Category Archives: Notes from the Field

Climate Change in Florida

MarineQuest Showcase

One in a series of videos celebrating our virtual MarineQuest 2020 event. Learn how FWRI researchers study the impacts of climate change on Florida’s ecosystems, fish and wildlife. Researchers will show us a guide they developed, the Climate Adaptation Explorer, to help other scientists and resource managers understand and address the current and future impacts of climate change in Florida.

Scallop Sitter Project Temporarily Postponed

Florida’s bay scallops (Argopectin irradians) have been called the potato-chips of the marine ecosystem – everything loves to eat them. Short-lived and widely consumed by a large array of predators – including humans – bay scallop numbers can fluctuate from year to year. Declining populations in many areas of the Gulf Coast prompted this effort, called the Scallop Sitter Project that began in 2016 to restore bay scallops in Florida’s panhandle. Overall goals of this project are to increase scallop abundance and recreational fishing opportunities in the Florida Panhandle. The Scallop Sitter Project is a volunteer program that involves local community members in the ongoing scallop restoration efforts of FWRI biologists.

The project is funded by restoration money set aside after the Deepwater Horizon oil spill and is intended to increase recreational fishing opportunities in the Florida Panhandle. The objectives of the project are to increase depleted scallop populations in some bays and reintroduce scallops in other suitable areas from which scallops have disappeared. Restoration efforts are focused on coastal estuaries within the Florida Panhandle.

FWRI biologists collect scallops before the opening of the scallop season and place them in cages in an exclusion zone in St. Joseph Bay that is protected from harvest. In addition, every year adult scallops are transported from St. Joseph Bay to a hatchery which then provides scientists with juvenile scallops the following year. Placing scallops in cages protects them from predators while also increasing the likelihood that scallops will successfully produce offspring during spawning season. In addition, biologists provide community volunteers with scallops to place in cages in St. Joseph and St. Andrew Bays. Volunteers maintain cages of scallops and report monthly survival and salinity data.

Monitoring of bay scallop spat (juvenile bay scallops) settlement is done using spat collectors during the peak settlement period for bay scallops, from August through March. In addition, spat that settle on collectors are used for restoration purposes. Surveys of adult scallop abundance are conducted in the spring and fall by diving and counting scallops along a transect. Planting scallops in cages and maintaining scallops is done throughout the year. The scallop sitter project takes place from July through December each year. Monitoring of scallop harvest is done through aerial surveys and boat ramp intercepts during the scallop season, which is from July through September. Spawning and grow-out of scallops for restoration purposes takes place from August through April of each year.

The Division of Marine Fisheries Management may use these modeling efforts to manage the recreational scallop fishery in Florida. The project began in April 2018 and is expected to end in December 2026. Funds from a Natural Resource Damage Assessment grant helped fund this project, which came from restoration money set aside after the Deepwater Horizon Oil Spill. If this project is successful, the model could be used to restore scallops in other areas of the state.

Due to the current pandemic, managers have decided to cancel the Scallop Sitter program for the 2020 summer season in an effort to protect the health of our volunteers. We want to thank all of our volunteers that were interested in participating in this year’s event. Please stay tuned for updates about next year’s Scallop Sitter program. We cannot wait to work together with our volunteers again soon!

The Hidden Promiscuity of Shoalgrass: Observations of Sexual Reproduction in Tampa Bay

By Penny Hall

Halodule wrightii, commonly called shoalgrass, is a fast-growing, pioneering seagrass species with a pantropical distribution.  As seagrass ecologists we’ve been taught that sexual reproduction is largely unimportant to the ecology of H. wrightii, and that growth is primarily due to clonal expansion.  For the past 60 years, the consensus view has been that population connectivity and maintenance of genotypic diversity were the products of frequent, storm-driven fragmentation events and rare seed setting, respectively.  Apart from the discovery of a few seed bank hot spots in coastal Texas, USA, this idea has been reinforced by a lack of evidence for sexual reproduction elsewhere in the Gulf of Mexico.  Halodule wrightii flowers, especially female flowers, are inconspicuous, and their ephemeral nature hinders documentation in the field; however, the broad geographical distribution of shoalgrass suggests that sexual reproduction is more common than the literature indicates.

