scholarly journals Large-scale coral reef rehabilitation after blast fishing in Indonesia

2018 ◽  
Vol 27 (2) ◽  
pp. 447-456 ◽  
Author(s):  
Susan L. Williams ◽  
Christine Sur ◽  
Noel Janetski ◽  
Jordan A. Hollarsmith ◽  
Saipul Rapi ◽  
...  
Keyword(s):  
Coral Reef ◽  
Large Scale ◽  
Blast Fishing

scholarly journals An economic analysis of blast fishing on Indonesian coral reefs

1999 ◽  
Vol 26 (2) ◽  
pp. 83-93 ◽  
Author(s):  
C. PET-SOEDE ◽  
H.S.J. CESAR ◽  
J.S. PET
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Large Scale ◽  
Cost Benefit ◽  
High Potential ◽  
Coastal Protection ◽  
Economic Costs ◽  
Vast Number ◽  
Potential Value ◽  
Blast Fishing

Characteristics, impacts and economic costs and benefits of blast fishing have been little investigated and they were therefore studied in Indonesia, at the scale of individual fishing households and of Indonesian society as a whole. Although illegal and highly destructive to coral reefs, blast fishing provides income and fish to a vast number of coastal fishers who claim that they have no alternative to make a living. Crew members in small-, medium- and large-scale blast fishing operations earned net incomes per month of US$55, 146 and 197 respectively. Boat owners in the same types of operations earned US$55, 393 and 1100 respectively. These incomes were comparable to the highest incomes in the conventional coastal fisheries. At the individual household level, the differences between the three types of operations show clear incentives for scale enlargement. The cost-benefit balance at the society level was calculated with an economic model. This analysis showed a net loss after 20 years of blast fishing of US$306 800 per km2 of coral reef where there is a high potential value of tourism and coastal protection, and US$33 900 per km2 of coral reef where there is a low potential value. The main quantifiable costs are through loss of the coastal protection function, foregone benefits of tourism, and foregone benefits of non-destructive fisheries. The economic costs to society are four times higher than the total net private benefits from blast fishing in areas with high potential value of tourism and coastal protection. This analysis of characteristics, impact and economics of blast fishing should help to raise the political will to ban blast fishing from Indonesian waters. Moreover, it allows for an evaluation of possible management solutions, taking into account their costs and the socio-economic framework that caused coastal fishers to start using explosives.

scholarly journals Stokes drift through corals

2021 ◽  
Author(s):  
Joseph J. Webber ◽  
Herbert E. Huppert
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Porous Layer ◽  
Large Scale ◽  
Fluid Layer ◽  
Ocean Waves ◽  
Stokes Drift ◽  
Inviscid Fluid ◽  
Porous Bed ◽  
Vertical Drift

AbstractMotivated by shallow ocean waves propagating over coral reefs, we investigate the drift velocities due to surface wave motion in an effectively inviscid fluid that overlies a saturated porous bed of finite depth. Previous work in this area either neglects the large-scale flow between layers (Phillips in Flow and reactions in permeable rocks, Cambridge University Press, Cambridge, 1991) or only considers the drift above the porous layer (Monismith in Ann Rev Fluid Mech 39:37–55, 2007). Overcoming these limitations, we propose a model where flow is described by a velocity potential above the porous layer and by Darcy’s law in the porous bed, with derived matching conditions at the interface between the two layers. Both a horizontal and a novel vertical drift effect arise from the damping of the porous bed, which requires the use of a complex wavenumber k. This is in contrast to the purely horizontal second-order drift first derived by Stokes (Trans Camb Philos Soc 8:441–455, 1847) when working with solely a pure fluid layer. Our work provides a physical model for coral reefs in shallow seas, where fluid drift both above and within the reef is vitally important for maintaining a healthy reef ecosystem (Koehl et al. In: Proceedings of the 8th International Coral Reef Symposium, vol 2, pp 1087–1092, 1997; Monismith in Ann Rev Fluid Mech 39:37–55, 2007). We compare our model with field measurements by Koehl and Hadfield (J Mar Syst 49:75–88, 2004) and also explain the vertical drift effects as documented by Koehl et al. (Mar Ecol Prog Ser 335:1–18, 2007), who measured the exchange between a coral reef layer and the (relatively shallow) sea above.

scholarly journals Incorporating feasibility and collaboration into large-scale planning for regional recovery of coral reef fisheries

