All posts by Michelle Kerr

A Light in the Fog: Shipboard Genetic Quantification of the Red Tide Alga Karenia brevis

By Alicia Hoeglund, Matt Garrett and Mary Harper

On January 11, on FIO’s new research vessel (R/V) the W. T. Hogarth, FWRI-HAB researchers assisted USF in deploying new infrastructure for oceanographic sensors and took advantage of this opportunity to test hand-held genetic sensors that can detect the red tide alga, Karenia brevis, in water samples collected while onboard. The genetic detection project, funded through a NOAA Prevention Control and Mitigation of HABs (PCMHAB) grant, utilizes a field-friendly approach that can provide genetic quantification of K. brevis in approximately one to three hours from the time of sample collection (see: http://fwcfieldnotes.com/2016/12/on-site-testing-for-red-tide-alga/). Samples collected just west of the Skyway Bridge and off of Pass-a-Grille (Pinellas County) were tested during this trip and provided our researchers with some of the lowest field concentrations of K. brevis observed with this technology to date: approximately 108 cells L-1 and 42 cells L-1, respectively. The limit of detection using our routine light microscopy procedure is 333 cells L-1, making this a very promising find for the development of this project!

Syringes funnel the sampled water into a column that contains the filter to which the RNA binds.

Although this was intended to be a short-day trip, thick sea fog delayed both the departure and the return of the R/V W.T. Hogarth, with researchers spending an unanticipated night at sea. A short reprieve from foggy conditions allowed the port to reopen briefly early in the morning of the 12th, and sea fog continued to impact the area throughout that day. A subsequent trip completed the installation of USF’s oceanographic sensor system, and water current, meteorological, and wave data are now being reported every one to three hours (http://www.ndbc.noaa.gov/).

Deployment of the real-time waves system and meteorological sensor: Once the concrete bottom mount and the Acoustic Doppler Current Profiler was dropped in the water by the ship’s crane, divers descended to remove the deploy cables and ensure the instrument was in the proper location and orientation.

Living Shoreline Suitability Model for Tampa Bay: A GIS Approach

By Chris Boland

Because of the threat of shoreline erosion from strong storm action and sea level rise affecting waterfront property values, considerable attention has been focused on shoreline protection.  In the recent past, shorelines have been “stabilized with hardened structures, such as bulkheads, revetments, and concrete seawalls.  Ironically, these structures often increase the rate of coastal erosion, remove the ability of the shoreline to carry out natural processes, and provide little habitat for estuarine species.”[1]  Alternatively, government agencies responsible for resource protection have proposed more natural bank stabilization and erosion control called “living shorelines,” which NOAA defines as: “… a range of shoreline stabilization techniques along estuarine coasts, bays, sheltered coastlines, and tributaries… [that]… incorporates [natural] vegetation or other living, natural ‘soft’ elements alone or in combination with some type of harder shoreline structure (e.g. oyster reefs or rock sills) for added stability… [to] maintain continuity of the natural land-water interface and reduce erosion while providing habitat value and enhancing coastal resilience.”[2]

Figure 1

FWRI’s Center for Spatial Analysis (CSA) has taken an interest in living shorelines in the Tampa Bay region and, as a state partner in the Gulf of Mexico Alliance (GOMA), became aware of the Virginia Institute of Marine Science’s (VIMS) Living Shoreline Suitability Model (LSSM)[3] and its application in Mobile Bay, Alabama.[4]  VIMS developed the LSSM in ESRI’s ArcGIS Model Builder based on a decision tree that can assist in identifying appropriate living shoreline treatments to an area (Figure 1).  Because of the LSSM’s success in identifying locations where a living shoreline restoration project may be effective, CSA’s Kathleen O’Keife and Chris Boland received grant funding from GOMA’s Habitat Resources Team (HRT) to apply the LSSM to the Tampa Bay region.

