Florida red tide knowledge and risk perception: Is there a need for tailored messaging

Harmful algal blooms of the toxic dinoflagellate, Karenia brevis, occur throughout the Gulf of Mexico. Recent research efforts sponsored by the National Institute of Environmental Health Sciences (NIEHS) and others found that Florida red tide causes both acute and possibly chronic health effects from the toxic aerosols. Florida red tide also demonstrated significant social and economic impacts to both coastal residents and visitors. In conjunction with the research, persistent outreach efforts were conducted over the 11-year period. The goal of this project was to assess potential needs for tailored messaging needed among different red tide information user groups. Survey participants included 303 local residents, both with asthma and without, and ‘snowbirds (seasonal residents that reside in the Sarasota area for more than 3 months but less than 6 months/year), also both with asthma and without. The questionnaire assessed Florida red tide knowledge and risk perception regarding Florida red tide using items drawn from two previously published surveys to allow comparison. Our results reveal that overall knowledge of Florida red tide has not changed. We found that knowledge was consistent across our selected groups and also did not vary by age, gender and education level. However, knowledge regarding consumption of seafood during Florida red tide has declined. Risk perception increased significantly for people who have asthma. Individuals responsible for public health communication regarding Florida red tide and human health concerns need to continue to pursue more effective outreach messages and delivery methods.     

Severe Karenia brevis red tides influence juvenile bottlenose dolphin (Tursiops truncatus) behavior in Sarasota Bay,Florida

Harmful algal blooms (HABs) are natural stressors in the coastal environment that may be increasing in frequency and severity. This study investigates whether severe red tide blooms, caused by Karenia brevis, affect the behavior of resident coastal bottlenose dolphins in Sarasota Bay, Florida through changes to juvenile dolphin activity budgets, ranging patterns, and social associations. Behavioral observations were conducted on free‐ranging juvenile dolphins during the summer months of 2005–2007, and behavior during red tide blooms was compared to periods of background K. brevis abundance. We also utilized dolphin group sighting data from 2004 to 2007 to obtain comparison information from before the most severe recent red tide of 2005 and incorporate social association information from adults in the study area. We found that coastal dolphins displayed a suite of behavioral changes associated with red tide blooms, including significantly altered activity budgets, increased sociality, and expanded ranging behavior. At present, we do not fully understand the mechanism behind these red tide‐associated behavioral effects, but they are most likely linked to underlying changes in resource availability and distribution. These behavioral changes have implications for more widespread population impacts, including increased susceptibility to disease outbreaks, which may contribute to unusual mortality events during HABs.     

Environmental exposures to Florida red tides: Effects on emergency room respiratory diagnoses admissions

Human exposure to Florida red tides formed by Karenia brevis, occurs from eating contaminated shellfish and inhaling aerosolized brevetoxins. Recent studies have documented acute symptom changes and pulmonary function responses after inhalation of the toxic aerosols, particularly among asthmatics. These findings suggest that there are increases in medical care facility visits for respiratory complaints and for exacerbations of underlying respiratory diseases associated with the occurrence of Florida red tides.This study examined whether the presence of a Florida red tide affected the rates of admission with a respiratory diagnosis to a hospital emergency room in Sarasota, FL. The rate of respiratory diagnoses admissions were compared for a 3-month time period when there was an onshore red tide in 2001 (red tide period) and during the same 3-month period in 2002 when no red tide bloom occurred (non-red tide period). There was no significant increase in the total number of respiratory admissions between the two time periods. However, there was a 19% increase in the rate of pneumonia cases diagnosed during the red tide period compared with the non-red tide period. We categorized home residence zip codes as coastal (within 1.6 km from the shore) or inland (>1.6 km from shore). Compared with the non-red tide period, the coastal residents had a significantly higher (54%) rate of respiratory diagnoses admissions than during the red tide period. We then divided the diagnoses into subcategories (i.e. pneumonia, bronchitis, asthma, and upper airway disease). When compared with the non-red tide period, the coastal zip codes had increases in the rates of admission of each of the subcategories during the red tide period (i.e. 31, 56, 44, and 64%, respectively). This increase was not observed seen in the inland zip codes.These results suggest that the healthcare community has a significant burden from patients, particularly those who live along the coast, needing emergency medical care for both acute and potentially chronic respiratory illnesses during red tide blooms.     

