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>

scholarly journals COMPARISON OF COMMERCIAL STRUCTURE-FROM-MOTION PHOTOGRAMMETY SOFTWARE USED FOR UNDERWATER THREE-DIMENSIONAL MODELING OF CORAL REEF ENVIRONMENTS

2017 ◽  
Vol XLII-2/W3 ◽  
pp. 127-131 ◽  
Author(s):  
J. H. R. Burns ◽  
D. Delparte
Keyword(s):  
Coral Reef ◽  
Structural Characteristics ◽  
Spatial Scales ◽  
3D Structure ◽  
Light Availability ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Physical Structure ◽  
Natural Environments ◽  
Ecological Processes

Structural complexity in ecosystems creates an assortment of microhabitat types and has been shown to support greater diversity and abundance of associated organisms. The 3D structure of an environment also directly affects important ecological parameters such as habitat provisioning and light availability and can therefore strongly influence ecosystem function. Coral reefs are architecturally complex 3D habitats, whose structure is intrinsically linked to the ecosystem biodiversity, productivity, and function. The field of coral ecology has, however, been primarily limited to using 2-dimensional (2D) planar survey techniques for studying the physical structure of reefs. This conventional approach fails to capture or quantify the intricate structural complexity of corals that influences habitat facilitation and biodiversity. A 3-dimensional (3D) approach can obtain accurate measurements of architectural complexity, topography, rugosity, volume, and other structural characteristics that affect biodiversity and abundance of reef organisms. Structurefrom- Motion (SfM) photogrammetry is an emerging computer vision technology that provides a simple and cost-effective method for 3D reconstruction of natural environments. SfM has been used in several studies to investigate the relationship between habitat complexity and ecological processes in coral reef ecosystems. This study compared two commercial SfM software packages, Agisoft Photoscan Pro and Pix4Dmapper Pro 3.1, in order to assess the cpaability and spatial accuracy of these programs for conducting 3D modeling of coral reef habitats at three spatial scales.

scholarly journals 3D assessment of a coral reef at Lalo Atoll reveals varying responses of habitat metrics following a catastrophic hurricane

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kailey H. Pascoe ◽  
Atsuko Fukunaga ◽  
Randall K. Kosaki ◽  
John H. R. Burns
Keyword(s):  
Coral Reef ◽  
Habitat Complexity ◽  
Coral Cover ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Complexity Metrics ◽  
Complete Destruction ◽  
Tabulate Coral ◽  
Before And After ◽  
Coral Reef Habitat

AbstractExtreme disturbances such as hurricanes can cause reductions in coral cover and three-dimensional (3D) structural complexity of coral reefs. We examined changes in structural complexity utilizing 3D reconstruction of a coral-reef site before and after Hurricane Walaka passed through Lalo of the Northwestern Hawaiian Islands. This event resulted in complete destruction of the coral-reef habitat, with dramatic changes in benthic cover from pre-hurricane tabulate coral to post-hurricane rubble. Rugosity and mean slope decreased after the hurricane, while structural complexity, captured by vector ruggedness measure (VRM), showed resolution-specific responses. This metric captured the structural complexity of rubble at a high raster resolution of 1 cm and that of tabulate coral at lower resolutions, resulting in decreases in mean VRM values at 2- and 4-cm resolutions but an increase at 1-cm resolution. Variability in profile and planform curvature was reduced after the hurricane due to a disappearance of extreme curvature values created by the tabulate coral after the hurricane. This study highlights the varying responses of habitat complexity metrics to the complete destruction of a coral reef and provides us with insights into how choices of habitat complexity metrics can affect quantitative assessments of 3D habitat structure.

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.