2018 ◽  
Vol 604 ◽  
pp. 211-222 ◽  
Author(s):  
KR Jones ◽  
JM Maina ◽  
S Kark ◽  
TR McClanahan ◽  
CJ Klein ◽  
...  
Keyword(s):  
Coral Reef ◽  
Large Scale ◽  
Coral Reef Fisheries

scholarly journals Improved Coastal Erosion Prevention Using a Hybrid Method with an Artificial Coral Reef: Large-Scale 3D Hydraulic Experiment

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2801
Author(s):  
Taeyoon Kim ◽  
Seungil Baek ◽  
Yongju Kwon ◽  
Jooyong Lee ◽  
Sung Min Cha ◽  
...  
Keyword(s):  
Coral Reef ◽  
Hybrid Method ◽  
Coastal Erosion ◽  
Large Scale ◽  
Local Scour ◽  
Return Flow ◽  
Structural Failure ◽  
Submerged Breakwater ◽  
Sediment Transportation ◽  
Erosion Mitigation

Coastal erosion, a worldwide social issue, has garnered substantial attention. Numerous methods have been implemented to control coastal erosion problems; however, the presence of rigid structures limits erosion mitigation, thereby causing various challenges. For instance, in the case of submerged breakwaters, local scour in front of the structure and scour caused by the flow occurring in open inlets affect the subsidence and stability of the structure and can also cause structural failure. To solve these problems, this paper proposes a hybrid method of using a submerged breakwater with an artificial coral reef installation; further, this study evaluates the attenuation of waves and mitigation of sediment transportation through large-scale 3D hydraulic experiments. We found that the hybrid method with an artificial coral reef installed in the open inlet shows excellent wave control and plays a clearly beneficial role in the advancement of the shoreline. The artificial coral reef method reduced the return flow generated by the drag force at the breakwater shoulder and open inlet. In addition, scour at the breakwater shoulder was inhibited by collecting the sand escaping offshore. Simultaneously, scour at the open inlet was also mitigated. The application of the hybrid method compensated for the problems caused by local scour and erosion in the submerged breakwater, thereby leading to the improvement of its function. Therefore, the hybrid method proposed in this paper was determined to be applicable not only for submerged breakwaters, but also for various structures for controlling coastal erosion.

scholarly journals A novel low-cost, high-precision sea temperature sensor for coral reef monitoring

2020 ◽  
Vol 96 (1) ◽  
pp. 97-110
Author(s):  
James Hendee ◽  
Natchanon Amornthammarong ◽  
Lewis Gramer ◽  
Andrea Gomez
Keyword(s):  
Coral Reef ◽  
High Precision ◽  
Temperature Sensor ◽  
Large Scale ◽  
Low Cost ◽  
Global Scale ◽  
Temperature Sensors ◽  
Sea Temperature ◽  
Temperature Regimes ◽  
Reef Monitoring

The role of elevated sea temperatures in coral bleaching has been well documented. Many of the sea temperature records utilized for purposes of widespread, multi-species bleaching predictions in recent publications have been acquired through satellite remote sensing. Satellites estimate sea temperatures at only a narrow range of depths near the surface of the ocean and may therefore not adequately represent the true temperatures endured by the world's coral ecosystems. To better characterize sea temperature regimes that coral reef ecosystems experience, as well as better define the individual thresholds for each species that bleaches, in situ sea temperature sensors are required. Commercial sensors are expensive in large quantities, however, reducing the capacity to conduct large- scale research programs to elucidate the range of significant scales of temperature variability. At the National Oceanic and Atmospheric Administration's (NOAA) Atlantic Oceanographic and Meteorological Laboratory (AOML), we designed a low-cost (roughly US$9 in parts) and high- precision sea temperature sensor that uses an Arduino microprocessor board and a high accuracy thermistor. This new temperature sensor autonomously records temperatures onto a memory chip and provides better accuracy (+0.05 °C) than a comparable commercial sensor (+0.2 °C). Moreover, it is not difficult to build; anyone who knows how to solder can build the temperature sensor. In March 2019, students at middle and high schools in Broward County, Florida, built close to 60 temperature sensors. During 2019, these sensors will be deployed by Reef Check, a global-scale coral reef monitoring organization, as well as by other programs to determine worldwide sea temperature regimes through the Opuhala Project (https://www. coral. noaa. gov/opuhala). This paper chronicles results from the initial proof-of-concept deployments for these AOML-designed sensors.