Historical perspective on Karenia brevis red tide research in the Gulf of Mexico

Research on Karenia brevis blooms in the Gulf of Mexico started with the 1946–1947 red tide along the Florida west coast. Early research was on the organism itself, its tolerances and requirements, and the environment in which it lived and grew. Control of blooms, as a management option, was pursued in the 1950s with little success. However, in the 1960s–1970s, new regulation of shellfish growing areas was a public health management success. Research on K. brevis blooms followed funding cycles and was sporadic until the late 1990s when the National Oceanic and Atmospheric Administration (NOAA) and the Environmental Protection Agency (EPA) funded the Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) and NOAA Monitoring and Event Response of Harmful Algal Blooms (MERHAB) programs. These particular funding programs, augmented by State of Florida appropriations, provided the opportunity to study K. brevis blooms on different temporal-spatial scales and consequently advanced the science. This review looks at historical research results in the light of today's advances.     

An epizootic of waterfowl associated with a red tide episode in Florida

During February and March, 1974, an epizootic involving lesser scaup (Aythya affinis) occurred in the Tampa Bay area on the west coast of Florida. Several thousand ducks are estimated to have died. Concurrent with this epizootic was a red tide caused by heavy blooms of the toxic dinoflagellate Gymnodinium breve intoxication were evident in some of the lesser scaup. A controlled experimental feeding of G. breve toxic material to White Pekin ducklings produced illness and death with signs comparable to some of those seen in the scaup.     

Lacaziosis and lacaziosis-like prevalence among wild, common bottlenose dolphins Tursiops truncatus from the west coast of Florida, USA

Lacaziosis (lobomycosis; Lacazia loboi) is a fungal skin disease that naturally occurs only in humans and dolphins. The first reported case of lacaziosis in a bottlenose dolphin Tursiops truncatus occurred in 1970 in Sarasota Bay, Florida, USA, and subsequent photo-ID monitoring of the Sarasota Bay dolphin population has revealed persistence of the disease. The objectives of this study were to estimate lacaziosis prevalence (P) in 2 bottlenose dolphin populations on the west coast of Florida (Sarasota Bay and Charlotte Harbor) and compare disease occurrence to other published estimates of lacaziosis in dolphin populations across the globe. Historic photographic records of dolphins captured and released for health assessment purposes (Sarasota Bay) and photo-ID studies (Charlotte Harbor) were screened for evidence of lesions consistent with lacaziosis. Health assessment data revealed a prevalence of lacaziosis in the Sarasota Bay bottlenose dolphin population between 2 and 3%, and analyses of photo-ID data provided a lacaziosis-like prevalence estimate of 2% for Charlotte Harbor dolphins. With the exception of lacaziosis prevalence estimates for dolphins inhabiting the Indian River Lagoon (P = 0.068; P = 0.12), no statistically significant differences were seen among Sarasota Bay, Charlotte Harbor, and other published estimates. Although lacaziosis is a rare disease among these dolphin populations, studies that assess disease burden among different populations can assist with the surveillance of this zoonotic pathogen.     

Review of Florida Red Tide and Human Health Effects

This paper reviews the literature describing research performed over the past decade on the known and possible exposures and human health effects associated with Florida red tides. These harmful algal blooms are caused by the dinoflagellate, Karenia brevis, and similar organisms, all of which produce a suite of natural toxins known as brevetoxins. Florida red tide research has benefited from a consistently funded, long term research program, that has allowed an interdisciplinary team of researchers to focus their attention on this specific environmental issue-one that is critically important to Gulf of Mexico and other coastal communities. This long-term interdisciplinary approach has allowed the team to engage the local community, identify measures to protect public health, take emerging technologies into the field, forge advances in natural products chemistry, and develop a valuable pharmaceutical product. The Review includes a brief discussion of the Florida red tide organisms and their toxins, and then focuses on the effects of these toxins on animals and humans, including how these effects predict what we might expect to see in exposed people.     

