969 resultados para Environmental toxicity


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research is part of the Socioeconomic Research & Monitoring Program for the Florida Keys National Marine Sanctuary (FKNMS), which was initiated in 1998. In 1995-96, a baseline study on the knowledge, attitudes and perceptions of proposed FKNMS management strategies and regulations of commercial fishers, dive operators and on selected environmental group members was conducted by researchers at the University of Florida and the University of Miami’s Rosenstiel School of Atmospheric and Marine Science (RSMAS). The baseline study was funded by the U.S. Man and the Biosphere Program, and components of the study were published by Florida Sea Grant and in several peer reviewed journals. The study was accepted into the Socioeconomic Research & Monitoring Program at a workshop to design the program in 1998, and workshop participants recommended that the study be replicated every ten years. The 10-year replication was conducted in 2004-05 (commercial fishers) 2006 (dive operators) and 2007 (environmental group members) by the same researchers at RSMAS, while the University of Florida researchers were replaced by Thomas J. Murray & Associates, Inc., which conducted the commercial fishing panels in the FKNMS. The 10-year replication study was funded by NOAA’s Coral Reef Conservation Program. The study not only makes 10-year comparisons in the knowledge, attitudes and perceptions of FKNMS management strategies and regulations, but it also establishes new baselines for future monitoring efforts. Things change, and following the principles of “adaptive management”, management has responded with changes in the management plan strategies and regulations. Some of the management strategies and regulations that were being proposed at the time of the baseline 1995-96 study were changed before the management plan and regulations went into effect in July 1997. This was especially true for the main focus of the study which was the various types of marine zones in the draft and final zoning action plan. Some of the zones proposed were changed significantly and subsequently new zones have been created. This study includes 10-year comparisons of socioeconomic/demographic profiles of each user group; sources and usefulness of information; knowledge of purposes of FKNMS zones; perceived beneficiaries of the FKNMS zones; views on FKNMS processes to develop management strategies and regulations; views on FKNMS zone outcomes; views on FKNMS performance; and general support for FKNMS. In addition to new baseline information on FKNMS zones, new baseline information was developed for spatial use, investment and costs-and-earnings for commercial fishers and dive operators, and views on resource conditions for all three user groups. Statistical tests were done to detect significant changes in both the distribution of responses to questions and changes in mean scores for items replicated over the 10-year period. (PDF has 143 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The evidence collected concerning the biocentric judgment that young children express when evaluating human actions on the environment leads some scholars to suggest that an essential understanding of the notion of living beings should appear earlier than previously believed. This research project aims to study that assumption. To this end, young children’s choice when they are put in situation of having to compare and choose the most negative option between environmentally harmful actions and the breaking of social conventions are examined. Afterwards, the results are categorized in relation to those obtained from the study of children’s grasp of the distinction between living beings and inanimate entities. The data is analysed according to the individuals’ age and overall, it suggests a lack of relationship between environmental judgment and the understanding of the concept of living beings. The final results are discussed in keeping with recent research in the field of moral development that underscores the role that unconscious emotional processing plays in the individual’s normative judgment.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An investigation was conducted into the deaths of more than 220 bottlenose dolphins (Tursiops truncatus) that occurred within the coastal bay ecosystem of mid-Texas between January and May 1992. The high mortality rate was unusual in that it was limited to a relatively small geographical area, occurred primarily within an inshore bay system separated from the Gulf of Mexico by barrier islands, and coincided with deaths of other taxa including birds and fish. Factors examined to determine the potential causes of the dolphin mortalities included microbial pathogens, natural biotoxins, industrial pollutants, other environmental contaminants, and direct human interactions. Emphasis was placed on nonpoint source pesticide runoff from agricultural areas, which had resulted from record rainfall that occurred during the period of increased mortality. Analytical results from sediment, water, and biota indicated that biotoxins, trace metals, and industrial chemical contamination were not likely causative factors in this mortality event. Elevated concentrations of pesticides (atrazine and aldicarb) were detected in surface water samples from bays within the region, and bay salinities were reduced to <10 ppt from December 1991 through April 1992 due to record rainfall and freshwater runoff exceeding any levels since 1939. Prolonged exposure to low salinity could have played a significant role in the unusual mortalities because low salinity exposure may cause disruption of the permeability barrier in dolphin skin. The lack of established