11th ICRS Abstract book - Nova Southeastern University

24.1108
Restoring An Artificial "Enhancement": Baseline Data To Assess Strategy
Effectiveness And Future Mitigation
Danielle MORLEY* 1,2 , Robin SHERMAN 3 , Lance JORDAN 1,2 , Richard SPIELER 1,4
1 Oceanographic Center, Nova Southeastern University, Dania Beach, FL, 2 National Coral
Reef Institute, Dania Beach, 3 Farquhar College of Arts and Sciences, Nova Southeastern
University, Ft. Lauderdale, FL, 4 National Coral Reef Institute / Guy Harvey Research
Institute, Dania Beach
In 1967, Broward County, Florida resource managers initiated a project to construct an
artificial reef to enhance recreational fishing using waste vehicle tires. An estimated two
million unballasted tires were deployed in bundles approximately 1.8km offshore in 21m
of water on sandy substrate separating the Middle and Outer reef tracts, running parallel
to the coast. Over time, bindings on the tire bundles failed and they became mobile with
normal currents and high energy storms. The tires have apparently moved extensively,
traveling kilometers from their original location to beaches and deeper waters offshore. It
has also been reported that loose tires have physically damaged benthic reef fauna on the
natural reef. Due to this damage, a large-scale removal plan of the tires has been initiated.
To assess damage and evaluate effectiveness of tire removal, an examination of existing
biota was accomplished. Live corals were absent on the Middle reef edge, buried by tires
but were present on the tires themselves. When compared to the impacted Middle reef
edge (tires present), adjacent natural reef control sites (tires absent) exhibited
significantly lower fish abundance and species richness. Removal of the tires will directly
reduce the abundance of fishes and affect the corals in the area. Future studies will
evaluate the loss of these resources relative to the gain in reduced impact to the natural
reef.
24.1109
Comparison Of The Benthic And Fish Assemblages On Three Types Of Artificial
Reef Modules
Sara THANNER* 1 , Stephen BLAIR 1 , Timothy MCINTOSH 1
1 Department of Environmental Resources Management, Miami-Dade County, Miami, FL
In 1988, offshore dredging for a beach renourishment project in Miami-Dade County,
Florida caused extensive damage to the second reef tract off of Sunny Isles Beach. In an
effort to restore and mitigate for the damage, the Sunny Isles Reef Restoration Project
began in August of 1991. Three different types of artificial reef modules, “Dome”, “M-
2”, and “Reef-Replacement”, were placed on the reef where the damaged occurred. The
goal of the restoration was to provide a basis for the biological recovery of the impacted
hard bottom, while minimizing the enhancement effects (e.g. over representation of a
specific community component) of the restoration modules used. The development of the
benthic and fish assemblages on the modules was monitored for the initial four years
following deployment. Monitoring efforts in 2003 sought to re-assess the modules to
determine the extent of change that had occurred since 1995. Species diversity and
density on each module type, similarity between the modules and the surrounding natural
reef, and possible enhancement effects of the modules were evaluated. The reassessment
indicated the diversity and density of benthic and fish assemblages increased on all
module types. The Dome and Reef-Replacement modules had the greatest similarity
(Bray-Curtis Index) with the surrounding reef at 49% and 48%, respectively for benthic
assemblages, and 21% and 15% respectively for the fish assemblages. Enhancement
effects were observed in the fish assemblages near the modules due to their greater relief
and extensive void space, particularly on the M modules. Dome and Reef Replacement
modules were considered the more appropriate mitigation as they developed biotic
communities more comparable to the natural reefs, had the lowest profiles and
incorporate natural substrate (lime rock) in their design. Exactly how similar these
artificial habitats will become relative to the natural reefs requires additional monitoring
efforts.
