BH-4 Identify and Protect Hard Bottom and Oyster Reef Habitats in Tampa Bay
ACTION:
Identify and protect hard bottom and oyster reef habitats in Tampa Bay.
STATUS:
Ongoing. Action revised from “Restrict impacts to hard-bottom communities and evaluate the
ecological effects of artificial hard-bottom habitat.” New action highlights mapping and
restoration efforts since 2006, notes permitting challenges and need for monitoring of ecological
effects of artificial hard bottom and oyster habitats.
BACKGROUND:
Hard bottom habitats in Tampa Bay include fossilized corals, rubble, limestone, other natural
“reef-like” material and artificial reefs. They provide important substrate for the attachment of
benthic species, including sponges, corals and oysters and attract and support a diverse
assemblage of marine invertebrates and fish, including many recreationally important species.
Oyster reefs are formed by the cumulative buildup of shell material from successive generations
of oysters. They occur predominately in shallow nearshore areas, especially in brackish waters
near creek and river mouths. Oyster reefs provide a number of ecological, economic and
recreational benefits, including food and habitat for a large number of species. They also can
reduce erosion and stabilize shorelines and improve water quality.
Hard bottom and oyster reefs in Tampa Bay are protected submerged habitats under state and
federal wetland regulations and are considered Essential Fish Habitat. They are relatively rare
and sparsely distributed in the Bay.
In 2014, the Southwest Florida Water Management District (SWFWMD) mapped an estimated
131.4 acres of oyster reef in Tampa Bay. SWFWMD anticipates regularly mapping oyster reefs
as part of the biannual seagrass surveys in Tampa Bay. Previous mapping efforts (O’Keefe 2006,
Drexler 2011) have highlighted the difficulty in assessing overall oyster habitat extent in the bay,
especially along mangrove and hardened shorelines.
SWFWMD has initiated two other projects to locate, characterize and create finer-scale, thematic
maps of hard bottom and oyster reef habitats in Tampa Bay. The first project, funded by the
Tampa Bay Environmental Restoration Fund, will focus on the southeast region of Tampa Bay
from the mouth of the Little Manatee River to the mouth of Terra Ceia Bay. The second project,
funded by SWFWMD, will focus on Old Tampa Bay, and areas adjacent to MacDill Air Force
Base, and Terra Ceia Bay/mouth of the Manatee River. These mapping projects will include
field surveys utilizing a combination of side scan sonar, underwater video and ground truthing.
Ground truthing will categorize biological communities associated with various hard bottom
habitats, bathymetric relief, natural or artificial hard bottom, and contiguous reef or hard rubble.
Protecting and restoring hard bottom and oyster reef habitats will contribute to improved water
quality, increased habitat, and shoreline stabilization in Tampa Bay. While restoration of all lost
hard bottom and oyster reef habitats in Tampa Bay’s urban watershed is likely unrealistic, an
alternative is to restore the proportion of habitats that existed historically. Analysis of aerial
photography of Old Tampa Bay from the 1970s showed 83.8 acres of oyster reef compared to the
2014 estimate of 59.3 acres of oyster reef in the same area. These historic and modern oyster reef
habitat maps can be used to establish restoration and protection targets for oyster reefs in Tampa
Bay (BH-1, BH-8).
Several organizations are leading important efforts to restore hard bottom and oyster reef habitats
by creating or enhancing existing hard bottom and oyster reefs. Tampa Bay Watch is working
with community volunteers to create and enhance oyster reefs by deploying clean, fossilized
oyster shells as a base upon which live oysters can settle and form natural reefs. Since 2001,
more than 4,700 volunteers have created almost 14,000 linear feet of oyster reef in the Bay using
more than 1,400 tons of oyster shell. Other projects have included installation of reef balls to
support shoreline stabilization and oyster reef formation along the MacDill Air Force Base
peninsula, the Alafia Banks, and the Kitchen.
Audubon of Florida created more than 2,000 linear feet of new oyster reef to improve water
quality, facilitate growth of native salt marsh and mangroves, and slow erosion of the Richard T.
Paul Alafia Bank Bird Sanctuary. The Sanctuary is one of the largest and most diverse waterbird
colonies in the continental United States, but is threatened by erosion from boat wakes and storm
waves.
