Category Archives: Notes from the Field

Recruitment of Juvenile Gag Grouper in the Eastern Gulf of Mexico

By Ted Switzer

Gags (Mycteroperca microlepis) support extensive commercial and recreational fisheries in the eastern Gulf of Mexico. A 2016 stock assessment did not support earlier assessments that indicated that gags are currently overfished and continue to undergo overfishing (South East Data Assessment and Review 33 update). Considering the status of Gag in the eastern Gulf of Mexico, it is especially important to improve understanding of its juvenile recruitment processes.

Study area of polyhaline seagrass habitats sampled in estuarine systems in the panhandle (St. Andrew Bay, Apalachicola Bay), Big Bend region (St. Marks, Econfina, and Steinhatchee), and peninsula (Tampa Bay and Charlotte Harbor) of Florida, USA (Schrandt et al. 2018).

Past research has shown that juvenile Gags generally occupy structured polyhaline (18-30 practical salinity units) habitats such as seagrass beds and oyster reefs for several months before emigrating to nearshore reefs (Figure 1). The reliance of Gags on estuarine nurseries, combined with a brief period of estuarine occupancy, greatly facilitates the accurate characterization of the strength of juvenile recruitment.

A comprehensive examination of long-term (10+ years) FWC/FWRI fisheries-independent data was conducted to characterize habitat selection and recruitment of juvenile Gags. Results from Apalachicola Bay, Tampa Bay and Charlotte Harbor habitat suitability analyses indicated that juvenile Gags selected polyhaline habitats with sloping bottoms and extensive seagrass coverage. These analyses indicated that the near shore, deeper water polyhaline seagrass habitats had been under sampled (Switzer et al. 2012).

A multi-gear survey (183-m haul seine and 6.1-m trawl) was designed to supplement long-term, fisheries-independent survey data on estuarine-dependent reef-associated fishes. The supplemental survey design specifically considered juvenile Gag recruitment ecology and thus targeted the deep, polyhaline (>18 psu) seagrass habitats that are used by age-0 Gags. Potential sampling sites were limited to generally polyhaline waters that contained at least 50% bottom coverage of seagrass, had a measurable slope and were between 1.0 and 7.6 m deep.

Gag begin their life offshore in a pelagic environment where they spend their first 30-60 days. Eventually they settle out onto shallow water seagrass beds, where they spend the summer months feeding and growing. In the fall they migrate to nearshore hard-bottom habitat. As they mature, they eventually migrate to deeper water reefs and as mature adults they form spawning aggregations and spawn during the winter months. Gag are hermaphrodites. They are born as females and as they grow eventually transition to be male.

This supplemental sampling was initiated in 2008 and polyhaline seagrass beds were sampled by bottom trawls (6.1-m otter trawl) and haul seines (183-m haul seines) in seven estuaries along Florida’s Gulf coast (Figure 2). Apalachicola Bay, Charlotte Harbor and Tampa Bay have been routinely sampled since the late 1990s; St. Andrew Bay and three estuaries in the Big Bend region between Cedar Key and Cape San Blas (St. Marks, Ecofina, and Steinhatchee), where Gag recruitment had been documented, were added for this study and have become part of the continuing survey.

Analyses of the data collected in the long-term and supplemental surveys (2008-2012) demonstrated the effectiveness of this sampling approach. The size ranges of Gags collected in both studies were similar, but age-0 individuals were captured more frequently and the catch-per-unit-effort (CPUE) was significantly higher in the supplemental surveys (Switzer et al 2015). These analyses will not only enhance our understanding of recruitment processes for juvenile Gags in the eastern Gulf but will also provide valuable insight into observed patterns of habitat use and the relative importance of various habitat types. Nevertheless, additional information on habitat availability, combined with a better understanding of the estuarine systems’ relative contributions to nearshore Gag populations, will be required to maximize the utility of these data in predicting fisheries productivity.

