Climate change and ocean acidification are both a result of increasing anthropogenic CO2 in the Earth’s atmosphere. These two global-scale stressors will impact coral reefs in differing ways, but the interaction of the two over the 21st century are expected to threaten the persistence of coral reef ecosystems. ACCRETE (Acidification, Climate, and Coral Reef Ecosystems TEam) researchers are actively researching how climate change and ocean acidification will, and, already are, affecting the construction (coral growth, calcification) and breakdown (bioerosion, dissolution) of coral reef ecosystems, as well as the associated ramifications this has for ecosystem function (e.g., biodiversity). To this end, ACCRETE scientists utilize a unique interdisciplinary approach that incorporates aspects of biology, chemistry, and geology within an ecological framework. Through field, laboratory, and modeling studies, this laboratory is improving our understanding of the rate and magnitude of climate change and acidification on coral reefs, as well as the ecological impacts of these changes.
ACCRETE is a subunit of the Coral Health and Monitoring Program (CHAMP) and is located within the Ocean Chemistry and Ecosystems Division (OCED) at the National Oceanic and Atmospheric Administration’s (NOAA) Atlantic Oceanographic and Meteorological Laboratory (AOML) in Miami, FL.
NOAA's Coral Reef Early Warning System (CREWS) and Integrated Coral Observing Network (ICON) are two closely related projects that have together amassed a long-term dataset of in situ measurements in the near environments of coral reefs throughout Florida, the Caribbean and the world. These observations are largely reported in close to real-time via satellite, radio and cellular networks and their data are immediately analyzed using expert systems models to produce useful predictions (termed "ecoforecasts") about ecological conditions that may impact coral reefs.
The first CREWS station was a buoy installed in the Bahamas in 2001. Since then, six fixed-pylon stations have been installed in the Bahamas, U.S. Virgin Islands, Puerto Rico, Jamaica, the Cayman Islands and Saipan (U.S. CNMI), with lifetimes spanning the years from 2002 to 2014. Two collaborative or "hybrid" CREWS stations were installed on land or on marine navigational beacons (2008 to present), and in later years CREWS has been installing buoys in Belize, the Cayman Islands, and Tobago (2013 onwards) with more buoys to come in Barbados and the Dominican Republic. Early CREWS data were processed by an expert system coded in CLIPS (C Language Integrated Production System).
Beginning in 2004, the CLIPS expert system was migrated to the more powerful G2 platform produced by the Gensym corporation and began to integrate data from non-CREWS sources including satellite observations, model output and other in situ experiments. This larger expert system became known as ICON. Today, the names CREWS and ICON are sometimes used interchangeably although CREWS now more properly refers to the in situ observing platforms and ICON refers to the G2 expert system and the ecoforecasts it produces.
The Marine and Estuarine Goal Setting for South Florida (MARES) project aims to reach a science-based consensus about the defining characteristics and fundamental regulating processes of a South Florida coastal marine ecosystem that is both sustainable and capable of providing the diverse ecological services upon which our society depends. Collaboration among stakeholders is being gathered during 12 public workshops planned over the three-year project period that started in September 2009.
MARES represents a collaboration among academic scientists, federal and state agency experts and non-governmental organizations working in close conjunction with federal and state environmental managers, private industry stakeholders and interested members of the public.
A three-step process is being used to develop ecosystem report cards.
Step 1 is the development of Integrated Conceptual Ecosystem Models (ICEMs) for three sub-regions of south Florida; The Florida Keys and Dry Tortugas, the Southwest Florida Shelf, the Southeast Florida Shelf, and the total marine ecosystem that couples each of the MARES ICEMs with existing models for Biscayne Bay, Florida Bay and the Caloosahatchee Estuary.
The ICEMs incorporate not only the best available information about relevant natural science, but also incorporate human dimensions science and societal processes. The models illustrate cause and effect relationships in the ecosystem, and also identify valued services provided by the ecosystem and account for ecosystem management activities (Responses) intended to mitigate the adverse effects on the ecosystem (Impacts).
Step 2 of the project is to develop Quantitative Ecosystem Indicators that can be monitored to measure change and reflect the condition of the ecosystem. They must be present throughout the coastal system and be a key attribute or effect in the ICEM. Indicators must also integrate the system-wide response to various ecosystem drivers. One example of a QEI is algal bloom status in Florida Bay. The concentration, duration and spatial extent of chlorophyll a with respect to historical conditions assess changes in the habitat.
Step 3 is the development of an Ecosystem Report Card. The reports provide an overview of the condition of the ecosystem using a stoplight approach with red, green, and yellow rankings. The Report Cards provide the public, managers, and researchers with a quick guide for identifying areas that require immediate attention and those that are meeting consensus goals quantified as indicator targets in step two.
Ocean currents and waves are like the life blood of coral reef ecosystems: they bring nutrients, prey, and new recruits, and may carry away or dilute particulates and harmful chemical compounds. Currents are the medium connecting reefs with estuaries, channels, mangrove forests and seagrass beds inshore, and with the deeper oceans that invariably lie offshore of the reef. Together with direct air-sea exchanges of heat, water, gases, momentum, and nutrients at the sea surface, ocean currents largely control the physical and chemical environment of coral reefs. Yet while significant advances have occurred, especially over the past 30 years, our scientific knowledge of the physical oceanography of coral reefs is far from complete.
The complex physical interplay between wind, waves, water density (which is determined largely by sea temperature, but also by salinity), pressure, solar radiation, and the hard boundaries of the ocean make physical oceanography a challenging subject. For coastal oceanography, especially near reefs, the complexity of and rapid gradients in sea-floor bottom topography heighten these challenges. Furthermore, wind and waves in such environments may cause relatively violent water motions and heavy sediment loads, and the ongoing ecology of the reef itself may cause significant biofouling. Thus, the gathering of useful physical data to enhance our understanding of coral reefs becomes a very significant operational and practical challenge in its own right.
Ocean currents are among the most difficult variables to directly measure in situ (i.e., in the natural environment of the reef). Because of the paucity of direct measurements of currents on reefs, CHAMP researchers are using other, more easily measured variables like sea and air temperature, wind, light attenuation, and coastal ocean color (from satellites) as proxies for detecting and interpreting significant reef circulation events. The onshore flux page describes these efforts in more detail. Understanding the connection of coral reefs with the wider world through larger-scale oceanography is also an active area of research using shipboard measurements.
Finally, sea temperature, a physical oceanographic variable, is in itself a significant driver of coral reef ecosystems. Understanding the balance of air-sea fluxes, convection, and ocean currents that force sea temperature change over reefs, the so-called reef heat budget, is a major area of research within CHAMP right now.