Books by Edwin A. Hernández-Delgado
Handbook of Latin America and the Environment, 2023
Low-tech coral farming and reef rehabilitation have become important tools to foster community-ba... more Low-tech coral farming and reef rehabilitation have become important tools to foster community-based participation in the management of coastal social-ecological systems. Lessons learned from coral demographic dynamics, ecosystem-level benefits, and sociological dynamics achieved in Culebra Island, Puerto Rico, are discussed. Important gaps regarding social-ecological interactions are also addressed. Coral reef rehabilitation efforts must be adaptive and focused on maximizing resilience as a long-term goal, with emphasis on
managing non-linear dynamics, thresholds, environmental and climate uncertainty, and ecological surprises. In this context, coral demographic modelling becomes fundamental to address, not only ecological, but also sociological concerns. Only through sustained support and input of harvested corals restored populations, and by increasing the spatial scale of reef rehabilitation, restored populations can remain viable and grow under present and projected environmental and climate conditions. Understanding sociological dynamics, learning from others experiences, integrating visioning and scenario building, leadership building, multi-sectorial agents and actor groups, and strengthening cross-sectorial social networking are necessary adaptive approaches to cope with future environmental and climate changes, and are an integral part of reef rehabilitation. The combined benefits to social-ecological systems are multiple.With proper planning, design, funding, local support, and implementation, these can have long-lasting impacts in restoring coastal resilience.
Low-tech coral farming and reef rehabilitation have become important communitybased coral reef ma... more Low-tech coral farming and reef rehabilitation have become important communitybased coral reef management tools. At least in the wider Caribbean region, these strategies have been successfully implemented to recover depleted populations of staghorn (Acropora cervicornis) and elkhorn coral (A. palmata). They have also been used with relative success to recover depleted fish assemblages. Indirectly, coral reef rehabilitation has also resulted in enhanced benthic spatial heterogeneity, in providing multiple new microhabitats for fish and invertebrate species; have contributed to the recovery of coastal resilience, increasing the protection of shorelines against erosion; and have fostered an increased interest of the tourism sector as an enhanced attraction for visitors and recreationists. Nevertheless, there is still a need to implement best management practices to improve the success of these strategies. In this chapter, lessons learned from the Community-Based Coral Aquaculture and Reef Rehabilitation Program in Culebra Island, Puerto Rico, are shared from a multi-disciplinary standpoint. Learning from past experiences is a critical process to improve science. In a time of significant projected climate change impacts and sea level rise, improving the scale of coral farming and reef rehabilitation has become a critical tool for coral reef conservation. But multiple roadblocks must still be overcome.
Timely information is critical for coral reef managers and decision-makers to implement sustainab... more Timely information is critical for coral reef managers and decision-makers to implement sustainable management measures. A Coral Reef Resilience Index (CRRI) was developed with a GIS-coupled decision-making tool applicable for Caribbean coral reef ecosystems. The CRRI is based on a five-point scale parameterized from the quantitative characterization of benthic assemblages. Separate subindices such as the Coral Index, the Threatened Species Index, and the Algal Index also provide specific information regarding targeted benthic components. This case study was based on assessments conducted in 2014 on 11
reef sites located across 3 geographic zones and 3 depth zones along the southwestern shelf of the island of Puerto Rico, Caribbean Sea. There was a significant spatial and bathymetric gradient (p < 0.05) in the distribution of CRRI values indicating higher degradation of inshore reefs. Mean global CRRI ranged from 2.78 to 3.17 across the shelf, ranking them as “fair.” The Coral Index ranged from 2.60 to 3.76, ranking reefs from “poor” to “good,” showing a general cross-shelf trend of improving conditions with increasing distance from pollution sources. Turbidity and ammonia were significantly correlated to CRRI scores. Multiple recommendations are provided based on coral reef conditions
according to observed CRRI rankings.
The main objective of this chapter was to identify most information gaps associated to the above ... more The main objective of this chapter was to identify most information gaps associated to the above topics in a context of a small over-populated Caribbean island, and in a context of the
projected climate change impacts. It was also aimed at reviewing some of the existing literature regarding the impact of tourism and urban development on a tropical coastal scenario and discussing some of the most significant case studies and lesson-learning experiences of the historical non-sustainable approaches used by the tourism and housing construction industry in PR. We also examined some of the current controversies regarding the proposed coastal tourism and housing development expansion strategy in PR, as well as
some of the most significant climate-related threats. Finally, we addressed the need to implement an alternative sustainable coastal tourism and housing development model, and made specific recommendations for reviewing and modifying existing strategies in a way that could also be helpful for other tropical countries that share similar situations.
