida and has now spread through most of the Caribbean. SCTLD was observed in Puerto Rico in December 2019 in Culebra Island. Since then, SCTLD has appeared along the east coast of Puerto Rico, affecting primarily shallow reefs in San Juan, Culebra and Vieques Island, and Fajardo. During late June and July 2020, four mesophotic reef habitats were surveyed at El Seco (off Vieques Island), on the southeast coast of Puerto Rico. SCTLD was observed at colonized pavement (CPRT – 23–30 m), bank coral reef (BCR – 35–40 m), patch coral reef (PCR – 36–42 m), and rhodolith (Rhodo – 40–50 m) habitats. The mean percent substrate cover by sessile-benthic categories varied significantly between habitats (PERMANOVA, p &lt; 0.001), with a higher mean (± SE) coral cover at BCR (26.95 ± 5.60%), followed by PCR (12.88 ± 3.88%). SCTLD was detected in all habitats, but the disease prevalence was significantly higher at BCR, ranging from 9.70 to 21.13% of colonies infected (Kruskal-Wallis ANOVA, p &lt; 0.007). Even though PCR habitats exhibited less coral cover, SCTLD prevalence was still elevated ranging from 6.66 to 15.07%. The deepest record of SCTLD at El Seco was 40.9 m. The majority (∼98%) of the corals infected with the disease were from the Orbicella complex spp. (faveolata/franksi). However, there were other infected species, such as Agaricia grahamae, A. lamarcki, Montastraea cavernosa, and Porites astreoides. As seen in the surveys conducted in 2011 and 2020, the loss of coral cover allows for the emergence of other benthic “detractors,” such as peyssonnelids, specifically Ramicrusta spp. Ramicrusta spp., an aggressive encrusting red alga known to take over available space and overgrow corals, significantly increased its substrate cover at the impacted reefs. Therefore, the severity and virulence of SCTLD will most likely have severe and long-lasting negative impacts on the coral communities at El Seco mesophotic reef system.

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