Sea-level rise will drive divergent sediment transport patterns on fore reefs and reef flats, potentially causing erosion on Atoll Islands

Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Earth Surface 125 (2020): e2019JF005446, doi: 10.1029/2019JF005446.Atoll reef islands primarily consist of unconsolidated sediment, and their ocean‐facing shorelines are maintained by sediment produced and transported across their reefs. Changes in incident waves can alter cross‐shore sediment exchange and, thus, affect the sediment budget and morphology of atoll reef islands. Here we investigate the influence of sea level rise and projected wave climate change on wave characteristics and cross‐shore sediment transport across an atoll reef at Kwajalein Island, Republic of the Marshall Islands. Using a phase‐resolving model, we quantify the influence on sediment transport of quantities not well captured by wave‐averaged models, namely, wave asymmetry and skewness and flow acceleration. Model results suggest that for current reef geometry, sea level, and wave climate, potential bedload transport is directed onshore, decreases from the fore reef to the beach, and is sensitive to the influence of flow acceleration. We find that a projected 12% decrease in annual wave energy by 2100 CE has negligible influence on reef flat hydrodynamics. However, 0.5–2.0 m of sea level rise increases wave heights, skewness, and shear stress on the reef flat and decreases wave skewness and shear stress on the fore reef. These hydrodynamic changes decrease potential sediment inputs onshore from the fore reef where coral production is greatest but increase potential cross‐reef sediment transport from the outer reef flat to the beach. Assuming sediment production on the fore reef remains constant or decreases due to increasing ocean temperatures and acidification, these processes have the potential to decrease net sediment delivery to atoll islands, causing erosion.This study was supported by the Strategic Environmental Research and Development Program through awards SERDP: RC‐2334, and RC‐2336. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.2021-03-2

Science-based restoration monitoring of coastal habitats, Volume Two: Tools for monitoring coastal habitats

Healthy coastal habitats are not only important ecologically; they also support healthy coastal communities and improve the quality of people’s lives. Despite their many benefits and values, coastal habitats have been systematically modified, degraded, and destroyed throughout the United States and its protectorates beginning with European colonization in the 1600’s (Dahl 1990). As a result, many coastal habitats around the United States are in desperate need of restoration. The monitoring of restoration projects, the focus of this document, is necessary to ensure that restoration efforts are successful, to further the science, and to increase the efficiency of future restoration efforts

An application of Bayesian Belief Networks to assess management scenarios for aquaculture in a complex tropical lake system in Indonesia

A Bayesian Belief Network, validated using past observational data, is applied to conceptualize the ecological response of Lake Maninjau, a tropical lake ecosystem in Indonesia, to tilapia cage farms operating on the lake and to quantify its impacts to assist decision making. The model captures ecosystem services trade-offs between cage farming and native fish loss. It is used to appraise options for lake management related to the minimization of the impacts of the cage farms. The constructed model overcomes difficulties with limited data availability to illustrate the complex physical and biogeochemical interactions contributing to triggering mass fish kills due to upwelling and the loss in the production of native fish related to the operation of cage farming. The model highlights existing information gaps in the research related to the management of the farms in the study area, which is applicable to other tropical lakes in general. Model results suggest that internal phosphorous loading (IPL) should be recognized as one of the primary targets of the deep eutrophic tropical lake restoration efforts. Theoretical and practical contributions of the model and model expansions are discussed. Short- and longer-term actions to contribute to a more sustainable management are recommended and include epilimnion aeration and sediment capping

11th International Coral Reef Symposium Abstracts

https://nsuworks.nova.edu/occ_icrs/1001/thumbnail.jp

The Future of Coral Reefs

This volume contains a series of papers prepared for presentation at the 14th International Coral Reef Symposium, originally planned for July 2020 in Bremen, Germany, but postponed until 2021 (online) and 2022 (in person) because of the COVID-19 pandemic. It contains a series of papers illustrating the breadth of modern studies on coral reefs and the response of the reef science community to the threats that coral reefs now face, above all from climate change. The first group of papers focus on the biology of a selection of reef organisms, ranging from sea fans to coral dwelling crabs. The next group describe studies of coral communities and ecological interactions in regions as diverse as Florida, Kenya, Colombia, and Norway. Further papers describe investigations into the effects of global warming (in the Maldives and in Timor-Leste) and of other impacts (UV blockers, ocean acidification). The final two papers describe the latest applications of satellite and camera technology to the challenge of mapping and monitoring reefs

The Great Barrier Reef: science use and management, a national conference. Proceedings volumes 1 and 2

The Great Barrier Reef is a marine ecosystem that is recognised worldwide for its unique biological and physical features. It is by far the largest single collection of coral reefs in the world and biologically supports one of the most diverse ecosystems known. The Great Barrier Reef Marine Park includes most of the Great Barrier Reef region and the Reef was added to the World Heritage List in 1981. The Great Barrier Reef Marine Park is a multiple-use protected area with zoning plans and permits for different activities being the main tools for Reef management. The Great Barrier Reef region supports direct economic activity estimated to be worth in excess of $I billion annually to Australia. Demands are rapidly increasing for information about, and access to, the Reef and its resources by tourists, other recreational users, commercial fishing and mariculture industries.This document contains proceedings from several authors not listed above