The lack of a scientifically-based methodology to guide watershed management strategies is partly... more The lack of a scientifically-based methodology to guide watershed management strategies is partly to blame for deficient to non-existent erosion control activities on Culebra and on most islands of the Caribbean. The main objective of this article is to describe an innovative framework by which technical knowledge gathered by marine ecologists, watershed scientists, and civil engineers can be best employed in the development of an erosion mitigation strategy. The approach proposed here is intended to explicitly define the principles behind the development of such interdisciplinary strategies and to maximize their benefits. Although the goal of erosion control is simply to alleviate the pressures associated with just one of the many sources of stress affecting coral reefs, the general framework described here could be emulated to address other land-based, non-point pollution sources affecting coral reef systems in Culebra and elsewhere. Isla de Culebra serves as the focus of our efforts because of its imminent need for the implementation of such types of mitigation efforts and to take advantage of previously-existing coral reef databases and
watershed assessments
Book chapter regarding low-tech coral aquaculture and reef rehabilitation experiences in Puerto R... more Book chapter regarding low-tech coral aquaculture and reef rehabilitation experiences in Puerto Rico (in Spanish).
A book chapter regarding anthropogenic impacts on coral reefs in Puerto Rico (in Spanish).
Papers by Edwin A. Hernández-Delgado
Frontiers in Marine Science, 2024
The ever-increasing need for coral restoration as a tool available to mitigate reef declines and ... more The ever-increasing need for coral restoration as a tool available to mitigate reef declines and aid in the recovery of lost ecosystem services requires improving restoration performance over time through an adaptive management framework to evaluate the status of restoration programs using uniform, consistent metrics. An evaluation tool, presented herein, allows restoration practitioners and managers to self-evaluate the robustness of each project and identify successful metrics, those metrics that need special attention, and changes to restoration strategies that can improve performance and aid recovery. This tool is designed to allow programs to track the progress of each key metric over time to assist in improving upon successes and learning from failures. The metrics within this restoration evaluation tool focus on published best-management practices and have resulted from extensive research conducted by restoration experts over the past 20 years. Common metrics of growth and survival are included, in addition to parameters vital to the operational success of restoration programs, such as coral reproduction, recruitment of associated reef taxa, increasing habitat for reef fisheries, and improving overall reef habitat. Five Caribbean restoration programs, each with at least 15 years of restoration experience, are presented as case studies. Each program was evaluated based on six restoration categories including: field-based nurseries, outplantings, programmatic management, education and outreach, event-driven restoration, and socioeconomic restoration. Category-specific metrics were scored with a binary scoring system and summarized using a stop-light indicator framework, where the resulting color/score indicates the operations tatus of the different program components (Scores >75% = green/successful; 50–74.9% = light green > yellow > orange/intermediate; <49.9% = red/sub-optimal). Composite scores may be used to evaluate individual projects, overall restoration programs, or even largescale state of regional restoration plans. Overall, four of the five programs scored >75% indicating most of these programs are performing well, are versatile, well managed, and sustainable. Outside of environmental factors and large-scale disturbance events, many programs described resource limitations, including funding and staffing, as reasons for scoring low on some metrics. A holistic evaluation rubric incorporated into programmatic self-assessment can ensure that restoration projects and programs are working towards success and sustainability.
Coasts, 2024
The climate crisis poses a grave threat to numerous small island developing states (SIDS), intens... more The climate crisis poses a grave threat to numerous small island developing states (SIDS), intensifying risks from extreme weather events and sea level rise (SLR). This vulnerability heightens the dangers of coastal erosion, chronic water quality degradation, and dwindling coastal resources, demanding global attention. The resultant loss of ecological persistence, functional services, and ecosystem resilience jeopardizes protection against wave action and SLR, endangering coastal habitats’
economic value, food security, infrastructure, and livelihoods. Implementing integrated strategies is imperative. A thorough discussion of available strategies and best management practices for coastal ecosystem restoration is presented in the context of SIDS needs, threats, and major constraints. Solutions must encompass enhanced green infrastructure restoration (coral reefs, seagrass meadows, mangroves/wetlands, urban shorelines), sustainable development practices, circular economy principles, and the adoption of ecological restoration policies. This requires securing creative and sustainable funding, promoting green job creation, and fostering local stakeholder engagement. Tailored to each island’s reality, solutions must overcome numerous socio-economic, logistical, and political obstacles. Despite challenges, timely opportunities exist for coastal habitat restoration and
climate change adaptation policies. Integrated strategies spanning disciplines and stakeholders necessitate significant political will.