The LSSM requires information about existing environmental conditions to correctly apply the decision tree, such as existing habitat, slope of coastal waters, environmental conditions (e.g. fetch, current speed, and sunlight shading), and potential construction barriers (e.g. nearby road or permanent structures).  The recently updated (June 2016) environmental sensitivity index (ESI) dataset, originally collected for oil spill response purposes, answered many of these required criteria and so became CSA’s base input dataset to the model.  CSA staff spent approximately four months of full-time work to manually review each of the 5,162 shoreline segments, which ranged in length from about 100 feet to about 500 feet and classified the remaining required data fields appropriately.

Once completed, the LSSM model was run based upon the derived input dataset and completed in less than an hour.  The model outputs resulted in additional fields that provide property owners and management entities with suggested Upland Best Management Practices (BMP) and Shoreline BMPs. [5]  The results are displayed in Figures 2 and 3.  Overall, the modified LSSM recommended the installation of a living shoreline to approximately 33% of the shoreline, protection from a “harder” landscape protection method to about 11% of the shoreline, and was unable to recommend a BMP to the rest (56%) Tampa Bay area’s shoreline, typically because the installation of a living shoreline would be obstructed by an existing shoreline condition.

Figure 2
Figure 3

The model results can be reviewed in CSA’s educational materials that were developed as grant deliverables.  The ArcGIS Online story map (http://arcg.is/0CPKD9) was developed to inform the general public of the use of living shorelines as a shoreline protection alternative, and the Web Mapping Application (http://arcg.is/2gr3Fca) was intended to assisting managers in identifying potential preservation and mitigation areas.

[1] (National Oceanic and Atmospheric Administration, n.d.)

[2] (National Oceanic and Atmospheric Administration (NOAA), 2015)

[3] (College of William and Mary: Virginia Institute Of Marine Science: Center for Coastal Resource Management, 2018)

[4] (Woodrey, 2016)

[5] (VIMS: Center for Coastal Resource Management Program, 2015)

 

Scallop Restoration in the Florida Panhandle

By Jennifer Granneman

Bay scallops (Argopecten irradians) may have a short life, typically living for about a year, but they play a big role in the economies of many coastal Floridian towns, like Steinhatchee and Port St. Joe.  In 2016, the scallop team within the molluscan fisheries group began a 10-year project to restore bay scallops to self-sustaining levels in Florida’s Panhandle.  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 goal of the project is to increase depleted scallop populations and reintroduce scallops in suitable areas from which scallops have disappeared.

Restoration efforts are focused on coastal estuaries within the Florida Panhandle that have been divided into five regions, as shown on the map.  Bay scallop populations in the Florida Panhandle are currently classified as ‘collapsed’ with population densities below 0.01 scallops per m2.  In St. Joseph Bay, this collapse may be due in part to a red tide event that occurred from winter 2015-spring 2016.  The red tide resulted in a lack of recruitment in 2016, leading to a sharp population decline.  Scallop restoration efforts were primarily focused on St. Joseph Bay in 2016-2017.  This year, restoration efforts will expand to St. Andrew Bay and St. George (regions 3 and 5).

The scallop team is planning to use a three-step approach to enhance bay scallop populations within targeted restoration areas in the Florida Panhandle by: (1) installing cages holding groups of adult bay scallops, (2) releasing hatchery-reared or naturally-harvested juvenile bay scallops (spat) at restoration sites, and (3) releasing hatchery-reared bay scallop larvae.  Each year, the scallop team collects adult scallops from St. Joseph Bay and brings them to a hatchery which provides juvenile scallops the following year.  These hatchery scallops are then placed in cages in a no-entry zone in St. Joseph Bay.  Placing scallops in cages protects them from predators and increases the likelihood that scallops will successfully produce offspring during the spawning season.  Beginning in 2017, scallop collectors were placed in St. Joseph Bay and St. Andrew Bay to collect wild scallop spat.  The spat are raised at the Florida State University Coastal and Marine Laboratory and once they reach a size of 30mm they will be planted in cages in their respective bays.  Last year we placed 2,500 wild and hatchery-produced scallops in cages in St. Joseph Bay.

