scholarly journals Rapid coral reef assessment using 3D modelling and acoustics: acoustic indices correlate to fish abundance, diversity and environmental indicators in West Papua, Indonesia

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10761
Author(s):  
Mika Peck ◽  
Ricardo F. Tapilatu ◽  
Eveline Kurniati ◽  
Christopher Rosado
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Low Cost ◽  
3D Models ◽  
3D Modelling ◽  
Fish Abundance ◽  
Live Coral ◽  
Underwater Cameras ◽  
West Papua ◽  
Structural Metrics

Background Providing coral reef systems with the greatest chance of survival requires effective assessment and monitoring to guide management at a range of scales from community to government. The development of rapid monitoring approaches amenable to collection at community level, yet recognised by policymakers, remains a challenge. Technologies can increase the scope of data collection. Two promising visual and audio approaches are (i) 3D habitat models, generated through photogrammetry from video footage, providing assessment of coral cover structural metrics and (ii) audio, from which acoustic indices shown to correlate to vertebrate and invertebrate diversity, can be extracted. Methods We collected audio and video imagery using low cost underwater cameras (GoPro Hero7™) from 34 reef samples from West Papua (Indonesia). Using photogrammetry one camera was used to generate 3D models of 4 m2 reef, the other was used to estimate fish abundance and collect audio to generate acoustic indices. We investigated relationships between acoustic metrics, fish abundance/diversity/functional groups, live coral cover and reef structural metrics. Results Generalized linear modelling identified significant but weak correlations between live coral cover and structural metrics extracted from 3D models and stronger relationships between live coral and fish abundance. Acoustic indices correlated to fish abundance, species richness and reef functional metrics associated with overfishing and algal control. Acoustic Evenness (1,200–11,000 Hz) and Root Mean Square RMS (100–1,200 Hz) were the best individual predictors overall suggesting traditional bioacoustic indices, providing information on sound energy and the variability in sound levels in specific frequency bands, can contribute to reef assessment. Conclusion Acoustics and 3D modelling contribute to low-cost, rapid reef assessment tools, amenable to community-level data collection, and generate information for coral reef management. Future work should explore whether 3D models of standardised transects and acoustic indices generated from low cost underwater cameras can replicate or support ‘gold standard’ reef assessment methodologies recognised by policy makers in marine management.

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 Coral Recruitment Spatial Distribution in its Relation With Coral Cover and Herbivorous Fish Abundance Within Conservation Area

2019 ◽  
Vol 24 (2) ◽  
pp. 91
Author(s):  
Zulfikar Afandy ◽  
Ario Damar ◽  
Syamsul Bahri Agus
Keyword(s):  
Spatial Distribution ◽  
Coral Reef ◽  
Coral Cover ◽  
Natural Habitat ◽  
Fish Abundance ◽  
Herbivorous Fish ◽  
Live Coral ◽  
Coral Recruitment ◽  
Conservation Area ◽  
Coral Colony

The continuity of coral reef ecosystem highly depends on the new coral larvae recruitment process. Hence, the information regarding distribution, the abundance of corals, and its relation to other variables are highly important in that ecosystem management. Research was conducted at nine stations represented each zone at the conservation area of Kapoposang Marine Tourism Park (TWP Kapoposang). This research aims at seeking for spatial variations of the abundance of coral recruitment at three primary zones monitored (core zone, sustainable fishing zone and utilization zone) and we further identified its relations with spatial variation of herbivorous fishes abundance and  coral cover’s condition at those zones. The coral recruitment observation employed transect quadrat sampling method with size of 1x1 meter and 10 times repetition at a similar depth, and the coral recruitment abundance measurement in natural habitat based on the amounts of juvenile corals has been defined as coral colony with size of ≤10 cm. Overall, this research has found 534 coral juveniles consisted of 19 genera and 7 families, and the average of juvenile coral density stood at 5.34±4.45 SE.m-2. The coral reef recruitment category at TWP Kapoposang could be classified as high and its abundance spatial distribution showed no significant differences between each zone, as well as not influenced by either herbivorous fish abundance variable or the percentage of live coral cover.

scholarly journals HUBUNGAN TUTUPAN BENTUK KARANG DENGAN KELIMPAHAN IKAN KARANG DI PERAIRAN PULAU CILIK TAMAN NASIONAL KARIMUNJAWA

2018 ◽  
Vol 7 (3) ◽  
pp. 246-252
Author(s):  
Lillah Gustilah ◽  
Anhar Solichin ◽  
Pujiono Wahyu Purnomo
Keyword(s):  
Coral Reef ◽  
Reef Fish ◽  
National Park ◽  
Coral Cover ◽  
Analysis Data ◽  
Fish Abundance ◽  
Live Coral ◽  
Central Java ◽  
Live Coral Cover ◽  
Coral Reef Ecosystems

