Gray's Reef National Marine Sanctuary
Gray's Reef National Marine Sanctuary
Gray's Reef Expedition 201
Mission Information

Welcome Aboard!

Scientists, staff and volunteers will conduct a research mission within Gray's Reef National Marine Sanctuary, located 16 miles off the coast of Sapelo Island, Georgia, aboard the NOAA Ship Nancy Foster beginning May 17th through May 29th. Please join us as we report on the activities and findings of this exciting mission!

Scientists aboard the Nancy Foster will be concentrating on five research projects:
   1) Fish Censuses
   2) Invertebrate Density and Abundance
   3) Piscivore Ecology
   4) Multibeam Mapping
   5) Dye Tracer Studies

Black seabass on sparsley colonized livebottom

Black seabass on sparsley colonized livebottom
(Photo: Greg McFall, GRNMS)

We will be posting daily mission logs on the website. So please visit regularly and click on each day's mission log to track progress and experiences.

The primary objective of the cruise is to collect information to better understand, manage, and protect Gray's Reef National Marine Sanctuary.

The five research projects will be conducted by scientists at various times during the expedition, as work on the ship goes on around the clock. For more information on the personnel aboard the Nancy Foster, please visit our Expedition Team Page.

Fish Censuses
NOAA is proposing to establish a research area in Gray's Reef later this year to increase the opportunity to scientifically discriminate between natural ecological changes within the sanctuary versus changes caused by humans.

One goal of the proposed research area is to determine the effect of bottom fishing on benthic (associated with the ocean bottom) fish populations. Therefore, this year from the NOAA Ship Nancy Foster, we plan to generate a baseline by conducting benthic habitat and fish community surveys at numerous sites located within and outside the proposed research area. At each site, we will measure ledge characteristics such as ledge height and determine the benthic habitat community (sponges, sea squirts, sea urchins, algae) present with a series of stationary photoquadrats.

Feather duster worm

Feather duster worm
(Photo: Greg McFall, GRNMS)

Invertebrate Density and Abundance
The research that will be conducted at Gray's Reef on this expedition by Dr. Danny Gleason and students from Georgia Southern University, is focused on the ecology of benthic marine invertebrates, such as sponges and corals. Their goal is to gain an understanding of the roles that biotic (e.g., competition, predation) and abiotic (e.g., temperature, sedimentation, current speed) factors play in shaping the community of benthic invertebrates that occur at Gray's Reef. Obtaining knowledge such as this is critical for implementing appropriate management strategies because these benthic invertebrates provide critical resources that support the vast array of fishes that inhabit these offshore reefs.

Piscivore Ecology
The objective of this project is to better understand the food web at Gray's Reef. Dr. Peter Auster and his team from the University of Connecticut's School of Marine Sciences at Avery Point will concentrate on the role of predators in the water column, the response of prey when a predator is present, and the link between feeding rates and population processes of demersal (bottom-dwelling) reef piscivores (fish-eating) fish. This work will be done using divers to quantify behavior of the fish and the rates of predation that occur. Diver observations will be supported by the use of hydroacoustic (underwater sound detection) survey systems and high frequency sonar to map fish distribution and movement over a broader area.

NOAA Ship Nancy Foster

NOAA Ship Nancy Foster in Gray's Reef
(Photo: David Patterson)

Multibeam Mapping
The seafloor of Gray's Reef National Marine Sanctuary was mapped in 2001, using both multibeam and side scanning sonar. Using information from this data, scientists produced a habitat map of the sanctuary's seafloor which is characterized into four categories: densely colonized livebottom, sparsely colonized livebottom, rippled sand and flat sand. The densely colonized ledges and outcroppings comprise only about one percent of all available habitat where fish are known to aggregate. Gray's Reef will be remapped during this year's expedition to provide scientists with information about how the sanctuary habitat has changed during the last ten years.

Dye Tracer Study
During the 2011 Nancy Foster cruise, Drs. Risa Cohen and Daniel Gleason from the Department of Biology at Georgia Southern University will continue studies investigating the extent to which the Altamaha River delivers dissolved substances to Gray's Reef National Marine Sanctuary (GRNMS).

This study addresses an important gap in our understanding of the role that rivers play in the health of offshore marine ecosystems. Specifically, a wealth of data has shown that urbanized watersheds deliver pollutants such as pesticides, mercury, and excess nitrogen that result from human activities to the coast, but the majority of these studies have focused on impacts to estuarine and near-shore systems.


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