The Artificial Reef Program of the Environmental Protection Commission of Hillsborough
County (EPC) manages eight artificial reefs in Tampa Bay that are popular angling spots. By
providing hard bottom substrates and communities which might not otherwise be available,
artificial reefs increase biological diversity and productivity. A 2005 study found that 385
species used the reefs, including sport fish such as grouper, tarpon and snook, as well as a variety
of crabs, shrimp, mollusks and worms. EPC will begin a 10-year update of this original study in
2016, enlisting observations from commercial and recreational fishermen. Research on artificial
reef design and associated community structure may yield valuable management information.
Threats to hard bottom and oyster reef habitats and their benthic communities include changes in
sediment accretion and removal from dredge and fill operations, channel modifications and
harbor expansions, sea level rise and ocean acidification, boat groundings, cumulative damage
from anchors, overfishing, harmful algal blooms, invasive species, parasites and pathogens.
The invasive Asian Green Mussel (Perna viridis) is a particular threat that should be monitored
on both natural and artificial reefs in Tampa Bay. Green mussels were first observed in Tampa
Bay in 1999 and are known to foul boat hulls, clog power plant cooling water intake structures
and displace native oyster and mussel populations. After initial rapid population growth in the
Bay, anecdotal evidence suggests that that population numbers have stabilized – although the
mechanism of their control is unknown.
Construction of Gulfstream’s natural gas pipeline in lower Tampa Bay impacted nearly 20 acres
of bay hard bottom. Impacts were mitigated by installing shallow-water limestone reefs in
Lower Tampa Bay and transplanting soft corals and sponges. The low-relief limestone reefs were
quickly colonized by plants and animals. The transplants of soft corals and sponges were largely
unsuccessful. A “frac out” that occurred during the horizontal drilling also impacted hard
bottom.
Additional hard-bottom impacts are likely in Tampa Bay as a result of dredging associated with
future harbor improvements. “Frac outs” may occur during installation of underwater
communications cables or other pipelines in the future.
Impacts to hard bottom and oyster reef habitats are not easily mitigated and greater recognition
and protection of theses rare habitats is needed. The effectiveness of current permitting and
mitigation rules in preserving hard bottom and oyster reef habitats throughout the Bay warrants
evaluation.
STRATEGY:
STEP 1 Monitor results and support comprehensive identification, characterization and
mapping of hard bottom and oyster reef habitats and their communities in Tampa Bay. Support
mapping of historic distributions of hard bottom habitat in Tampa Bay. Utilize protocols and
techniques adapted from SWFWMD pilot project to support baywide mapping and assessment of
hard-bottom communities.Support expanding mapping activities into unmapped Bay segments.
Responsible parties: SWFWMD, other state, regional or local agencies
Schedule: Ongoing
Cost: $$$ (No TBEP funding required)
Benefit/Result/Deliverable: A comprehensive map of historic and current hard bottom
and oyster reef habitat in Tampa Bay is important for establishing historic and baseline
conditions and for setting restoration and protection targets.
STEP 2 Develop bay-wide goals for protection and restoration of hard bottom and oyster reef
habitats. Incorporate into the Bay Habitat Master Plan. Track and consider implications of
possible DEP re-classification of bay waters as Class II (Suitable for shellfish propagation or
harvesting). Ensure consistency in federal/state definitions used to describe hardbottom types.
Responsible parties: TBEP
Schedule: 2017
Cost: $-$$ (TBEP funding through CWA Section 320 funds)
Benefit/Result/Deliverable: Protection and restoration targets will support the “Restoring
the Balance” paradigm of natural resource management in the Bay.
STEP 3 Monitor community structure and population dynamics of species associated with
natural and artificial hard bottom and oyster reef habitats. Incorporate monitoring of established
mitigation sites (such as the limestone reefs created for the Gulfstream pipeline). Monitor
populations of the invasive Asian green mussel or other potential invasive species that may
emerge.
Responsible parties: EPCHC, Tampa Bay Watch, FWC, Audubon of Florida
Schedule: Ongoing
Cost: $-$$ (No TBEP funding required)
Benefit/Result/Deliverable: Greater understanding of the long-term ecosystem impacts of
natural and artificial bottom habitats; monitoring of habitats for invasive species may
allow early risk detection and management.
STEP 4 Support community-based oyster reef restoration activities and artificial reef creation.