The scientific issues surrounding remote detection of submerged coral ecosystems

1998 ◽  
Vol 22 (2) ◽  
pp. 190-221 ◽  
Author(s):  
Heather Holden ◽  
Ellsworth LeDrew
Keyword(s):  
Remote Sensing ◽  
Coral Reef ◽  
Coral Reefs ◽  
Large Scale ◽  
Aerial Photographs ◽  
Coastal Zones ◽  
Global Status ◽  
Coral Reef Ecosystems ◽  
Remote Estimation

According to the 1993 colloquium on the ‘Global status of coral reefs', our understanding of the global role of coral reefs is inadequate. To increase our understanding, an accurate large-scale mapping and monitoring programme is necessary. Historically, coastal zones have been mapped using traditional surveying tools such as topographic maps, nautical charts, existing aerial photographs and direct observations. Although less expensive than digital imagery, exclusive use of these traditional tools may not be practical for monitoring large or remote coral reef ecosystems accurately. Researchers are attempting to develop an adequate coral reef mapping system based on digital remote sensing, but are impeded by issues such as effects of the intervening water column and spectral distinction of bottom types. The two variables discussed, which will contribute to our understanding of the global role of coral reefs, are: 1) remote sensing of submerged coral reefs in general; and 2) remote sensing of coral bleaching in particular. A summary of radiative transfer theory is presented and case studies of attempts at mapping remotely the geographic extent and health of submerged ecosystems, as well as a discussion of the remote estimation of water depth and quality. Problems in the translation and delivery of information to the end user are presented, and possible solutions suggested.

scholarly journals Herbivory, Connectivity, and Ecosystem Resilience: Response of a Coral Reef to a Large-Scale Perturbation

PLoS ONE ◽  
2011 ◽  
Vol 6 (8) ◽  
pp. e23717 ◽  
Author(s):  
Thomas C. Adam ◽  
Russell J. Schmitt ◽  
Sally J. Holbrook ◽  
Andrew J. Brooks ◽  
Peter J. Edmunds ◽  
...  
Keyword(s):  
Coral Reef ◽  
Large Scale ◽  
Ecosystem Resilience ◽  
Scale Perturbation

scholarly journals Climate Change Induced Thermal Stress Caused Recurrent Coral Bleaching over Gulf of Kachchh and Malvan Marine Sanctuary, West Coast of India

2021 ◽  
Author(s):  
Mohit Arora ◽  
Kalyan De ◽  
Nandini Ray Chaudhury ◽  
Mandar Nanajkar ◽  
Prakash Chauhan ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Coral Reef ◽  
Coral Reefs ◽  
Coral Bleaching ◽  
Large Scale ◽  
Heat Waves ◽  
Southern Oscillation ◽  
Coral Cover ◽  
Imminent Threat ◽  
Marginal Reefs

Coral reefs are one of the most sensitive, productive, and invaluable biological resources on the earth. However, coral reefs are facing unprecedented stress due to ongoing climate changes and intensified anthropogenic disturbances globally. Elevated Sea Surface Temperature (SST) has emerged as the most imminent threat to the thermos-sensitive reef-building corals. The 2010–2014-2016 El Niño Southern Oscillation (ENSO) caused prolonged marine heat waves (MHWs) that led to the most widespread coral bleaching and mortality in the tropical Indi-Pacific regions. Coral bleaching prediction is vital for the management of the reef biodiversity, ecosystem functioning, and services. Recent decades, satellite remote sensing has emerged as a convenient tool for large-scale coral reef monitoring programs. As thermal stress is a critical physical attribute for coral bleaching hence, the present study examines the effectiveness of the elevated SSTs as a proxy to predict coral bleaching in shallow water marginal reefs. Advanced Very High-Resolution Radiometer (AVHRR) satellite data from the NOAA Coral Reef Watch’s (CRW) platform has been used for this study. Coral bleaching indices like Bleaching Threshold (BT), Positive SST Anomaly (PA), and Degree Heating Weeks (DHW) are computed to analyze the thermal stress on the coral reefs. The computed thermal stress from satellite-derived SST data over regions concurrence with the mass coral bleaching (MCB) events. This study concludes that in the last decades (2010 to 2019) the coral cover around these regions has dramatically declined due to higher SST, which indicates that the thermal stress induced recurrent bleaching events attributed to the coral loss.

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