Florida Fish Research Articles

Distribution and Abundance of Introduced Fishes in Florida's Charlotte Harbor Estuary

A growing number of non-native fishes have been introduced into Florida waters in recent years, yet little information has been available on their distribution and abundance in southwest Florida. The ichthyofauna of the Charlotte Harbor estuary, Florida, was intensively sampled from 1989 through 2007. We collected eight introduced fish taxa: African jewelfish (Hemichromis letourneuxi), blue tilapia (Oreochromis aureus), brown hoplo (Hoplosternum littorale), grass carp (Ctenopharyngodon idella), Mayan cichlid (Cichlasoma urophthalmus), sailfin catfishes (Pterygoplichthys spp.), spotted tilapia (Tilapia mariae), and walking catfish (Clarias batrachus). These fishes were found principally in tidal rivers, especially the Caloosahatchee River. Other introduced species, such as Asian swamp eel (Monopterus albus), blackchin tilapia (Sarotherodon melanotheron), and pike killifish (Belonesox belizanus), are known to occur in neighboring bay systems but have yet to be reported in the Charlotte Harbor estuary. Continued monitoring will help us detect additional species that are introduced to the estuary, expansions in the ranges of documented species, and assemblage-level changes.

Shallow water acoustic propagation in West Indian manatee habitats.

As part of the Manatee Avoidance Technology program of the Florida Fish and Wildlife Conservation Commission, several experiments were conducted between the years 2004 and 2008 in the coastal waters of Florida within typical West Indian manatee (Trichechus manatus latirostris) habitats. The primary purpose of these experiments was to evaluate several vocalization enhancement and noise suppression algorithms. Most of the experiments were conducted in brackish waters having depths less than 30 ft with silt and grassy seabeds. The analysis of the data collected during these experiments revealed certain phenomena pertinent to manatee communication. This talk will focus on the acoustic propagation characteristics observed at these manatee habitats. More specifically, the repetitive loud and fading patterns due to Lloyd’s mirror effect measured from opportunistic sources and the results of controlled transmission loss experiments will be detailed. The effects of such phenomena on manatee communication will be d...

Mercury contamination in spotted seatrout, Cynoscion nebulosus: An assessment of liver, kidney, blood, and nervous system health

Marine fishes in South Florida (Florida Keys–Florida Bay–Everglades region) accumulate higher concentrations of mercury (Hg) in their tissues than similar fishes from other areas of the southeastern U.S., though it is not known whether these elevated levels affect fish health. In this study, we used quantifiable pathological and biochemical indicators to explore Hg-associated differences in marine fish from South Florida, where Hg contamination is high, and from Indian River Lagoon, Florida, which served as a reference area. Hg concentrations in all tissues of mature spotted seatrout ( Cynoscion nebulosus) from South Florida were significantly higher than those from Indian River Lagoon and were within the threshold range of those in studies where effects of Hg exposure have been observed. The distribution of Hg among tissues followed the same trend in both areas, with the greatest concentration in kidney tissue, followed by liver, muscle, brain, gonad, and red blood cells. Blood-plasma biochemistry showed that concentrations of iron, inorganic phosphate, lactate dehydrogenase, and aspartate aminotransferase were significantly less in South Florida. Also, fructosamine and alkaline phosphatase were significantly less in South Florida. Liver histology revealed that pyknosis/necrosis, interstitial inflammation, and bile duct hyperplasia were found only in seatrout from South Florida, and steatosis/glycogen was more frequently found in Indian River Lagoon specimens. In renal tissue, interstitial inflammation, glomerular dilatation and thickening, and tubular degeneration and necrosis were more frequently found in South Florida specimens. Changes in the liver cytoskeleton and morphology may explain some of the differences in blood parameters between study areas. Neurochemical analyses showed that brain N-methyl- d-aspartic acid (NMDA) receptors (but not those of muscarinic cholinergic receptors, monoamine oxidase, or acetylcholinesterase) were significantly less in fish from South Florida than from Indian River Lagoon. These findings provide compelling evidence that elevated Hg could cause quantifiable pathological and biochemical changes that might influence the health of spotted seatrout and could also affect other marine fish species.