toxicity data for marine mammals, particularly dermal absorption and bioaccumulation, precludes accurate toxicological interpretation of results beyond a simple comparison to terrestrial mammalian models. Results clearly indicated that significant periods of agricultural runoff and accompanying low salinities co-occurred with the unusual mortality event in Texas, but no definitive cause of the mortalities was determined. (PDF file contains 25 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Los hidrocarburos aromáticos policíclicos (PAHs) son un grupo de compuestos mutagénicos a los que los seres vivos estamos expuestos continuamente. En la primera fase del metabolismo de estos xenobióticos se generan epóxidos, intermediarios reactivos, capaces de generar aductos con el DNA produciendo lesiones en el material genético. Además, también se generan especies reactivas de oxígeno (ROS) que causan estrés oxidativo dañando las células. Este tipo de lesiones puede conducir a la aparición de cáncer y enfermedades neurodegenerativas como el Alzehimer, la enfermedad de Parkinson y la distrofia lateral amiotrófica. Ciertos compuestos denominados antioxidantes tienen capacidad de combatir estos radicales reactivos. Este estudio tiene como objetivo analizar el efecto de seis antioxidantes (Coenzima Q10, butil hidroxianisol, silibin, licopeno, turmérico y 6-gingerol) frente a la toxicidad de uno de estos intermediarios reactivos, el (±)-anti-11, 12-dihidróxido-13,14-epóxido- 11,12,13,14-tetrahidrodibenzo[a, l]pireno (DBPDE) en células XEM2 de mamífero. Se empleó el ensayo de mutación HPRT para determinar la tasa de supervivencia y la frecuencia de mutación de las células después de ser tratadas con el DBPDE y los antioxidantes. La toxicidad del DBPDE se comprobó y se observó dos posibles efectos para los antioxidantes. Por un lado, la CoQ10 y el 6-gingerol mostraron un efecto protector frente al PAH. Sin embargo, los otros antioxidantes no presentaron efecto protector. El BHA, el silibin, el licopeno y el turmérico presentaron una toxicidad similar a la del DBPDE. Esto puede ser debido a que los antioxidantes son específicos en el tipo de radicales que neutralizan y a la dosis empleada. Los antioxidantes solo tienen efecto protector cuando se emplea su dosis óptima. En otras concentraciones pueden ser incluso dañinos.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The United States and Japanese counterpart panels on aquaculture were formed in 1969 under the United States-Japan Cooperative Program in Natural Resources (UJNR). The panels currently include specialists drawn from the federal departments most concerned with aquaculture. Charged with exploring and developing bilateral cooperation, the panels have focused their efforts on exchanging information related to aquaculture which could be of benefit to both countries. The UJNR was begun during the Third Cabinet-Level Meeting of the Joint United States-Japan Committee on Trade and Economic Affairs in January 1964. In addition to aquaculture, current subjects in the program include desalination of seawater, toxic microorganisms, air population, energy, forage crops, national park management, mycoplasmosis, wind and seismic effects, protein resources, forestry, and several joint panels and committees in marine resources research, development, and utilization. Accomplishments include: Increased communication and cooperation among tecbnical specialists; exchanges of information, data, and research findings; annual meetings of the panels, a· policy-coordinative body; administrative staff meetings; exchanges of equipment, materials, and samples; several major technical conferences; and beneficial effects on international relations. (PDF file contains 56 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Maladaptive behavior has been reported as a phenotypical feature in Prader–Willi syndrome (PWS). It severely limits social adaptation and the quality of life of children and adults with the syndrome. Different factors have been linked with the intensity and form of these behavioral disturbances but there is no consensus about the cause. Consequently, there is still controversy regarding management strategies and there is a need for new data. Methods: The behavior of 100 adults with PWS attending a dedicated center was assessed using the Developmental Behavior Checklist for Adults (DBC-A) and the PWS-specific Hyperphagia Questionnaire. The DBC-A was completed separately by trained caregivers at the center and relatives or caregivers in a natural setting. Genotype, gender, age, degree of obesity and cognitive impairment were analyzed as variables with a hypothetical influence on behavioral features. Results: Patients showed a relatively high rate of behavioral disturbances other than hyperphagia. Disruptive and social relating were the highest scoring DBC-A subscales whereas anxiety/antisocial and self-absorbed were the lowest. When hospital caregiver and natural caregiver scores were compared, scores for the latter were higher for all subscales except for disruptive and anxiety/antisocial. These effects of institutional management were underlined. In the DBC-A, 22 items have descriptive indications of PWS behavior and were used for further comparisons and correlation analysis. In contrast to previous reports, rates of disturbed behavior were lower in patients with a deletion genotype. However, the behavioral profile was similar for both genotypes. No differences were found in any measurement when comparing type I and type II deletions. The other analyzed variables showed little relevance. Conclusions: Significant rates of behavioral disorders were highlighted and their typology described in a large cohort of adults with PWS. The deletion genotype was related to a lower severity of symptoms. Some major behavioral problems, such as hyperphagia, may be well controlled if living circumstances are adapted to the specific requirements of individuals with PWS.