Category Archives: Research Spotlight

Research Spotlight

Recently Documented Tilapia Oreochromis spp. Population in Newnan’s Lake

By Jason O’Connor and Chris Anderson

Tilapia Oreochromis spp. are members of the cichlid family that are native to North Africa and the Middle East (Figure 1). At least two species of Tilapia are well-established throughout peninsular Florida. Blue Tilapia Oreochromis aureus were introduced to the state (via research ponds) by FWC’s predecessor the Florida Game and Fresh Water Fish Commission in 1961 to evaluate their utility as food, game, forage and weed control within the state. Some of these fish were distributed to the public and were subsequently released into freshwater ecosystems in south-central Florida. Nile Tilapia Oreochromis niloticus have been collected in Florida since at least 1972, however, details of their introduction and establishment are less well-documented than for the Blue Tilapia. The two species readily hybridize in the wild, and many specimens collected in Florida exhibit hybrid traits. Both species are largely herbivorous, consuming a mix of plant matter, detritus, and occasionally zooplankton, small insects and fish. Tilapia are farmed at aquaculture facilities throughout the state, and established wild populations support commercial fisheries in central and southern portions of the peninsula. Tilapia are not traditionally sought by recreational anglers, but they do support localized bowfishing oriented recreational fisheries, often in springs and spring runs (e.g., Silver Glen Springs).

Figure 1: Tilapia Oreochromis sp. collected from Newnans Lake via electrofishing in February 2022. Photo credit: Christian Fernandez.

Although initially introduced in south-central parts of the state, Tilapia have spread throughout much of peninsular Florida, and now occur in most major drainages east and south of the Suwannee River, with a few isolated records from other states surrounding the panhandle (Figure 2). The Orange Creek Basin, a sub-drainage of the St. John’s River in north-central Florida, is one of the northern-most occupied watersheds in the state (Figure 3). Major lakes in the Orange Creek Basin include Orange, Lochloosa and Newnans. The fish communities in these lakes have been intensively sampled for decades, and although Tilapia have been regularly documented in Orange and Lochloosa lakes for over 15 years, they are rarely encountered on Newnans Lake. Prior to 2021, there had only been 2 documented records of Tilapia in Newnans (both in April 1999), despite annual fish surveys using a variety of sampling methods since 1989. However, we observed a single Tilapia in March 2021 while electrofishing in Prairie Creek, the primary outflow of Newnans Lake. Then in November 2021, we collected two individuals in the northern end of the lake while surveying for Black Crappie Pomoxis nigromaculatus. The following spring (February-March 2022), we observed numerous Tilapia in throughout the lake while surveying for Largemouth Bass. The majority of the individuals collected have been around the same size (35-43 cm), which suggests that much of the population may be from a single annual cohort.

Unfortunately, we don’t have enough information to determine whether the current population expansion of Tilapia in Newnans represents a novel invasion or population growth of an existing low-density population. If this represents a novel invasion, it may have been caused by human-mediated translocation or via natural immigration from established populations within the Orange Creek Basin. There are numerous anecdotal reports of people moving non-native fish among waterbodies in Florida, particularly for species of recreational or commercial importance. It is also possible that the frequency of historically high water levels throughout the Orange Creek Basin since 2017 has facilitated movement of individuals from established populations to Newnans via a series of creeks and canals. Alternatively, it is conceivable that an established population has existed in Newnans since at least 1999 but has occurred at densities below the detection limits of our sampling gears. If this is the case, then the recent population expansion may have been a result of increased access to quality spawning habitat due to sustained high water levels, which increased recruitment in recent years.

Figure 2: Distribution of Tilapia Oreochromis spp. in Florida and surrounding states obtained from FishNet2 (, 2022-04-08).

