scholarly journals Comparing Coral Colony Surveys From In-Water Observations and Structure-From-Motion Imagery Shows Low Methodological Bias

2021 ◽  
Vol 8 ◽  
Author(s):  
Courtney S. Couch ◽  
Thomas A. Oliver ◽  
Rhonda Suka ◽  
Mia Lamirand ◽  
Mollie Asbury ◽  
...  

As the threats to coral reefs mount, scientists and managers are looking for innovative ways to increase the scope, scale, and efficiency of coral reef monitoring. Monitoring changes in coral communities and demographic features provides key information about ecosystem function and resilience of reefs. While most monitoring programs continue to rely on in-water visual survey methods, scientists are exploring 3D imaging technologies such as photogrammetry, also known as Structure-from-Motion (SfM), to enhance precision of monitoring, increase logistical efficiency in the field, and generate a permanent record of the reef. Here, we quantitatively compare data generated from in-water surveys to SfM-derived metrics for assessing coral demography, bleaching, and diversity in the main Hawaiian Islands as part of NOAA’s National Coral Reef Monitoring Program. Our objectives were to compare between-method error to within-method error, test for bias between methods, and identify strengths and weaknesses of both methods. Colony density, average colony diameter, average partial mortality, prevalence of bleaching, species richness, and species diversity were recorded using both methods within the same survey areas. For all metrics, the magnitude of between-method error was comparable to the within-method error for the in-water method and between method error was significantly higher than within-method error for SfM for one of the seven metrics. Our results also reveal that a majority of the metrics do not vary significantly between methods, nor did we observe a significant interaction between method and habitat type or method and depth. Exceptions include estimates of partial mortality, bleaching prevalence, and Porites juvenile density–though differences between methods are generally small. Our study also highlights that SfM offers a unique opportunity to more rigorously quantify and mitigate inter-observer error by providing observers unlimited “bottom time” and the opportunity to work together to resolve difficult annotations. However, the necessary investment in equipment and expertise does present substantial up-front costs, and the time associated with curating imagery, photogrammetric modeling, and manual image annotation can reduce the timeliness of data reporting. SfM provides a powerful tool to reimagine how we study and manage coral reefs, and this study provides the first quantified methodological comparison to validate the transition from standard in-water methods to SfM survey methods for estimates of coral colony-level surveys.

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8167 ◽  
Author(s):  
Henri Vallès ◽  
Hazel A. Oxenford ◽  
Alex Henderson

Monitoring the state of coral reefs is necessary to identify drivers of change and assess effectiveness of management actions. There are several widely-used survey methods, each of which is likely to exhibit different biases that should be quantified if the purpose is to combine datasets obtained via different survey methods. The latter is a particularly important consideration when switching methodologies in long-term monitoring programs and is highly relevant to the Caribbean today. This is because of the continuing need for regionally comparable coral reef monitoring datasets and the fact that the Global Coral Reef Monitoring Network (GCRMN)-Caribbean node is now recommending a photoquadrat (PQ) method over the chain intercept transect method widely adopted by the members of the first truly regional monitoring network, Caribbean Coastal Marine Productivity Program (CARICOMP), in the early-1990s. Barbados, a member of the CARICOMP network, has been using a variation of the chain intercept method in its long-term coral reef monitoring program for more than two decades. Now a member of GCRMN-Caribbean, Barbados is considering switching to the PQ method in conformity with other regional members. Since we expect differences between methods, this study seeks to quantify the nature of those differences to inform Barbados and others considering switching methods. In 2017, both methods were concurrently implemented at 21 permanent monitoring plots across three major reef types in Barbados. Differences in % cover estimates for the six major benthic components, that is, hard corals, sponges, gorgonians, macroalgae, turf algae and crustose coralline algae, were examined within and among reef types. Overall, we found a complex pattern of differences between methods that depended on the benthic component, its relative abundance, and the reef type. We conclude that most benthic components would require a different conversion procedure depending on the reef type, and we provide an example of these procedures for Barbados. The factors that likely contribute to the complex pattern of between-method differences are discussed. Overall, our findings highlight that switching methods will be complicated, but not impossible. Finally, our study fills an important gap by underscoring a promising analytical framework to guide the comparison of ecological survey methods on coral reefs.


Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2081
Author(s):  
Mary E. Allen ◽  
Chloe S. Fleming ◽  
Sarah B. Gonyo ◽  
Erica K. Towle ◽  
Maria K. Dillard ◽  
...  

Despite being among the most valuable ecosystems on Earth, coral reefs face ongoing threats that could negatively impact the human populations who depend on them. The National Coral Reef Monitoring Program (NCRMP) collects and monitors data on various aspects of U.S. coral reefs to provide a holistic understanding of the status of the reefs and adjacent human communities. This paper explores results from the NCRMP’s first socioeconomic monitoring cycle using an ecosystem services framework and examines how these results can be used to improve coral reef management in the following U.S. coral reef jurisdictions: American Samoa, the Commonwealth of the Northern Mariana Islands, Florida, Guam, Hawai’i, Puerto Rico, and the U.S. Virgin Islands. Results suggest that residents in the U.S. Pacific coral reef basin may hold stronger cultural and provisioning values, whereas residents in the U.S. Atlantic coral reef basin may hold stronger regulating values. These findings suggest that outreach efforts have been successful in communicating benefits provided by coral reef ecosystems to the public. They also provide insight into which ecosystem services are valued in each jurisdiction, allowing resource managers to make science-based decisions about how to communicate conservation and management initiatives.