Strong Gag year-classes have been documented as persisting as the fish grow and enter the fishery. Accordingly, accurate estimation and prediction of juvenile recruitment is critical to the effective assessment and management of at-risk fisheries. Variability of estuarine nekton assemblages is valuable as an indicator of environmental quality.  Therefore, the patterns discerned from the supplemental sampling have important implications for fisheries managers.

Monitoring Suburban Florida Sandhill Cranes

By Tim Dellinger

The Florida sandhill crane (Antigone canadensis pratensis) is one of five sandhill crane sub-species found in North America.  Florida sandhills are non-migratory and range from southeastern Georgia to the Everglades.  The current population estimate is around 4,600 birds and it is state-listed as Threatened in Florida.

Like other crane species, Florida sandhills need wetlands as well as uplands.  Wetlands such as shallow depression marshes and lake edges are used for nesting, foraging, and roosting.  Uplands with low vegetation, such as private ranchland and dry prairie, are used for foraging and loafing.  Both habitat types are equally important to cranes.  Unfortunately, wetlands are often drained and open uplands bulldozed to make way for roads, shopping malls, and subdivisions.  Remarkably, however, some cranes are remaining in or moving to urbanized areas and living among us.

Staff banding and tagging a Florida sandhill crane captured in a strip mall parking lot in Seminole County.

In 2017 we began a project examining how Florida sandhills are using urbanized areas.  We are currently tagging adult cranes with cellular GPS transmitters in suburbs and developed areas.  The transmitters collect GPS locations at 30-minute intervals and are uploaded to us daily.  We are also tagging Florida sandhills in rural and conservation areas to help us better understand survivorship, productivity, and habitat use along the urban gradient.

Preliminary data show that some urban cranes solely inhabit suburban or developed areas.  They use suburban yards, grassy roadsides, golf courses, and open areas around colleges and hospitals as uplands, and retention ponds or lake edge for wetlands.  However, most urban cranes regularly moved between rural areas or conservation lands to suburban areas to meet their daily needs.  Preliminary movement data for Florida sandhills tagged on conservation lands show that all individuals use some man-made habitat daily, either a mowed area near a road, a yard with a bird feeder, or improved pastureland. We will continue to tag cranes during 2019.

Diamondback Terrapin Status Assessment

By Traci Castellón

The diamondback terrapin (Malaclemys terrapin) is a once common estuarine turtle that experienced serious declines a century ago and has declined further in recent decades due to numerous pressures including habitat loss and drowning in crab traps. The Florida coastline represents approximately 20% of the species range and is home to five of seven subspecies, three of which occur only in Florida. However, little is known about the status and distribution of diamondback terrapins in Florida.

Ornate diamondback terrapin (M.t. macrospilota)

With funding from a State Wildlife Grant, FWRI is collaborating with partners statewide to conduct a biological status assessment of the diamondback terrapin in Florida. The project includes population assessments in three locations with known terrapin populations (Banana River, Florida Bay and the middle Florida Keys), and, where possible, we are also helping facilitate population assessments and surveys by partners elsewhere in the state.

Another major component of the work is collection of tissue samples from terrapins statewide for a genetic analysis to assess validity of the currently recognized subspecies taxonomy and, where possible, to conduct population-level genetic analyses to assess effective population sizes, gene flow and possible signs of inbreeding depression. Other efforts include gathering and consolidating existing data from partners to update the known distribution of terrapins statewide and using these data to develop a spatial model to quantify habitat availability. Finally, we will estimate the magnitude of past and future population reductions based on historic and projected future habitat losses.

East coast Florida diamondback terrapin (M.T. tequesta)

To date we have developed numerous partnerships, mapped > 5,500 individual sightings, collected > 300 tissue samples for genetic analysis, completed one season of mark-recapture work in the Banana River, and will begin fieldwork in Florida Bay and the Florida Keys in November 2018.