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Some 25 to 30 yr ago, when we as students were beginning our respective careers and were developing for the first time our awareness of marine mammals in the waters separating western North America from eastern Asia, we had visions of eventually bridging the communication gap which existed between our two countries at that time. Each of us was anxious to obtain information on the distribution, biology, and ecological relations of "our" seals and walruses on "the other side," beyond our respective political boundari~s where we were not permitted to go to study them. We were concerned that the resource management practices on the other side of the Bering and Chukchi Seas, implemented in isolation, on a purely unilateral basis, might endanger the species which we had come to know and were striving to conserve. At once apparent to both of us was the need for free exchange of biological information between our two countries and, ultimately, joint management of our shared resources. In a small way, we and others made some initial efforts to generate that exchange by personal correspondence and through vocal interchange at the annual meetings of the North Pacific Fur Seal Commission. By the enabling Agreement on Cooperation in the Field of Environmental Protection, reached between our two countries in 1972, our earlier visions at last came true. Since that time, within the framework of the Marine Mammal Project under Area V of that Agreement, we and our colleagues have forged a strong bond of professional accord and respect, in an atmosphere of free intercommunication and mutual understanding. The strength and utility of this arrangement from the beginning of our joint research are reflected in the reports contained in this, the first compendium of our work. The need for a series of such a compendia became apparent to us in 1976, and its implementation was agreed on by the regular meeting of the Project in La Jolla, Calif., in January 1977. Obviously, the preparation and publication of this first volume has been excessively delayed, in part by continuing political distrust between our governments but mainly by increasing demands placed on the time of the contributors. In this period of growing environmental concern in both countries, we and our colleagues have been totally immersed in other tasks and have experienced great difficulty in drawing together the works presented here. Much of the support for doing so was provided by the State of Alaska, through funding for Organized Research at the University of Alaska-Fairbanks. For its ultimate completion in publishable form we wish to thank Helen Stockholm, Director of Publications, Institute of Marine Science, University of Alaska, and her staff, especially Ruth Hand, and the numerous referees narned herein who gave willingly oftheir time to review each ofthe manuscripts critically and to provide a high measure of professionalism to the final product. (PDF file contains 110 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aquaculture depends largely upon a good aquatic environment. The quality of the aquatic medium determines success to a large extent in aquaculture. The medium is particularly vulnerable to excessive abstraction (i.e surface or groundwater) and contamination from a range of sources (industrial, agricultural or domestic) as well as risks of self-pollution. Environmental management options proffered so far include: improvements in farming performance (especially related to feed and feeding strategies, stocking densities, water quality management, disease prevention and control, use of chemicals, etc.) and in the selection of sites and culturable species, treatment of effluents, sensitivity of recipient waters and enforcement of environmental regulations and guidelines specific to the culture system. There are presently conceptual frameworks for aquatic environment management backed by legal administrative tools to create or enforce rational system for water management, fisheries and aquaculture development strengthened by adaptive institutionalisation

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fish assemblage structure of Maryland's coastal lagoon complex was analyzed for spatial and seasonal patterns for the period 1991-2000. Data was made available by Maryland Department of Natural Resources from their MD Coastal Bays Finfish Survey. Dominant species from separate trawl and wiw surveys included blue crab Callinectes sapidus (erroneously included here as a "fish" due to its dominance and commercial importance), bay anchovy Anchoa mitchilli, spot Leiostomous xanthurus, silver perch Bairdiella ehrysoura, and Atlantic menhaden Brevwrtia tyrannus. Ninety-four fish species were identified in the two surveys, a diversity substantially higher than other survey records for Middle Atlantic Bight estuarine and lagoon systems (richness=26 to 78 species). Total species richness for the trawl survey was highest in Chincoteague and lowest in Assawoman and Sinepuxent. On the other hand, mean richness per tow (-area) and related Shannon Weiner Diversity Index were significantly higher in the northern two bays (Assawoman and Isle of Wight Bays) than in the two southern bays (Chincoteague or Sinepuxent Bays). For the seine survey, effort-adjusted diversity indices were significantly lower for Chincoteague Bay than for the other three bays. Higher relative abundances were observed in the northern bays than in the southern bays. The trawl survey exhibited the lowest catch-per-site in Sinepuxent