Florida red tide and brevetoxins: Association and exposure in live resident bottlenose dolphins (Tursiops truncatus) in the eastern Gulf of Mexico,U.S.A.

Bottlenose dolphins (Tursiops truncatus) along the Gulf of Mexico are frequently exposed to blooms of the toxic alga, Karenia brevis, and brevetoxins associated with these blooms have been implicated in several dolphin mortality events. Studies on brevetoxin accumulation in dolphins have typically focused on analyses of carcasses from large‐scale die‐offs; however, data are scarce for brevetoxin loads in live individuals frequently exposed to K. brevis blooms. This study investigated in vivo brevetoxin exposure in free‐ranging bottlenose dolphins resident to Sarasota Bay, Florida, utilizing samples collected during health assessments performed during multiple K. brevis blooms occurring from 2003 to 2005. Brevetoxins were detected by ELISA and LC‐MS in 63% of bottlenose dolphins sampled (n= 30) concurrently with a K. brevis bloom. Brevetoxins were present in urine and gastric samples at concentrations ranging from 2 to 9 ng PbTx‐3 eq/g, and in feces at concentrations ranging from 45 to 231 ng PbTx‐3 eq/g. Samples from individuals (n= 12) sampled during nonbloom conditions (≤1,000 cells/L) were negative for brevetoxin activity. Brevetoxin accumulation data from this study complement dolphin carcass and prey fish data from the same study area, and aid in evaluating impacts of harmful algal blooms on sentinel marine animal species along the west Florida coast.     

Karenia brevis red tides,brevetoxins in the food web,and impacts on natural resources: Decadal advancements

As recently as a decade ago, Karenia brevis red tides and their effects on animal resources in the Gulf of Mexico were principally perceived as acute blooms that caused massive fish kills. Although occasional mortalities of higher vertebrates were documented, it has only been in the past decade that conclusive evidence has unequivocally demonstrated that red tides and their brevetoxins are lethal to these organisms. Brevetoxins can be transferred through the food chain and are accumulated in or transferred by biota at many trophic levels. The trophic transfer of brevetoxins in the food web is a complex phenomenon, one that is far more complicated than originally conceived. Unexplained fish kills and other animal mortalities in areas where red tide is endemic are being increasingly linked with post-bloom exposures of biota to brevetoxins. Mass mortality events of endangered Florida manatees (Trichechus manatus latirostris) follow a consistent spatial and temporal pattern, occurring primarily in the spring in southwestern Florida. Persistent blooms can also cause a cascade of environmental changes, affecting the ecosystem and causing widespread die-offs of benthic communities. Ongoing fish kills from sustained blooms can lead to short-term declines in local populations. Although animal populations in areas where red tide is endemic are unquestionably at risk, it remains to be determined to what extent populations can continue to recover from these sustained effects.     

Why no red tide was observed on the West Florida Continental Shelf in 2010

Over the past two decades, the two most anomalous years for water properties on the west Florida continental shelf were 1998 and 2010. In both instances, the shelf was ventilated by relatively cold, nutrient-rich waters of deep ocean origin, which reset the background state underlying shelf ecology. The ventilation in both of these years derived from prolonged interactions of the Gulf of Mexico Loop Current with the shelf slope near the Dry Tortugas located on the southwest corner of the shelf. By contacting relatively shallow isobaths, the boundary current interactions there set the entire shelf into motion, facilitating upwelling across the shelf break, even to DeSoto Canyon some 500 km away, and then across the shelf to the near shore. Such prolonged and intense upwelling of nutrient-rich water in 2010 contrasted with the more typically occurring locally wind driven upwelling conditions, whereby waters upwelled at the near shore are from the inner shelf, versus the deep ocean. Thus not all upwelling scenarios have similar consequences. Whereas the typical wind driven upwelling scenario is necessary for Karenia brevis red tide blooms to manifest along the coastline, the rarer, deep ocean induced upwelling scenario (as occurred in 1998 and particularly in 2010) acts to suppress K. brevis red tides because of the elevated inorganic nutrient conditions that they facilitate. Hence, minimal cell counts above background were observed in 1998, and no cell counts above background were observed in 2010. We conclude that the lack of red tide along the west coast of Florida in 2010 was due to anomalously large and protracted upwelling of nutrient-rich waters of deep ocean origin caused by Loop Current and eddy interactions with the shelf slope.     

