Effects of Zinc in an Outdoor Freshwater Microcosm System.

A long-term exposure outdoor microcosm study was conducted to evaluate the effects of zinc (Zn) on zooplankton, phytoplankton, and periphyton in a freshwater system. Five Zn treatment concentrations (nominal: 8, 20, 40, 80, and 160 μg/L Zn) and an untreated control with 3 replicates each were used. Various physical and chemical characteristics of the microcosms and biological assessment endpoints (e.

Acute toxicity and risk assessment of permethrin, naled, and dichlorvos to larval butterflies via ingestion of contaminated foliage.

Three Florida native larval butterflies (Junonia coenia, Anartia jatrophae, Eumaeus atala) were used in the present study to determine the acute toxicity, hazard, and risk of a 24h ingestion of leaves contaminated with the adult mosquito control insecticides permethrin, naled, and dichlorvos to late 4th and early 5th in-star caterpillars. Based on 24-h LD50s for ingestion, naled was more acutely toxic than permethrin and dichlorvos to caterpillars. Hazard quotients using the ratio of the highest doses and the 90th percentile doses from field measurements in host plant foliage following actual mosquito control applications to the toxicological benchmarks from laboratory toxicity tests indicate potential high acute hazard for naled compared to permethrin and dichlorvos.

Effects of contaminated St. Lucie River saltwater sediments on an amphipod (Ampelisca abdita) and a hard-shell clam (Mercenaria mercenaria).

The St. Lucie estuary (SLE) ecosystem in South Florida has been shown to be contaminated with metals and pesticides. Our earlier studies also showed that aquatic organisms, especially benthic species in the SLE ecosystem, might be potentially at high risk from copper (Cu) exposure.

Occurrence and distribution of endosulfan in water, sediment, and fish tissue: an ecological assessment of protected lands in south Florida.

Over the past 30 years, endosulfan, one of the last polychlorinated pesticides still in use, has received considerable attention and has been the subject of a number of international regulations and restriction action plans worldwide. This study aimed to monitor the presence and to assess the potential transport of endosulfan within the protected areas of Everglades National Park, Biscayne National Park, and Big Cypress National Preserve, South Florida, USA. Endosulfan sulfate was the major metabolite detected in all matrices in areas along the C-111 and C-111E canals, which drain the Homestead agricultural area and discharge to either Florida or Biscayne Bays, both of which are critical wildlife habitats.

Human pharmaceuticals in the aquatic environment: a review of recent toxicological studies and considerations for toxicity testing.

Although an increasingly large amount of data exists on the acute and chronic aquatic toxicity of pharmaceuticals, numerous questions still remain. There remains a dearth of information pertaining to the chronic toxicity of bivalves, benthic invertebrates, fish, and endangered species, as well as study designs that examine mechanism-of-action (MOA)-based toxicity, in vitro and computational toxicity, and pharmaceutical mixtures. Studies examining acute toxicity are prolific in the published literature; therefore, we address many of the shortcomings in the literature by proposing "intelligent" well-designed aquatic toxicology studies that consider comparative pharmacokinetics and pharmacodynamics.

Bioconcentration and depuration of endosulfan sulfate in mosquito fish (Gambusia affinis).

Endosulfan is an insecticide which has been widely used in agriculture. The technical grade material consists of two isomers (alpha and beta). Under natural environmental conditions, endosulfan is metabolized through oxidation and the main metabolite in the environment is endosulfan sulfate.

Bioaccumulation and toxicity of copper in outdoor freshwater microcosms.

This study characterizes the effects of copper (Cu) on Florida apple snails (Pomacea paludosa) and mosquito fish (Gambusia affinis) using a replicated outdoor microcosm design. Soils used in this study were collected from two Cu-enriched citrus agricultural sites in South Florida (Agler property (AGLR) in St. Lucie County and Sunrise Boys property (SRB) in Palm Beach County) and a reference site (Equus property) in St.

Use of butterflies as nontarget insect test species and the acute toxicity and hazard of mosquito control insecticides.