Pulau Cilik merupakan salah satu dari 27 Pulau yang membentuk kepulauan Karimunjawa, Jawa Tengah. Kondisi terumbu karang yang masih baik menjadikan Pulau Cilik sebagai salah satu objek wisata. Adanya kegiatan pariwisata dikhawatirkan dapat mengganggu kondisi ekosistem terumbu karang. Tujuan dari penelitian ini untuk mengetahui jenis dan perbedaan kelimpahan ikan antar kedalaman dan hubungan kerapatan bentuk karang dan kelimpahan ikan karang di berbagai tingkat kedalaman yang berbeda di Pulau Cilik Taman Nasional Karimunjawa, Jawa Tengah. Penelitian ini dilaksanakan pada bulan September 2016 di perairan Pulau Cilik Taman Nasional Karimunjawa, Jawa Tengah. Metode penelitian yang digunakan dalam penelitian bersifat deskriptif. Pengamatan dilakukan pada 4 stasiun yaitu barat, selatan, utara dan timur Pulau Cilik terdapat 2 titik kedalaman titik 1 3 m dan 10 m, masing-masing dilakukan pengulangan pengamatan 2 kali. Pada setiap titik dilakukan pengukuran parameter fisika dan kimia air, pengamatan kondisi bentuk karang dan kelimpahan ikan. Analisis data meliputi indeks keanekaragaman, keseragaman dan perhitungan persentase tutupan karang hidup, karang mati, pasir dan pecahan karang. Data yang telah diperoleh selanjutnya dianalisa statistik dengan uji t, yaitu membandingkan kelimpahan ikan karang antara kedalaman 3 m dan 10 m serta membandingkan perbedaan hubungan antara bentuk karang dan ikan karang. Hasil Bentuk karang yang terdapat di Pulau Cilik yaitu bentuk karang keras dan kelimpahan ikan karang yang mendominasi adalah jenis ikan Pomacentridae. Hubungan kerapatan terumbu karang dengan kelimpahan ikan karang terdapat hubungan positif dengan nilai koefisien korelasi (R) sebesar 0,6861 pada kedalaman 3 m dan 10 m, Persentase tutupan terumbu karang hidup termasuk kategori baik (>50%). Cilik Island is one of 27 island that form the Karimunjawa islands, Central Java. The condition of coral reefs are still outstanding to make Cilik Island as one of tourist destinations. The existence of tourism activities is worried to disrupt the condition of coral reef ecosystems. The aim of this research is to recognise the types and differences of fish abundance between depth and the relation of coral cover density and abundance of reef fish at different level of depth in Cilik Island Karimunjawa National Park, Central Java. This research was conducted in September 2016 in the waters of Pulau Cilik Karimunjawa National Park, Central Java. The research method used in the research is descriptive method. The observations were conducted on 4 stations, they are west, south, north and east of Cilik Island has 2 points depth point of 3m and 10m,each of observation was reapeted twice. At each point, It was conducted the measurement on physical and chemical parameters of water, observation of coral cover condition and fish abundance. Analysis data included index of diversity, uniformity and calculation of percentage of live coral cover, dead corals, sand and coral fragments. The obtained data were then analyzed statistically with t-test, by comparing the abundance of reef fish between 3 m and 10 m of depth and comparing the differences between coral cover and reef fish. The results of coral shape found in Pulau Cilik is the form of hard corals and the abundance of reef fish that dominate is Pomacentridae fish species. The correlation of coral reef density with abundance of reef fish has positive correlation with correlation coefficient value (R) 0,6861 at depth of 3 m and 10 m. The percentage of live coral cover is good category (> 50%). 

scholarly journals Temporal comparison and predictors of fish species abundance and richness on undisturbed coral reef patches

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1459 ◽  
Author(s):  
Elena L.E.S. Wagner ◽  
Dominique G. Roche ◽  
Sandra A. Binning ◽  
Sharon Wismer ◽  
Redouan Bshary
Keyword(s):  
Species Richness ◽  
Coral Reef ◽  
Reef Fish ◽  
Fish Species ◽  
Patch Size ◽  
Coral Cover ◽  
Species Abundance ◽  
Fish Abundance ◽  
Live Coral ◽  
Live Coral Cover

Large disturbances can cause rapid degradation of coral reef communities, but what baseline changes in species assemblages occur on undisturbed reefs through time? We surveyed live coral cover, reef fish abundance and fish species richness in 1997 and again in 2007 on 47 fringing patch reefs of varying size and depth at Mersa Bareika, Ras Mohammed National Park, Egypt. No major human or natural disturbance event occurred between these two survey periods in this remote protected area. In the absence of large disturbances, we found that live coral cover, reef fish abundance and fish species richness did not differ in 1997 compared to 2007. Fish abundance and species richness on patches was largely related to the presence of shelters (caves and/or holes), live coral cover and patch size (volume). The presence of the ectoparasite-eating cleaner wrasse,Labroides dimidiatus, was also positively related to fish species richness. Our results underscore the importance of physical reef characteristics, such as patch size and shelter availability, in addition to biotic characteristics, such as live coral cover and cleaner wrasse abundance, in supporting reef fish species richness and abundance through time in a relatively undisturbed and understudied region.