Predictive Ecological Modeling of Harmful Algal Blooms

We have thus far constructed a series of coupled ecological/physical models to predict the origin and fate of harmful algal blooms of the toxic dinoflagellate, Gymnodinium breve, on the West Florida shelf. We find that (1) the maximal population growth rate of G. breve must be ～0.80 day^?1 during initiation of a red tide, but as little as 0.08 day^?1 during its decay, (2) diatoms dominate when estuarine and shelf-break supplies of nitrate are made available to a model community of small and large diatoms, coccoid cyanophytes and Trichodesmium, non-toxic and red-tide dinoflagellates, microflagellates, and coccolithophores, (3) a numerical recipe for large red tides of G. breve requires DON supplies, mediated by iron-starved, nitrogen-fixers, while small blooms may persist on sediment sources of DON, (4) selective grazing must be exerted on the non-toxic dinoflagellates, and (5) vertical migration of G. breve in relation to seasonal changes of summer downwelling and fall/winter upwelling flow fields determines the duration and intensity of red tide landfalls along the barrier islands and beaches of the west coast of Florida, once other losses are specified. Given poorly known initial and boundary conditions and the expense of shipboard monitoring programs, however, bio-optical moorings or remote sensors are the most likely sources of model validation and improved HAB forecasts. Accordingly, the bio-optical implications of our ecological models must be included in future simulation analyses of HABs on both the West Florida shelf and within other coastal regions. Of particular importance for initiation of the coupled biophysical models is an improved understanding of the relationship of remotely sensed surface signals to shade-adapted dinoflagellates, aggregating below the first optical depth of the water column.     

REPRODUCTION IN FEMALE MANATEES OBSERVED IN SARASOTA BAY, FLORIDA

Resightings of recognizable individual Florida manatees, Trichechus manatus latirostris , in Sarasota Bay provided information on life history and reproductive parameters. These parameters have been documented at winter aggregation sites, but few data existed for Florida's west coast at non-winter sites. Life history data are needed to estimate annual reproduction and survival rates and construct population models for manatees along west central Florida. Observations of 113 recognizable manatees of known sex sighted between 1993 and 1997 indicated a 1: 1 sex ratio. Fifty-three females produced at least 55 calves during five years of observation. Two large, presumably sexually mature females were never observed with calves in over five years of monitoring. Not surprisingly, several reproductive parameters matched those measured in previous studies at winter sites with a mean of 1.8 seasons of calf dependence, 2.2 seasons between births, and age of sexual maturity at 3–4 yr. Birth rates, fecundity, and proportions of females with calves varied only slightly among investigations.     

Brevetoxin exposure,superoxide dismutase activity and plasma protein electrophoretic profiles in wild-caught Kemp's ridley sea turtles (Lepidochelys kempii) in southwest Florida

