National Park Service

South Florida/Caribbean I&M Network (SFCN)

Marine Exploited Invertebrates Monitoring

Spiny lobsters (Panulirus argus) in Dry Tortugas National Park
Spiny lobsters (Panulirus argus) in Dry Tortugas National Park.

Monitoring Summaries and Reports by Parks and Partners


The SFCN lobster monitoring protocol is currently under development.

Resource Briefs, Reports, and Data

There are currently no additional SFCN resource briefs, reports, or data concerning this monitoring topic.



The exploited invertebrate assemblage (spiny lobster, pink shrimp, queen conch, crabs, sponges, oysters and whelk) includes herbivores, filter feeders, intermediate feeders, and omnivores. These species are under heavy fishing and commercial harvest pressure outside SFCN park boundaries and in some cases within park boundaries, have complicated reproductive cycles, frequently use multiple habitats inside and outside park boundaries, and can be affected by regional connectivity and stressors. Balancing resource extraction and environmental degradation with sustainability is a key management concern. The impacts of fishery management tools such as marine protected areas (BUIS, portions of DRTO) are of interest to resource managers and the public.

The Spiny lobster (Panulirus argus) life cycle includes both a free-swimming larval phase and a benthic adult life stage. Adult spiny lobsters feed mainly on gastropods, chitons, bivalves, corals and scavenged food remains. Adults are heavily harvested outside parks and a managed harvest within BISC and VIIS.

Queen conch (Strombus gigas) This is a heavily harvested species with strict take/no-take regulations in all of the marine parks in the SFCN.

Pink shrimp (Farfantepenaeus duorarum) function as both a predatory and prey species within the marine ecosystem, providing a large amount of biomass in Florida Bay and Biscayne Bay. They are sensitive to changes in hydrological modifications, salinity patterns, and circulation effects on larval transport. Florida Bay is an important nursery ground for larval recruitment to the Dry Tortugas region commercially harvested fishery. Pink shrimp are both recreationally and commercially harvested within Biscayne Bay.

Crabs (Stone, Blue and others) Stone crabs are a highly valuable marine resource, The Florida stone crab fishery provides 99% of all stone crab landings in the United States and the stone crab fishery is always in the top five fisheries of Florida.

Oysters (Crassostrea virginica) are filter feeders and become prey to many species of fish and larger invertebrates. Oysters develop into oyster bar communities which form an extensive habitat along western edge of EVER. Oysters were once present in greater numbers within Biscayne Bay, but are now rare. Oysters have a strong association with moderate saline conditions and are being considered an indicator of proper hydrological flows for Biscayne Bay. Their shell accumulations provide information about the physical, chemical and biological conditions that allow them to flourish.

Whelk - This mollusk is a harvested species in the Virgin Islands with size and number limits placed upon them.

Wool Sponges - BISC Bay is a sponge harvest sanctuary. Offshore of the islands, commercial harvesting of sponges is regulated by state of Florida regulations. These were heavily harvested around the turn of the century for bathing and washing, but that harvest has decreased since the invention of synthetic sponges. They provide filtration of sediments and other marine particles to help improve water clarity, and provide shelter for juvenile fish and other invertebrates. Extraction of sponges in the other south Florida parks is regulated by the state.

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Monitoring Questions

What are the status, variability, and trends in exploited invertebrates: Lobster (relative abundance/density, distribution, size structure, sex ratio, regional harvest); Conch (density, distribution, size structure/maturity); pink shrimp (density, distribution, harvest); blue crab (harvest); stone crab (harvest); oysters (distribution); sponges (harvest); whelks (density, size structure)?

Status and Trends

Pink Shrimp

Status and trends for juvenile pink shrimp are reported as part of the South Florida Ecosystem Restoration Task Force 2010 System-wide Ecological Indicators for Everglades Restoration (See page 30-31 in this report) and the RECOVER: 2009 System Status Report Seagrass Fish & Invertebrate Assessment Network.


Biscayne National Park released a 10 year assessment of lobster mini-season trends in BISC, 2002-2011 report.


Status and trends for oysters are reported as part of the RECOVER: 2009 System Status Report.

Basic Approach

SFCN will be monitoring spiny lobster and testing protocols for conch to see if they can be incorporated into seagrass monitoring with little additional effort. Otherwise SFCN will be working with existing programs to gather and summarize their reports and to analyze regional harvest data.


Relative abundance/density, size structure, sex ratio, and regional harvest at BUIS, DRTO, EVER, VICR, and VIIS. SFCN will conduct pilot protocol testing for lobster monitoring, evaluating the use of timed searches at coral monitoring sites as well as investigating other potential fisheries independent monitoring techniques for the purpose of creating a "Spiny Lobster" protocol. Long-term monitoring conducted by FWRI is in a transitional period where past methodologies are being evaluated for power and efficacy. SFCN will stay abreast of those decisions when making our determination of what methodologies and sampling design to use and will try to coordinate with those efforts if appropriate. SFCN will also investigate coordinating with BISC lobster creel surveys and will assess commercial harvest data from the state of Florida.


Density, size structure/maturity at BISC and EVER. SFCN will conduct pilot conch counts during seagrass surveys to see if there is sufficient power to evaluate trends. Measurements of carapace length and presence of lip indicating maturity will be taken. Conch data are already available from the NOAA Biogeography team's fish and benthic monitoring in USVI parks to assess power using their methodology in the USVI.

Pink Shrimp

Density, distribution, and harvest at BISC and EVER. SFCN will seek to acquire and summarize the reports from the existing program being conducted by Joan Browder and Mike Roblee to estimate juvenile populations in Florida Bay. Commercial harvest data from the state of Florida for BISC will be evaluated

Blue Crab

Harvest at BISC. Commercial harvest data from the state of Florida for BISC will be evaluated. Other monitoring is deferred due to staff/time/funding demands.

Stone Crab

Harvest at BISC. Commercial harvest data from the state of Florida for BISC will be evaluated. SFCN will also seek to acquire and summarize the reports from an existing stone crab fishery-independent monitoring program (Anne McMillen-Jackson, FWRI). Other monitoring is deferred due to staff/time/funding demands.


Distribution at EVER. Monitoring of oysters is deferred due to staff/time/funding demands.


Harvest at BISC. Commercial harvest data from the state of Florida for BISC will be evaluated. Other monitoring is deferred due to staff/time/funding demands.


Density, size structure at VIIS. SFCN will coordinate with park monitoring if this is implemented but otherwise is not establishing a monitoring program at this time. SFCN will acquire south Florida commercial landings data from the Fish and Wildlife Research Institute website.

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Last Updated: July 12, 2017 Contact Webmaster