Streamline process and support research to aid in permitting restoration activities involving
oyster reef and/or live bottom habitats. Support research on artificial reef design (e.g., high vs
low relief structure; reef ball vs WADs vs oyster bags) and evaluate the ecological effects of
artificial hard-bottom habitats.
Responsible parties: TBEP, Tampa Bay Watch, EPCHC
Schedule: Restoration projects are ongoing; specific research not yet funded, but projects
could begin in FY 2016-2016
Cost: $ (TBEP funding through CWA Section 320 funds)
Benefit/Result/Deliverable: Comprehensive restoration of hard-bottom habitats utilizing
the most successful techniques and providing the greatest ecological benefit.
STEP 5 Evaluate the effectiveness of current permitting and mitigation rules for hard-bottom
substrate impacts in Tampa Bay. Promote mooring fields and buoys where appropriate to
minimize vessel/anchor damage to hardbottom.
Responsible parties: FDEP Beaches and Coastal Systems; FWC Artificial Reef Group,
Hard Bottom Working Group, EPCHC, SWFWMD
Schedule: FY 2017-2018
Cost: $ (No TBEP funding required)
Benefit/Result/Deliverable: Rule review and revisions, if appropriate, will improve the
success of hard-bottom creation and mitigation projects by ensuring that impacts to those
habitats are adequately addressed.
STEP 6 Assist in the development and implementation of recommendations to protect hard
bottom and oyster reef habitats and minimize or mitigate impacts to them (e.g, anchor damage,
dredging, channel modification).
Responsible parties: ACOE, TBEP, THP Steering Committee, FDEP, FWC, EPCHC
Schedule: Ongoing
Cost: $ (No TBEP funding required)
Benefit/Result/Deliverable: Enhanced protection and restoration of natural hard-bottom
habitats in Tampa Bay.
STEP 7 Promote public stewardship of hard bottom and oyster reef habitats, especially among
anglers and divers. Examples may include “Adopt A Reef” cleanup programs for artificial reefs,
and designation of “Snorkel Reefs” in shallow water that encourage the public to snorkel.
Responsible parties: Local cities and counties; EPCHC, TBEP, FDEP, FWC
Schedule: Ongoing
Cost: $ (No TBEP funding required)
Benefit/Result/Deliverable: Enhanced protection and restoration of natural hard-bottom
habitats in Tampa Bay.
References, Notes
Dix, T.L, T.M. Ash, D.J. Karlen, B.K. Goetting, C.M. Holden and S.M. Estes. 2005. The
epifaunal community structure on artificial reefs in Tampa Bay. Environmental
Protection Commission of Hillsborough County Technical Report. Grant Agreement
#FWCC-02045. 102 p.
Drexler, M. 2011. Population Biology, Ecology, and Ecosystem Contributions of the Eastern
Oyster (Crassostrea virginica) from natural and artificial habitats in Tampa Bay, Florida.
A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Science, College of Marine Science, University of South Florida. 109 p.
O’Keefe, K., W. Arnold and D. Reed. 2006. Tampa Bay oyster mapping and assessment:
Prepared by Florida Fish and Wildlife Conservation Commission, Fish and Wildlife
Research Institute: St. Petersburg, Tampa Bay Estuary Program Technical Publication
03–06, 38 p.
Potential Figures:
1970s Old Tampa Bay Historical Oyster Reef Map (SWFWMD 2013)
2014 bay-wide Oyster Reef Habitat Map (SWFWMD 2014)
Potential Tables:
Table: 2014 estimates of oyster reef, seagrass and attached macroalgae in Tampa Bay. Data
from SWFWMD.
Bay Segments
Oyster (6540)
Patchy
Seagrass
(9113)
Continuous Attached
Seagrass Macroalgae
Total
(9116)
(9121)
Seagrass
BOCA CIEGA BAY
32.49
1,784.51
7,095.92
HILLSBOROUGH BAY
12.24
1,324.17
649.24
245.46
1,973.41
LOWER TAMPA BAY
10.89
2,958.99
4,678.53
480.84
7,637.52
MANATEE RIVER
0.16
463.19
193.12
MIDDLE TAMPA BAY
11.71
4,045.82
5,648.39
101.56
9,694.21
OLD TAMPA BAY
59.30
5,362.12
4,910.41
117.77
10,272.53
TERRA CIEA BAY
4.61
427.75
752.56
41.17
1,180.30
8,880.42
656.31
Grand Total
131.42
16,366.54
23,928.16
986.79
40,294.71
Table: 1970s estimates of tidal flats, oyster reef and seagrass in Old Tampa Bay. Data from
SWFWMD.