                Regardless of whether we are witnessing a new invasion of Tilapia or simply a population boom of a historically low-density population, this population expansion has resulted in the greatest frequency of Tilapia observations/collections by FWC in Newnans in the last two decades. Although research on the impacts of Tilapia in large, natural ecosystems is lacking, pond/mesocosm studies on the impacts of high-density Tilapia populations have documented substantial reductions of age-0 production, recruitment, and growth of Largemouth Bass Micropterus salmoides, the most popular freshwater sportfish in Florida. The existence of the long-term fish community dataset provides a unique opportunity to evaluate potential effects that Tilapia establishment/population expansions have on fish populations/communities in a large, natural ecosystem. This highlights the importance of long-term sampling programs (e.g., Freshwater Fisheries Long-term Monitoring Project) for tracking the spread, and abundance of non-native fishes so that their potential impacts on native fish populations and communities can be assessed. Additionally, the Newnans population is currently one of the northernmost established Tilapia populations in Florida. Since climate change will likely facilitate expansion of their established range into the Florida panhandle, information on the effect of Tilapia invasion/expansion on native fish communities in Newnans Lake would inform fisheries managers about potential undesirable impacts if/when new invasions/expansions occur.

Figure 3.: Map of the Orange Creek Basin (outlined in yellow) obtained from the St. Johns River Water Management District.

Research Spotlight

Using the Imaging FlowCytobot (IFCB) During Collaborative Research Surveys: Real-time assessment of red tide in offshore areas

By Mary Harper, Eric Muhlbach, Matt Garrett, Celia Villac & Kate Hubbard.

IFCB images of different Karenia brevis cell morphologies that represent particular physiological states.

By land, sea, air, and space, the FWRI Harmful Algal Blooms (HAB) team worked with a large partner network to monitor and track the most recent red tide event that endured from December 2020 to November 2021. During the bloom, an average of 180 water samples collected weekly by FWRI staff, FWC-Law Enforcement (LE), local counties, the Florida Department of Agriculture and Consumer Services, the Florida Department of Environmental Protection, community scientists, and other partners were examined by light microscopy to determine abundance of the red tide organism, Karenia brevis. A combination of satellite imagery (from partners at USF and NOAA, e.g., cover image) and weekly aerial surveys (with FWC-LE; image 2, below) helped to keep “a bird’s eye view” on the bloom event, which at one point extended along the Panhandle, Big Bend, and Southwest Florida coasts. To validate nearshore and aerial/satellite observations and conduct routine offshore sampling, in 2018, the HAB team started to participate in bi-monthly research surveys on the West Florida Shelf, led by NOAA-Atlantic Oceanographic & Meteorological Laboratory (NOAA-AOML).

Image 2: Aerial image taken during a red tide assessment carried out on August 2nd, depicting the R/V Walton Smith offshore during the August 2021 NOAA-AOML cruise.

During these surveys, scientists sample a series of transects where red tide is commonly present (Figure 3). In addition to collecting samples for lab-based analysis, HAB scientists are able to detect red tide onboard using an Imaging FlowCytobot (IFCB), an imaging flow cytometer that samples autonomously every 20 minutes, and then captures high-resolution images of all microscopic particles present . The IFCB delivers data that can be used to map out the distribution and abundance of K. brevis in near real-time. This technology provides a picture of current conditions and allows us to communicate with the ship while the survey is being conducted. This approach also helps prioritize shore-based analysis after the cruise. As our IFCB dataset grows, we are adding to our understanding of the environmental conditions that may trigger or sustain blooms, important for forecasting and hindcasting key bloom dynamics. Additionally, ongoing work to improve IFCB classification has resulted in discrimination of different morphologies of K. brevis, which will provide further insight into the physiological state and/or life cycle stage of cells in the environment.

Figure 3: IFCB-based quantification of K. brevis in underway samples from the October 4-10th NOAA-AOML survey (see legend for range in cell concentrations). Note consistency with red tide patch areas shown in cover image, and that the abundance determined with the IFCB is less than the light microscopy observations. 

Research Spotlight

MarineQuest 2021

This October 14th, FWRI celebrated the 26th annual MarineQuest, our open house education event normally held at FWRI headquarters in St. Petersburg. This year was the 2nd year in a row that the event was held digitally, both in the interest of safety and for accessibility for folks outside the state. Many areas of research within Florida were explored, such as sandhill crane banding, searching for skunks and weasels with Cowboy, the scat-sniffing dog, how our fisheries monitoring teams keep track of populations throughout Tampa Bay and other Florida estuaries, and more. We were also joined throughout the day by several of our research groups as they took us through the process of aging fish, rescuing manatees, and processing water samples for red tide. And new this year: “Science Snippets,” where we joined FWRI scientists as they turned the camera on themselves to share research insights and interesting science facts. We extend a huge thank you to all our researchers and staff who contributed to make MarineQuest an excellent science-focused event. We’re hoping to see everyone next year in person.