Because of their vulnerable population status, assessing exposure levels and impacts of toxins on the health status of Gulf of Mexico marine turtle populations is critical. From 2011 to 2013, two large blooms of the red tide dinoflagellate, Karenia brevis, occurred along the west coast of Florida USA (from October 2011 to January 2012 and October 2012 to April 2013). Other than recovery of stranded individuals, it is unknown how harmful algal blooms affected the Kemp's ridley sea turtles (Lepidochelys kempii) inhabiting the affected coastal waters. It is essential to gather information regarding brevetoxin exposure in these turtles to determine if it poses a threat to marine turtle health and survival. From April 2012 to May 2013, we collected blood from 13 immature Kemp's ridley turtles captured in the Pine Island Sound region of the Charlotte Harbor estuary. Nine turtles were sampled immediately after or during the red tide events (bloom group) while four turtles were sampled between the events (non-bloom group). Plasma was analyzed for total brevetoxins (reported as ng PbTx-3 eq/mL), superoxide dismutase (SOD) activity, total protein concentration and protein electrophoretic profiles (albumin, alpha-, beta- and gamma-globulins). Brevetoxin concentrations ranged from 7.0 to 33.8 ng PbTx-3 eq/mL. Plasma brevetoxin concentrations in the nine turtles sampled during or immediately after the red tide events were significantly higher (by 59%, P = 0.04) than turtles sampled between events. No significant correlations were observed between plasma brevetoxin concentrations and plasma proteins or SOD activity, most likely due to the small sample size; however alpha-globulins tended to increase with increasing brevetoxin concentrations in the bloom group. Smaller (carapace length and mass) bloom turtles had higher plasma brevetoxin concentrations than larger bloom turtles, possibly due to a growth dilution effect with increasing size. The research presented here improves the current understanding of potential impacts of environmental brevetoxin exposure on marine turtle health and survival.     

Karenia brevis causes high mortality and impaired swimming behavior of Florida stone crab larvae

The dinoflagellate Karenia brevis causes harmful algal blooms commonly referred to as red tides that are prevalent along Florida’s gulf coast. Severe blooms often cause fish kills, turbid water, and hypoxic events all of which can negatively impact local fisheries. The stone crab, Menippe mercenaria, is a ˜$25 million per year fishery that occurs primarily along Florida’s gulf coast. On the west Florida shelf, red tides occur from fall through spring, although severe blooms can occur during the summer. During the summer, stone crabs are reproductive and release larvae that are transported offshore where K. brevis blooms originate. This study determined the effects of K. brevis exposure on the survivorship, vertical swimming behavior, and oxygen consumption of stage-1 larval stone crabs. Survivorship was determined by exposing larvae to high (> 1 × 10⁶ cells L⁻¹) and medium (˜1 × 10⁵ cells L⁻¹) K. brevis concentrations for 96-hrs and were compared to controls that had no algae present. Larval swimming behavior (i.e., geotaxis) and oxygen consumption were monitored after 6-hr exposure to K. brevis. After 96-hrs of exposure, mortality was 100% and 30% for larvae in the high and medium concentrations of K. brevis, respectively, relative to the control. Larval swimming behavior was reversed in the K. brevis treatment; however oxygen consumption rates did not differ among treatments. These results suggest that severe blooms during the summer may reduce larval supply and serve as a potential bottleneck for new individuals recruiting into the fishery in years following a K. brevis bloom.     

Chloroplast and microsatellite DNA diversities reveal the introduction history of Brazilian peppertree (Schinus terebinthifolius) in Florida

Brazilian peppertree (Schinus terebinthifolius) is a woody perennial that has invaded much of Florida. This native of northeastern Argentina, Paraguay, and Brazil was brought as an ornamental to both the west and east coasts of Florida at the end of the 19th century. It was recorded as an invader of natural areas in the 1950s, and has since extended its range to cover over 280 000 ha. Our goals were to understand the history of this invasion, as one step toward understanding why this exotic was so successful, and ultimately to improve development of biological control agents. We sampled plants from the native and exotic ranges, particularly Florida, and genotyped these individuals at nuclear and chloroplast loci. Nuclear microsatellite and cpDNA loci reveal strong genetic population structure consistent with limited dispersal in the introduced and native ranges. Bayesian clustering of microsatellite data separates the east and west coast plants in Florida into distinct populations. The two chloroplast haplotypes found in Florida are also concordant with this separation: one predominates on the east coast, the other on the west coast. Analysis of samples collected in South America shows that haplotypes as distinct as the two in Florida are unlikely to have come from a single source population. We conclude that the genetic evidence supports two introductions of Brazilian peppertree into Florida and extensive hybridization between them. The west coast genotype likely came from coastal Brazil at about 27 degrees south, whereas the east coast genotype probably originated from another, as yet unidentified site. As a result of hybridization, the Florida population does not exhibit low genetic variation compared to populations in the native range, possibly increasing its ability to adapt to novel environments. Hybridization also has important consequences for the selection of biocontrol agents since it will not be possible to identify closely co-adapted natural enemies in the native range, necessitating more extensive host testing.     