Coral reef condition in several dive points around Bunaken Island, North Sulawesi

2014 ◽  
pp. 44
Author(s):  
Robert Towoliu
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Integrated Management ◽  
Good Condition ◽  
Live Coral ◽  
Core Zone ◽  
Integrated Management System ◽  
North Sulawesi ◽  
Live Coral Cover ◽  
Reef Condition

In order to know the coral reef conditions at several diving points around Bunaken Island, three dive locations (Ron’s point, Lekuan, and Tawara) were chosen as representative locations receiving pressures from snorkeling and SCUBA diving activities, while  core zone was representative of location for  no diving and fishing activities.  Results showed that location with diving activities had live coral cover  ranging from 16.89% to 45.78% at 3 and 10m depths, with condition range of bad to moderate, while the location for no diving and fishing activities (core zone) had live coral cover of 55.03% at 3m and 58.15% at 10m, respectively,  with good condition category.  The present study indicated that the diving activities have affected the coral reef condition, so that a sustainable integrated management system is needed to use the marine ecotourism potency without degrading the coral reef condition in Bunaken Island. Untuk mengetahui kondisi terumbu karang di beberapa lokasi penyelaman di Pulau Bunaken, tiga lokasi penyelaman(Ron’s point, Lekuan, dan Tawara) dipilih mewakili lokasi dengan tekanan aktivitas penyelaman snorkeling maupun SCUBA, sedangkan satu lokasi lainnya yaitu zona inti dipilih mewakili lokasi tanpa aktivitas penyelaman maupun aktivitas penangkapan ikan.  Hasil penelitian ini memperlihatkan bahwa lokasi dengan tekanan aktivitas penyelaman memiliki prosentase tutupan karang batu/hidup berkisar antara 16,89% - 45,78% pada kedalaman 3 dan 10m, dengan kategori kondisi terumbu karang buruk sampai cukup, sedangkan pada lokasi yang tidak memiliki aktivitas penyelaman memiliki prosentase tutupan karang batu/hidup sebesar 53,03% pada 3m dan 58,15% pada 10m dengan kategori kondisi terumbu karang adalah baik.  Hasil penelitian ini mengindikasikan bahwa aktivitas penyelaman snorkeling maupun SCUBA berdampak pada kondisi terumbu karang di Pulau Bunaken, sehingga sangat diperlukan system pengelolaan yang terpadu dan berkesinambungan dalam memanfaatkan secara maksimal potensi ekowisata bahari tanpa merusak ekosistem terumbu karang di Pulau Bunaken.

scholarly journals Evaluation of coral reef carbonate production models at a global scale

2015 ◽  
Vol 12 (5) ◽  
pp. 1339-1356 ◽  
Author(s):  
N. S. Jones ◽  
A. Ridgwell ◽  
E. J. Hendy
Keyword(s):  
Coral Reef ◽  
Predictive Power ◽  
Numerical Models ◽  
Coral Cover ◽  
Light Availability ◽  
Global Scale ◽  
Data Set ◽  
Carbonate Production ◽  
Future Global Warming ◽  
Atmospheric Co2 Concentrations

Abstract. Calcification by coral reef communities is estimated to account for half of all carbonate produced in shallow water environments and more than 25% of the total carbonate buried in marine sediments globally. Production of calcium carbonate by coral reefs is therefore an important component of the global carbon cycle; it is also threatened by future global warming and other global change pressures. Numerical models of reefal carbonate production are needed for understanding how carbonate deposition responds to environmental conditions including atmospheric CO2 concentrations in the past and into the future. However, before any projections can be made, the basic test is to establish model skill in recreating present-day calcification rates. Here we evaluate four published model descriptions of reef carbonate production in terms of their predictive power, at both local and global scales. We also compile available global data on reef calcification to produce an independent observation-based data set for the model evaluation of carbonate budget outputs. The four calcification models are based on functions sensitive to combinations of light availability, aragonite saturation (Ωa) and temperature and were implemented within a specifically developed global framework, the Global Reef Accretion Model (GRAM). No model was able to reproduce independent rate estimates of whole-reef calcification, and the output from the temperature-only based approach was the only model to significantly correlate with coral-calcification rate observations. The absence of any predictive power for whole reef systems, even when consistent at the scale of individual corals, points to the overriding importance of coral cover estimates in the calculations. Our work highlights the need for an ecosystem modelling approach, accounting for population dynamics in terms of mortality and recruitment and hence calcifier abundance, in estimating global reef carbonate budgets. In addition, validation of reef carbonate budgets is severely hampered by limited and inconsistent methodology in reef-scale observations.