Research Spotlight

Red Tide Response 2021

Staff at FWRI’s headquarters in St. Petersburg have been uniquely positioned to respond to this year’s severe red tide blooms impacting the Tampa Bay region. Below are a series of photos cataloguing the Research Institute’s monitoring and response efforts. View our Flickr album for more photos from FWC’s red tide response.

Harmful algal bloom research staff are seen here with an imaging flow cytobot, which when deployed in Tampa Bay continuously images water samples to identify red tide cells.
FWC Director Eric Sutton (left) with FDEP Interim Secretary Hamilton surveying a fish kill in a Tampa Bay canal.
Harmful algal bloom research scientist Kate Hubbard (left) advises Director Sutton and Secretary Hamilton before departing on a red tide survey.
FWC staff prepare to board an aircraft used for aerial red tide surveys.
A distinct frontal boundary of the red tide bloom located roughly 10 miles offshore of Pinellas County in the Gulf of Mexico. The distinct lines or boundaries that are clearly visible are usually created by two water masses of two different densities that don’t easily mix.
Trichodesmium erythraeum is a cyanobacterium, or blue-green alga, that forms colonies in tropical and subtropical seas around the world. In the Gulf of Mexico, it appears in high concentrations as golden-brown surface mats, often referred to as “sea sawdust.” Blooms can cause dermatitis or “swimmer’s itch” and are sometimes associated with fish kills.
A distinctive streaky red tide bloom approximately 3 miles offshore of Treasure Island in Pinellas County.

Research Spotlight

Long Term Monitoring Program Studies Red Tide Impacts on Southwest Florida Fisheries

By Eric Weather

Just after sunrise, on an eerily calm October morning in 2017, we idled our 24’ mullet skiff loaded with sampling nets under the Cortez Bridge approaching Sarasota Bay.  Over the past 10 years these waters have become familiar territory for the researchers of FWRI’s Fisheries Independent Monitoring (FIM) group.  Through a partnership with the Sarasota Bay Estuary Program, FIM has been sampling fish populations in Sarasota Bay on a bi-monthly basis since 2009.  These clear, shallow embayment’s are characterized by lush seagrass beds, a mix of urbanized and mangrove shorelines and heavy boat traffic.  However, on this morning, we had the feeling that we were the only life in the bay.  As our wake rippled through floating masses of decomposing fish carcasses, the smell of decay surrounded us like a dense fog.  The distended bellies of Catfish, Pinfish, Pigfish, Spot, puffers, Sheepshead, snappers, Spotted Seatrout and a whole host of other species littered the surface of the water.  A thick white wrack of carcasses lined the shores of the bay.  The typically chattery seabirds were silent, and we followed their lead.

The news of a rapidly spreading red tide bloom was already circulating, particularly in the Lee and Charlotte County areas.  Sampling trips conducted by FIM’s Charlotte Harbor field lab had reported evidence of an extensive bloom and FWRI’s Harmful Algal Bloom (HAB) group was beginning to ramp up sampling to monitor the event.  We anticipated encountering evidence of the bloom, but the devastation we experienced that day was more extreme than we imagined.  As the shock wore off, we got down to business as usual:  navigating to sites, pulling seine nets, trawling, collecting environmental and water quality data.   We were glad to be capturing the impacts of this event in our data with the hopes of tracking the environmental response over the coming months.

The FIM program has been collecting standardized fisheries data in Tampa Bay and Charlotte Harbor since 1989.  Soon after, field labs were established in Apalachicola Bay, Cedar Key, Jacksonville and the Indian River Lagoon to keep a finger on the pulse of fish populations around the state.  These long-term data sets have proven essential for providing fisheries managers with abundance trends to guide their decisions.  In response to public outcry to take action for the SW Florida fisheries during this red tide event, FWC closed the Common Snook and Redfish fisheries to harvest in southwest Florida through an executive order beginning in August, 2018.  Six months later, Spotted Seatrout were added to the list of species protected by this executive order.  Meanwhile, FIM continued to do what it has been doing for 30 years:  sample, report, repeat.  Data processing and quality assurance measures were fast-tracked as FIM began providing monthly updates on key species to FWC’s Department of Marine Fisheries Management (DMFM). 