Vulnerability and resilience of seagrasses to hurricane and runoff impacts along Florida’s west coast

Many climate change models predict increasing frequency and severity of tropical cyclones (hurricanes) in the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. To assess this potential threat to seagrass communities in Florida’s Big Bend region, we performed a habitat change analysis based on aerial seagrass surveys performed prior to, and after, the extremely active Atlantic cyclone seasons of 2004 and 2005. To provide a regional context for changes in the Big Bend region, we also compared impacts there with changes in three other West Florida estuaries. Our analysis showed that storm impacts on seagrasses varied along Florida’s west coast. Physical disturbance caused minor losses in parts of Charlotte Harbor and the Big Bend region. However, heavy rainfall in Florida and Georgia associated with Frances and Jeanne combined with winter rains to cause complete loss of 1,500 ha of seagrasses and thinning of another 1,700 ha in the vicinity of the Suwannee River mouth. In Tampa Bay, Sarasota Bay, and Charlotte Harbor, despite localized losses, total seagrass area actually increased between 2004 and 2006. On the other hand, Tampa Bay, Sarasota Bay, and Charlotte Harbor all showed significant, and more pronounced, declines in seagrass cover as the result of another major rainfall and runoff event: the 1997–1998 El Nino event. Our results indicate that light stress, likely caused by suspended sediments, phytoplankton blooms, and dissolved organic matter, resulted in seagrass losses extending up to 40 km from the mouth of the Suwannee River. We conclude that water quality impacts, especially if they are persistent, can be more damaging than physical impacts of moderate (Category 1–3) tropical cyclones. We also conclude that runoff-related impacts on seagrasses vary depending on the timing, volume, and persistence of storm runoff in relation to normal seasonal runoff patterns and seagrass growth in each estuary.     

Firm-level economic effects of HABS: A tool for business loss assessment

While the economic consequences of HABs may seem obvious, there is little empirical evidence to support the assertion or its magnitude relative to other environmental effects. As scientists learn more about the effectiveness of alternative HAB prevention, mitigation, and control strategies and agencies prepare for a suite of environmental events, information on potential economic losses are needed at the firm level to evaluate and justify continued HAB-related expenditures. To determine the extent of monetary losses that some firms may have incurred due to blooms of Karenia brevis (red tides) in Southwest Florida, 7 years of daily proprietary data were obtained from three beachfront restaurants and supplemented with environmental data from nearby weather stations. The statistical models revealed that reductions in daily sales ranged from $868 to $3734 (13.7%–15.3% on average) when red tide conditions were present. Estimated losses are compared to other environmental events and were found to coincide with those from other studies. The incidence of red tide events (as noted by each restaurant manager) corresponded with cell counts that averaged 180,853 cells/l as measured within 6 miles. Collectively this information supports the hypothesis of localized economic losses and provides a threshold cell count for future loss projections.     

Recreational exposure to aerosolized brevetoxins during Florida red tide events

During two separate Karenia brevis red tide events, we measured the levels of brevetoxins in air and water samples, conducted personal interviews, and performed pulmonary function tests on people before and after they visited one of two Florida beaches. One hundred and twenty-nine people participated in the study, which we conducted during red tide events in Sarasota and Jacksonville, FL, USA. Exposure was categorized into three levels: low/no exposure, moderate exposure, and high exposure. Lower respiratory symptoms (e.g. wheezing) were reported by 8% of unexposed people, 11% of the moderately exposed people, and 28% of the highly exposed people. We performed nasal–pharyngeal swabs on people who experienced moderate or high exposure, and we found an inflammatory response in over 33% of these participants. We did not find any clinically significant changes in pulmonary function test results; however, the study population was small. In future epidemiologic studies, we plan to further investigate the human health impact of inhaled brevetoxins.     