2020 ◽  
Vol 635 ◽  
pp. 233-242 ◽  
Author(s):  
PJ Edmunds ◽  
B Riegl

Coral reefs have long attracted attention because of their biological and economic importance, but this interest now has turned to examining the possibility of functional extirpation. Widespread declines in coral abundances have fueled the shift in motivation for studying reefs and catalyzed the proliferation of monitoring to record the changes underway. Despite appreciation of monitoring as a scientific endeavor, its primary use has continued to be the quantification of cover of coral, macroalgae, and a few other space holders. The limitations of coral cover in evaluating the consequences of changing coral abundance were highlighted decades ago. Yet neglect of the tools most appropriate for this task (demographic approaches) and continuing emphasis on a tool (coral cover) that is not ideal, indicates that these limitations are not widely appreciated. Reef monitoring therefore continues to underperform with respect to its potential, thus depriving scientists of the approaches necessary to project the fate of coral reefs and test hypotheses focused on the proximal causes of declining coral cover. We make the case that the coral reef crisis creates a need for coral demography that is more acute now than 4 decades ago. Modern demographic approaches are well suited to meet this need, but to realize their potential, consideration will need to be given to the possibility of expanding ecological monitoring of coral reefs to provide the data necessary for demographic analyses of their foundation taxon, the Scleractinia.


2020 ◽  
Vol 4 (2) ◽  
pp. 396-402
Author(s):  
Adib Mustofa ◽  
Budhi Agung Prasetyo

Data integration of structured ecosystem monitoring is crucial to support decision making for better marine ecosystem management. Coral reef monitoring data had been carried out in several separated studies in Lampung Province. However, lacks data integration among scientists and institutions making them inefficient as a basis of science for ecosystem management and decision making. This study was aimed to integrate available coral reef data in the last 15 years in Lampung Province and inform the spatial status of coral reef cover through WebGIS. Secondary data of coral reef study in the last 15 years were acquired from published articles and online-available-institutional reports. Data were then converted to digital mode prior to publishing them in the form of a website database through WebGIS. Results suggested that there were four main areas of coral reef studies in Lampung Province, namely Lampung bay, Krakatau, Bakauheni, and Lampung west coast. One-way ANOVA analysis of the last 5-year coral data shown there were no spatial differences on coral cover the four areas. Coral cover in Lampung west coast was generally in good shape at 56.13±1.74% and was higher compared to those in Lampung bay, Bakauheni, dan Krakatau regions, at 46.57±2.23%, 36.48±1.58%, and 35.6±3.69%, respectively. All coral data was published through WebGIS at https://sll.itera.ac.id/research/webgis . It is recommended this WebGIS could serve as a reference to conduct long-term coral reef monitoring in Lampung since it provides coordinates and coral reef status as baseline data for further analysis of coral reefs ecosystem.


2015 ◽  
Vol 58 (1) ◽  
pp. 51 ◽  
Author(s):  
Aldo Cróquer ◽  
Denise Debrot ◽  
Eduardo Klein ◽  
Martina Kurten ◽  
Sebastian Rodríguez ◽  
...  

<span>En este estudio se describe la condición de las comunidades bentónicas e ictícolas en cuatro arrecifes que fueron monitorizados durante 2003 y 2004 en Venezuela: Dos Mosquises Sur y Madrizquí en el Parque Nacional Archpiélago Los Roques y Caimán y Cayo Norte en el Parque Nacional Morrocoy. Para ello, empleamos los protocolos de CARICOMP y AGRRA para describir la comunidad bentónica e ictícola, respectivamente. La cobertura de los cinco principales grupos bentónicos difirió entre arrecifes (ANOVA anidado, p &lt; 0.05) más no entre parques. A pesar de pertenecer a diferentes parques la estructura de la comunidad bentónica entre Dos Mosquises Sur y Cayo Norte mostró un índice de similitud (Bray-Curtis) de 76%, mientras que Caiman difirió entre 57 y 68% con respecto a todos los arrecifes. Como se esperaba, la cobertura coralina, algas esponjas y octocorales no cambió entre 2003 y 2004. De forma similar, la comunidad de peces tampoco cambió en el tiempo y estuvo dominada por especies de herbívoros (Pomacentridae, Scaridae and Labridae). Sin embargo, en Los Roques los carnívoros de importancia comercial (e.g. lutjanidos y serranidos) fueron más abundantes que en Morrocoy. Aunque se esperaba encontrar diferencias en la comunidad bentónica e ictícola de Los Roques y Morrocoy, solo la de peces reflejó las diferencias, encontrándose en mejor estado de salud en Los Roques, mientras que CNOR, localizado en Morrocoy, presentó una cobertura similar o ligeramente mayor que los arrecifes localizados en Los Roques. Por lo tanto, los resultados de este estudio muestran que los arrecifes oceánicos no necesariamente se encuentran en mejor estado que los costeros. La inclusión de 3 nuevos sitios y la reincorporación de Caimán ha expandido y mejorado las capacidades de monitoreo de Venezuela y representa el primer paso hacia la creación de un sistema de monitoreo de arrecifes en el país.</span>


2020 ◽  
Vol 12 (3) ◽  
pp. 489 ◽  
Author(s):  
Manuel González-Rivero ◽  
Oscar Beijbom ◽  
Alberto Rodriguez-Ramirez ◽  
Dominic E. P. Bryant ◽  
Anjani Ganase ◽  
...  