This unusually persistent red tide finally began to dissipate in the winter of 2018/2019.  Fisheries monitoring data have been used to track the impact and subsequent recovery of Common Snook, Redfish, Spotted Seatrout and other important estuarine species.  With the executive order set to expire in May 2021, FWC staff summarized these data at the February FWC Commission meeting. 

As with other recent environmental perturbations (2005 red tide, 2010 cold kill), data indicated Snook, Redfish and Spotted Seatrout were resilient to the 2018/2019 red tide event and did not experience long-term negative effects (Snook example, Fig 1).  However, as has been reported by local anglers and charter captains, some of these important estuarine species were showing relatively lower abundances prior to the red tide.  To address the potential long-term population concerns, DMFM hosted a series of workshops in April 2021 to provide information and gather opinions from local recreational and charter anglers (Workshops). The FWC Commission is set to meet again in May to further discuss future management of Snook, Redfish and Spotted Seatrout in SW Florida (Commission Meetings). 

As the water begins to warm, the enthusiastic birds and boat activity seem to be back in Sarasota Bay.  The bait is showing up on the shallow flats and FIM will be out monitoring again in April.   Pulling nets and identifying, counting and measuring hundreds of fish in these incredibly productive and resilient estuaries in an effort to provide the best possible data to help guide future management decisions. 

Research Spotlight

Age and Growth in the Time of COVID

By Jessica Carroll

On March 9th, the FWRI Marine Fisheries Age and Growth lab started the transition into a work-at-home approach. As a group, we wanted to remain on track and continue to accomplish goals and we saw no other solution than to transition offsite. The first step was to assess each home environment with an eye for chemical safety and usable areas from which lab operations could be conducted. There were varying solutions to ventilation needs required to safely use our liquid coverslip, but a mix of open-air workstations, fans, and even a portable fume hood have all been safely, and effectively utilized. Once safe areas were set up in homes, the lab was essentially gutted and partitioned out to staff; everything from manila folders and glue guns to saws and microscopes were assigned out and sent home with approval. Thankfully, after some initial purchasing, we had enough equipment to provide each staff member with an entire lab setup for processing and ageing. Thus, large batches of otoliths were split and assigned to individuals.

Processing and ageing goals are directed on a quarterly basis, but each member completes assignments in their own time and returns to the lab as needed to deliver completed work and grab new samples. Sample batches are reintegrated upon delivery at the lab. Daily progress communications are critical to ensuring there is constant productivity and enough prepared in advance for the next trip into the office to swap samples. Microsoft Teams has been essential in keeping morale high and communication lines open; we use Teams to QA/QC ageing assignments (live camera from one person on shared desktop), conduct discussions about productivity, challenges and improvements to the offsite system, and do teambuilding activities. As we’ve progressed into a reopening plan, staff have transitioned to one assigned day a week in the lab embedding small otoliths (which require more chemicals and a stronger ventilation system than can be provided at home). This system works to ensure a constant supply of otoliths available for sectioning at home.

From the start of the offsite transition, the FWRI Age and Growth Lab has processed just over 21,000 and aged 32,000 otoliths. Surprisingly, 2020 turned out to be a record ageing year, and we were able to maintain our standard level of otolith processing. We were able to successfully pivot priorities and turnaround 2019 east coast red snapper ageing for SEDAR73 in the span of a month and a half. We have met all data delivery deadlines and have provided completed ageing for 15 data requests, including multiple SEDARs. Additionally, we continue to collaborate (and publish) with other agencies and universities, participated in SEDAR68 and SEDAR73, have continued to be active with outreach planning and requests (including 2020’s digital MQ), and provide field assistance and support for our research section. The success of this transition hinges on the flexibility, problem-solving abilities and dedication of our age and growth staff. COVID-19 has been the biggest hurdle ever to cross our paths, but thanks to the hard work and diligence of this team, we’ve been able to take it in stride and continue moving forward.

An at-home lab, ready for science!

Research Spotlight

North Atlantic Right Whale Research – MarineQuest

As many of you know, FWRI held our first ever virtual MarineQuest in October. In case you missed it, we wanted to share the work our biologists are doing on North Atlantic right whale research — they’ll explain how the populations are monitored off Florida’s coasts, the biggest threats for the species, and how citizens can help.

