Stillwater Research Group, Inc. St Petersburg Florida Ecology Low Relief Artificial Reef Research Grouper-Snapper-Grunt

Stillwater Research Group, Inc.
A Florida Not for Profit Corporation

Egmont Key Experimental Reef:

SRG, in cooperation with Delta Seven Inc, Hillsborough County, Gator Dredging, and Walter Marine recently began work on the installation of an experimental design for a special kind of artificial reef.

Funding:

Gulf of Mexico Foundation.
In Kind Service by the listed Partners

Partners

Delta Seven, Inc.
Gator Dredging
Walter Marine
Maximo Marina
Carroll's Building Materials
Coastal Group Services

Please note that this installation is experimental in nature. In the video, you will see different sizes of disks, some with rock embedded and some without. Future installations would need to be designed to account for sediment stability, current and wave energy conditions, and the intended residents. The experimental site is in 22 feet of water. Visibility is typically poor, but sufficient to support algal growth. Immediately adjacent to this installation is a well aged artificial reef which is being used for comparative purposes. We thank Walter Marine for accommodating our design and making the adjustments to meet the experiment needs.

Project Scientists

Lauren M. Waters
Dr. Thomas R. Cuba

The plan was to provide different cavity types, sizes, and spacing to allow for the team to monitor travel among modules. Too close, and large predators would see the space as an ambush point. Too far and the residents would hesitate to cross to adjacent modules.

3D multibeam sonar view provided by
George F. Young survey team.

Research

The purpose of the research was to construct an artificial reef designed specifically to provide refuge for sub adults of the grouper-snapper-grunt comlpex (see Hixon and Beets 1993, Ecological Monographs, 63: 77 - 101 and subsequent papers) in order to improve the habitat availability and suitability for the middle phases of the ontogenetic pathway of these species. The improved habitat quality, as well as the increased availability, will increase the numbers of fishes which can recruit as adults to larger structure.

To do so, the team constructed an artificial reef designed to structurally mimic natural reefs in Tampa Bay which were lost to fill activities. The reef is composed of a mixture of natural (limestone) and artificial (concrete) materials. It was constructed in a manner designed to inhibit colonization by predatory fishes (grouper) greater than 8-10 inches in length.

The location of the structure is such that post juvenile stages of these fish can recruit from grass and rubble beds and that fishes becoming too large can easily recruit to nearby higher relief structure located in areas designated for fishing at an existing managed artificial reef site. Applying the habitat suitability concepts defined in the Hixon papers (see above) the reef is designed to trigger behavior in larger members of the targeted genera which will keep them from dominating the reef. The same triggers will attract and hold the mid size members of these genera, protecting them from larger predators and increasing their survival rate. The same habitat criteria will make the site suitable for colonization by epilithos and subsequently by small prey fish assuring an abundant food supply for the mid size members of the target genera. The combination of prey, reduced predation, and location, will provide for increased recruitment of mid size fishes, and thus greater availability of mature fish to the larger adjacent reef resulting in an increase in the speed and efficiency of recruitment.

Small Grouper using habitat.

Video Links

The links are low visibility, raw, and uncut. They
are included so that the viewer can examine the reef
for themselves without waiting for the report.
The videos do not, of course, convey our field notes.
There is more diving to do and the final report is due in the fall.

Coastal Services installing the base unit from Gator Dredging barge.

18 inch size "Oyster Balls."

Design Sketch of Ecosystems Reef Module.

Typical Ecosystems module. Units with only two or three layers were used in this experiment.

This site is sponsored by:

Delta Seven Inc.

	Stillwater Research Group, Inc. A Florida Not for Profit Corporation	E-mail Stillwater Research Group
	Egmont Key Experimental Reef: SRG, in cooperation with Delta Seven Inc, Hillsborough County, Gator Dredging, and Walter Marine recently began work on the installation of an experimental design for a special kind of artificial reef.	Funding: Gulf of Mexico Foundation. In Kind Service by the listed Partners
Partners Delta Seven, Inc. Gator Dredging Walter Marine Maximo Marina Carroll's Building Materials Coastal Group Services	Please note that this installation is experimental in nature. In the video, you will see different sizes of disks, some with rock embedded and some without. Future installations would need to be designed to account for sediment stability, current and wave energy conditions, and the intended residents. The experimental site is in 22 feet of water. Visibility is typically poor, but sufficient to support algal growth. Immediately adjacent to this installation is a well aged artificial reef which is being used for comparative purposes. We thank Walter Marine for accommodating our design and making the adjustments to meet the experiment needs.	Project Scientists Lauren M. Waters Dr. Thomas R. Cuba
The plan was to provide different cavity types, sizes, and spacing to allow for the team to monitor travel among modules. Too close, and large predators would see the space as an ambush point. Too far and the residents would hesitate to cross to adjacent modules. 3D multibeam sonar view provided by George F. Young survey team.	Research The purpose of the research was to construct an artificial reef designed specifically to provide refuge for sub adults of the grouper-snapper-grunt comlpex (see Hixon and Beets 1993, Ecological Monographs, 63: 77 - 101 and subsequent papers) in order to improve the habitat availability and suitability for the middle phases of the ontogenetic pathway of these species. The improved habitat quality, as well as the increased availability, will increase the numbers of fishes which can recruit as adults to larger structure. To do so, the team constructed an artificial reef designed to structurally mimic natural reefs in Tampa Bay which were lost to fill activities. The reef is composed of a mixture of natural (limestone) and artificial (concrete) materials. It was constructed in a manner designed to inhibit colonization by predatory fishes (grouper) greater than 8-10 inches in length. The location of the structure is such that post juvenile stages of these fish can recruit from grass and rubble beds and that fishes becoming too large can easily recruit to nearby higher relief structure located in areas designated for fishing at an existing managed artificial reef site. Applying the habitat suitability concepts defined in the Hixon papers (see above) the reef is designed to trigger behavior in larger members of the targeted genera which will keep them from dominating the reef. The same triggers will attract and hold the mid size members of these genera, protecting them from larger predators and increasing their survival rate. The same habitat criteria will make the site suitable for colonization by epilithos and subsequently by small prey fish assuring an abundant food supply for the mid size members of the target genera. The combination of prey, reduced predation, and location, will provide for increased recruitment of mid size fishes, and thus greater availability of mature fish to the larger adjacent reef resulting in an increase in the speed and efficiency of recruitment. Small Grouper using habitat. Video Links The links are low visibility, raw, and uncut. They are included so that the viewer can examine the reef for themselves without waiting for the report. The videos do not, of course, convey our field notes. There is more diving to do and the final report is due in the fall.	Coastal Services installing the base unit from Gator Dredging barge.
		18 inch size "Oyster Balls."
Design Sketch of Ecosystems Reef Module.		Typical Ecosystems module. Units with only two or three layers were used in this experiment.

This site is sponsored by: Delta Seven Inc.	Copyright Stillwater Research Group, Inc. 2009 All Rights Reserved