Ecosystem monitoring is central to effective management, where rapid reporting is essential to provide timely advice. While digital imagery has greatly improved the speed of underwater data collection for monitoring benthic communities, image analysis remains a bottleneck in reporting observations. In recent years, a rapid evolution of artificial intelligence in image recognition has been evident in its broad applications in modern society, offering new opportunities for increasing the capabilities of coral reef monitoring. Here, we evaluated the performance of Deep Learning Convolutional Neural Networks for automated image analysis, using a global coral reef monitoring dataset. The study demonstrates the advantages of automated image analysis for coral reef monitoring in terms of error and repeatability of benthic abundance estimations, as well as cost and benefit. We found unbiased and high agreement between expert and automated observations (97%). Repeated surveys and comparisons against existing monitoring programs also show that automated estimation of benthic composition is equally robust in detecting change and ensuring the continuity of existing monitoring data. Using this automated approach, data analysis and reporting can be accelerated by at least 200x and at a fraction of the cost (1%). Combining commonly used underwater imagery in monitoring with automated image annotation can dramatically improve how we measure and monitor coral reefs worldwide, particularly in terms of allocating limited resources, rapid reporting and data integration within and across management areas.


2010 ◽  
Vol 35 (1) ◽  
pp. 31-41
Author(s):  
Suharsono

Indonesia is the largest archipelagic country in the world, composed of 18,110 islands with a coastline of 108,900 km long, extending some 5000 km long and 2000 km wide located between Asia and Australia. Coral reefs have important meaning and value for the coastal communities in term of economic, social, and cultural conditions. About 1.5 million people are traditional fishermen who live in subsistence level and depend on their lives fully on coral reefs' resources. The Indonesian coral reef contributed 14% of the world, distributed unevenly from Sabang to Merauke with the highest concentration around Sulawesi and Maluku. The species richness and the biodiversity of the Indonesian corals amounted to 590 species belonging to 82 genera or about 80% of the currently existing coral species in the world. Monitoring program has been done from 1993 to 2010 and it shows the trend of improvement in the term of live coral cover. The condition of coral reefs in Indonesia taken from 84 locations and 1048 sites were 50.54% in excellent condition, 26.72% in good condition, 37.21% in fair condition, and 30.82% in bad condition. Improving trends in live coral cover across all project sites shows that the live coral covers has increased in all monitored sites across all project districts with average yearly live coral coverage increase is about 2-5%. The National Policy, Strategy, and Action Plan was established, with its main objective of managing the coral reef ecosystems based on the balance between conservation and utilization, and it was reflected in the Law No. 27 of 2007 concerning coastal management and small islands. The most remarkable result of the program is community awareness, namely the decrease of fishing activities shows that the destructive fishing activities in all project district are now non-existent of at a minimal level. A special text books on marine lives for elementary, secondary, and high school is the most widely adopted by local education service as a book of local content. Whereas institutional strengthening program constitutes the most difficult, energy and time consuming activities. It is due to the rivaly between the local institution and the lac of officials' and the communities' knowledge on the conservation based management principle.


2024 ◽  
Vol 74 (10) ◽  
pp. 6139-2024
Author(s):  
MICHAŁ SCHULZ ◽  
ALEKSANDRA ŁOŚ ◽  
PATRYCJA SKOWRONEK ◽  
ANETA STRACHECKA

Coral reefs are the most productive ecosystems on Earth. They ensure the conservation of biodiversity and are a live habitat for 25% of all marine organisms. The main relationship on the coral reef is the symbiosis between corals and algae from the genus Symbiodinium (commonly called zooxanthellae). The authors of this publication have characterized and described the factors limiting the occurrence of coral reefs, including: water temperature, salinity, access to sunlight, contamination, physicochemical and hydromechanical parameters of water. Moreover anthropogenic threats to coral reefs have been specified, including diving tourism, ecological disasters (e.g. oil spills) and the development of marine aquaristics. Rapid changes in the basic living conditions are dangerous for corals and their symbionts and may cause the unsuitability of the new environment resulting in diseases such as coral bleaching. Corals bleaching is a disease associated with the break of the coral and algae relationship which results in a coral reef death on a global scale. Awareness of these negative factors, often related to human activity, may allow us to better understand the ecological processes that are the basis of reef functioning and might enable us to prevent and oppose to the changes and ecological recessions of coral reefs.


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