Bay and the highest in Assawoman Bay. The seine survey had the lowest catch-per-site in Chincoteague Bay while the other three embayments were of similar magnitude. There was clear seasonality in assemblage structure with peak abundance and diversity in the summer compared to other seasons. Blue crabs in particular showed a c. 2-fold decline in relative abundance from early summer to fall, which is likely attributable to harvest removals (i.e., an exploitation rate of c. 50%). Seagrass coverage, although increasing over the course of the 10 year survey, did not have obvious effects on species diversity and abundance across or within the embayments, although it did have positive associations with two important species: bay anchovy and summer flounder Pavalich thys dentatus. Atlantic menhaden were most dominant in Assawoman Bay, which could be related to higher primary production typically observed in this Bay in comparison to the other three. (PDF contains 99 pages)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Alliance for Coastal Technologies (ACT) Workshop entitled, "Biological Platforms as Sensor Technologies and their Use as Indicators for the Marine Environment" was held in Seward, Alaska, September 19 - 21,2007. The workshop was co-hosted by the University of Alaska Fairbanks (UAF) and the Alaska SeaLife Center (ASLC). The workshop was attended by 25 participants representing a wide range of research scientists, managers, and manufacturers who develop and deploy sensory equipment using aquatic vertebrates as the mode of transport. Eight recommendations were made by participants at the conclusion of the workshop and are presented here without prioritization: 1. Encourage research toward development of energy scavenging devices of suitable sizes for use in remote sensing packages attached to marine animals. 2. Encourage funding sources for development of new sensor technologies and animal-borne tags. 3. Develop animal-borne environmental sensor platforms that offer more combined systems and improved data recovery methodologies, and expand the geographic scope of complementary fixed sensor arrays. 4. Engage the oceanographic community by: a. Offering a mini workshop at an AGU ocean sciences conference for people interested in developing an ocean carbon program that utilizes animal-borne sensor technology. b. Outreach to chemical oceanographers. 5. Min v2d6.sheepserver.net e and merge technologies from other disciplines that may be applied to marine sensors (e.g. biomedical field). 6. Encourage the NOAA Permitting Office to: a. Make a more predictable, reliable, and consistent permitting system for using animal platforms. b. Establish an evaluation process. c. Adhere to established standards. 7. Promote the expanded use of calibrated hydrophones as part of existing animal platforms. 8. Encourage the Integrated Ocean Observing System (IOOS) to promote animal tracking as effective samplers of the marine environment, and use of animals as ocean sensor technology platforms. [PDF contains 20 pages]

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Alliance for Coastal Technologies (ACT) Workshop on Trace Metal Sensors for Coastal Monitoring was convened April 11-13, 2005 at the Embassy Suites in Seaside, California with partnership from Moss Landing Marine Laboratories (MLML) and the Monterey Bay Aquarium Research Institute (MBARI). Trace metals play many important roles in marine ecosystems. Due to their extreme toxicity, the effects of copper, cadmium and certain organo-metallinc compounds (such as tributyltin and methylmercury) have received much attention. Lately, the sublethal effects of metals on phytoplankton biochemistry, and in some cases the expression of neurotoxins (Domoic acid), have been shown to be important environmental forcing functions determining the composition and gene expression in some groups. More recently the role of iron in controlling phytoplankton growth has led to an understanding of trace metal limitation in coastal systems. Although metals play an important role at many different levels, few technologies exist to provide rapid assessment of metal concentrations or metal speciation in the coastal zone where metal-induced toxicity or potential stimulation of harmful algal blooms, can have major economic impacts. This workshop focused on the state of on-site and in situ trace element detection technologies, in terms of what is currently working well and what is needed to effectively inform coastal zone managers, as well as guide adaptive scientific sampling of the coastal zone. Specifically the goals of this workshop were to: 1) summarize current regional requirements and future targets for metal monitoring in freshwater, estuarine and coastal environments; 2) evaluate the current status of metal sensors and possibilities for leveraging emerging technologies for expanding detection limits and target elements; and 3) help identify critical steps needed for and limits to operational deployment of metal sensors as part of routine water quality monitoring efforts. Following a series of breakout group discussions and overview talks on metal monitoring regulatory issues, analytical techniques and market requirements, workshop participants made several recommendations for steps needed to foster development of in situ metal monitoring capacities: 1. Increase scientific and public awareness of metals of environmental and biological concern and their impacts in aquatic environments. Inform scientific and public communities regarding actual levels of trace metals in natural and perturbed systems. 2. Identify multiple use applications (e.g., industrial waste steam and drinking water quality monitoring) to support investments in metal sensor development. (pdf contains 27 pages)