Research Spotlight

The State Reef Fish Survey

The Florida Fish and Wildlife Conservation Commission (FWC) is pleased to announce an expansion of recreational fishing surveys to collect enhanced data for reef fishes. The new State Reef Fish Survey (SRFS) builds on proven success along the Gulf Coast of Florida. The Gulf Reef Fish Survey (GRFS) was implemented in 2015 to provide more timely and precise data needed to manage and assess important reef fish stocks, which has supported enhanced recreational fishing opportunities along the west coast of Florida. The expanded statewide survey replaced GRFS and started July 1, 2020, which means that anglers and spear fishers are now able to contribute to improving data for important fish stocks along the Keys and Atlantic Coast of Florida, as well as the Gulf. SRFS will use several methods to collect vital information on recreational fishing for reef fishes, including a mail survey, in-person interviews, and at-sea observations.

The SRFS mail survey collects information on the types of reef fish that are important to anglers and divers who fish recreationally in Florida and helps gauge how often people participate in these economically important activities throughout the state. Anyone with the State Reef Fish Angler designation may receive a questionnaire in the mail that asks about saltwater recreational fishing activities over the past month. A new set of participants will be randomly selected each month, which means that individuals are only asked to provide this information periodically. The new State Reef Fish Angler designation is required for anyone 16 years of age and older to legally harvest certain reef fish when fishing recreationally from a privately-operated boat in Florida. This requirement is in addition to applicable saltwater recreational fishing license requirements.

The previous Gulf Reef Fish Angler designation was required on the west coast of Florida to legally harvest: red snapper, vermilion snapper, gray triggerfish, gag, red grouper, black grouper, greater and lesser amberjacks, banded rudderfish, and almaco jack. Three additional species are included in the new statewide requirement: hogfish, mutton snapper, and yellowtail snapper. Anyone with a State Reef Fish Angler designation may harvest all 13 reef fish species anywhere in Florida, in accordance with all applicable size and bag limits, seasons, and gear requirements. Anglers and spear fishers with a valid Gulf Reef Fish Angler designation will have all the same privileges as the statewide designation and do not need to sign up again until it is time to renew. At the time of renewal, make sure to request the new State Reef Fish Angler designation.

In-person interviews will be conducted by FWC biologists at boat ramps and marinas throughout the state to collect detailed information on the numbers and types of reef fishes harvested during recreational fishing. Interviews will be conducted at sites where recreational boat parties that target reef fishes are more likely to return, and these data will supplement interviews also conducted over a larger number of sites as part of the Marine Recreational Information Program (MRIP). The FWC is a cooperative partner in this national survey, administered through NOAA Fisheries, that provides vital statistics for a wide variety of state- and federally-managed saltwater finfish in Florida. By supplementing the national survey, FWC biologists will intercept anglers and spear fishers that specifically target reef fish species more frequently. These types of trips are less common than those targeting popular near-shore species, such as seatrout, red drum, flounder, and snook. Using the dockside interview data in combination with the mail portion of SRFS, described above, will enable FWC to provide a more precise measure of the total numbers of reef fishes harvested and released during recreational fishing in Florida. On the Gulf Coast, this has led to longer recreational fishing seasons in state and federal waters for red snapper and greater flexibility for managers to re-open the fishery when a season is impacted by weather and other unforeseen factors. On the Atlantic Coast of Florida, FWC will continue enhanced survey efforts during federal harvest seasons for red snapper in addition to the new SRFS. The enhanced survey efforts are still needed to closely track red snapper landings in-season, and the new survey will provide more precise estimates for fish released year-round.

In addition to the mail survey and dockside interviews, anglers fishing recreationally from for-hire vessels may also be accompanied by an FWC biologist to observe reef fishes that are released at-sea. This information provides important insight into the overall health of fish stocks, how many fish will be available to harvest in future years, and how well fish survive following catch-and-release. Information provided through the mail survey, dockside interviews, and at-sea observations will also help fishery managers better understand the relative importance of artificial and natural reef habitats in Florida.

Recreational fishing is a valued past-time for Floridians and is an important driver for the economy of this state. Together, all of the data collected through the new State Reef Fish Survey will provide a clearer picture of the health of reef fish stocks throughout the state and help ensure the long-term sustainability of recreational fishing in Florida.