Map Classification
6510 - Tidal Flats
6540 - Oysters
9113 - Patchy Seagrass
9116 - Continuous Seagrass
Seagrass Total
Acres
7,701.72
83.83
3,937.64
3,884.51
7,822.15
Table 1: 2014 estimates of oyster reef, seagrass and attached macroalgae in Tampa Bay. Data
from SWFWMD.
Bay Segments
Oyster
(6540)
Patchy Continuous Attached
Seagrass Seagrass Macroalgae Total
(9113)
(9116)
(9121) Seagrass
BOCA CIEGA BAY
32.49
1,784.51 7,095.92
HILLSBOROUGH BAY
12.24
1,324.17
LOWER TAMPA BAY
10.89
2,958.99 4,678.53
MANATEE RIVER
0.16
MIDDLE TAMPA BAY
11.71
4,045.82 5,648.39
101.56
9,694.21
OLD TAMPA BAY
59.30
5,362.12 4,910.41
117.77
10,272.53
TERRA CIEA BAY
4.61
41.17
1,180.30
Grand Total
131.42
986.79
40,294.71
463.19
427.75
649.24
8,880.42
245.46
1,973.41
480.84
7,637.52
193.12
752.56
16,366.54 23,928.16
656.31
Table 2: 1970s estimates of tidal flats, oyster reef and seagrass in Old Tampa Bay. Data from
SWFWMD.
Map Classification
6510 - Tidal Flats
6540 - Oysters
9113 - Patchy Seagrass
9116 - Continuous
Seagrass
Seagrass Total
Acres
7,701.72
83.83
3,937.64
3,884.51
7,822.15
CCMP Milestones for BH-4
BH-4 Identify and Protect Hard Bottom and Oyster Reef Habitats in Tampa Bay
1996-2006
Action Title: Restrict impacts to hard-bottom communities
TBEP played a role in the following:




Funded development of the first hard bottom map of Tampa Bay. The survey discovered
previously-undocumented natural hard bottom habitat in Tampa Bay, and identified
multiple species of tropical and subtropical organisms living on them. TBEP Technical
Report #07-94.
Evaluated existing dredged holes in Tampa Bay, and developed recommendations for
improving habitat quality in each evaluated hole. Recommendations for some holes
included encouragement of hard bottom habitats by installing artificial reef material .
TBEP Technical Report #04-05.
Funded evaluation of various methods to map oyster bars in Tampa Bay. Due to the low
relief of oyster found in Tampa Bay, semi-automated mapping techniques were found not
to be effective. Using traditional mapping techniques, an 85% accuracy was achieved for
free-standing oyster reefs. TBEP Technical Report #03-06.
Supported an evaluation of impacts from the invasive green mussel (Perna viridis) in
Hillsborough Bay. TBEP Technical Report #04-04.
2006-2016
Action Title: Restrict impacts to hard-bottom communities
TBEP played a role in the following:



Distributed Boater Guides and other educational materials about safely boating in the
bay’s waters. Boaters Guides include locations of artificial reefs and tips to avoid
impacts when fishing or diving on them.
Funded a survey of fauna inhabiting natural and artificial reefs in Tampa Bay.
Observations indicated that structure size, complexity and type of material play a critical
role in site selection for fishes, and suggest a correlation between the size and complexity
of the structure and the size of the fish using the habitat. TBEP Technical Report #02-07.
The Tampa Bay Environmental Restoration Fund is funding a project to map hard-bottom
habitats in Tampa Bay, using both aerial photos for shallow water and underwater
imaging technology for deeper water hard bottom habitats. Ongoing.

The Tampa Bay Environmental Restoration Fund has also awarded funds for several
projects to assess and create hard bottom habitat and oyster reefs in Tampa Bay,
including an ongoing hard-bottom mapping project; several living shoreline and oyster
reef restoration projects; and shoreline protection through installation of oyster bags.