Diversity, Sep 27, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Routledge eBooks, Apr 21, 2023
Diversity
The persistence and resilience of marginal shallow coral reefs at their limits of environmental t... more The persistence and resilience of marginal shallow coral reefs at their limits of environmental tolerance have declined due to chronic environmental degradation and climate change. However, the consequences for the natural recovery ability of reefs of disturbance remain poorly understood. This study considered the potential for natural recovery through coral recruitment on fringing reefs across different geographic regions under contrasting environmental conditions in Puerto Rico. Reefs in areas with significant water quality degradation and more severe physical impacts of hurricanes were expected to have lower coral recruit density and diversity, and therefore less potential for recovery. Sixteen reefs were assessed across three geographic regions. Degraded reefs sustained a lower percentage of live coral cover and had higher macroalgae and turf algae abundance. Locations affected by high PO4, NH3+ and optical brightness concentrations, high turbidity, and high sea surface temperat...
Reef Encounter, 2019
Reef Encounter is the Magazine Style Newsletter of the International Coral Reef Society. It was f... more Reef Encounter is the Magazine Style Newsletter of the International Coral Reef Society. It was first published in 1983. Following a short break in production it was re-launched in electronic (pdf) form. Contributions are welcome, especially from members.
Ocean & Coastal Management, 2019
The impact of fecal contamination of coastal waters and coral reefs is a major cause of concern i... more The impact of fecal contamination of coastal waters and coral reefs is a major cause of concern in marine reserves in Puerto Rico. The measurement of the association between septic tank frequency in watersheds of creeks draining into these reserves and coastal water quality and coral reef condition is of importance in configuring pollution control policy. Fecal coliforms and enterococci assays were used to measure the density of fecal contaminants across the Tres Palmas Marine Reserve (TPMR) in Rincon, Puerto Rico. Inshore waters are intermittent creeks, receiving fecal pollution only from faulty septic tanks. Fecal indicators measurements showed higher densities near the southernmost creek mouth emptying into TPMR, a finding consistent with a larger amount of dwellings with septic tanks within this watershed (Vista Azul creek). A Septic Weight Index was constructed to analyze sewage impact from all watersheds draining into the marine reserve. Linear Regression analyses showed a significant association between these non-point source fecal pollution sources and both coastal water quality and impact on some parameters measuring the condition of Acropora palmata coral reef colonies.
Environmental Management and Sustainable Development, 2017
Unsustainable land uses may result in poor watershed management, increased soil erosion, poorly-p... more Unsustainable land uses may result in poor watershed management, increased soil erosion, poorly-planned urban development, increased runoff, and sewage pollution, creating an environmental stress gradient across coastal coral reefs. This study was aimed at: 1) Evaluating water quality within and outside the Canal Luis Peña Natural Reserve (CLPNR), Culebra Island, Puerto Rico; 2) Determining if there was any significant environmental stress gradient associated to land-based non-point source pollution; and 3) Characterizing shallow-water coral reef communities across the gradient. Strong gradient impacts associated to sediment-laden and nutrient-loaded runoff pulses, in combination with non-point raw sewage pulses, and sediment bedload, impacted coastal coral reefs. Water quality showed significant spatio-temporal fluctuations (p<0.0001), largely responding to heavy rainfall and subsequent runoff pulses. Benthic community structure showed significant spatial variation along the env...
Capítulo que describe las alternativas tecnológicas para el cultivo y la restauración de los arre... more Capítulo que describe las alternativas tecnológicas para el cultivo y la restauración de los arrecifes de coral en el contexto de los impactos del cambio climático.
