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Ballast Water (ballast + water)
Selected AbstractsDoes saltwater flushing reduce viability of diapausing eggs in ship ballast sediment?DIVERSITY AND DISTRIBUTIONS, Issue 3 2006Sarah A. Bailey ABSTRACT Flushing of ballast tanks with seawater has been proposed to reduce the risk of invasion associated with residual ballast in ,no ballast on board' ships. The efficacy of this procedure, however, has not been determined. Using diapausing eggs isolated from ballast sediments , as well as from Lake Erie sediment , this study investigated the impact of salinity (0, 8 and 35,) and temperature (10, 20 and 30 °C) on the cumulative abundance and species richness of hatched zooplankton taxa. The rate and amount of hatching varied dramatically between sediments and across salinity,temperature regimes. Although exposure to saline water inhibited emergence of freshwater taxa during the exposure phase of all trials, mixed results were evident after diapausing eggs were returned to freshwater. The efficacy of salinity as a ballast treatment method was temperature dependent, although the direction of the effect was case-specific. Exposure of eggs to saline water was less effective at 10 and 30 °C than at 20 °C. Although flushing ballast tanks with open ocean water is expected to significantly reduce the number of active invertebrates living in residual ballast water (a potentially larger source of invaders), our results indicate that the most effective treatment conditions for reduction of diapausing egg viability is 8, salinity at 20 °C. [source] Grasping at the routes of biological invasions: a framework for integrating pathways into policyJOURNAL OF APPLIED ECOLOGY, Issue 2 2008P. E. Hulme Summary 1Pathways describe the processes that result in the introduction of alien species from one location to another. A framework is proposed to facilitate the comparative analysis of invasion pathways by a wide range of taxa in both terrestrial and aquatic ecosystems. Comparisons with a range of data helped identify existing gaps in current knowledge of pathways and highlight the limitations of existing legislation to manage introductions of alien species. The scheme aims for universality but uses the European Union as a case study for the regulatory perspectives. 2Alien species may arrive and enter a new region through three broad mechanisms: importation of a commodity, arrival of a transport vector, and/or natural spread from a neighbouring region where the species is itself alien. These three mechanisms result in six principal pathways: release, escape, contaminant, stowaway, corridor and unaided. 3Alien species transported as commodities may be introduced as a deliberate release or as an escape from captivity. Many species are not intentionally transported but arrive as a contaminant of a commodity, for example pathogens and pests. Stowaways are directly associated with human transport but arrive independently of a specific commodity, for example organisms transported in ballast water, cargo and airfreight. The corridor pathway highlights the role transport infrastructures play in the introduction of alien species. The unaided pathway describes situations where natural spread results in alien species arriving into a new region from a donor region where it is also alien. 4Vertebrate pathways tend to be characterized as deliberate releases, invertebrates as contaminants and plants as escapes. Pathogenic micro-organisms and fungi are generally introduced as contaminants of their hosts. The corridor and unaided pathways are often ignored in pathway assessments but warrant further detailed consideration. 5Synthesis and applications. Intentional releases and escapes should be straightforward to monitor and regulate but, in practice, developing legislation has proved difficult. New introductions continue to occur through contaminant, stowaway, corridor and unaided pathways. These pathways represent special challenges for management and legislation. The present framework should enable these trends to be monitored more clearly and hopefully lead to the development of appropriate regulations or codes of practice to stem the number of future introductions. [source] Invasion genetics of the Eurasian round goby in North America: tracing sources and spread patternsMOLECULAR ECOLOGY, Issue 1 2009JOSHUA E. BROWN Abstract The Eurasian round goby Neogobius melanostomus (Apollonia melanostoma) invaded the North American Great Lakes in 1990 through ballast water, spread rapidly, and now is widely distributed and moving through adjacent tributaries. We analyse its genetic diversity and divergence patterns among 25 North American (N = 744) and 22 Eurasian (N = 414) locations using mitochondrial DNA cytochrome b gene sequences and seven nuclear microsatellite loci in order to: (i) identify the invasion's founding source(s), (ii) test for founder effects, (iii) evaluate whether the invasive range is genetically heterogeneous, and (iv) determine whether fringe and central areas differ in genetic diversity. Tests include FST analogues, neighbour-joining trees, haplotype networks, Bayesian assignment, Monmonier barrier analysis, and three-dimensional factorial correspondence analysis. We recovered 13 cytochrome b haplotypes and 232 microsatellite alleles in North America and compared these to variation we previously described across Eurasia. Results show: (i) the southern Dnieper River population was the primary Eurasian donor source for the round goby's invasion of North America, likely supplemented by some alleles from the Dniester and Southern Bug rivers, (ii) the overall invasion has high genetic diversity and experienced no founder effect, (iii) there is significant genetic structuring across North America, and (iv) some expansion areas show reduced numbers of alleles, whereas others appear to reflect secondary colonization. Sampling sites in Lake Huron's Saginaw Bay and Lake Ontario significantly differ from all others, having unique alleles that apparently originated from separate introductions. Substantial genetic variation, multiple founding sources, large number of propagules, and population structure thus likely aided the goby's ecological success. [source] Detection of the Dinozoans Pfiesteria piscicida and P. shumwayae: A Review of Detection Methods and Geographic Distribution,THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2005PARKE A. RUBLEE Abstract. Molecular methods, including conventional PCR, real-time PCR, denaturing gradient gel electrophoresis, fluorescent fragment detection PCR, and fluorescent in situ hybridization, have all been developed for use in identifying and studying the distribution of the toxic dinoflagellates Pfiesteria piscicida and P. shumwayae. Application of the methods has demonstrated a worldwide distribution of both species and provided insight into their environmental tolerance range