A History of Florida's Fish and Wildlife Research Institute

A History of Florida's Fish and Wildlife Research Institute

Survival Time Analysis of Least Killifish (Heterandria formosa) and Mosquitofish (Gambusia affinis) in Acute Exposures to Endosulfan Sulfate

Single-species flow-through toxicity tests were conducted to determine the times-to-death of two indigenous fish to South Florida--least killifish (Heterandria formosa) and mosquitofish (Gambusia affinis)--from acute exposure to endosulfan sulfate. Mortalities were recorded within 8-h periods from test initiation to termination at 96 h. The 96-h LC(50)s for least killifish and mosquitofish estimated using the trimmed-Spearman-Karber method were 2.0 and 2.3 microg/l, respectively. An accelerated failure time model was used to estimate times to death at selected concentrations. Data were fit to log-normal, log-logistic, and Weibull distributions. Acute toxicity data fit to the Weibull distribution produced a better relative fit than log-normal or log-logistic distributions for both toxicity tests. The survival-time profiles and associated statistics illustrate the benefit of considering exposure duration as well as concentration when predicting acute risk to species' populations. Both toxicity tests had similar outcomes from exposure to endosulfan sulfate, with least killifish being slightly more likely to die at lower concentrations and shorter time periods than mosquitofish. From the models generated by the toxicity tests, times-to-death for least killifish and mosquitofish were estimated for environmentally relevant concentrations of total endosulfan at a site of concern in South Florida. When the results from the current toxicity tests were compared to environmental concentrations from previous screening-level ecological risk assessments, the durations necessary to potentially kill 10% or more of the populations of the two native south Florida fish species were estimated to be 77 and 96 h for least killifish and mosquitofish, respectively. However, the exposure values included the alpha and beta isomers as well as endosulfan sulfate; therefore, an understanding of their toxicity might be important in understanding the survival dynamics of fish species in endosulfan sulfate-contaminated sites.

Postmortem Length Changes in Six Florida Fish Species Stored on Ice

AbstractRepresentatives of six species of fishes belonging to the families Lutjanidae, Centropomidae, Pomatomidae, Scombridae, Carangidae, and Sciaenidae were stored on ice for 6 h after being euthanatized, in order to assess postmortem length changes. Standard length, fork length (where applicable), total length using the relaxed caudal fin method, and rigor mortis were measured immediately after deaths and at 30 min intervals thereafter. Two species, lane snapper Lutjanus synagris and common snook Centropomus undecimalis, showed an increase in mean total lengths during the first hour after death. Common snook continued to increase in mean total length for the duration of the study, while lane snapper subsequently decreased. Declines in mean standard, fork, and total lengths also were observed in bluefish Pomatomus saltatrix, Spanish mackerel Scomberomorus maculatus, and Florida pompano Trachinotus carolinus. Minimal changes in mean standard and total length were observed for spotted seatrout Cynoscion nebulosus. There was little direct correlation between rigor mortis and length variation for any of the studied species. The observed length changes may have implications for both law enforcement personnel and anglers.

Determining electric fishing sample size for monitoring fish communities in three Florida lakes

Fisheries Management and EcologyVolume 16, Issue 5 p. 409-412 Determining electric fishing sample size for monitoring fish communities in three Florida lakes K. I. BONVECHIO, K. I. BONVECHIOSearch for more papers by this authorM. J. CATALANO, M. J. CATALANOSearch for more papers by this authorR. E. SAWYERS, R. E. SAWYERSSearch for more papers by this authorS. CRAWFORD, S. CRAWFORDSearch for more papers by this author K. I. BONVECHIO, K. I. BONVECHIOSearch for more papers by this authorM. J. CATALANO, M. J. CATALANOSearch for more papers by this authorR. E. SAWYERS, R. E. SAWYERSSearch for more papers by this authorS. CRAWFORD, S. CRAWFORDSearch for more papers by this author First published: 10 September 2009 https://doi.org/10.1111/j.1365-2400.2009.00681.xCitations: 7 Kimberly I. Bonvechio, Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, 601 W. Woodward Ave., Eustis, FL 32726, USA (e-mail: kim.bonvechio@myfwc.com) Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume16, Issue5October 2009Pages 409-412 RelatedInformation