Research Spotlight

Survivorship and Productivity of Florida Sandhill Cranes on Conservation Lands and Suburban Areas in Florida

The Florida sandhill crane (Antigone canadensis pratensis) is a familiar sight for residents and visitors alike to areas of Florida, but unfortunately, they are becoming less familiar. Faced with substantial population decline due to habitat loss, Florida sandhill cranes have also experienced long periods of drought and degradation of remaining habitat, which has all contributed to their decline. This study will compare adult crane habitat use, survival, and reproduction between suburban and conservation areas, with an emphasis on identifying specific causes of mortality. Additionally, researchers will also determine vegetation associations used by cranes in suburban habitats and conservation areas from movement data.

Non-migratory sandhill cranes were once widely distributed across the southeast and into the Caribbean, however, the species was extirpated from most of its natural range by the early 1900s. Conversion of prairie to agriculture or development, draining of wetlands, and overhunting were and are the main factors threatening sandhill cranes. Spatial models suggest the total available Florida sandhill crane habitat declined 42% between 1974 and 2003. The Florida sandhill crane is currently listed as State Threatened and as a Species of Greatest Conservation Need in the state’s Wildlife Action Plan.

Florida sandhill cranes inhabit open areas, typically prairie and pastureland in the uplands and shallow marshes with emergent vegetation in wetland areas. Most preferred Florida sandhill crane habitat is privately owned and can be lost through development at any time. As the amount of preferred habitat has declined, an increasing number of Florida sandhill cranes have inhabited suburban and urban areas, such as airports, residential subdivisions and golf courses. Cranes in these areas may face additional challenges compared to birds in natural areas. For example, cranes require water levels sufficient to protect nests and themselves from terrestrial predators but low enough to prevent nests and roosts from flooding. In suburban areas, cranes often use man-made ponds or water retention areas that can receive large amounts of water run-off from developed sites (e.g., highways, lawns, golf courses and buildings) resulting in rapid increases in water levels that cause nest failure or leave the areas too deep to be utilized. Other threats to suburban cranes include domestic pets, automobile traffic, fences, human disturbance and environmental contaminants. This project was developed to assess threats to the survival and productivity of Florida sandhill cranes in suburban areas compared to the same parameters for conservation areas.

Researchers capturing a suburban Florida sandhill crane with a pneumatic net launcher in Lake County.

To capture cranes, FWRI researchers survey areas for cranes then learn their routine or bait the area if necessary. Researchers then capture the cranes using a hand-held net gun, ground snares or by simple hand grabbing. After capture, cranes are radio-tagged and color-banded, which is helpful for researchers for visual and radio monitoring after release. Cranes are captured and marked from April through October, before the arrival of migratory sandhill cranes that overwinter in Florida. Currently, FWRI has cranes marked from Marion County in the north to Highlands County in the south, Pasco County in the west and to Indian River County in the east.

This project seeks to fill important gaps in our understanding of Florida sandhill crane ecology identified in the Florida Sandhill Crane Species Action Plan. Causes of population decline are not well understood, so this project will benefit cranes by providing habitat use, survival, and productivity data for unstudied habitats (e.g., conservation areas and urban/suburban habitats) needed for development and implementation of management and conservation recommendations.

About halfway complete, this project has radio-tagged their target sample size (n=17) of suburban cranes, and 15 of 17 conservation land birds. Researchers have color-banded 49 cranes, out of a goal of 100+ before the project ends, which is set for June 30, 2021. Data generated from this project will be used to develop conservation recommendations and initiate plans to conserve Florida sandhill cranes. Future research may involve tagging young-of-the-year cranes in suburban and conservation areas to compare survival and movements of these birds to those from past studies of similar aged cranes on improved pastureland.

Key partners for this project include the State Wildlife Grants, the Bernard Lewis Charitable Foundation, Florida State Forest Service, Florida State Parks, Lake County Parks and Trails, Orlando Wetlands Park and St. John’s River Water Management District. FWRI researchers could not have initiated, nor can they complete this project, without the assistance of these partners.