scholarly journals Using virtual reality to estimate aesthetic values of coral reefs

2018 ◽  
Vol 5 (4) ◽  
pp. 172226 ◽  
Author(s):  
Julie Vercelloni ◽  
Sam Clifford ◽  
M. Julian Caley ◽  
Alan R. Pearse ◽  
Ross Brown ◽  
...  
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Structural Complexity ◽  
Natural Environments ◽  
Natural Ecosystems ◽  
Aesthetic Value ◽  
Natural Systems ◽  
Holistic Conservation ◽  
Past Experiences ◽  
Aesthetic Values

Aesthetic value, or beauty, is important to the relationship between humans and natural environments and is, therefore, a fundamental socio-economic attribute of conservation alongside other ecosystem services. However, beauty is difficult to quantify and is not estimated well using traditional approaches to monitoring coral-reef aesthetics. To improve the estimation of ecosystem aesthetic values, we developed and implemented a novel framework used to quantify features of coral-reef aesthetics based on people's perceptions of beauty. Three observer groups with different experience to reef environments (Marine Scientist, Experienced Diver and Citizen) were virtually immersed in Australian's Great Barrier Reef (GBR) using 360° images. Perceptions of beauty and observations were used to assess the importance of eight potential attributes of reef-aesthetic value. Among these, heterogeneity, defined by structural complexity and colour diversity, was positively associated with coral-reef-aesthetic values. There were no group-level differences in the way the observer groups perceived reef aesthetics suggesting that past experiences with coral reefs do not necessarily influence the perception of beauty by the observer. The framework developed here provides a generic tool to help identify indicators of aesthetic value applicable to a wide variety of natural systems. The ability to estimate aesthetic values robustly adds an important dimension to the holistic conservation of the GBR, coral reefs worldwide and other natural ecosystems.

scholarly journals CONDITION OF CORAL AND REEF FISH IN THE LOCATION OF FISH CATCHING USING DYNAMITE FISHING IN KAPOPOSANG WATER PARK AND THE SURROUNDING SEA

2020 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Mahmudin Mahmudin ◽  
Chair Rani ◽  
Hamzah Hamzah
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Cover ◽  
Low Cost ◽  
Fish Abundance ◽  
Live Coral ◽  
Coral Reef Ecosystem ◽  
Control Location ◽  
Target Fish ◽  
Reef Ecosystem

Dynamite fishing is one of the causes of damage to the coral reef ecosystem in Indonesia. Fishing activities using explosives (dynamite fishing) occur because of the desire of fishermen to get a lot of catch with low cost in a short time. Kapoposang Water Park (WP) is a region rich in marine biological resources. However, dynamite fishing activities which are still found within the area have caused the coral reef ecosystem to be severely damaged. The results showed a lower difference in the percentage of live coral cover at dynamite fishing locations (DF1, DF2) compared to control locations (K1, K2). In addition, the highest average values of coral fish abundance were found at locations K1, DF1, and DF2. Conversely, the results of the analysis found the lowest fish abundance at the K2 location. Different from the average number of reef fish species that were higher at the control location (K1, K2) compared to dynamite fishing locations (DF1, DF2). For the target fish biomass there is no real difference between the control location and dynamite fishing.

scholarly journals Status of Coral Reefs in the Water of Spermonde, Makassar, South Sulawesi

2021 ◽  
Vol 324 ◽  
pp. 03007
Author(s):  
Ni Wayan Purnama Sari ◽  
Rikoh Manogar Siringoringo ◽  
Muhammad Abrar ◽  
Risandi Dwirama Putra ◽  
Raden Sutiadi ◽  
...  
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Coral Cover ◽  
Public Awareness ◽  
Live Coral ◽  
Health Index ◽  
Point Count ◽  
Live Coral Cover ◽  
Reef Health ◽  
Index Value