Low-Head Saltwater Recirculating Aquaculture Systems Utilized for Juvenile Red Drum Production

The USDA Agricultural Research Service and the Harbor Branch Oceanographic Institute - Florida Atlantic University (HBOI-FAU) Center for Aquaculture and Stock Enhancement are collaborating to evaluate low-head recirculating aquaculture system (RAS) designs for inland low salinity aquaculture production of marine finfish. As part of this project, the systems described were utilized to intensively produce red drum (Sciaenops ocellatus) juveniles that would be part of the Florida Fish and Wildlife Conservation Commission's (FWC) Saltwater Hatchery Network Initiative. The design and performance data collected from these systems will be utilized in the engineering and determination of design costs for a statewide public-private saltwater hatchery network. The current low-head RAS design that was evaluated for the Phase I (25 mm to 60 mm standard length, SL) through Phase II (60 mm to > 100 mm SL) production of red drum juveniles included a nine-tank system and a ten-tank system. Tank diameters were 1.5 m with a water depth of approximately 1.0 m. Mechanical and biological filtration mechanisms included polygeyser filters, sand filters, moving bed torrus filters, and filter pads. For the Phase II to Phase III (100 to 180 mm SL) production, the red drum juveniles were cultured in four larger-scale replicated RAS low-head systems. Mechanical and biological filtration mechanisms in these systems included moving bed torrus filters, long-flow pathway moving media bed filters, and rotary micron screen drum filters, along with supplemental liquid oxygen addition. The systems presented indicate that intensive inland culture of marine species for commercial aquaculture production or stock enhancement purposes is possible even under the technical constraints of low-head system operation.