Major partners include Eastern Florida State College; Sanibel-Captiva Conservation Foundation; the US Geological Survey’s Wetland and Aquatic Research Center; University of Florida’s Department of Wildlife Ecology and Conservation, Florida Sea Grant Extension, Nature Coast Biological Station, and Florida Museum of Natural History; Florida Department of Environmental Protection’s Indian River Lagoon and Tomoka Marsh Aquatic Preserves; North Florida Land Trust; Florida Audubon; Flagler College; Brevard Zoo; and FWC’s Fisheries Independent Monitoring, Habitat and Species Conservation Section, and Florida Keys Wildlife Environmental Area; as well as many dedicated volunteers, students and citizen scientists.

Ornate diamondback terrapin (M.t. macrospilota)

Please send diamondback terrapin sightings to Traci.Castellon@MyFWC.com.

Florida Coastal Mapping Program

By Rene Baumstark

The Florida Coastal Mapping Program (FCMaP) was initiated in 2017 as a coordinating body of Florida State and Federal partners who have a goal of achieving consistent, state-wide, high resolution seafloor data for Florida’s coastal zone in the next decade. These data will provide critical baseline information to support a range of applications including coastal security, resource management, fisheries, storm surge modeling, boating safety, and tourism, as well as future uses, such as renewable energy and offshore aquaculture.

An inventory of existing high-resolution seafloor mapping data collected on Florida’s shelf was undertaken by a technical team comprised of FCMaP partners. The footprints and metadata for 345 datasets were compiled and assessed on whether they met certain criteria such as age, spatial coverage, and resolution.  For the inventory, gap analysis, and prioritization process, the Florida peninsula was separated into six regions based on geomorphological characteristics: Panhandle, Big Bend, West Peninsula, Keys, Southeast, and Northeast. In consideration of differing sensor and survey design requirements, results in each region were further divided into two depth ranges: nearshore (shoreline out to 20 meters) and shelf (20 meters to the continental shelf break).

The gap analysis revealed that less than 20% of Florida’s coastal waters have been mapped using modern bathymetric methods (multibeam sonar or aerial lidar). The overall lack of high-resolution seafloor mapping for Florida is surprising given that Florida’s coastal areas generate more than $30 billion dollars a year in revenue, which is the 2nd highest in the nation. The region with the least amount of high resolution data is the Big Bend nearshore where less than 3% has been mapped with modern technologies. Where any data do exist, they are often lead-line measurements from the late 1800s, with one data point per 100 m2.  The data disparity between regions is large and by comparison, the best-mapped region, Southeast, FL, has modern bathymetry for 86% of its area. The reason for the discrepancy is two-fold; Southeast FL is very densely populated, and the shelf is extremely narrow in comparison with the Big Bend.

High resolution mapping gap assessment results for inshore and deeper waters for six subregions around Florida. The best mapped area are shallow waters of the SE Florida region where 39% of the seafloor has been mapped.

FCMaP is presently soliciting input from managers, planners, and decision-makers to prioritize coastal and seafloor mapping needs. A mapping prioritization tool developed by NOAA (Kendall et al., 2018; Battistia, et al., 2017) was adapted to be a FL-specific application and is being rolled out region by region via a series of stakeholder workshops. Representatives from multiple federal, state, academic, and private entities are introduced to FCMaP and discuss the relevance of high resolution seafloor maps to their regions science and management needs. A single representative from each agency is then tasked with populating the tool with input from their colleagues Analytics are then run on to generate a cumulative prioritization for the region that can be displayed as a map product, and the associated justifications for the mapping need statistically evaluated.

To demonstrate the value of a coordinated approach, FCMaP partners have also engaged in a demonstration seafloor mapping effort in the Big Bend Region. High resolution bathymetry will be collected for select key management areas. These data will be some of the first modern bathymetry collected in this region and the map products will contribute to management efforts such as fisheries stock assessments, seagrass distribution, and oyster reef occurrences. In addition, outcomes from the demonstration will be used used to investigate the influence of the variable geologic framework on coastal response and evolution, providing both enhanced management capacity and science for improved understanding of coastal behavior in this little-understood region of the eastern Gulf of Mexico.

