Missions Header Graphic
2010 Aquarius Mission - If Reefs could talk
Mission info 2007 Nancy Foster Cruise
 

Aquarius 2010 Expedition Blog:
Oct. 18, 2010

By John Burke, Fisheries Biologist
Center for Coastal Fisheries and Habitat Research
NOAA Ocean Service, Beaufort, NC

View from among the submerged mangrove prop roots looking out to a seagrass meadow
View from among the submerged mangrove prop roots looking out to a seagrass meadow. Click here for a larger image. (Photo: NOAA)
This morning I took Chris Taylor and Brian Degan to the Miami International Airport for their flight home to North Carolina. The three of us have been surveying a variety of important marine habitats around Key Largo using sonar systems. Chris and Brian will be missed, not just by me but the whole disparate team of artists, biologists, educators and production personnel that make up the Aquarius Mission.

 View from among the submerged mangrove prop roots looking out to a seagrass meadow.
John Pennekamp Coral Reef State Park's seagrass/algae nursery area shelter for many juvenile fishes like the schoolmaster at the end of the video clip. Schoolmasters reside on Conch and other offshore reefs as adults. Click here to watch the video. (Photo: NOAA)
If a reef could talk I suspect it'd say "Keep corals connected! The whole is the sum of the parts." While our understanding of the "whole system" is limited, some important habitats and their connections have been identified. Many of the fishes seen on coral reefs during the day feed elsewhere at night and start out life in quite different habitats. For many species, the reef with its abundance of resident predators is not the neighborhood to grow up in. Nearby plant and algae dominated habitats such as seagrass meadows and the submerged mangrove prop root habitats provide nursery grounds for a wide range of coral reef fishes. These vegetated habitats provide abundant food and suitable hiding places insuring high survival and rapid growth for the juvenile stages of many species. One common pattern of movement for fish that reside on reefs as adults is: the smallest juveniles live in the seagrass, move to mangrove or shallow patch reefs with growth and inhabit increasingly deeper reefs as they mature.

Mangrove stands, the submerged prop root habitat and typical predators juvenile barracuda, mangrove snapper
Mangrove stands, the submerged prop root habitat and typical predators; juvenile barracuda, mangrove snapper and snook. Click here to watch the video. (Photo: NOAA)
The complex structure provided by the corals and sponges of the reef provides a diverse group of fishes with shelter from large predators such as sharks, barracudas and jacks. Many of these species do most of their feeding elsewhere. During twilight the grunts, snappers, goatfish and cardinalfish, to name a few important fish families, leave the reef to feed on the abundant invertebrates that live in the soft bottom habitats that surround reefs. This nocturnal feeding behavior develops during the juvenile stage in some species when they inhabit mangroves. Mangrove surveys within the John Pennekamp State Park this week showed there are plenty of predators to hide from.

Video showing output from the DIDSON sound camera in a mangrove channel during nightfall.  The first image shows a cruising snook of about 2 feet in length near sunset.  The second shows a school of juveniles leaving the mangrove pursued by a snook.
Video showing output from the DIDSON sound camera in a mangrove channel during nightfall. The first image shows a cruising snook of about 2 feet in length near sunset. The second shows a school of juveniles leaving the mangrove pursued by a snook. Click here to watch the video. (Photo: NOAA)
Though waiting till twilight to move from sheltering mangrove prop roots to their more open feeding grounds gives juvenile fish an edge over predators, it is clear from observations with the sound camera (DIDSON, imaging sonar) in the mangrove channels of John Pennekamp State Park that this migration is still dangerous.

These three habitats; mangroves, seagrass beds and coral reefs are vital parts of the coral reef ecosystem. Fishes provide some of their many vital habitat linkages that support the ecosystem as a whole. Restoration and maintenance of coral reef ecosystem health will require conservation of these habitats in their landscape context. This will insure that the habitat interconnections, so vital to this vibrant ecosystem, are conserved.

leaving site indicates a link leaves the site. Please view our Link Disclaimer for more information.
Revised October 19, 2010 by Sanctuaries Web Team | Contact Us | Web Site Owner: National Ocean Service
National Ocean Service | National Oceanic and Atmospheric Administration | Privacy Policy | For Employees | User Survey
http://sanctuaries.noaa.gov/missions/2010aquarius/blog_101810.html