Permits and Regulatory Requirements

Journal of Contemporary Water Research & EducationVolume 132, Issue 1 p. 19-26 Free Access Permits and Regulatory Requirements Tamim Younos, Tamim Younos Virginia Polytectnic Institute and State UniversitySearch for more papers by this author Tamim Younos, Tamim Younos Virginia Polytectnic Institute and State UniversitySearch for more papers by this author First published: 01 May 2009 https://doi.org/10.1111/j.1936-704X.2005.mp132001004.xCitations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat References California Coastal Act (CCA). 1976. California Coastal Commission. http://www.coastal.ca.gov/ccatc.html California Environmental Quality Act. 2003 (CEQA). http://www.capital.ucla.edu/ep-ceqa.html Desalination in Florida and Worldwide. 1999. http://www2.hawaii.edu/~nabil/desaltbk.htm. Desalination Task Force. 2003. – Desalination Issues Assessment Report. Prepared by the Center for Collaborative Policy, California State University , Sacramento , CA . 52 pp. http://www.owue.water.ca.gov/recycle/desal/Docs/IAR.pdf Desalination Task Force. 2003 – Draft Final Report. California Department of Water Resources , Sacramento , CA . 63 pp. http://www.owue.water.ca.gov/recycle/desal/Docs/FinalReport.htm DOE Environmental Policy and Guidance. Resource Conservation and Recovery Act (RCRA). http://www.eh.doe.gov/oepa/laws/rcra.html Florida Department of Environmental Protection. http://www.dep.state.fl.us/law/ Florida Fish and Wildlife Conservation Commission. http://www.floridaconservation.org/ Lawson, L.G. 2004. Toxics Management Program Implementation Guide. Guidance Memo No. 00-2012 . Office of Water Permit Program, Division of Water Permit Coordination. Virginia Department of Environmental Quality , Richmond , Virginia . http://www.deq.virginia.gov/waterguidance/pdf/042012.pdf. (January 2005). LBG-GUYTON Associates. 2003. Brackish Groundwater Manual for Texas Regional Water Planning Groups. Prepared for Texas Water Development Board. 160 pp. McFarland, E.R., 2000, Computer model aids management of ground water resources in eastern Virginia [abs.]: in 1999 Proceedings of the Virginia Water Research Symposium - Integrating Science into the Development and Implementation of Effective Water Resource Policies, Richmond, Virginia. Virginia Water Resources Research Center, Virginia Tech , Blacksburg , VA . p. 146. National Pollution Discharge Elimination System (U.S. EPA) http://cfpub.epa.gov/npdes/ R. W. Beck, Inc. 2004. Guidance Manual for Permitting Requirements in Texas for Desalination Facilities Using Reverse Osmosis Processes. Prepared for the Texas Water Development Board. http://www.twdb.state.tx.us/RWPG/rpgm_rpts/2003483509.pdf The Clean Water Act. http://www.epa.gov/region5/water/cwa.htm The Endangered Species Act. U.S. Fish and Wildlife Service. http://endangered.fws.gov/esa.html The Safe Drinking Water Act (SDWA). http://www.epa.gov/safewater/sdwa/ The Superfund Amendments and Reauthorization Act. http://www.epa.gov/superfund/action/law/sara.htm The Water Desalination Act. U.S. Bureau of Reclamation. http://www.usbr.gov/pmts/water/desal.html TWDB. 2003. Desalination–Frequently asked questions. Texas Water Development Board. www.twdb.state.tx.us/Desalination/Desal/Frequently%20asked%20questions.asp. Accessed March 31, 2005. TWDB. 2002. Large-Scale Demonstration Seawater Desalination in Texas. Report of Recommendations For the Office of Governor Rick Perry. Prepared by Texas Water Development Board. 31 pp. Virginia Administrative Code. 2001. http://www.deq.virginia.gov/waterresources/pdf/gwwith.pdf U.S. Army Corps of Engineers. 1991. Regulatory Programs. http://www.usace.army.mil/inet/functions/cw/cecwo/reg/index.htm. (January 2005) U.S. Army Corps of Engineers Regulatory Program. Section 10 of the Rivers and Harbors Act of 1899. http://www.usace.army.mil/inet/functions/cw/cecwo/reg/rhsec10.htm U.S. EPA. 2002. Whole Effluent Toxicity. National Pollution Discharge Elimination Systems (NPDES). http://cfpub.epa.gov/npdes/wqbasedpermitting/wet.cfm (January 2005) Virginia Coastal Plain Model (VCPM). 2002. Withdrawal Simulations. Virginia Department of Environmental Quality . Richmond , Virginia . Personal Communication (Ms. Robin Patton). Younos, T. 2004. The Feasibility of Using Desalination to Supplement Drinking Water Supplies in Eastern Virginia. VWRRC Special Report SR25-2004. Virginia Water Resources Research Center, Virginia Tech , Blacksburg , VA . 114 pp. Notes Virginia follows the national goals set out by National Pollutant Discharge Elimination System (NPDES) that regulates water quality. It requires Whole Effluent Toxicity (WET) tests to be performed by persons responsible for discharging a pollutant that may be considered toxic to organisms in the receiving water. The authority to use WET tests for regulating discharge is found under 9VAC 25-31-220 D.1. a.-d. Brine disposal and discharge from water treatment plants fall under this category (U.S. EPA 2002, Lawson 2004). Citing Literature Volume132, Issue1December 2005Pages 19-26 ReferencesRelatedInformation

Effects of Karenia brevis harmful algal blooms on nearshore fish communities in southwest Florida

Blooms of the toxic alga Karenia brevis, commonly referred to as 'Florida red tides,' occur along Florida's west coast on a near-annual basis, causing massive fish kills. However, few quantitative data on the ecological effects of red tides on fish communities exist. We surveyed fish communities in 5 habitats within Sarasota Bay and the adjacent Gulf of Mexico during the summers of 2004 to 2007 using a purse seine. We collected contemporaneous data on fish densities, fish spe- cies composition, K. brevis cell densities, water temperature, salinity, dissolved oxygen, and turbid- ity. Fish density (catch per unit effort (CPUE)) and species richness were significantly lower in all habitats during red tides. Shannon-Wiener diversity indices were significantly lower in 4 of 5 habitats during red tides. Classification and regression tree analysis showed significant negative relationships between K. brevis density and non-clupeid CPUE, and between K. brevis density and species rich- ness. Fish community structure differed significantly between red tide and non-red tide conditions. Canonical correspondence analysis showed that of all the environmental factors investigated, K. bre- vis density had the greatest influence on community structure. Most trophic guilds were negatively associated with K. brevis density, whereas the guild that included clupeids was positively associated with K. brevis density. Florida's fish kill database showed that 96% of local fish kills during 2003 to 2007 occurred during red tides. We concluded that red tides caused the observed changes in fish abundance and community structure. Harmful algal blooms occur throughout the world and may play an important, yet little understood, role in regulating fish communities.