Honeybees are the standard insect test species used for toxicity testing of pesticides on nontarget insects for the U.S. Environmental Protection Agency (U.

A review of personal care products in the aquatic environment: environmental concentrations and toxicity.

Considerable research has been conducted examining occurrence and effects of human use pharmaceuticals in the aquatic environment; however, relatively little research has been conducted examining personal care products although they are found more often and in higher concentrations than pharmaceuticals. Personal care products are continually released into the aquatic environment and are biologically active and persistent. This article examines the acute and chronic toxicity data available for personal care products and highlights areas of concern.

Acute toxicity and effects analysis of endosulfan sulfate to freshwater fish species.

Endosulfan sulfate is a persistent environmental metabolite of endosulfan, an organochlorine insecticide-acaricide presently registered by the United States Environmental Protection Agency. There is, however, limited acute fish toxicity data for endosulfan sulfate. This study determines the acute toxicity (LC₅₀s and LC₁₀s) of endosulfan sulfate to three inland Florida native fish species (mosquitofish [Gambusia affinis]; least killifish [Heterandria formosa]; and sailfin mollies [Poecilia latipinna]) as well as fathead minnows (Pimephales promelas).

Endosulfan and its metabolite, endosulfan sulfate, in freshwater ecosystems of South Florida: a probabilistic aquatic ecological risk assessment.

Endosulfan is an insecticide-acaricide used in South Florida and is one of the remaining organochlorine insecticides registered under the Federal Insecticide Fungicide and Rodenticide Act by the U.S.EPA.

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.

Exposure routes of copper: short term effects on survival, weight, and uptake in Florida apple snails (Pomacea paludosa).

The uptake and effects (survival, weight) of copper (Cu) on Florida apple snails (Pomacea paludosa) via exposures to copper-enriched agricultural soil-water and water-only treatments were investigated. Soils were collected from citrus sites in south Florida and flooded with laboratory freshwater for 14d. Neonate apple snails (96-h-old) were then exposed to either Cu from a soil-overlying water (i.

Effects of copper in flooded Florida agricultural soils on Hyalella azteca.

This study examined the uptake and effects of copper (Cu) from flooded agricultural soils to epibenthic amphipods (Hyalella azteca) using 10-day sediment toxicity tests. Soils were collected from 10 citrus agricultural sites in South Florida. One sediment toxicity test was conducted with one flooding of the 10 soils, and based on the results of this test a second sediment toxicity test was conducted with 4 of the soils, after four 14-day flooding and four 14-day drying intervals over 4 months.

Effects of sublethal chronic copper exposure on the growth and reproductive success of the Florida apple snail (Pomacea paludosa).

Florida apple snails (Pomacea paludosa) were exposed to three concentrations of copper (Cu), in water (8 microg/L, 16 microg/L, 24 microg/L), for one generation to examine uptake and the effects on survival, growth, and reproduction of the F(0) generation and survival, growth, and whole body Cu of the F(1) generation. During a 9-month Cu exposure, apple snails exposed to 8-16 microg/L Cu had high Cu accumulation (whole body, foot, viscera, and shell) and significantly reduced clutch production (8-16 microg/L) and egg hatching (16 microg/L). Apple snails exposed to the 24 microg/L Cu had low survival and the treatment was therefore terminated.

Aquatic risk assessment of pesticides in surface waters in and adjacent to the Everglades and Biscayne National Parks: I. Hazard assessment and problem formulation.

An aquatic risk assessment under the U.S. Environment Protection Agency (EPA) ecological risk framework was conducted for atrazine, metolachlor, malathion, chlorpyrifos, and endosulfan in the C-111 freshwater basin (eastern boundary of the Everglades National Park), northeast Florida Bay, and south Biscayne Bay in South Florida.

Aquatic risk assessment of pesticides in surface waters in and adjacent to the Everglades and Biscayne National Parks: II. Probabilistic analyses.