 

References

Battista, T., Buja, K., Christensen, J., Hennessey, J., and Lassiter, K. 2017. Prioritizing Seafloor Mapping for Washington’s Pacific Coast: Sensors, 17(4). https://doi.org/10.3390/s17040701

Kendall, M.S., K. Buja, and C. Menza. 2018. Priorities for Lakebed Mapping in the Proposed Wisconsin-Lake Michigan National Marine Sanctuary. NOAA Technical Memorandum NOS NCCOS 246. Silver Spring, MD. 24 pp.

Light Pollution and Sea Turtle Hatchling Orientation

By Shigetomo Hirama

Sea turtles are long-lived animals that utilize multiple developmental habitats. In all of the habitats, sea turtles encounter with various threats. Although some are naturally occurring (at least they seem to be), the majority of threats are caused by human. These anthropogenic threats in-water habitats include: fisheries’ activities, oil spills, debris ingestions, debris entanglements, boat strikes, dredging, and direct harvesting. On the beach, beach driving, artificial lighting (light pollution), armoring (sea walls, rock revetments, and other infrastructures), oil spills, and egg poaching are threats to nesting and hatchling turtles. Among these threats on the beaches, the installment of armoring structure – sea walls, rock revetments, and other infrastructures – are probably the most important threats, considering sea level rise as a consequence of climate change. Armoring structures are known to increase speed of erosion and may cause permanent loss of beach sand. Although it may not be as important, artificial lighting also is significant threats to the turtles. The artificial lighting differs from the armoring in terms of solving the issues. Coastal armoring, such as a sea wall, is difficult to remove once it is placed; however, we can change light bulb or retrofit light fixtures relatively easily. Through the present project, we provide valuable information to stakeholders to reduce hatchling mortality and increase chance of hatchlings’ survivorship.

Playalinda Beach. An example of a beach with no light pollution.

Artificial lighting alters natural illuminant environment and impacts behavior of wildlife. Nocturnal animals such as bats, moths, and some species of birds, are more susceptible to light pollution than others. Sea turtle hatchlings crawl toward ocean using the visual cues immediately after emerging from sand. The hatchlings disorient on the beach if the intensity of artificial light is relatively high and may never enter the ocean.

Cocoa Beach. An example of a beach with moderate to severe light pollution.

We have been quantifying accuracy of hatchling orientation in over the 20 Florida beaches in past five years. Hatching orientation is one of the subjects of sea turtle biology that has been studied well. Surprisingly, no known work has provided the benchmark orientation data that were collected at a natural beach and compared with the information that were collected at the beaches with varying levels of light pollution. The results of present project showed the accuracy of hatchling orientation varied widely depending on the beaches. The quantitative data of the project are currently in process of publishing in a peer-reviewed journal. In the present article, I provide photographic images that were taken by same camera, setting, and lens at the beaches with no (Playalinda), moderate to severe (Cocoa Beach), and severe (Miami Beach) light pollutions. We hope the data we provide would guide to take practical actions to reduce light pollution.

Miami Beach. An example of a beach with severe light pollution.

Vessel Use Patterns in the Florida Keys National Marine Sanctuary

By Casey Butler, Maria Cooksey, Gabrielle Renchen and Emily Hutchinson

The Keys Fisheries Research program took to the skies in partnership with the Florida Keys National Marine Sanctuary (hereafter Sanctuary) management team to conduct an aerial survey of vessel use in the Sanctuary. Within the boundaries of the Sanctuary lie nationally significant marine resources, including hundreds of uninhabited Keys, the world’s third largest barrier reef, hard-bottom habitat, seagrass beds, mangrove trees, and more than 6,000 species of marine life. The Florida Keys are home for ~79,000 year-round residents and provide a destination for ~5 million visitors annually. Over the last few decades the number of registered vessels has increased, but the activities of these boaters and how their use of Sanctuary resources have changed over time is not well known. Understanding the patterns of boating activity in the Sanctuary is vital to evaluating the sustainable use of the valuable marine resources of the Sanctuary.

Whale Harbor Sandbar is the most popular sandbar in the Keys (331 boats were observed on the Sunday of Memorial Day Weekend 2016).