The pipefish Anarchopterus tectus in western South Atlantic: clarification of its southernmost distribution

The island pipefish (Anarchopterus tectus Dawson, 1978) ranges from Florida in the USA to Venezuela in Western North Atlantic (Dawson, 1978, 1982; Fritzche & Vincent, 2002), although some authors state that its distribution extends southwards to Argentina in western South Atlantic (e.g. Robins & Ray, 1986; Carvalho-Filho, 1999; Froese & Pauly, 2008). This latter claim, however, is in error and resulted from a lapsus calami (see Dawson, 1978). Here we record A. tectus from north-eastern and eastern Brazil based on museum specimens and an underwater photograph, thus extending its range considerably southwards and including this species among the reef fish fauna of western South Atlantic. We examined three specimens housed in two Brazilian scientific collections, MZUSP (Museu de Zoologia da Universidade de Sao Paulo) and ZUEC (Museu de Zoologia da Universidade Estadual de Campinas). The northernmost specimen is MZUSP 46335, a female 99.2 mm SL (standard length), 18+35 rings, 11 pectoral-fin rays, collected at Fernando de Noronha Archipelago (~03°50'S 32°25'W), off north-eastern Brazil. Specimen MZUSP 64634 is a male 93.7 mm SL, 17+33 rings, 11 pectoral-fin rays, collected at Riacho Doce (~09°34'S 35°40'W), Alagoas, coastal north-eastern Brazil. The southernmost specimen is ZUEC 6312, a juvenile male 37.5 mm SL, 17+34 rings, 11 pectoral-fin rays, collected at Praia do Forte, Mata de Sao Joao (~12°35'S 38°01'W), Bahia, coastal eastern Brazil. The latter specimen was photographed alive soon after collection (Figure 1). The counts of the three specimens are within the range reported for A. tectus by Dawson (1982). An individual with the diagnostic upwards arched short snout, and head and body cirri, was photographed underwater (Figure 2) at Abrolhos Archipelago off Bahia coast (~17°59'S 38°40'W), a little southwards to the locality of the ZUEC specimen. In addition to the three specimens housed in Brazilian collections, a specimen (UFLA 19240), identified as Anarchopterus tectus by C.E. Dawson in August 1977 and collected at ‘Isla Itaparica’ (= Ilha de Itaparica) (~13°04'S 38°46'W), Bahia, Brazil, is displayed at the FLMNH Ichthyology Master Database of the University of Florida Fish Collection, searchable at http://www.flmnh. ufl.edu/scripts/dbs/fish_pub_proc.asp. It strikes us that the UFLA specimen is not referred to in the revision of western Atlantic pipefishes (Dawson, 1982), the more so as the identifier of this specimen is the author of A. tectus (Dawson, 1978). This specimen apparently went overlooked by further authors, and the southernmost reported record for A. tectus remained Venezuela in the western North Atlantic (Dawson, 1978, 1982; Fritzche & Vincent, 2002), the mistaken southward records notwithstanding. Our report extends the known distribution range for this reef pipefish about 4000 km southwards in straight line and about 5500 km of coastline, and its occurrence in western South Atlantic is substantiated by at least four museum specimens.

