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lack of natural protection will also increase sedimentation and nutrient releases to the Lagoon. Not only do these natural areas provide protection and pollution prevention, they also act as important habitats for numerous organisms during some portion of their lives. Finally, mangroves act as sinks for organic carbon, which means they store carbon inside their structure instead of releasing it to the atmosphere. If large mangrove forests die off because of sea level rise, this carbon will be released and act as a negative feedback for drivers of climate change. Such die -offs would have the potential to speed up rates of climate change. Sea level rise will change the current patterns and flow rates of the Lagoon and tributaries, which in turn will modify estuarine habitats and their primary and secondary productivity. The Indian River Lagoon National Estuary Program (IRLNEP) is currently studying sea level rise using a risk-based vulnerability assessment of the Lagoon to climate change following the US Environmental Protection Agency's (EPA) workbook Being Prepared for Climate Change. The first half of the study determined the biggest stressor associated with sea level rise, was found in the impaired waters categories (water quality). Sea level rise will be a major stressor to the risk of impaired waters because it is a permanent change, whereas the other stressors, such as precipitation and storms, provide temporary risks. Comparing lagoon -wide historical trends from 1980-2008, decreasing trends were found in dissolved oxygen concentrations, pH (becoming more acidic), and salinity. The only increasing trend in the study was found in temperature measurements. Now that phase one of their study is complete, the IRLNEP will work on phase two, which includes an action plan to help the Lagoon as a whole. These metrics will be considered when creating the Lagoon Management Plan for the County. Based on the information above, it appears that the County may benefit from taking part in a shoreline mapping project. There appears to be a data gap in the mapped extent of mangrove and marsh habitats, as well as their landward uses for the County. Data gaps also occur in understanding the rates of sediment accumulation within the Lagoon. Historically, sea level rise has been offset by natural rates of sediment accumulation along habitats. However, data now suggests that sedimentation rates are not able to keep up with current rates of sea level rise. As mentioned previously, sea level rise trends and predictions were based off of data collected from the Lake Worth Pier. There seems to be a gap in understanding of the specific sea level rise rates occurring in the County. 6. Land Use Changes (Part 1) Determining past and future land use changes are important in understanding current issues in the Lagoon and determining resiliency for the future. Past land use changes need to be understood to account for possible nutrient leaching impacts to the Lagoon. For example, studies in South Florida showed how phosphorus leaching from the soil due to past chemical management was still occurring 30 years after the retirement of orchards (agriculture use) and impacting the quality of nearby waterbodies. As the County historically was a widespread agricultural community, it is important to understand where those agricultural practices took place to understand how that might impact nutrient leaching levels in the future. While the impact to the Lagoon is not well understood currently, as more data becomes available it will then be incorporated into recommendations. It is also important to note where vacant lands are in the County and to identify what they are zoned for in order to understand how they may be used in the future. Monitoring of Environmental Resource Permits (ERP) issued by state agencies will allow the County to anticipate changes that may actively occur in the future and plan accordingly. 99