Gray's Reef National Marine Sanctuary
Gray's Reef National Marine Sanctuary
2017 Gray's Reef Research Cruise Photos
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Gray's Reef Research
Expeditions 2017

Project Overview

NOAA Ship Nancy Foster

NOAA Ship Nancy Foster
(Photo: NOAA)

Gray's Reef National Marine Sanctuary has a variety of ongoing research and monitoring projects that will be continued during this research expedition. Projects will investigate questions related to fish and invertebrate abundance and distribution, habitat and human impacts. The expedition, underway June 9th - 23rd, will be aboard the NOAA Ship Nancy Foster.

In addition to Gray's Reef, scientist and staff from participating institutions on this reasearch cruise are representing Georgia Southern University, Valdosta State University, University of Connecticut, NOAA National Marine Fisherie Service, Beaufort Laboratory, National Center for Coastal Ocean Science and Louisiana State University.

Dive boat launch

Dive boat launch
(Photo: NOAA)

During the research cruise, the Chief Scientist is responsible for ensuring the scientific staff are trained in planned operations and are knowledgeable of project objectives and priorities. The ship's Commanding Officer is responsible for ensuring all operations conform to the ship's accepted practices and procedures

Diving and sampling will be conducted in and near waters of Gray's Reef National Marine Sanctuary (GRNMS), as required to support invertebrate studies and fish surveys. Exact locations of these sites will be determined while at sea based on a variety of factors and will be provided to the ship's navigation crew the night before a site is to be visited.

Either three small boats will be needed simultaneously or one small boat for dawn/ dusk dives and two small boats simultaneously to support these projects. Each small boat will carry 4-5 divers and will conduct 2-4 dives before returning to the ship. A NOAA Divemaster will be on board for all dive operations on this project and will follow all NOAA diving policies and regulations. Dives may be conducted in teams of two, three or four people. Each team will dive between one and six times daily.

Invertebrate Abundance and Diversity
   Assessment

Gray's Reef National Marine Sanctuary (GRNMS) is located 19 miles offshore of Sapelo Island, Georgia, and protects 22 square miles of rocky carbonate-cemented sandstone reefs. These rocky reefs consist of ledges that can be as tall as six feet and provide shelter for a diverse community of invertebrates, algae, and fishes.

NOAA established a research area in Gray's Reef to increase the opportunity to scientifically discriminate between natural ecological changes within the sanctuary versus changes caused by humans.

Danny Gleason collecting data

Danny Gleason collecting data
(Photo: Sarah Fangman, GRNMS)

One goal of the research area is to document the abundance and diversity of sessile invertebrate populations. Invertebrates will be quantified in 0.5 x 0.5 m (0.25 m2) quadrats placed along ledges found within and outside the research area to identify and photograph invertebrate organisms present on the bottom.

At each ledge, quadrats will be placed at 3 points: a) on the ledge immediately adjacent to the scarp, b) 2 m awayfrom the scarp on the sandy portion of the ledge and c) 5 m away from the scarp on the sandy portion of the ledge. Quadrats will be placed in these positions to take into account gradations in community composition. A minimum of 10 quadrats will be completed at each of the 3 positions on a ledge.

A total of 20 sites will be monitored: 10 inside and 10 outside the no-take Research Area, and potentially some additional dives outside of Gray's Reef. It is estimated that 2 sites per day can be completed with 4 divers available.

Picivore Ecology

Schooling spadefish with predators above

Schooling spadefish with predators above
(Photo: Peter Auster, UCONN, Mystic Aquarium)

Dr. Peter Auster and his team will conduct simultaneous split-beam and multibeam sonar surveys along lines delineated for specific study reefs both inside and outside the Research Area within Gray's Reef (as performed previously starting in 2011). They will address questions that have emerged from previous observations. That is: how do prey resources at reefs vary over the course of day-night periods and at different tidal stages; do aggregations of prey fish on and off reefs have a characteristic pattern in relation to density and school shape; do predators follow prey away from reefs and interact differently than on reefs?

Surveys will be conducted early morning, mid-day, late afternoon, postsunset, sometime during middle night time hours and prior to sunrise (with actual timing determined bytime of sunset and sunrise). Surveys will focus on one reef each day, from a set of ten reefs previously surveyed.

This project is a collaboration between University of Connecticut Department of Marine Sciences, Mystic Aquarium and NOAA's National Centers for Coastal Ocean Science.

Gray's Reef Hardbottom Community Survey

Brian Degan conducting fish survey

Brian Degan conducting fish survey
(Photo: Sarah Fangman, GRNMS)

Visual fish surveys will be conducted along 50 m transects with an estimated width of 5m on each side targeting mobile conspicuous fishes.

Prey fish surveys will be conducted along 30 m transects with an estimated width of 1m on each side to survey the cryptic (or juvenile) prey species 10 cm and less in length.

Habitat structure quantification will be surveyed at fixed intervals along the fish survey transects (5, 15, 25, 35 and 45 m) several ledge measurements will be collected: total ledge height and undercut height, undercut depth. At each ledge measurement location, macroalgae and invertebrate height will be recorded. Maximum height of an individual will be recorded to the nearest centimeter.

The team will update these webpages with daily logs describing our progress with these planned investigations. Please check back to keep up with our progress!


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