Influence of Anthropogenic Pressures on the Bioactivity Potential of Sponges and Soft Corals in the Coral Reef Environment

The wealth of marine sponges and soft corals in Indonesian waters represents a rich source of natural products. However, anthropogenic pressures potentially decrease diversity in coral reefs. Presented here are trends for tropical sponge and soft coral biodiversity and their bioactivity potential under the influence of increasing anthropogenic pressures. Samples were collected along transects (near, mid, and far) at Karimunjawa and Seribu Islands Marine National Parks and environmental parameters (salinity, pH, dissolved oxygen (DO), phosphate, nitrate, and ammonia), sponge and soft coral biodiversity, and the bioactivity potential of those organisms (50% Growth Inhibition (GI50) of cancer cell lines H460-Lung, MCF7-Breast, and SF268-CNS) are compared. The environmental conditions and biodiversity were found to be significantly different between groups of sampling sites (P<0.05). Canonical Discriminant Analysis (CDA) revealed DO was the discriminant factor driving the separation between groups (90.1%). Diversity tended to be higher in the Far group with strong and significant relation to DO (R= 0.611, P<0.05) and ammonia (R = -0.812, P<0.05). The CDA also showed that an increase in bioactivity (low % GI50) of sponge and soft coral extracts was related to a canonical function (57.21%) consisting of high DO, high pH, and low nutrients. These findings indicate the production of bioactive compounds is related to diversity and complexity of coral reef systems. Therefore, strategies for marine protection by mitigating the impacts of anthropogenic pressures needs to be optimized in order to conserve the overall environment and sustain its natural bioactivity potential indefinitely.

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Distribution and biological implications of plastic pollution on the fringing reef of Mo’orea, French Polynesia

10.7287/peerj.preprints.2697 ◽

2017 ◽

Author(s):

Elizabeth Janice Connors

Keyword(s):

Coral Reef ◽

Soft Coral ◽

French Polynesia ◽

Plastic Pollution ◽

Reef Environment ◽

Fringing Reef ◽

Coral Reef Environment ◽

Time Frames ◽

The Impact ◽

First Time

Plastic pollution has been recognized as a major pollutant of the open ocean, but the extent and impact of plastic pollution on the coral reef environment has yet to be fully understood. In this study, the distribution of both macro- (>5mm) and micro- plastic (<5mm) of a typical coral reef ecosystem— the fringing reef of an isolated South Pacific island, Mo’orea, French Polynesia—was quantified. During the course of the study, macroplastic was found on every beach on the island, and distribution of plastic was categorized by site type and the presence of Turbinaria oranata, a common macroalgae of Mo’orea. Microplastic (plastic pieces <5mm) was found in the water column of the fringing reef of the island, at a concentration of 0.74 plastic pieces per square meter. To test the impact on coral reef organisms of the plastic pollution found in the fringing reef, microplastic was exposed to a species of soft coral, Discosoma spp.in a laboratory setting. The resilience of Discosoma spp.in fluctuating temperatures and rising CO2 levels is well understood, but the effect of plastic pollution on Discosoma spp. and other corallimorphs has never before been analyzed. This study reports for the first time the ingestion of microplastic by the soft coral Discosoma spp. Positively buoyant and negatively buoyant microplastic were both ingested over different time frames. In addition, wild (not experimentally introduced) microplastic was found in the stomach cavity of the organism. These findings indicate that plastic debris are being ingested by Discosoma spp. and may impair the health of this prevalent coral reef organism.

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Distribution and biological implications of plastic pollution on the fringing reef of Mo’orea, French Polynesia

10.7287/peerj.preprints.2697v1 ◽

2017 ◽

Author(s):

Elizabeth Janice Connors

Keyword(s):

Coral Reef ◽

Soft Coral ◽

French Polynesia ◽

Plastic Pollution ◽

Reef Environment ◽

Fringing Reef ◽

Coral Reef Environment ◽

Time Frames ◽

The Impact ◽

First Time

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Evaluating the feasibility and advantage of a multi-purpose submerged breakwater for harbor protection and benthic habitat enhancement at Kahului Commercial Harbor, Hawai‘i: case study

SN Applied Sciences ◽

10.1007/s42452-020-04072-4 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Yuko Stender ◽

Michael Foley ◽

Ku’ulei Rodgers ◽

Paul Jokiel ◽

Amarjit Singh

Keyword(s):