After an historic mass mortality of Thalassia testudinum left vast areas of central Florida Bay bare in the summer of 2015, we observed a rapid influx of H. wrightii, sparking debate about the possible existence of seed banks.  Sediment cores collected from these areas in 2017 contained seeds, suggesting either a long-term seed bank or the un-noticed sexual reproduction of H. wrightii persisting in the understory a dense T. testudinum canopy.  This finding encouraged us to look for evidence of sexual reproduction elsewhere in the state.  To date, we have documented flowers and/or seeds in every estuary we have sampled, including St Andrews Bay, the Big Bend, Charlotte Harbor – and received word of seeds from the Florida Panhandle to the Indian River Lagoon.  It appeared past time to better understand the reproductive ecology of this important early colonizer.  With the help of an intrepid Eckerd College intern, we set out to map seed banks throughout Tampa Bay. Using a coring technique based on our previous efforts, we collected samples from 5 sections of the bay, all in shallow H. wrightii and mixed-species beds, during the winter of 2019.  What we discovered is evidence for widespread, albeit sparse, seed reserves and fairly commonplace flowering throughout Tampa Bay.  Then, in May of 2019, a serendipitous return to our Boca Ciega Bay seed hotspot yielded widespread flowering in the area, both sexes in abundance, followed by fruit maturation that appeared to take an additional month.  What to make of these preliminary data is not yet clear, but it is certain that our understanding of H. wrightii population structure and movement ecology can no longer ignore its reproductive capacity.  Much more sexual reproduction is happening than previously appreciated.

Our plans to continued work at these sites included genetics, seed viability tests, estimates of pollination distances, and more exacting floral and seed counts, as well as a proper botanical description of floral structures and fruit maturation.  But, as with so much in 2020, the COVID-19 pandemic has put a halt to our plans.  It appears that the sexual secrets of this ubiquitous, yet enigmatic, plant are safe for at least another season.

Adapting to a Changing Gulf Region, A New Online Course is Now Live

By Lily Becker

Adapting to a Changing Gulf Region, a new online course hosted by FWC, the American Society of Adaptation Professionals (ASAP), and the Gulf of Mexico Alliance (GOMA), launched in June with biweekly seminars ongoing through early October.  The course covers a broad curriculum of climate change adaptation and resilience topics across nine distinct sessions.  Aligned to ASAP’s Knowledge and Competencies Framework for Climate Change Adaptation and Resilience Professionals, each session includes a presentation on a foundational climate change adaptation concept tied to one or more illuminating regional case studies.  Session topics span from introductory concepts in climate change adaptation for natural resources to more integrative, interdisciplinary areas of focus aimed at weaving connections between the changing role of resource managers and conservation practitioners in an uncertain future and the broader themes of community resilience, the built environment, building trust and stakeholder engagement, and equity and justice.  Read the full course syllabus here for more detail.

As are the session topics, the roster of participants enrolled in the course is broad.  The one hundred natural resource and conservation practitioners from across the Gulf Coast region taking the course this summer represent a broad range of locations, areas of expertise, sectors, and career stages.  Beyond simply learning new ideas, the course aims to offer an opportunity for those enrolled to build connections with each other and become more familiar with regional adaptation and resilience projects recently completed or in-progress. 

While enrollment for the course is now closed, the good news is that all seminar sessions are open for anyone to audit on a drop-in or recurring basis.  While sessions on the Climate-Smart Conservation Cycle, managing for change, vulnerability, and communicating climate change have now past, much more is still to come!  In August, we look forward to learning about making the jump from planning to implementing adaptation (August 12th) and overcoming barriers to climate change adaptation (August 26th).  September will bring two more sessions addressing risk and ethically integrating urban resilience priorities with natural resource management.  Finally, a synthesis session on October 7th will bring the inaugural course to a close.  Register here to attend any or all upcoming sessions.

Range Extension of Spotted Bullhead in the Withlacoochee River South

By Jennifer Moran

The Spotted Bullhead, Ameiurus serracanthus, has one of the smallest known distributions in the genus Ameiurus and can be found in southeastern Alabama, southern Georgia, and northern Florida. It’s current known range in Florida is restricted to rivers that drain into the Gulf of Mexico which include the Yellow, Ochlockonee, Apalachicola, Choctawhatchee, Suwannee, St. Marks, and St. Andrews Bay basins. They are typically found in small to medium rivers with slow to moderate currents and prefer deeper water with rock or sand substrate. However, they also occur over mud bottoms typically near stumps or woody debris. Spotted Bullheads can be distinguished by a black blotch on the base of the dorsal fin, a relatively large eye, dark barbels, and round light or yellow colored spots on a dark body (cover image). They also have 15-20 large saw-like teeth on the posterior edge of their pectoral spines.   