11th International Coral Reef Symposium Proceedings

A defining theme of the 11th International Coral Reef Symposium was that the news for coral reef ecosystems are far from encouraging. Climate change happens now much faster than in an ice-age transition, and coral reefs continue to suffer fever-high temperatures as well as sour ocean conditions. Corals may be falling behind, and there appears to be no special silver bullet remedy. Nevertheless, there are hopeful signs that we should not despair. Reef ecosystems respond vigorously to protective measures and alleviation of stress. For concerned scientists, managers, conservationists, stakeholders, students, and citizens, there is a great role to play in continuing to report on the extreme threat that climate change represents to earth’s natural systems. Urgent action is needed to reduce CO2 emissions. In the interim, we can and must buy time for coral reefs through increased protection from sewage, sediment, pollutants, overfishing, development, and other stressors, all of which we know can damage coral health. The time to act is now. The canary in the coral-coal mine is dead, but we still have time to save the miners. We need effective management rooted in solid interdisciplinary science and coupled with stakeholder buy in, working at local, regional, and international scales alongside global efforts to give reefs a chance.https://nsuworks.nova.edu/occ_icrs/1000/thumbnail.jp

The ecomics of ecosystems and biodiversity: scoping the scale

The G8 decided in March 2007 to initiate a “Review on the economics of biodiversity loss”, in the so called Potsdam Initiative: 'In a global study we will initiate the process of analysing the global economic benefit of biological diversity, the costs of the loss of biodiversity and the failure to take protective measures versus the costs of effective conservation. The study is being supported by the European Commission (together with the European Environmental Agency and in cooperation with the German Government. “The objective of the current study is to provide a coherent overview of existing scientific knowledge upon which to base the economics of the Review, and to propose a coherent global programme of scientific work, both for Phase 2 (consolidation) and to enable more robust future iterations of the Review beyond 2010.

Regional-Scale Forecasting for Coastal Storm Hazard Early Warning Systems

Sandy beach and dune systems often provide coastal communities with the first line of defence from the impacts of extreme storm events. During a storm’s approach, communities have a crucial opportunity to take preemptive actions to minimise the social, economic, and environmental impacts of the storm. Predicting coastal storm hazards, especially at the regional scale, however, is challenging due to the complexities of the hydrodynamic and morphodynamic processes occurring on erodible coastlines in high wave energy conditions. This thesis examines the nature and severity of coastal storm hazards and investigates approaches to effectively forecast these hazards for operational Early Warning Systems (EWSs). First, a conceptual framework for classifying coastal storm hazards is introduced. The Storm Hazard Matrix presents an integrated approach to categorising coastal flooding and beach erosion hazards. The Flooding Hazard Scale is based on the Storm Impact Scale first proposed by Sallenger (2000). The new Erosion Hazard Scale is based on several different morphological changes in beaches due to storms, including changes in beach width and dune erosion. The framework is demonstrated on two contrasting extreme storm events and successfully distinguishes between the severity of localised coastal flooding and/or beach erosion hazards. The enhanced insight provided by using the framework has the potential to be especially valuable for EWS applications. Next, a simple classification approach to forecast coastal storm erosion hazards based on the Erosion Hazard Scale is developed based on dune impact exposure (Larson et al., 2004), cumulative storm wave energy (Dolan and Davis, 1992; Harley et al., 2009) and the Dune Stability Factor (Armaroli et al., 2012). Two coastal change datasets are used to investigate the performance of the approach in terms of temporal variability and spatial variability. In each dataset, all events or locations of significant erosion impacts are correctly identified. The approach tended to be conservative with few false alarms (and no misses), demonstrating its predictive capability with limited input data and computational resources. Finally, machine learning techniques are investigated to leverage the increasing availability of coastal topographic and hydrodynamic data. A gradient boosted random forest ensemble model is trained using an extreme coastal storm erosion hazard dataset. The model is demonstrated by hindcasting regional-scale coastal storm erosion hazards over a period of 5 years. Additionally, an investigation of the training data requirements and interpretation of the model feature importance characteristics are also performed. The findings and insights discussed in this thesis represent the state-of-the-art approaches to forecasting coastal storm hazards at the regional scale and can serve to inform the implementation of future EWSs

Goods and Services of Marine Bivalves

The aim of this book is to review and analyse the goods and services of bivalve shellfish. How they are defined, what determines the ecological functions that are the basis for the goods and services, what controversies in the use of goods and services exist, and what is needed for sustainable exploitation of bivalves from the perspective of the various stakeholders. The book is focused on the goods and services, and not on impacts of shellfish aquaculture on the benthic environment, or on threats like biotoxins; neither is it a shellfish culture handbook although it can be used in evaluating shellfish culture. The reviews and analysis are based on case studies that exemplify the concept, and show the strengths and weaknesses of the current applications. The multi-authored reviews cover ecological, economic and social aspects of bivalve goods and services. The book provides new insights for scientists, students, shellfish producers, policy advisors, nature conservationists and decision makers. This book is open access under the CC BY license.publishedVersio