Applying Habitat Equivalency Analysis for Coral Reef Damage Assessment and Restoration

Quantifying economic damages and restoration measures for injuries to coral reefs has been a difficult task. In the U.S., habitat equivalency analysis (HEA) has emerged as a novel tool that combines biological and economic information to identify replacement habitats of an appropriate scale to substitute for the interim losses resulting from coral reef injuries. This article provides a review of the basic principles underlying HEA and a discussion of important considerations in applying HEA. These considerations include: how to describe coral reef functions and related human uses, recovery rates of coral reef organisms at injured sites with natural and active restoration, selection of replacement habitats and growth rates of organisms in these habitats, and the role of time and discount rates in the analysis. While HEA offers many advantages, specific decisions made in the application process can have a dramatic effect on the scale and cost of restoration and replacement habitat decisions. Management agencies and the scientific community need to be involved in developing standards for quantifying coral reef functions and recovery rates and the role of replacement projects in restoration planning

Skeletal Architecture and Density Banding Analysis Technique for Diploria strigosa by X-ray Computed Tomography

Coral skeletal density information is a useful growth parameter and may be coupled with extension rates to determine calcification rates. The conventional process for density determination is often cumbersome and requires some parameters which are difficult to precisely specify (e.g., Mass absorption coefficients). We have developed a technique and windows based computer program which enables the rapid collection of coral density data. The coral skeleton slab is xradiographed with an aluminum wedge. Thickness and density of the aluminum wedge, thickness of the coral slab, density of pure coral aragonite, and digitized images of the coral and wedge x-radiographs provide necessary input. The program uses the wedge image and an empirically determined ratio of relative mass absorption coefficients, (thus removing difficulties with absolute values) in an equation relating wedge optic density and thickness to coral skeletal density. A transect is defined on the coral x-radiograph image, normal to growth band boundaries. Optic density of pixels are converted to skeletal density, averaged, and plotted. Variations of skeletal density along the transect are expressed as peaks and valleys corresponding to high and low density band portions. Measurements of extension, density, and calcification can be calculated for a variety of characterizations of annual and subannual band portions

11th International Coral Reef Symposium Abstracts

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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

Fractal Patterns of Coral Communities: Evidence from Remote Sensing (Arabian Gulf, Dubai, U.A.E.)

In this study, the spatial character of benthic communities is investigated in an Arabian Gulf shallow subtidal carbonate ramp setting, using IKONOS satellite imagery. The patchy distribution of three assemblages of live and dead corals on extensive (but also fragmented) hardground pavements was investigated using a variety of spatial statistics. It was found that the spatial expression of the benthic groups display characteristics that approximate to power-law distributions over several orders of magnitude to an extent that suggests fractal behaviour. Pronounced anisotropy was observed between the spatial patterns in the near-shore and off-shore region which is attributed to different mechanisms of patch formation controlled by the local hydrodynamic regime. The study area is know to be subjected to recurrent and cyclic thermal induced mass mortality events on a decadal time scale, inhibiting reef framework development and likely to be a controlling mechanism in the patchiness of the benthic communities

The Origin of Variations in the Isotopic Record of Scleractinian Corals: II. Carbon

This study examines the relationship between the δ13C of the skeleton of a zooxanthellate coral (Montastraea annularis) growing on the Florida Reef Tract and environmental variables (insolation and temperature), physiological variables (growth rate, respiration, calcification, and photosynthesis). Colonies of this species were grown in the field for a 2.5 year study period, during which the rates of photosynthesis, respiration, and calcification were measured on fifteen separate occasions, spaced approximately equally throughout the study period. The corals were stained with alizarin-red S within seven days after each set of physiological measurements. At the end of the period the corals were sacrificed and their skeletal extension, density, and skeletal δ13C determined. Despite substantial high-frequency variations, a strong seasonal cycle was evident in the skeletal δ13C records of all the corals throughout the experimental period. The skeletal δ13C and δ18O values varied approximately in phase, and showed a weak, but statistically significant positive relationship with each other. The δ13C of the coral skeletons, when corrected for changes in the δ13C of dissolved inorganic carbon (DIC), exhibited an inverse correlation with P/R, a finding opposite to what was expected based on current models of isotopic fractionation in coral skeletons. Although such findings tend to support the model of Erez (1978) that increases in photosynthesis act to isotopically deplete the δ13C of the coral skeleton, we note that the inverse association between δ13C and P/R arises because of a slight positive association between δ13C and respiration. We therefore believe that the association may be a result of seasonal variation in some parameters of the system which was not constrained in our study. Alternatives include (1) variations in the δ13C of the DIC which are translated into the δ13C of the food chain, (2) changes from heterotrophy to autotrophy, and (3) changes in the partitioning of δ13C between the zooxanthellae and the coral tissue. Based on previous studies which we have carried out we believe that changes in the skeletal δ13C are not related to sexual reproduction or growth rate. Contrary to previous work we were unable to measure any significant differences in the skeletal δ13C between the fast growing tops of the coral and the slower growing sides