FWRI scientists flew in small planes over the breathtaking waters of the Keys and recorded the type, location, and activity of every boat, personal water craft, kayak, paddleboard, etc. Over the course of 29 flights in 2016, we counted 52,107 boats. The number of boats peaked at nearly 5,000 during the opening days of lobster season and summer holidays. On average, 19% of boats were involved in fishing, 19% were involved in diving, 13% were anchored (with no visible activity), and 9% of boats were at sandbars. Many of the boats we observed (29%) were in transit at the time; however, these boats likely participated in other activities throughout the day. In addition to diving and fishing, other watersports (e.g., kayaking, paddle boarding, jet skiing) and partying at sandbars were popular among the Sanctuary’s visitors and reflect alternative ways in which people enjoy Florida Keys waters. Our research team conducted a similar aerial survey in 1992, and the comparison of vessel use data between 1992 and 2016 shows that there has been a major increase (~400%) in the popularity of watersports (e.g., kayaking, paddle boarding, jet skiing) and partying at sandbars.

The 1992 aerial survey took place prior to the establishment of the Sanctuary Preservation Areas (Figure 1, SPAs). Establishment of the SPAs in 1997 limited consumptive activities within these areas and was intended to reduce conflicts between fishermen and divers. Because these areas were open to fishing during the 1992 aerial survey – including hook-and-line, recreational lobstering and commercial fishing, this allows us to examine how SPA implementation affected stakeholder activity. Currently, we are evaluating changes in dive and fishing boat spatial distributions after the SPAs were established.

Sombrero Reef, a Sanctuary Preservation Area (SPA) off of Marathon hosts many divers and snorkelers throughout the year.

Besides providing an outstanding office view for our scientists, this project provided essential information to the Florida Keys National Marine Sanctuary managers regarding vessel use in the Sanctuary and how that use has changed over time, which should aid in future management decisions regarding Sanctuary resources.

Watch our video for a glimpse of the scenery from the Florida Keys National Marine Sanctuary aerial survey project:  https://www.youtube.com/watch?v=TxQH3zRdYzk

Gopher Frog Monitoring Project

By Aubrey Greene

The gopher frog is currently being considered for federal protection under the Endangered Species Act. While the gopher frog has experienced serious declines throughout the rest of its range, Florida currently represents a stronghold for the species. Consequently, the gopher frog was delisted as a state-designated Species of Special Concern in January 2017. As a part of the delisting process, a state species action plan was developed for the gopher frog. This action plan calls for the development of a statewide monitoring program for the species. Before the species was delisted, we began a pilot study to increase our understanding of species detection and wetland occupancy rates, as well as to determine the best methodology for a long-term gopher frog monitoring program.

Surveys for the gopher frog monitoring project started in Fall 2015. This project uses seasonal dipnet surveys and frogloggers (automated frog call recorders) to track the status of gopher frogs in 100 wetlands over time. Additional wetlands are also surveyed as time allows to locate new breeding wetlands and track the status of the species in additional known breeding ponds. During FY 2017-18, we surveyed 114 ponds in 22 counties on 29 public or conservation lands for gopher frogs, finding tadpoles in 72 ponds in 21 counties on 24 public lands. These surveys discovered one previously unknown gopher frog breeding pond and observed breeding for the first time in decades in some previously known ponds. Many of the “rediscovered” observations were made in the months following Hurricane Irma, which filled most of the study ponds.

An image of a sonogram of a gopher frog call.

As the data collection phase of this project comes to a close at the end of 2018, in-depth data analyses will begin. Froglogger recordings are already being analyzed using software that recognizes the specific call signature of the species. Unfortunately, this is a very long process due to the large amount of data collected over the three-year project. Dipnet and froglogger data will be analyzed to determine the annual and seasonal patterns of wetland occupancy in each region of the state, as well as the effects of different variables on species detection and wetland occupancy. We will also examine data from both methods to make recommendations about the most efficient sampling methods.