Poster Mini-Symposium 24: Reef Restoration
24.1110
Effects Of A Novel Invertebrate Substrate On Fish Assemblages Associated With
Concrete Modules
Judy ROBINSON* 1 , Lance ROBINSON 2 , Brian BUSKIRK 1 , Richard SPIELER 1
1 Marine Biology, Nova Southeastern University Oceanographic Center, Dania Beach, FL,
2 Nova Southeastern University Oceanographic Center, Dania Beach, FL
Most coral reef restoration efforts have concentrated on limited target organisms, e.g. returning
coral populations, usually by transplant, or fish populations, by providing artificial refuge.
Normally these restoration efforts do not make specific attempts to increase the non-coral
invertebrate assemblages which provide an important forage base for the majority of coral reef
fishes. We hypothesized addition of a substrate for invertebrate recruitment to concrete artificial
reefs would provide a forage source for fish, and potentially create a more natural assemblage
of fish and invertebrates. Thirty-two commercial concrete reef modules (Reefballs®) were
deployed with one of four treatments: 1) with invertebrate substrate (3M High Pro Stripping
Pads) and internal fish refuge (concrete blocks), 2) with only invertebrate substrate, 3) with only
internal refuge and, 4) without added substrate or refuge (control). During a 2-year period
(2005-2007), fish counts were performed quarterly by divers on SCUBA. Twenty-nine families
and 112 species of fish were identified. An apparent preferential selection of treatment type was
noted for several species. Larger reef fish such as Gymnothorax miliaris, Gymnothorax vicinus,
and Lachnolaimus maximus associated with treatments that offered internal refuge (blocks). In
addition, there were often more Balistes capriscus, Acanthurus chirurgus, Lutjanus synagris
and Haemulon melanurum, on these modules. No significant difference (GLM) was found
between treatments with internal refuge with or without substrate; however, the combination of
internal refuge and invertebrate substrate showed the highest abundance for these species. In
contrast, Stegastes partitus and Thalassoma bifasciatum were significantly more abundant on
modules with invertebrate substrates than on block alone or control. This study provides insight
into the effects of invertebrate refuge on fish assemblages, highlights the value of artificial
substrate design in the establishment of a diverse fish community, and ultimately may provide a
unique method for enhancing coral reef restoration efforts.
24.1111
A Pre-Designed Artificial Reef Planted With Corlas As A Tool To Attract Fish & Relieve
Diving Pressure Off Natural Reef
Omer POLAK* 1,2 , Fuad AL-HORANI 3 , Yaron PITKOVSKI 4 , Nadav SHASHAR 1,4
1 Ben-Gurion University, Beer Sheva, Israel, 2 Interuniversity Institute for Marine Sciences, Eilat,
Israel, 3 Marine Science Station, Aqaba, Jordan, 4 Ben-Gurion University, Eilat Campus, Eilat,
Israel
In recent years there has been sporadic use of coral transplantation on Artificial Reefs (AR).
ARs are used for the fishing industry and to some extent in tourism. AR location, design, and
biodiversity may increase attractiveness to divers and thus enhance visitation frequency or
length of stay. To try and relieve pressure off the nearby MPA and assess divers' attractiveness
a pre-designed AR (4x4x4 m) was deployed in Eilat, Red Sea. The study followed divers'
behavior inside and outside the MPA and compared a similar sized reef knoll to the AR before
deployment, after deployment and following coral transplantation. Concurrently, fish count was
visually censused during all phases of the deployment and compared to diving behavior. Initial
results suggest that the AR, at all phases mentioned, attract divers of different experience level
similarly to the adjacent knoll. However, possibly due to its small size, it did not significantly
alter diving behavior to nearby MPA. The introduction of transplanted corals has increased
species richness significantly by ~30% within matter of days, but did not change divers'
behavior. The use of an actively transplanted AR was effective for increasing fish biodiversity
but less effective for changing diving behavior. Increase of AR size as well as increased
community involvement, may increase visiting time and generate a change in diving behavior.
It is apparent that Diving Aggregating Device (DAD) has different needs than the familiar Fish
Aggregating Devices (FAD).
Supported by the USAID- MERC program
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