Revista de biologia tropical
Coral reefs have largely declined across the northeastern Caribbean following the 2005 massive bl... more Coral reefs have largely declined across the northeastern Caribbean following the 2005 massive bleaching event. Climate change-related sea surface warming and coral disease outbreaks of a white plague-like syndrome and of yellow band disease (YBD) have caused significant coral decline affecting massive reef building species (i.e., Orbicella annularis species complex) which show no apparent signs of recovery through larval sexual recruitment. We addressed coral recruit densities across three spur and groove reef locations along the western shelf of remote Mona Island, Puerto Rico: Punta Capitán (PCA), Pasa de Las Carmelitas (PLC), and Las Carmelitas-South (LCS). Data were collected during November 2012 along 93 haphazard transects across three depth zones (<5m, 5-10m, 10-15m). A total of 32 coral species (9 octocorals, 1 hydrocoral, 22 scleractinians) were documented among the recruit community. Communities had low densities and dominance by short-lived brooder species seven years...
&amp;amp;quot;&amp;amp;quot;Sewage impacts in coral reef ecosystems are a major concern. ... more &amp;amp;quot;&amp;amp;quot;Sewage impacts in coral reef ecosystems are a major concern. Previous study showed evidence that coral reefs along a significant portion of the southwestern Puerto Rico shelf are being severely impacted by non point source sewage pollution, mostly from inadequate septic tanks. In this project we analyzed the impact of non point source water pollution on water quality and coral reefs in coastal waters of the Tres Palmas Marine Reserve in Rincon. Both inorganic and microbiological marine water quality indicators were used as impact parameters. The analysis of non point pollution sources was carried out through the use of Remote Sensing and Geographic Information Systems techniques and land based water sampling. For coral reef evaluation, we randomly selected 54 sampling stations at each survey area within and outside the Tres Pal mas Marine Reserve subdivided on 9 replicate stations per site. The presence of threatened Elkhorn coral, Acropora palmata, and dead standing skeletons within each 100m2 plot was noted. Average densities detected in coastal water stations within or near the Tres Palmas Reserve ranged from 0.1 to 15.3 CFU/1 00 mL of Faecal coliforms and 5 to 27 CFU/1 00 mL of Enterococci, but occasional pulses exceeded legal standards. This confirms the presence of microbiological contamination by rainfall runoff and possible overflows of septic tanks located close to the coast. Most residences along the Tres Pal mas Marine Reserve coastal watersheds use septic tanks. Intermittent creeks serve as conduits of septic tank overflows or bypass discharges from several &amp;amp;quot;barriadas&amp;amp;quot; within the selected sub-watersheds. The analysis of 223 colonies of A. palmata suggests that corals are showing unmistakable historical signs of partial mortality of colonies associated with recurrent rainfall runoff.&amp;amp;quot;&amp;amp;quot;
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Books by Edwin A. Hernández-Delgado
managing non-linear dynamics, thresholds, environmental and climate uncertainty, and ecological surprises. In this context, coral demographic modelling becomes fundamental to address, not only ecological, but also sociological concerns. Only through sustained support and input of harvested corals restored populations, and by increasing the spatial scale of reef rehabilitation, restored populations can remain viable and grow under present and projected environmental and climate conditions. Understanding sociological dynamics, learning from others experiences, integrating visioning and scenario building, leadership building, multi-sectorial agents and actor groups, and strengthening cross-sectorial social networking are necessary adaptive approaches to cope with future environmental and climate changes, and are an integral part of reef rehabilitation. The combined benefits to social-ecological systems are multiple.With proper planning, design, funding, local support, and implementation, these can have long-lasting impacts in restoring coastal resilience.
reef sites located across 3 geographic zones and 3 depth zones along the southwestern shelf of the island of Puerto Rico, Caribbean Sea. There was a significant spatial and bathymetric gradient (p < 0.05) in the distribution of CRRI values indicating higher degradation of inshore reefs. Mean global CRRI ranged from 2.78 to 3.17 across the shelf, ranking them as “fair.” The Coral Index ranged from 2.60 to 3.76, ranking reefs from “poor” to “good,” showing a general cross-shelf trend of improving conditions with increasing distance from pollution sources. Turbidity and ammonia were significantly correlated to CRRI scores. Multiple recommendations are provided based on coral reef conditions
according to observed CRRI rankings.
