Ian Enochs

2015

This proposal describes a two-year extension (FY14-15) to the previously funded (FY10-13) "Coral Growth of the Florida Reef Tract with Accelerating Ocean Acidification," which focused exclusively on the Florida Keys portion of the Florida Reef Tract. The previous CRCP funded work has been extremely important to management of both US and international coral reefs, as well as other habitats or organisms impacted by OA, because it revealed that coral reefs surrounded by, or immediately downstream of seagrass beds may serve as OA refugia (Manzello et al. 2012). This has resulted in one of the first real-world actions that can be done locally to mitigate OA - the careful management of seagrasses given their ability to act as carbon sinks. In fact, oyster hatcheries are now planning to use seagrasses as a biosolution to corrosive, acidified water that have recently damaged hatchery production. Support from this work has also shown that the common clionaid sponge, /Pione lampa/, will experience an OA-induced increase in its rate of biologically-mediated chemical erosion that is nearly double the expected decline in coral calcification rate (Enochs et al. In revision). The Enochs’ study also showed that the majority of Florida Keys coral reefs are presently in a net erosional state and calcification would need to increase by 30% in order to compensate for the projected OA-enhanced bioerosion. These findings show that OA will accelerate coral reef degradation more rapidly than previously predicted. These findings are highly pertinent to the northern Florida Reef Tract, or SEFCRI region, as in this region clionaid sponges are more abundant, coral cover in generally very low, and seagrasses are nearly non-existent. Furthermore, the ubiquity of inlets and outfalls releases nutrient rich and/or sediment laden freshwater to the coastal waters of this region. Freshwater runoff and riverine inputs are known to be enriched in dissolved inorganic carbon, and diluted lower saline waters are known to have elevated pCO2 (e.g., Manzello et al. 2013). Given all of these factors, we anticipate the majority of these reefs are already net erosional as well, and are likely degrading even faster than those in the Florida Keys. In summary, this work will fulfill an urgent need of local managers, shed light on the hypothesized increased sensitivity of the northern Florida Reef Tract to OA, as well as fulfill the class O NCRMP/OAP requirements (while increasing spatial and temporal resolution). This project will serve as a cornerstone for management of the northern Florida Reef Tract in a high-CO2 world.ReferencesEnochs I, et al. (In revision) Ocean acidification enhances the bioerosion of a common coral reef sponge: implications for the persistence of the Florida Reef Tract. Bull Mar Sci Manzello D, et al. (2012) Ocean acidification of the Florida Reef Tract. PLoS ONE 7: e41715. doi:10.1371/journal.pone.0041715 Manzello D, et al. (2013) Tropical cyclones cause CaCO3 undersaturation of coral reef seawater in a high-CO2 world. JGR-Oceans 118:5312-5321, doi: 10.1002/jgrc.20378

Reef framework structures, which are the end result of coral calcification, act as natural breakwaters for Florida residents of the SE coast and their three dimensional architecture is a main draw for SCUBA divers. Reef structures are vital to reef associated biodiversity and fisheries, such as economically important fisheries like the spiny lobster, in addition to local tourism-based economies. There is thus an urgent need to know just how the building (coral growth) and persistence (bioerosion) of these reef structures may change with ocean acidification. As a first step, the variability of seawater carbonate chemistry from reef waters must be related to coral growth parameters (calcification, density, extension), and rates of bioerosion in the real-world. These findings are highly pertinent to the northern Florida Reef Tract, as clionaid sponges are more abundant, coral cover in generally very low, and seagrasses are much less abundant than what occurs in the Florida Keys. Furthermore, the ubiquity of inlets and outfalls release nutrient-trich and/or sediment-laden freshwater to the coastal waters of this region. Freshwater runoff and riverine inputs are enriched in CO2. Given all of these factors, we anticipate the majority of these reefs are already net erosional as well, and are likely degrading even faster than those in the Florida Keys. A better understanding of the environmental controls on the processes of both reef growth and loss will allow resource managers to better predict and model the trajectory of these habitats to increasing CO2 over the 21st century.

• Florida

Climate Change

Completed

https://www.coris.noaa.gov/search/rest/find/document?searchText=projectNumber%3A172%20OR%20projectTitle%3A"Coral%20Growth%20and%20Reef%20Framework%20Persistence%20of%20the%20SEFCRI%20region%20of%20the%20Florida%20Reef%20Tract%20with%20Ocean%20Acidification"&start=1&max=10&f=searchPage