Observations of the condition of coral reefs have been carried out in Spermonde waters from 2015 to 2018. The method used in this observation uses Underwater Photo Transect (UPT), and the data obtained is analyzed using CPCe (Coral Point Count with Excel Extensions) software. The results show that the percentage of coral cover has increased from year to year. The percentage of live coral cover in 2015 was 19.64%, 23.60 in 2016, 23.72% in 2017, and 27.83% in 2018. The increase in live coral cover from year to year is thought to occur due to the availability of nutrients. or increasing public awareness, considering this location is one of the most famous tourist attractions in Makassar. Coral reef health index values can be used to classify coral reef health. Through the analysis of the coral reef health index, an index value of 4 was obtained, which means that the condition of the coral reefs is in the “moderate” category.

scholarly journals KEPADATAN MEGABENTOS PADA EKOSISTEM TERUMBU KARANG DI PERAIRAN DESA PERLANG BANGKA TENGAH, BANGKA BELITUNG

2019 ◽  
Vol 13 (2) ◽  
pp. 173-177
Author(s):  
Arham Hafidh Akbar ◽  
Sudirman Adibrata ◽  
Wahyu Adi
Keyword(s):  
Coral Reef ◽  
Data Collection ◽  
Coral Cover ◽  
Live Coral ◽  
Coral Reef Ecosystems ◽  
Tridacna Maxima ◽  
Belt Transect ◽  
Tridacna Gigas ◽  
Drupella Cornus ◽  
Diadema Setosum

This study aims to analyze the density of megabenthos in coral reef ecosystems in the waters of Perlang Village. This research was conducted in November 2019 in the waters of Perlang Village with the megabentos data collection method using the Bentos Belt Transect (BBT) method based on COREMAP CTI LIPI (2017) with 5 data collection stations. The results found 603 individuals consisting of 9 species from 4 megabenthos families in coral reef ecosystems. Species found at the study site are Diadema setosum, Diadema antillarium (Familli Deadematidae), Drupella cornus, Drupella rugosa (Family Murcidae), Trochus sp, Trochus conus, Tectus pyramis (Family Trochidae), Tridacna gigas, and Tridacna maxima (Family Tridacnidae) . The highest attendance percentage of all stations was obtained by Diadema setosum of 47.93% (289 people). Percentage of live coral cover from 5 observation stations ranged from 57.44% - 91.78%. Observation pensions that received the highest percentage of cover values ​​were at pension 2 with 91.78% in the very good category.

scholarly journals Keanekaragaman dan Biomassa Ikan Karang serta Keterkaitannya dengan Tutupan Karang Hidup di Perairan Manggis, Kabupaten Karangasem, Bali

2018 ◽  
Vol 5 (2) ◽  
pp. 164
Author(s):  
I Made Raditya Putra ◽  
I Gusti Ngurah Putra Dirgayusa ◽  
Elok Faiqoh
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Coral Cover ◽  
Total Biomass ◽  
Live Coral ◽  
Strong Positive Correlation ◽  
Living Coral ◽  
Positive Correlation ◽  
Live Coral Cover

The existence of coral reef fish is closely related to the availability of coral reef resource as a habitat. Coral reef fish is a biota that has a fascination with a variety of color patterns and fascinating. Differences in coral cover conditions will affect the abundance of coral reef fish, especially those with strong linkages to living corals. This research was conducted in June - August 2017 by using line intercept transect (LIT) method for coral cover percentage and visual census method for biodiversity and biomass of coral reef fish with 3 research stations in Manggis waters, Karangasem. From the research results, it shows that the diversity index ranged between 2.54 - 2.70 which means the diversity of coral reef fish in the medium category and the stability of the community is in the medium. Furthermore, total biomass of coral reef fish ranged between 186,17 - 1692,08 kg / ha. The results stated that the percentage of live coral cover in Manggis waters ranged from 3.83% to 12.44% which means that live coral cover is categorized as bad. A very strong positive correlation between living coral conditions and coral reef fish biomass was 92.42%. Meanwhile, the relationship between living coral conditions and the diversity of coral reef fish had a strong positive correlation of 65.4%. The diversity of coral reef fish in waters is not only caused by live coral cover; however, it is caused by coral reef ecosystems that are associated in the bottom of the waters.

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