Cooperative conservation efforts to help recover an endangered south Florida butterfly

Abstract. The Miami blue (Cyclargus thomasi bethunebakeri) (Lycaenidae) is a small, brightly coloured butterfly endemic to Florida. It was once locally common across much of the south Florida mainland south through the Florida Keys to the Dry Tortugas. Over the last few decades, ever‐expanding urbanisation and the associated loss of coastal habitat have lead to a significant reduction in the taxon's overall geographical distribution and numerical abundance. The butterfly is currently limited to two small extant populations in the Lower Florida Keys, making it one of the most imperilled insects in North American and warranting a state of Florida listing as endangered. As part of a large‐scale, model cooperative recovery programme led by the Florida Fish and Wildlife Conservation Commission, the University of Florida, the National Park Service, and the Florida Department of Environmental Protection, efforts are underway to conserve the butterfly through captive propagation, organism re‐introduction to state and federal lands, and research on the biology, population ecology, genetic diversity, and non‐target impact of mosquito control adulticides.

Categorizing Introduced Fishes Collected from Public Waters

Introduced plants and animals have been a prominent worldwide environ- mental issue for decades; however, considerable debate and confusion remain over how to list and otherwise categorize these species. This paper describes a process for categorizing exotic freshwater fi shes that have been found in public waters. The basis of this process has been used by the Florida Fish and Wildlife Conservation Commission for nearly 30 years. Reproducing exotic fi shes are grouped into three subcategories (established, possibly established, and localized) using species-spe- cifi c biological and population characteristics resulting in a list that is helpful for prioritizing research and management activities. The purpose of this paper is to stimulate interest in standardizing processes for categorizing introduced species based on how well they adapt to new environments.

Field tests of a directional parametric acoustic alarm designed to alert manatees of approaching boats.

The efficacy of the alarm was documented during controlled slow boat approaches under two experimental conditions: (1) approaches without an alarm and (2) same boat approaches with an alarm. Experiments conducted in a NASA security area provided controlled environmental conditions and minimized anthrogenic acoustical variables. An array of GPS instrumented buoys were deployed to acoustically and visually grid sites. HD aerial video synchronized with these buoys documented behavior and acoustic conditions at focal animal positions and throughout sites. Bathymetry and propagation measurements indicate shallow water constraints along with Lloyd’s mirror effect resulting in significant transmission losses at frequencies of 1 kHz. This could account for the lack of response observed during 94% of the boat approaches without the alarm. In contrast, 100%, of the alarm approaches elicited overt avoidance responses. The change in behavior during approach trials was significantly greater during alarm trials F=76.74, df=1, p<0.01). The distance at which manatees responded was significantly greater during alarm trials (F=143.42, df=1, p<0.01). Applying conservative critical ratio estimates for wideband noise, manatees could not detect no‐alarm approaches at distances of 9 m, while manatees responded to alarm approaches up to 35 m away at levels 18 dB above their estimated critical ratios. [Work funded by the U.S. Department of Defence Legacy Resource Management Program, (Navy), Florida Inland Navigation District, and Florida Fish and Wildlife Conservation Commission.]

Mercury levels and fish consumption practices in women of child-bearing age in the Florida Panhandle

The southeastern United States, and in particular the coastal areas along the Gulf of Mexico (Gulf Coast) in Florida, experience some of the highest levels of mercury deposition in the country. Although the State of Florida's coastal border is among the longest in the United States, and the State has issued fish consumption advisories due to mercury on multiple fish species, few data have been systematically collected to assess mercury levels in the human population of the state or to assess the efficacy of the consumption advisories. Because of the generally high rate of seafood consumption among coastal populations, the human population in the Florida Panhandle, near Pensacola, FL is potentially exposed to elevated levels of mercury. In the present study, we analyzed hair mercury levels in women of child-bearing age (16–49 years) who had resided near Pensacola, FL for at least 1 year. We also surveyed the fish consumption practices of the cohort and evaluated awareness of the Florida Fish Consumption Advisory. Hair mercury levels were significantly higher in women who consumed fish within the 30 days prior to sampling ( p<0.05) and in those women who were unaware of the consumption advisory ( p<0.05). Only 31% of the women reported knowledge of the consumption advisory and pregnant women exhibited lower awareness of the advisory than non-pregnant women. The data suggest that public health interventions such as education and fish advisories have not reached the majority of women in the counties surrounding Pensacola who are most at risk from consumption of fish with high levels of mercury.

