South Florida/Caribbean Network seagrass community monitoring: Protocol narrative

Davis, Andy; Feeley, Michael; Londoño, Mario; Richter, Lee; Patterson, Judd; Atkinson, Andrea

Seagrass communities in nearshore coastal ecosystems provide important habitat for numerous species including recreationally and commercially important juvenile fish and invertebrate species, sea turtles, and wading and diving birds. These ecosystems also increase water clarity by reducing the impact of wave energy and helping to stabilize sediments. However, these communities are sensitive to natural and anthropogenic effects such as eutrophication, pollution, physical damage and changes in hydrological patterns (Lapointe et al. 1994; Fourqurean et al. 2002). Seven native seagrass species occur inside or in close proximity to seven of the South Florida/Caribbean Network (SFCN) parks. Seagrass communities in the SFCN parks have been exposed to significant anthropogenic stress, such as eutrophication and changes in salinity patterns associated with water management in south Florida, among other effects. More recently, an invasive exotic seagrass species has been responsible for seagrass community changes in the U.S. Virgin Islands. The South Florida/Caribbean Network is developing monitoring programs for natural resource “vital signs” including seagrass communities within the network’s parks. As several partners already monitor seagrass communities in and near network parks, the South Florida/Caribbean Seagrass Community Monitoring: Protocol Narrative (SFCN seagrass protocol) is focused on the gaps in existing monitoring programs, including offshore Biscayne National Park, Buck Island Reef National Monument, Salt River National Historical Park and Ecological Preserve, and Virgin Islands National Park. Partners already monitor Biscayne Bay, Florida Bay (in Everglades National Park) and Dry Tortugas National Park. The primary objective of the SFCN seagrass protocol is to monitor trends in seagrass cover, community composition and the presence of invasive exotic species within mapped seagrass habitat in network parks. Secondary objectives for the SFCN seagrass protocol are: • Collect ancillary information (i.e., water depth, sediment depth, substrate type, canopy height, Lobatus gigas [Queen Conch] counts) that can be used to improve understanding of seagrass species and habitat relationships or provide information to support another vital sign. • When requested by park management and logistically feasible, compare trends in seagrass cover, species composition, and the presence of invasive exotic species within and outside of parks to evaluate the effectiveness of park management actions. • When requested by park management and logistically feasible, perform additional “episodic” monitoring in response to unforeseen events or circumstances. Seagrass is monitored using a stratified random survey where sites are monitored by teams of divers deploying four 0.25 square meter (2.7 square foot [ft2]) quadrats which are assessed using a Braun-Blanquet methodology. Sampling in parks will occur in rotation with parks revisited once every three years after a baseline is established. As extensive seagrass monitoring is already conducted by well-established programs, the network developed the SFCN seagrass monitoring protocol using established methods described in A Seagrass Monitoring Program for Texas Coastal Waters: Multiscale Integration of Landscape Features with Plant and Water Quality Indicators (Dunton et al. 2011; also referred to as ‘The Texas Seagrass Protocol’), Spatial and Temporal Pattern in Seagrass Community Composition and Productivity in South Florida (Fourqurean et al. 2001), and Integrating Scales of Seagrass Monitoring to Meet Conservation Needs (Neckles et al. 2012). The sample design is a stratified random design using depth as strata and a random selection of points within each stratum. The Texas seagrass protocol is based on the work by Jim Fourqurean of Florida International University (FIU) (Fourqurean et al. 2001) and Neckles et al. (2012), and is currently being used in the Gulf Coast Network (GULN).

South Florida/Caribbean Network seagrass community monitoring: Protocol narrative

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