Coral Reef ◽

Coral Cover ◽

Ecological Impact ◽

Coastal Protection ◽

Benthic Habitat ◽

Engineering Structures ◽

Camera System ◽

Reef Environment ◽

Submerged Breakwater ◽

Coral Reef Environment

AbstractConstruction of breakwaters provides an engineering solution for coastal protection. However, little effort has been made toward understanding the ecological impact on local coral reef ecosystems and developing engineering structures that would enhance the coral reef environment. A submerged breakwater proposed for Kahului Commercial Harbor, Hawai‘i, provided an opportunity to design a multi-purpose ‘reef structure’ to mitigate wave impacts while providing new coral reef habitat. This design involved ecological and environmental considerations alongside engineering principles, serving as a model for environmentally sound harbor development. This field study evaluated environmental conditions and reef community composition at the proposed site in a gradient extending outward from the harbor, using in situ data with multivariate analyses. Benthic and topographic features in the area were assessed using a towed drop camera system to relate to biological factors. Results that support breakwater topography should follow the natural spur and groove and depth of the adjacent reef and orient with wave direction. A deep area characterized by unconsolidated substrata and low coral cover would be replaced with the shallow, sloping hard bottom of the breakwater, and provide an exemplary area for corals to flourish while protecting the harbor from large ocean swells. Surfaces on shallow sloping hard bottoms receive higher levels of irradiance that benefits coral growth. Optimal levels of water motion facilitate sediment removal and promote coral recruitment and growth. The design of the Kahului Harbor submerged multi-purpose structure serves as a model for design of shoreline modification that enhances, rather than degrades, the local coral reef environment.

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Estimation of Sand Distribution in Coral Reef Environment using Colour Segmentation and Colour Thresholding Methods

Universiti Malaysia Terengganu Journal of Undergraduate Research ◽

10.46754/umtjur.v1i3.83 ◽

2019 ◽

Vol 1 (3) ◽

pp. 96-104

Author(s):

Pauleen Ong ◽

Muhammad Suzuri Hitam ◽

Zainuddin Bachok ◽

Mohd Safuan Che Din

Keyword(s):

Coral Reef ◽

Extraction Methods ◽

Colour Difference ◽

Reef Environment ◽

Still Images ◽

Point Count ◽

Automatic Computer ◽

Computer Based ◽

Coral Reef Environment ◽

Colour Segmentation

At present, marine scientists employ manual method to estimate the components in coral reef environment, where Coral Point Count with Excel extensions (CPCe) software is used to determine the coral reef components and substrate coverage. This manual process is laborious and time consuming, and needs experts to conduct the survey. In this paper, a prototype for estimating the distribution of sand cover in coral reef environment from still images by using colour extraction methods was introduced. The colour segmentation called delta E was used to calculate the colour difference between two colour samples. Another method used was colour threshold by setting the range of sand colour pixels. The system was developed by using a MATLAB software with image processing toolbox. The developed system was semi-automatic computer-based system that can be used by researchers even with little knowledge and experience to estimate the percentage of sand coverage in coral reef still images.

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Change Detection in Coral Reef Environment Using High-Resolution Images: Comparison of Object-Based and Pixel-Based Paradigms

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi7110441 ◽

2018 ◽

Vol 7 (11) ◽

pp. 441 ◽

Cited By ~ 11

Author(s):

Zhenjin Zhou ◽

Lei Ma ◽

Tengyu Fu ◽

Ge Zhang ◽

Mengru Yao ◽

...

Keyword(s):

Coral Reef ◽

Change Detection ◽

Accuracy Assessment ◽

Detection Accuracy ◽

Reef Environment ◽

Object Based ◽

Coral Reef Environment ◽

Study Sites ◽

Object Area ◽

Segmentation Image

Despite increases in the spatial resolution of satellite imagery prompting interest in object-based image analysis, few studies have used object-based methods for monitoring changes in coral reefs. This study proposes a high accuracy object-based change detection (OBCD) method intended for coral reef environment, which uses QuickBird and WorldView-2 images. The proposed methodological framework includes image fusion, multi-temporal image segmentation, image differencing, random forests models, and object-area-based accuracy assessment. For validation, we applied the method to images of four coral reef study sites in the South China Sea. We compared the proposed OBCD method with a conventional pixel-based change detection (PBCD) method by implementing both methods under the same conditions. The average overall accuracy of OBCD exceeded 90%, which was approximately 20% higher than PBCD. The OBCD method was free from salt-and-pepper effects and was less prone to images misregistration in terms of change detection accuracy and mapping results. The object-area-based accuracy assessment reached a higher overall accuracy and per-class accuracy than the object-number-based and pixel-number-based accuracy assessment.

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