Comparison of Largemouth Bass Assessment Metrics between Standardized and Historical Sampling Designs at Six Florida Lakes

AbstractStandardized protocols for sampling fish in lentic systems were recently established for the Florida Fish and Wildlife Conservation Commission. One of the main concerns of state biologists is that standard sampling methods could reduce the value and comparability of long‐standing, fixed‐transect historical data sets. Therefore, largemouth bass Micropterus salmoides were sampled by electrofishing in six lakes using both the historical and the new standard methods in spring 2006. Based on a two‐way analysis of variance, the mean log‐transformed catch per unit effort (CPUE) and proportional size structure of quality‐size fish (PSSQ) and preferred‐size fish (PSSP) did not differ significantly between the two sampling methods for any lake, when all samples were included. Based on bootstrapping analyses, which controlled for differences in sample sizes between the standard and historical methods, the variation associated with mean CPUE was generally higher for the standard method, whereas the variation associated with mean PSSP was generally higher for the historical method. Aside from PSSQ, the sample size required to obtain adequate levels of power and detection were met only by the standard method, for which a larger number of samples were collected. Our study suggests that the point estimates (i.e., means) from the historical methods can be used in trend analyses in concert with the new standard methods but that the standard method provides for better comparisons among water bodies.

Estimates of fish consumption rates for consumers of bought and self-caught fish in Connecticut, Florida, Minnesota, and North Dakota

Fish consumption rates derived from national surveys may not accurately reflect consumption rates in a particular population such as recreational anglers. Many state and local health agencies in the U.S. have conducted area-specific surveys to study fish consumption patterns in local populations, assess exposure to environmental contaminants, or evaluate compliance with fish advisories. The U.S. Environmental Protection Agency (EPA) has analyzed the raw data from fish consumption surveys in Florida, Connecticut, Minnesota, and North Dakota for the purpose of deriving distributions of fish consumption rates and studying the variables that may be more predictive of high-end consumers. Distributions of fish consumption for different age cohorts, ethnic groups, socioeconomic statuses, types of fish (i.e., freshwater, marine, estuarine), and source of fish (i.e., store-bought versus self-caught) were derived. Consumption of fish and shellfish for those who consume both caught and bought fish is higher than those who reported eating only bought or only self-caught. Mean fish consumption per kilogram of body weight ranged from 0.11 g/kg-day to 2.3 g/kg-day. The highest values were observed in Florida for children 1 < 6 years of age. The Florida data show a statistically significant increase in the percentage of the population reporting fish and shellfish consumption with an increase in household income and education. This trend was not observed in the other states.

Lake management (muck removal) and hurricane impacts to the trophic state of Lake Tohopekaliga, Florida