In addition to traditional approaches to restoration, our vision for restoring scallops also includes educating the public about our ongoing restoration projects and asking them to be contributing partners in these efforts.  To that end, we have recruited 200 volunteers to help restore scallops in St. Joseph Bay and St. Andrew Bay.  In April, we will provide scallops and predator exclusion cages to these volunteers at workshops held in Panama City and Port St. Joe which will be hosted by our partners at Sea Grant.  Our volunteers, or ‘Scallop Sitters’, will place their cages with scallops off privately-owned docks, or, if they have a boat, they will place these cages in the bay.  We will give a webinar to discuss this project and provide training for our ‘Scallop Sitters’ through the FWC webinar series on April 16.  Volunteers that are unable to attend our workshops in April will be able to view this webinar and participate in our scallop restoration program. We hope that by partnering with the community we will increase our chances of successful restoring scallops to stable levels (>0.1 scallops/m2) in St. Joseph Bay and St. Andrew Bay.  If you have questions about the program or want to get involved, please email us at bayscallops@myfwc.com.

If you would like more information about this restoration program, check out these links: http://myfwc.com/research/saltwater/mollusc/bay-scallops/restoration/current-projects/

http://myfwc.com/research/saltwater/mollusc/bay-scallops/restoration/help-restore/

FWC promotional video: https://www.youtube.com/watch?v=kBC478TnbWc

Panhandle outdoor show: https://www.youtube.com/watch?v=uiFhbA7KONU

Apple Snails and Snail Kites

By Jenn Bernatis, Ph.D.

Changes in Florida’s freshwater ecosystems over the decades have had a myriad of impacts on native species. Now, we are looking at the possibility of relying on an invasive snail, Pomacea maculata, to support the federally listed Snail Kite (Rostrhamus sociabilis plumbeus). Snail Kites feed almost exclusively on Apple Snails, but population declines in the native Florida Apple Snail (Pomacea paludosa) appear to be occurring in traditional kite nesting areas. Over the last 12 years, the invasive P. maculata (Island Apple Snail) has spread throughout the state becoming an alternate food source in many systems where Snail Kites nest. Many of these nesting sites are manipulated for a variety of reasons, yet definitive impacts on the snails and birds remains uncertain.

East Lake Tohopekaliga is a nesting site for Snail Kites and home to both the Florida Apple Snail and Island Apple Snail. The lake is slated for an extensive restoration including draw-down, scraping and removal of sediment, and vegetation treatments. This system has provided state and federal researchers with the opportunity to monitor both snail and bird activity pre-restoration, during restoration, and post-restoration. The data collected during this period will provide much-needed data that can be used in determining future restoration activities at sites with Apple Snails.

At this time four sampling events, two summer and two winter, have been conducted. These sampling events use a combination of throw traps, transects, wading, snorkeling, and scuba diving to locate snails. More than 800 sites have been sampled around the lake ranging from 0.25 m to 2.25 m deep. More than half of the snails collected have been in depths greater than 0.75 m. The majority of the sites with snails have some sort of vegetation, either emergent or submersed, but a few snails have been collected at sites with no vegetation. More snails have been collected in the summer, as this is also peak reproductive period than in the winter. This finding demonstrates conclusively that snails utilize deeper water and that Apple Snail surveys need to focus on a range of depths and not just the shallow marsh areas.

Tracking the snails long term will provide information critical to dealing with Apple Snail populations. Although invasive Apple Snails are economically and potentially ecologically damaging, they are serving a critical role as a food source for the Snail Kite. Understanding the movement patterns and use of the water column by Apple Snails will allow managers to better anticipate the impacts on Snail Kites and adjust management plans accordingly. Likewise, the research will provide information that may be of use in developing snail eradication programs. Previous tactics have included draw-downs in an attempt to kill the snails through desiccation. This is not an applicable approach as it is known that invasive Apple Snails can survive out of the water for at least a year. The question that will be answered is, “Are the snails burying?” which they are capable of, or “Are the snails following the water?” at which point the draw-down will have minimal impacts on Apple Snails. If the snails bury, and scraping is part of the proposed activity, then reintroducing the Apple Snails, preferably the native, may need to be considered in locations with Snail Kite nesting history. Ultimately, this study will fill in missing data gaps on snail ecology and provide necessary information when working with systems with Apple Snails and particularly those with Snail Kites.