projected climate change impacts. It was also aimed at reviewing some of the existing literature regarding the impact of tourism and urban development on a tropical coastal scenario and discussing some of the most significant case studies and lesson-learning experiences of the historical non-sustainable approaches used by the tourism and housing construction industry in PR. We also examined some of the current controversies regarding the proposed coastal tourism and housing development expansion strategy in PR, as well as
some of the most significant climate-related threats. Finally, we addressed the need to implement an alternative sustainable coastal tourism and housing development model, and made specific recommendations for reviewing and modifying existing strategies in a way that could also be helpful for other tropical countries that share similar situations.
watershed assessments
Papers by Edwin A. Hernández-Delgado
economic value, food security, infrastructure, and livelihoods. Implementing integrated strategies is imperative. A thorough discussion of available strategies and best management practices for coastal ecosystem restoration is presented in the context of SIDS needs, threats, and major constraints. Solutions must encompass enhanced green infrastructure restoration (coral reefs, seagrass meadows, mangroves/wetlands, urban shorelines), sustainable development practices, circular economy principles, and the adoption of ecological restoration policies. This requires securing creative and sustainable funding, promoting green job creation, and fostering local stakeholder engagement. Tailored to each island’s reality, solutions must overcome numerous socio-economic, logistical, and political obstacles. Despite challenges, timely opportunities exist for coastal habitat restoration and
climate change adaptation policies. Integrated strategies spanning disciplines and stakeholders necessitate significant political will.
managing non-linear dynamics, thresholds, environmental and climate uncertainty, and ecological surprises. In this context, coral demographic modelling becomes fundamental to address, not only ecological, but also sociological concerns. Only through sustained support and input of harvested corals restored populations, and by increasing the spatial scale of reef rehabilitation, restored populations can remain viable and grow under present and projected environmental and climate conditions. Understanding sociological dynamics, learning from others experiences, integrating visioning and scenario building, leadership building, multi-sectorial agents and actor groups, and strengthening cross-sectorial social networking are necessary adaptive approaches to cope with future environmental and climate changes, and are an integral part of reef rehabilitation. The combined benefits to social-ecological systems are multiple.With proper planning, design, funding, local support, and implementation, these can have long-lasting impacts in restoring coastal resilience.
reef sites located across 3 geographic zones and 3 depth zones along the southwestern shelf of the island of Puerto Rico, Caribbean Sea. There was a significant spatial and bathymetric gradient (p < 0.05) in the distribution of CRRI values indicating higher degradation of inshore reefs. Mean global CRRI ranged from 2.78 to 3.17 across the shelf, ranking them as “fair.” The Coral Index ranged from 2.60 to 3.76, ranking reefs from “poor” to “good,” showing a general cross-shelf trend of improving conditions with increasing distance from pollution sources. Turbidity and ammonia were significantly correlated to CRRI scores. Multiple recommendations are provided based on coral reef conditions
according to observed CRRI rankings.
projected climate change impacts. It was also aimed at reviewing some of the existing literature regarding the impact of tourism and urban development on a tropical coastal scenario and discussing some of the most significant case studies and lesson-learning experiences of the historical non-sustainable approaches used by the tourism and housing construction industry in PR. We also examined some of the current controversies regarding the proposed coastal tourism and housing development expansion strategy in PR, as well as
some of the most significant climate-related threats. Finally, we addressed the need to implement an alternative sustainable coastal tourism and housing development model, and made specific recommendations for reviewing and modifying existing strategies in a way that could also be helpful for other tropical countries that share similar situations.
watershed assessments
economic value, food security, infrastructure, and livelihoods. Implementing integrated strategies is imperative. A thorough discussion of available strategies and best management practices for coastal ecosystem restoration is presented in the context of SIDS needs, threats, and major constraints. Solutions must encompass enhanced green infrastructure restoration (coral reefs, seagrass meadows, mangroves/wetlands, urban shorelines), sustainable development practices, circular economy principles, and the adoption of ecological restoration policies. This requires securing creative and sustainable funding, promoting green job creation, and fostering local stakeholder engagement. Tailored to each island’s reality, solutions must overcome numerous socio-economic, logistical, and political obstacles. Despite challenges, timely opportunities exist for coastal habitat restoration and
climate change adaptation policies. Integrated strategies spanning disciplines and stakeholders necessitate significant political will.