Lake Tohopekaliga is a large (surface area 9,800 ha) and shallow (mean depth 2.1 m) natural lake in central Florida. Cultural eutrophication and lake water level stabilization led to accelerated growth of invasive native and non-native aquatic macrophytes, resulting in the buildup of thick deposits of organic matter along the shoreline. Those shoreline areas were often devoid of oxygen, and the muck buildup filled feeding grounds for wading birds and spawning fish. Muck build up has also reduced aesthetics and boat access. To remove organic accumulation, the lake water level was dropped and heavy equipment was used to scrape the plants and dead organic materials from the underlying sand substrates from more than 1,420 ha of the littoral zone. Most of this material was heaped into large piles in shallow parts of the lake to form 29 artificial islands with basal areas from 0.4 to 3.3 ha each. Our study was designed to determine: (1) amount of nutrients stored in islands relative to annual inflows, (2) nutrient release to the lake from the islands, and (3) changes in lake trophic state due to the muck scraping and construction of the islands. The lake enhancement project was completed in late summer 2004, and the average thickness of organic materials in the scrapped areas was reduced from 46 cm to 1.6 cm, improving access and aesthetics tremendously. The islands stored several times the annual inflow of total phosphorus (TP, 3.1 times) and Total Nitrogen (TN, 6.5 times) and thus could potentially affect the lake's trophic state by leaching nutrients. Our study of water quality in the vicinity of the islands indicates that the islands had no statistically significant impact on the water chemistry of the lake through leaching of nutrients. In the 2 years following the muck removal, substantial increases in average TP (39%), chlorophyll (56%), and color (53%) and a decline in dissolved oxygen (−10%) were found in open water stations. An unintended complication to our experimental design was the occurrence of 3 major hurricanes with high winds and heavy rainfalls that passed over the Lake Tohopekaliga area immediately following the muck removal project. To account for the effects of hurricane activity we examined monthly TP, TN, chlorophyll, Secchi depth data, and quarterly color values measured for 55 relatively small (median surface area 33 ha), nearby lakes. Our sample of 55 nearby lakes showed significant increases in TP (8.2%), TN (4.1%), chlorophyll (20.1%), and water color (23.8%), and decreases in Secchi depth (−8.2%) coinciding with the passage of the hurricanes. Additionally, data from a larger control lake (Kissimmee, surface area 19,800 ha) located 10 km south of Lake Tohopekaliga showed a much larger increase in total phosphorus (66%). Therefore, some or possibly all of the differences we measured before and after scraping could have been the result of low quality water (high nutrients and organic color) flushed into the lake following the heavy rains (93 cm in August and September of 2004) accompanying the storms. The effects of muck removal cannot be completely separated from those of hurricanes because they both occurred at the same time. However, aquatic plant (Florida Department of Environmental Protection) and water chemistry (Florida Fish and Wildlife Conservation Commission) data collected after this project was completed show that submersed aquatic macrophytes in Lake Tohopekaliga have returned and total phosphorus and chlorophyll concentrations are down to levels measured prior to muck scraping and hurricane impacts. Thus, the changes in water chemistry caused by muck removal and/or the hurricanes were relatively short lived (approximately 2 years).

Marine Stock Enhancement in Florida: A Multi-Disciplinary, Stakeholder-Supported, Accountability-Based Approach

Saltwater fishery management in Florida, USA, is mandated to include user-supported hatchery-based stock enhancement. Scientists at the Florida Fish and Wildlife Conservation Commission and Mote Marine Laboratory have taken a multi-disciplinary, quantitative approach to develop effective strategies for integrating stocking into traditional fishery management, with an initial focus on red drum (Sciaenops ocellatus). With consensus from stakeholders, particularly from a well-informed advisory board, focus has shifted over the past 8 years from production-oriented stocking to an assessment-driven developmental approach. The goal is to develop and expand economically successful and ecologically sound stocking technology for rapidly replenishing depleted fish stocks in a multi-billion dollar (US) saltwater recreational fishing industry. Release-recapture experiments for red drum have been underway in Tampa Bay for 6 years. This research has involved replicate stratified releases of ∼ 4 million red drum hatchlings, which are identifiable via genetic testing. More than 20,000 red drum tissues have been tested. These were obtained from fishery-independent and dependent sampling and from an angler-return program,. Of these, approximately 3,000 specimens have been assigned to hatchery breeding pairs. Experimental results, especially those based on hatchery fish recruited to the recreational fishery, have provided managers with valuable information about size at release, release timing, release habitat, and post-release movement.

Antidepressant Secondary Metabolites from Three Florida Sponges

Depression is very common nervous system disorder and according to WHO it is the third most common illness in the world after infectious diseases and heart diseases [1]. All clinically used antidepressant drugs suffer from very serious side effect (e.g. suicidal thoughts) and require about six weeks before the full therapeutic effect occurs [2]. In our search for possible leads to control depression we have investigated three Florida sponges: Verongula rigida, Smenospongia aurea and S. cerebriformis. Several known compounds were isolated and evaluated in the porsolt forced swim test and chick anxiety-depression model. Among the examined metabolites, 5,6-dibromo-N,N-dimethyltryptamine (1) exhibited significant antidepressant action while 5-bromo-N,N-dimethyltryptamine (2) caused reduction in locomotor activity, which indicates potential sedative action. This study reveals the potential of marine natural products as leads to control depression. Acknowledgements: We are grateful to Mr. J. Diers for testing (1) in the forced swim test. This research was conducted pursuant to the Florida Fish and Wildlife Conservation Division of Marine Fisheries Management Special Activity License.