National Rivers and Streams Assessment

By Jamie Richardson

From the vast blackwaters of the Suwannee River to a braided creek in Pensacola to a pin-straight residential canal in the greater Miami area, our NRSA crew has been everywhere, man (cue Johnny Cash). For three months, personnel of the Freshwater Plants Research Program travelled all over Florida to sample a variety of unique ecosystems using multiple standardized sampling techniques. For shallow systems, like Pole Branch Creek in rural Calhoun County, our team of 5-7 samplers packed in all our gear and our backpack electrofishing unit and waded through the sites to complete our surveys. But for deeper and wider systems like the extensive Kissimmee River, we conducted our surveys via two boats loaded down with sampling equipment – one for our habitat crew, the other for our fish crew. On every system we recorded observations about habitat type and condition of the banks. We used specialized equipment and techniques to evaluate characteristics like slope, discharge and fish community assemblage. We also collected samples of water, algae, benthic macroinvertebrates, and fish tissue. All samples and data were recorded and sent to the U.S. Environmental Protection Agency (EPA) for analysis.

The National Rivers and Streams Assessment (NRSA) is a nationwide survey designed by the EPA that takes place in all lower 48 states. Rivers, streams and canals all over the country have been randomly selected for sampling. The resulting data provide an unbiased representation of our nation’s flowing waterways for comparing these systems with others in their region. This is part of a major ongoing effort by the EPA called the National Aquatic Resource Surveys. The purpose of these surveys is to assess the conditions of our nation’s waterbodies and to track them over time. NRSA is just one aspect of the big picture and takes place over two consecutive summers, occurring every 5 years. This season was the first of their 2018-19 sampling event.

As our season is wrapping up, we proudly look back at all we have learned, experienced, and accomplished this summer. This project has provided us the opportunity to use new tools and techniques, such as densiometers to measure canopy coverage and stadia rods or sonar to document channel depths and substrate type along thalwegs. It has also encouraged us to connect with other FWC offices, Water Management District personnel, and local land owners or managers. With the help of their local knowledge and expertise we have successfully completed half of the selected survey sites during this first year. We look forward to continuing this work next summer as we prepare to tackle the rest of our sites which include larger river ecosystems such as the Escambia and Apalachicola Rivers.

Our NRSA Sampling Crew included: Jamie Richardson, Kyle Miller, Emily McPartlin, Amanda Christensen (volunteer), Greg Knothe, Siobhan Gorham, & Craig Mallison. A special thanks to: Travis Tuten, John Knight, Kate Harriger, Chelsea Myles-McBurney, Kayla Smith, & Jason O’Connor for their assistance.

Assessing the Effects of the East Lake Tohopekaliga Littoral Habitat Restoration on Shallow Water Fish Communities

By Chris Anderson

East Lake Tohopekaliga (ELT) is a 4843-ha mesotrophic lake located in the Kissimmee Chain of Lakes in Osceola County. In the 1960s, water control structures and canals were constructed in the Kissimmee Chain for flood control. These structures stabilized water levels in ELT and the other lakes in the chain, reducing the magnitude of seasonal water level fluctuations. The water level stabilization eventually led to increased accumulation of organic material and excessive growth of invasive aquatic plants that contributed to an accelerated rate of lake succession in ELT. The vast monocultures of invasive aquatic vegetation (e.g., torpedograss Panicum repens and cattails Typha sp.) growing within the littoral zone created and trapped additional organic material and ultimately resulted in the formation and expansion of floating tussocks. Extremely dense vegetation and tussocks resulted in degraded fish and wildlife habitat and limited recreational access for homeowners, anglers and boaters.

Map of East Lake Tohopekaliga, St. Cloud, Florida, depicting the three treatment areas that will be restored and two unrestored control areas.

