Review of Scientific Research in and Around the Designated Research Area of Gray's Reef National Marine Sanctuary (NW Atlantic)

A research area (8.27mi2) was designated within the 22 mi2 Gray’s Reef National Marine Sanctuary (GRNMS) in December 2011. The purpose of this research area is to increase the opportunity to discriminate scientifically between natural and human-induced change to species, communities, and associated habitats. The ability to conduct investigations in a marine environment relatively free of direct human influences is critical to meet the resource protection and scientific research mandates of GRNMS. Although allowable fishing gear is limited in the sanctuary, recreational fishing continues to impact the sanctuary resources.

The projects described in this report demonstrate that the GRNMS Research Area (RA) is being utilized as designated. That is, it is functioning as a site to study the effects of natural variability from local and regional ecological processes (e.g., predation, competition, climate change, storms) where the direct effects of fishing will not mask, or add a degree of ambiguity, to the interpretation of results. Prior to designation of the RA in 2011, fishing was allowed throughout the sanctuary, and there were no options to study the broad suite of questions governing conservation and sustainable use of natural resources knowing that direct human uses were not directly influencing outcomes.

Over the past several years, 16 projects were implemented along three strands linked to the Research Area. On one strand are those studies that directly and explicitly compare the status of faunal groups inside and outside the RA (e.g., reef fish, invertebrate communities and key taxa on ledges, pelagic forage fish). On the second strand are those studies that simply use the RA as an unimpacted study site (e.g., high spatial resolution acoustic tagging of fishes). Finally, on the third strand are those studies that focus on processes or approaches that support work in the RA now or in the future (e.g., data buoy, sediment processes, acoustic tag detection with mobile platforms, towed video for assessing halo predators).

This report summarizes the status of projects after only five years since RA establishment (2011). This is a relatively short period of time to expect unambiguous results of contrasts due to management status. Indeed, the literature is replete with empirical data demonstrating that response to spatial management occurs over longer periods as ecological processes that mediate population and community dynamics shift due to changes in disturbance regimes and responses to protection stabilize. In any case, current results of the inside-outside comparisons, given the statistical limits in the ability to detect change, suggest that to date human uses outside the RA have minimal impacts and are sustainable. Such results demonstrate the utility of the RA as a reference site that allows continuing assessment of change from multiple drivers absent direct fishing and other use effects regardless of the status of human impacts outside the boundaries. However, the uncertainties of patterns in human use within GRNMS before and after designation of the RA and into the future are important to acknowledge. Understanding current and future patterns of fishing and vessel use, linked to variation in ecological metrics from seafloor habitats, is needed to make optimal use of the results of comparisons between closed and open areas and to demonstrate that zoning boundaries match the reality of human pressures on the water.

Key Words

Research Area, Gray’s Reef National Marine Sanctuary, South Atlantic Bight, Georgia, Benthic Community, Fish Community, Hard Bottom, Live Bottom, Temperate Reef, Sub-tropical Reef, Benthic Invertebrate, Fish Distribution, Movement Patterns, Water Quality, Sediment, Marine Protected Area