scholarly journals Quantification of The Effects of Coral Reef Degradation On Butterflyfish Populations in The Southern Great Barrier Reef

2021 ◽  
Vol 4 (1) ◽  
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Fish Abundance ◽  
Live Coral ◽  
Reef Degradation ◽  
Significant Difference ◽  
Reef Health ◽  
Coral Reef Degradation ◽  
Abundance And Diversity ◽  
A Minor

Because of their wide abundance on coral reefs, butterflyfishes’ presence or absence can function as an indicator for overall reef health. A survey of both healthy and degraded coral reef flats off Heron Island in Queensland, Australia was conducted to determine the effects of decreasing coral cover on corallivorous fishes. During a four-day period at the end of October, 2013, four species of butterflyfish – two obligate and two facultative corallivorous butterflyfish species – were tallied along two transects in the reef flats. From a total of 291 individuals, there was a significant difference in habitat composition choice between healthy and degraded habitats seen by a p= 2.234e-10. Additionally, means extracted from log-transformed data suggest that the twelve percent decrease in live coral between transects of the healthy habitat caused a disproportionate decrease in fish abundance. This suggests that a minor loss of coral cover can result in a dramatic loss of fish abundance and diversity and may point towards a threshold where living coral can no longer sustain original population abundances of coral reef communities.

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 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 ACCURACY ASSESSMENT OF UNDERWATER PHOTOGRAMMETRIC THREE DIMENSIONAL MODELLING FOR CORAL REEFS

2016 ◽  
Vol XLI-B5 ◽  
pp. 821-828 ◽  
Author(s):  
T. Guo ◽  
A. Capra ◽  
M. Troyer ◽  
A. Gruen ◽  
A. J. Brooks ◽  
...  
Keyword(s):  
Coral Cover ◽  
Accuracy Assessment ◽  
Low Cost ◽  
Three Dimensional ◽  
Point Clouds ◽  
3D Modelling ◽  
Relative Accuracy ◽  
3D Point Clouds ◽  
The Individual ◽  
Working Distance

Recent advances in automation of photogrammetric 3D modelling software packages have stimulated interest in reconstructing highly accurate 3D object geometry in unconventional environments such as underwater utilizing simple and low-cost camera systems. The accuracy of underwater 3D modelling is affected by more parameters than in single media cases. This study is part of a larger project on 3D measurements of temporal change of coral cover in tropical waters. It compares the accuracies of 3D point clouds generated by using images acquired from a system camera mounted in an underwater housing and the popular GoPro cameras respectively. A precisely measured calibration frame was placed in the target scene in order to provide accurate control information and also quantify the errors of the modelling procedure. In addition, several objects (cinder blocks) with various shapes were arranged in the air and underwater and 3D point clouds were generated by automated image matching. These were further used to examine the relative accuracy of the point cloud generation by comparing the point clouds of the individual objects with the objects measured by the system camera in air (the best possible values). Given a working distance of about 1.5 m, the GoPro camera can achieve a relative accuracy of 1.3 mm in air and 2.0 mm in water. The system camera achieved an accuracy of 1.8 mm in water, which meets our requirements for coral measurement in this system.

Low Cost Methods Used to Create 3D Models

2017 ◽  
Author(s):  
Agnieszka Chmurzynska ◽  
Karolina Hejbudzka ◽  
Andrzej Dumalski
Keyword(s):  
Laser Scanning ◽  
3D Model ◽  
Low Cost ◽  
3D Models ◽  
3D Modelling ◽  
Kinect Sensor ◽  
Applied Technology ◽  
Gaming Environment

During the last years the softwares and applications that can produce 3D models using low-cost methods have become very popular. What is more, they can be successfully competitive with the classical methods. The most wellknown and applied technology used to create 3D models has been laser scanning so far. However it is still expensive because of the price of the device and software. That is why the universality and accessibility of this method is very limited. Hence, the new low cost methods of obtaining the data needed to generate 3D models appeare on the market and creating 3D models have become much easier and accessible to a wider group of people. Because of their advantages they can be competitive with the laser scanning. One of the methods uses digital photos to create 3D models. Available software allows us to create a model and object geometry. Also very popular in the gaming environment device – Kinect Sensor can be successfully used as a different method to create 3D models. This article presents basic issues of 3D modelling and application of various devices, which are commonly used in our life and they can be used to generate a 3D model as well. Their results are compared with the model derived from the laser scanning. The acquired results with graphic presentations and possible ways of applications are also presented in this paper.

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