A lake drawdown and subsequent habitat restoration is set to begin on October 1, 2019. It will be a collaborative effort by FWC’s Aquatic Habitat Restoration/Enhancement subsection (habitat restoration), the South Florida Water Management District (water level regulation schedule changes), and the United States Army Corps of Engineers (overseeing drawdown). Once ELT has been dewatered, FWC biologists will utilize a combination of herbicide treatments and prescribed burning as well as mechanical removal of woody vegetation, tussocks and organic sediment to restore the littoral zone habitat (Figure 1). Herbicide treatments and prescribed burning will be used to control/remove monotypic stands of invasive vegetation (e.g., torpedograss and cattails) along the northern and western shores. Mechanical removal of woody vegetation (e.g., willows Salix sp. and water primrose Ludwigia spp.), tussocks and organic sediments will be completed along the eastern shore. Two areas along the southern shore will not receive any treatment and will be considered control areas. Once the habitat restoration is complete, ELT will be refilled via precipitation during the summer of 2020.

Fish captured in a mini-fyke net.

To evaluate the effects of the restoration, fisheries biologists are assessing potential changes in fish community composition, water quality, and habitat structure/composition in shallow (< 2 feet deep) littoral habitats pre- and post-restoration.  Researchers are deploying mini-fyke nets (MFNs) and dissolved oxygen (DO) logging sondes to sample the fish communities and DO regimes, respectively, in each treatment/control area (18 sites per area, 90 sites per year). Qualitative assessments of aquatic vegetation and quantitative assessments of organic sediment depth are also completed at each sampling site. Pre-restoration sampling will continue until the restoration begins in 2019 and post-restoration sampling will be conducted for at least two years after ELT has refilled.

Mini-fyke net and dissolved oxygen logger deployed in monotypic stand of torpedograss.

In 2016, the first year of pre-restoration sampling, a total of 4,847 fish comprising 26 species were captured across all successfully sampled sites (n = 88). Habitat data from 2016 indicated that the eastern shore (Mechanical Removal and Scraping area; Figure 1) had significantly deeper organic sediments and significantly lower aquatic plant density than the other four treatment/control areas of ELT. The second year of pre-restoration sampling was scheduled for 2017 but was cancelled because precipitation from Hurricane Irma resulted in water levels that were too high to effectively sample the littoral zone. Results from this study will help researchers and managers understand how habitat restorations influence shallow water fish communities, water quality, and habitat structure/composition. Understanding the effects that different restoration actions have on those parameters will provide managers with an idea of how future restorative efforts may influence the ecology of littoral habitats in lakes.

Wrapping Up the Statewide Reddish Egret Survey

By Andrew Cox

The reddish egret (Egretta rufescens) is North America’s rarest heron and is state-listed as Threatened in Florida. In 2016 we visited 305 coastal islands during the first statewide survey of the species to document its distribution, estimate Florida’s population size, and learn more about its nest-site selection patterns. In 2017 we attended to the less glamorous side of our work – sitting at our desks, crunching numbers and writing.

Reddish egrets were primarily concentrated in four areas of Florida: in and near Merritt Island National Wildlife Refuge, Florida Bay, the Lower Keys, and the Tampa Bay area south to Marco Island. The species has continued to slowly expand northward on the Gulf coast, with nesting occurring in Cedar Keys National Wildlife Refuge. There were an estimated 480 (95% CI: 375–606) nesting pairs at the 58 sites where birds we found birds. The largest colony we found had 23 nesting pairs, which is fewer than the three largest colonies documented in Florida Bay during 1978. Half of all colonies had 3 or fewer pairs.

Reddish egret foraging behavior can be something of a spectacle as birds move throughout tidal flats and other shallow estuarine waters in a graceful, high-energy pursuit of prey. Foraging habitat is probably the largest limiting factor for reddish egret populations, and our nest-site selection analysis confirmed that it was the most substantial predictor of occupancy and abundance of nesting reddish egrets. These results confirm the importance of incorporating foraging habitat into our restoration planning and highlight the need to understand how the shallow flats upon which reddish egrets rely will be affected by sea-level rise.

The photo accompanying this article was taken by Anne Macias. Anne was a retiree in Bonita Springs and a strong advocate for Florida’s birds. She took great pride in the colony of nesting wading birds in her neighborhood and raised awareness of their importance within her community. Our jobs are made that much easier by people like Anne. Anne unfortunately passed away earlier this year and will be deeply missed.