Florida Coral Reef Damage from Nuclear Submarine Grounding and Proposed Restoration

The United States submarine Memphis grounded in approximately 10 m water depth on a tropical coral reef ofT southeast Florida in February, 1993. The grounding caused extensive physical and biological damage to the reef substrate and to the coral community. As part of a claim by the State of Florida against the United States, the impact of the grounding was assessed, and the area of damage was determined through field and photographic studies. A recovery rate for the reef was assigned from literature estimates. The NOAA Habitat Equivalency Model (HEM) was used to calculate the reef area needed to be replaced in order to compensate for damages. A plan devised to restore the reef included: removal of loose rubble generated from the grounding; stabilization of reef faces in danger of collapse: emplacement of six different types of artificial reefs; transplantation of reef-building corals (15% of the number damaged) to bare damaged substrate and to the artificial reefs; and a 20 year monitoring period to assess restoration plan efficacy. Settlement of the claim in April, 1997 resulted in an award of $750,000 to the Ecosystem Management Trust Fund of the State of Florida. Utilization of this fund necessitates a revised plan to restore the damaged reef within economic constraints. This plan will involve rubble removal/stabilization, artificial reef emplacement, stony coral transplantation, and monitoring

The State of Coral Reef Ecosystems of Southeast Florida

The northern extension of the Florida reef tract and a complex of limestone ridges run parallel to the subtropical Atlantic coastline of southeast Florida. Spanning 170 km from the northern border of Biscayne National Park (BNP) in Miami-Dade County to the St. Lucie Inlet in Martin County, the reefs and hardbottom areas in this region support a rich and diverse biological community (Figure 5.1). Nearshore reef habitats in southeast Florida include hardbottom areas, patch reefs and worm reefs (Phragmatopoma spp.) exhibiting abundant octocoral, macroalgae, stony coral and sponge assemblages. Offshore, coral reef associated biotic assemblages occur on linear Holocene Acropora palmata mid-shelf and shelf margin reefs that extend from Miami Dade County to Palm Beach County (Lighty, 1977; Figure 5.2). Anastasia Formation limestone ridges and terraces colonized by reef biota characterize the reefs from Palm Beach County to Martin County (Cooke and Mossom, 1929). The coastal region of southeast Florida is highly developed, containing one third of Florida’s population of 16 million people (U.S. Census Bureau, 2006). Many southeast Florida reefs are located just 1.5 km from this urbanized shoreline. Despite their unique position as the highest latitude reefs along the western Atlantic seaboard, the reefs of southeast Florida have only recently received limited scientific and resource management attention. Andrews et al. (2005) discussed the reefs of southeast Florida and the critical need to implement actions that fill resource knowledge gaps and address conservation and threats to reef health. This report further examines and updates the list of stressors imperiling the health of southeast Florida’s reefs, and presents information gained from new research, monitoring and management efforts to determine the extent and condition of reef resources in this distinctive region

A Windows-based Program for Image Processing Coral Skeletal Densitometry

Coral skeletal density information is a useful growth parameter and may be coupled with extension rates to determine calcification rates. The conventional process for density determination is often cumbersome and requires some parameters which are difficult to precisely specify (e.g., Mass absorption coefficients). We have developed a technique and windows based computer program which enables the rapid collection of coral density data. The coral skeleton slab is xradiographed with an aluminum wedge. Thickness and density of the aluminum wedge, thickness of the coral slab, density of pure coral aragonite, and digitized images of the coral and wedge x-radiographs provide necessary input. The program uses the wedge image and an empirically determined ratio of relative mass absorption coefficients, (thus removing difficulties with absolute values) in an equation relating wedge optic density and thickness to coral skeletal density. A transect is defined on the coral x-radiograph image, normal to growth band boundaries. Optic density of pixels are converted to skeletal density, averaged, and plotted. Variations of skeletal density along the transect are expressed as peaks and valleys corresponding to high and low density band portions. Measurements of extension, density, and calcification can be calculated for a variety of characterizations of annual and subannual band portions

Coral Reefs of the World

Coral Reefs of the World is a series presenting the status of knowledge of the world\u27s coral reefs authored by leading scientists. The volumes are organized according to political or regional oceanographic boundaries. Emphasis is put on providing authoritative overviews of biology and geology, explaining the origins and peculiarities of coral reefs in each region. The information is so organized that it is up to date and can be used as a general reference and entry-point for further study. The series will cover all recent and many of the fossil coral reefs of the world. Prospective authors and/or editors should consult the Series Editors B.M. Riegl and R.E. Dodge for more details. Any comments or suggestions for future volumes are welcomed: Dr. Bernhard M. Riegl/Dr. Richard E. Dodge Nova Southeastern University Dania Beach, FL 33004 USA e-mail: [email protected] and [email protected]://nsuworks.nova.edu/occ_facbooks/1065/thumbnail.jp