In June 2020, 11 FWRI freshwater fisheries research biologists completed an electrofishing sample below the Lake Rousseau dam on the Withlacoochee River South near Yankeetown. We sampled 34 100-m sites in accordance with the long-term monitoring river protocol over two days and collected 8 Spotted Bullheads on 7 different sites (Figure 2). This is the first reported Spotted Bullhead collection south of the Suwannee River which was thought to be the southern extent of their range. The Spotted Bullheads collected were sampled near limestone outcroppings over sand, rock, and mud bottoms. Total length and weight ranged from 64-219 mm and 3-155 g respectively. We collected one individual as a voucher specimen from the random selected transects. On the second day of sampling, a more efficient sampling method that consisted of lowering the pulse rate setting was used to collect 4 more individuals. Using lower pulse rate settings have been found to be an effective way to sample catfish. The bullheads collected on the second day were preserved and tissue samples were collected for genetics, both of which will be deposited into the Florida Museum of Natural History and available for future work.

Figure 2: Locations of Spotted Bullheads collected on randomly selected transects along the lower Withlacoochee River South.

Previous sampling on the Withlacoochee River South included other native catfish species such as Brown Bullhead (Ameiurus nebulosus), Yellow Bullhead (Ameiurus natalis), Channel Catfish (Ictalurus punctatus), Tadpole Madtom (Noturus gyrinus), andWhite Catfish (Ameiurus catus). The collection of Spotted Bullheads in the Withlacoochee River South extends the known range by 20 miles south from the Suwannee River. Other sampling efforts on the Withlacoochee and surrounding rivers have not documented Spotted Bullheads which could be attributed to the amount of effort as well as the type of habitat being sampled. Analysis of the genetic material collected during this sampling event can be used to determine if this population is genetically distinct from samples collected previously on the Suwannee and other rivers within the known range. More sampling needs to be done on other rivers south of the Suwannee to capture a more accurate picture of the Spotted Bullheads newly extended range which could include the Waccasassa, Rainbow, and upper part of the Withlacoochee River South. The 11 biologists that were involved in the sampling event are currently collaborating on publishing this exciting find in a note.

Effects of Translocation on Gopher Frog Movement and Survival

By Traci Castellón and Anna Deyle

Mitigation translocation is an increasingly common practice that involves moving animals out of harm’s way at development sites and releasing them somewhere else. However, the conservation value of translocation has been questioned because survival is often low and there are potential risks to existing populations at release sites (e.g., disease transmission). Translocation of amphibians in particular has been debated due to early failures, but outcomes have improved with time.

The gopher frog (Lithobates capito) is a species of conservation concern that frequently lives with gopher tortoises (Gopherus polyphemus) in their burrows. Because they live in tortoise burrows, gopher frogs are often encountered when burrows are excavated for gopher tortoise translocation, a relatively common mitigation technique in Florida. Although gopher frogs have occasionally been translocated along with tortoises, until now there had been no systematic effort to monitor their survival.

To assess the potential value of gopher frog translocation, biologists with FWRI and HSC conducted an experimental translocation of 23 gopher frogs and used radio-telemetry to compare their survival and movements to 24 non-translocated frogs. Survival of translocated frogs was only slightly lower (59%) than that of non-translocated frogs (66%), and there was no indication of long-distance dispersal or homing behaviors that sometimes cause translocation failure.

The most important predictor of frog mortality was movement outside the safety of burrows, where frogs were vulnerable to mortality from predation and roadkill. Mortality was higher for translocated frogs because many dispersed from their release burrows, then made extensive movements through the unfamiliar landscape. These movements and associated mortality were elevated during the first month following translocation, but surviving frogs eventually settled into burrows where survival was high. Non-translocated frogs also had high mortality during surface movements, but their movements were primarily associated with visits to breeding ponds.

Dispersal away from release sites is a typical response to translocation for many groups of animals, as is the eventual “settling” behavior we observed. The high mortality immediately following release is also common and considered a “cost” of translocation. Nonetheless, more than half of the translocated frogs survived and may now contribute to long-term persistence of the population where they were released. These results provide preliminary support for gopher frog translocation as a conservation measure, particularly when all suitable habitat at a development site will be destroyed. However, given the mortality we observed, leaving frogs at development sites may be a better option when suitable habitat and breeding ponds will remain.

      Because frogs’ movements immediately after release strongly influenced mortality, research is needed to evaluate soft release techniques, such as short-term penning that prevents animals from immediately leaving the area and helps them settle. Soft release has improved outcomes for other taxa, but it has not been adequately investigated for amphibians. Further research is also needed to assess longer term survival and reproductive success of translocated frogs, as well as potential risks to recipient populations.