Research Spotlight

Florida Horseshoe Crab Watch – Linked with Limulus

Ancient and distinctive, most Floridians recognize the American horseshoe crab (Limulus Polyphemus) in our marine waters by its smooth, helmet like carapace, scientists refer to as the prosoma. Perhaps surprising to many Floridians, the stock status of horseshoe crabs is poorly understood, thus spurring on the need for this study. The program is a collaboration with Florida Sea Grant, and several NGOs across the state that engages citizens in monitoring established horseshoe crab spawning beaches through the citizen science group, “Linked with Limulus.” Volunteers are a vital part of this study, so engaging volunteer coordinators in coastal Florida counties to establish new volunteer groups is a priority. The data from this study will be incorporated into the next Atlantic States Marine Fisheries Commission Horseshoe Crab Benchmark Stock Assessment and inform state managers, in Florida and beyond, to population and spawning trends.

Horseshoe crabs are important for several reasons: shorebirds rely on their eggs as a primary food source during their long migrations (the decrease in horseshoe crab abundance has contributed to notable declines of many shorebird species); they are used as bait in the eel and whelk fisheries; and are of extreme importance in the biomedical industry – their copper-based blue blood is used to test the sterility of all injectable drugs and medical equipment.

Surveying horseshoe crab spawning beaches provides much needed data on spawning population trends, sex ratios and other biologically important information. Like sea turtles, they come ashore to sandy beaches to mate and lay eggs. Beaches are surveyed in the spring and fall, during the full and new moon at high tide, coinciding with peak spawning. At each beach, volunteers survey 3 consecutive days around the new and full moons. Data collected during each survey includes number of animals, mating pairs or aggregations, and any tagged animals. A subsample of crabs is collected for tagging with a U.S. Fish and Wildlife Service horseshoe crab tag. Prior to tagging, sex, age, prosoma width, weight, injuries, and mating status is recorded.

Current sampling areas include beaches in Hernando, Hillsborough, Pinellas, Brevard, Manatee, Volusia, Indian River, Martin, Franklin, Nassau, Dixie, Levy, and Taylor counties. FWC is actively working to incorporate sites in Monroe, Charlotte, Lee, Palm Beach, Collier, Miami-Dade, and Broward counties.

The paucity of Florida-specific data have not allowed the State of Florida to conduct Atlantic and Gulf of Mexico population assessments, and further limited the capacity of the Atlantic States Marine Fisheries Commission horseshoe crab stock assessments. The stock status of Florida horseshoe crabs is poorly understood, due to the limited amount of targeted fishery sampling along the Atlantic coast. In addition to the scientific goals, volunteer involvement from the public has increased knowledge of biology and fishery specific issues, and further supported conservation of Florida natural resources.

Training events are held to train volunteer coordinators on how to conduct surveys, manage volunteer involvement, develop sampling schedules and train volunteers. Volunteer training events educate and train volunteers on horseshoe crab biology and management, as well as the importance of collecting scientifically accurate data.

FWRI staff and Florida Sea Grant/ IFAS will continue finding interested persons willing to serve as volunteer coordinators in coastal counties with horseshoe crab populations. Criteria for site selection is determined by using public reporting data collected since 2002. Training events will be scheduled to specifically train volunteer coordinators on how to educate, and train volunteers on the scientific collection of data, coordinate sampling events and select sampling locations. Additionally, volunteer training events will be held to properly educate and train citizens who will be collecting seasonal horseshoe crab spawning data. In addition, the trained coordinators and volunteers will be responsible for the collection of data from 21 established beaches, in 6 locations as well as 5 locations, and 14 beaches to be added at the beginning of the funding period. Beaches are surveyed each year in the spring and fall coinciding with peak spawning, the full moon and high tides. At each beach, volunteers will survey 3 consecutive days around the new and full moons.

Florida Sea Grant is a key partner in this project. Claire Crowley serves as principal investigator from FWRI. Berlynna Heres is the Florida Horseshoe Crab Watch coordinator and organizes all volunteer coordinators throughout the state, conducts trainings, and actively samples at beaches on the west coast of Florida. Savanna Berry, researcher with the University of Florida Sea Grant/IFAS, serves as the Cedar Key volunteer coordinator, and worked extensively to develop protocols, and training videos, used at all locations.

Florida Horseshoe Crab Watch volunteers measuring the prosoma width of a horseshoe crab before tagging.