A screening-level aquatic probabilistic risk assessment was completed to determine the potential risks of organic pesticides found in surface waters of the C-111 freshwater basin (11 sites at the east boundary of the Everglades National Park) and adjacent estuarine tidal zones (two sites in northeast Florida Bay, one site in south Biscayne Bay) in south Florida. It followed the US Environmental Protection Agency (USEPA) ecological risk framework and focused only on the acute and chronic risks of endosulfan and chlorpyrifos individually and jointly with atrazine, metolachlor, and malathion by comparing distributions of surface water exposure concentrations with the distributions of species toxicity data. The highest risk of acute effects was associated with endosulfan exposure to freshwater arthropods at S-178/site C on the C-111 system, followed by endosulfan effects to estuarine arthropods at Joe Bay in northeast Florida Bay.

Copper uptake and depuration by juvenile and adult Florida apple snails (Pomacea paludosa).

The present study characterized copper (Cu) uptake and depuration by juvenile and adult Florida apple snails (Pomacea paludosa) from water, soil, and diet. During a 28-day uptake period, juvenile apple snails were exposed to aqueous Cu and adult apple snails were exposed to Cu-contaminated soil, water, and food. In the follow-up 14-day depuration period, both juvenile and adult apple snails were held in laboratory freshwater with background Cu concentrations<4 microg/l.

Effects of salinity on native estuarine fish species in South Florida.

Variable and high salinities have been identified as key stressors in Florida Bay. The Comprehensive Everglades Restoration Plan (CERP) includes water redistribution projects that are intended to restore natural freshwater flows to northeastern Florida Bay. The present salinity regimes in the area, which span from hypo- to hypersaline, will be altered as a result of these actions.

Metal concentrations in osprey (Pandion haliaetus) populations in the Florida Bay estuary.

Mercury and trace metal contamination is a concern in the Florida Bay estuary, but the effects on biological pathways are not very well understood. The analysis of mercury and trace metals (beryllium, vanadium, chromium, cobalt, nickel, copper, arsenic, cadmium, antimony, and lead) was conducted on tissues of adult and juvenile osprey (Pandion haliaetus) to examine the bioaccumulation and distribution in Florida Bay. Mercury concentrations were found at levels associated with decreased reproductive success, and no significant differences were found between adult and juvenile samples.

Aquatic risk assessment of copper in freshwater and saltwater ecosystems of South Florida.

A screening-level aquatic risk assessment was conducted for copper in south Florida's freshwater and saltwater environments. Risk was quantified by comparing the overlap between the probability distributions of copper exposure from surface water and sediment with the probability distributions of effects data obtained from laboratory studies. Copper concentrations in surface water and sediment in south Florida were summarized by county.

Aquatic risk assessment of herbicides in freshwater ecosystems of South Florida.

Widespread, high-volume use and subsequent off-site transport of herbicides, specifically photosystem II inhibitors (PSII), on agricultural and noncultivated lands in south Florida has resulted in frequent detections in freshwater systems. In light of the current restoration efforts as part of the Comprehensive Environmental Restoration Plan (CERP), increased water flows containing detectable herbicide levels into the Everglades ecosystem and adjacent areas may have adverse consequences to the unique plant communities present in the region. The potential impact of individual herbicides to aquatic plant and algae species was examined using a probabilistic risk assessment approach.

Copper desorption in flooded agricultural soils and toxicity to the Florida apple snail (Pomacea paludosa): implications in Everglades restoration.

Copper (Cu) desorption and toxicity to the Florida apple snail were investigated from soils obtained from agricultural sites acquired under the Comprehensive Everglades Restoration Plan. Copper concentrations in 11 flooded soils ranged from 5 to 234 mg/kg on day 0 and from 6.2 to 204 mg/kg on day 28 (steady-state).

Sediment toxicity in the St. Lucie River Watershed and Everglades Agricultural Area.

DDD, DDE and ametryn were the most frequently detected pesticides in sediment in the St. Lucie River Watershed (SLR) and Everglades Agricultural Area (EAA). Concentrations of organochlorine compounds typically exceeded NOAA (SQuiRTs) TELs for freshwater sediment.