Monitoring Karenia brevis blooms in the Gulf of Mexico using satellite ocean color imagery and other data

Harmful algal blooms (HABs) of Karenia brevis are a recurrent problem in the Gulf of Mexico, with nearly annual occurrences on the Florida southwest coast, and fewer occurrences on the northwest Florida and Texas coasts. Beginning in 1999, the National Oceanic and Atmospheric Administration has issued the Gulf of Mexico HAB Bulletins to support state monitoring and management efforts. These bulletins involve analysis of satellite imagery with field and meteorological station data. The effort involves several components or models: (a) monitoring the movement of an algal bloom that has previously been identified as a HAB (type 1 forecast); (b) detecting new blooms as HAB or non-HAB (type 2); (c) predicting the movement of an identified HAB (type 3); (d) predicting conditions favorable for a HAB to occur where blooms have not yet been observed (type 4). The types 1 and 2 involve methods of bloom detection requiring routine remote sensing, especially satellite ocean color imagery and in situ data. Prediction (types 3 and 4) builds on the monitoring capability by using interpretative and numerical modeling. Successful forecasts cover more than 1000 km of coast and require routine input of remotely sensed and in situ data.The data sources used in this effort include ocean color imagery from the Sea-Viewing Wide Field-of-View Sensor/OrbView-2 satellite and processed using coastal-specific algorithms, wind data from coastal and offshore buoys, field observations of bloom location and intensity provided by state agencies, and forecasts from the National Weather Service. The HAB Bulletins began in coordination with the state of Florida in autumn of 1999 and included K. brevis bloom monitoring (type 1), with limited advisories on transport (type 3) and the detection of blooms in new areas (type 2). In autumn 2000, we improved both the transport forecasts and detection capabilities and began prediction of conditions favorable for bloom development (type 4). The HAB Bulletins have had several successes. The state of Florida was advised of the potential for a bloom to occur at the end of September 2000 (type 4), and the state was alerted to the position of blooms in January 2000 and October 2001 in areas that had not been previously sampled (type 3). These successful communications of HAB activity allowed Florida agencies responsible for shellfish management and public health to respond to a rapidly developing event in a timely, efficient manner.     

Fish Sound Production in the Presence of Harmful Algal Blooms in the Eastern Gulf of Mexico

This paper presents the first known research to examine sound production by fishes during harmful algal blooms (HABs). Most fish sound production is species-specific and repetitive, enabling passive acoustic monitoring to identify the distribution and behavior of soniferous species. Autonomous gliders that collect passive acoustic data and environmental data concurrently can be used to establish the oceanographic conditions surrounding sound-producing organisms. Three passive acoustic glider missions were conducted off west-central Florida in October 2011, and September and October 2012. The deployment period for two missions was dictated by the presence of red tide events with the glider path specifically set to encounter toxic Karenia brevis blooms (a.k.a red tides). Oceanographic conditions measured by the glider were significantly correlated to the variation in sounds from six known or suspected species of fish across the three missions with depth consistently being the most significant factor. At the time and space scales of this study, there was no detectable effect of red tide on sound production. Sounds were still recorded within red tide-affected waters from species with overlapping depth ranges. These results suggest that the fishes studied here did not alter their sound production nor migrate out of red tide-affected areas. Although these results are preliminary because of the limited measurements, the data and methods presented here provide a proof of principle and could serve as protocol for future studies on the effects of algal blooms on the behavior of soniferous fishes. To fully capture the effects of episodic events, we suggest that stationary or vertically profiling acoustic recorders and environmental sampling be used as a complement to glider measurements.