and temporal changes in distribution. Genetic variability among geographic locations generally appears low in rDNA genes, and detection of the organisms in ballast water is consistent with rapid dispersal or high gene flow among populations, but additional sequence data are needed to verify this hypothesis. The rapid development and application of these tools serves as a model for study of other microbial taxa and provides a basis for future development of tools that can simultaneously detect multiple targets. [source] Unintentional dispersal of aquatic invertebrates via footwear and motor vehicles in a Mediterranean wetland areaAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 5 2010Aline Waterkeyn Abstract 1.Several human activities, such as actions for nature conservation, research and recreational activities, are closely associated with inland aquatic habitats that are usually considered as isolated island habitats. In this study, the possibility of unintentional dispersal of aquatic invertebrates among water bodies via footwear and motor vehicles was investigated. 2.Mud samples collected from boots and from the tyres and wheel cases of cars used for field work by biologists (Camargue, Southern France) were hatched under laboratory conditions and also checked for the presence of unhatched propagules. A large number of organisms hatched and invertebrate propagules from a wide range of taxa were encountered (including Artemia, freshwater large branchiopods, Cladocera, Ostracoda, Rotifera, Turbellaria, Nematoda, etc.). The results also demonstrated that different research groups tend to transport the aquatic invertebrates typical for their respective study systems. 3.Human dispersal of aquatic invertebrates has been studied mainly on large continental scales, such as in the case of transoceanic transport via ballast water in ships. This study provides evidence that dispersal via footwear and motor vehicles may result in frequent dispersal of aquatic invertebrates on a local scale, and we presume also occasionally over longer distances. Given the rapid spread of invasive zooplankton species (e.g. Artemia franciscana encountered in this study), we promote caution and recommend cleaning before transport of any equipment which comes in contact with water or aquatic sediment. Copyright © 2010 John Wiley & Sons, Ltd. [source] Factors influencing densities of non-indigenous species in the ballast water of ships arriving at ports in Puget Sound, Washington, United StatesAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 3 2009Jeffery R. Cordell Abstract 1.Oceanographic characteristics and the presence of international shipping in Puget Sound, Washington, USA contribute to its vulnerability to non-indigenous species (NIS) invasions. To evaluate NIS arriving in ballast water, zooplankton was sampled in 380 ballast tanks of ships after they entered Puget Sound. 2.Taxa were classified into a higher risk group of coastal organisms (including known NIS), and a lower risk group of largely oceanic species. Most ships reported conducting mid-ocean ballast water exchange (BWE). However, despite state regulations requiring BWE, and apparent compliance by ship operators, most sampled tanks from both transpacific and coastal routes had coastal zooplankton densities exceeding internationally proposed discharge standards. 3.BWE efficiency models and controlled before-and-after BWE experiments indicate that BWE consistently removes most coastal zooplankton. However, this study found that although the empty,refill method of BWE significantly reduced coastal plankton compared with un-exchanged tanks, the flow-through method did not, and in either case remaining coastal plankton densities presented appreciable risks of introducing NIS. 4.Densities of high risk taxa were consistently and significantly higher from US domestic trips dominated by tank ships carrying ballast water from California, and lower in samples from trans-Pacific trips dominated by container ships and bulk carriers with ballast from Asia. These findings are probably a result of the dense and diverse NIS assemblages present in California and other US west coast estuaries and the comparatively short transit times between them and Puget Sound. 5.While it appears that BWE can effectively replace NIS with less risky ocean species, new reporting, verification, and operational procedures may be necessary to enhance BWE efficacy. In the long-term, the introduction of ballast water treatment technologies may be required to significantly reduce the discharge of risky organisms from commercial ships if BWE practices do not become more effective. Copyright © 2008 John Wiley & Sons, Ltd. [source] Comprehensive review of the records of the biota of the Indian Seas and introduction of non-indigenous speciesAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 2 2005D.V. Subba Rao Abstract 1.Comparison of the pre-1960 faunal survey data for the Indian Seas with that for the post-1960 period showed that 205 non-indigenous taxa were introduced in the post-1960 period; shipping activity is considered a plausible major vector for many of these introductions. 2.Of the non-indigenous taxa, 21% were fish, followed by Polychaeta (<11%), Algae (10%), Crustacea (10%), Mollusca (10%), Ciliata (8%), Fungi (7%), Ascidians (6%) and minor invertebrates (17%). 3.An analysis of the data suggests a correspondence between the shipping routes between India and various regions. There were 75 species common to the Indian Seas and the coastal seas of China and Japan, 63 to the Indo-Malaysian region, 42 to the Mediterranean, 40 and 34 to western and eastern Atlantic respectively, and 41 to Australia and New Zealand. A further 33 species were common to the Caribbean region, 32 to the eastern Pacific, 14 and 24 to the west and east coasts of Africa respectively, 18 to the Baltic, 15 to the middle Arabian Gulf and Red Sea, and 10 to the Brazilian coast. 4.The Indo-Malaysian region can be identified as a centre of xenodiversity for biota from Southeast Asia, China, Japan, Philippines and Australian regions. 5.Of the introduced species, the bivalve Mytilopsis sallei and the serpulid Ficopomatus enigmaticus have become pests in the Indian Seas, consistent with the Williamson and Fitter ,tens rule'. Included amongst the biota with economic impact are nine fouling and six wood-destroying organisms. 6.Novel occurrences of the human pathogenic vibrios, e.g. Vibrio parahaemolyticus, non-01 Vibrio cholerae, Vibrio vulnificus and Vibrio mimicus and the harmful algal bloom species Alexandrium spp. and Gymnodinium nagasakiense in the Indian coastal waters could be attributed to ballast water introductions. 7.Introductions of alien biota could pose a threat to the highly productive tropical coastal waters, estuaries and mariculture sites and could cause economic impacts and ecological surprises. 8.In addition to strict enforcement of a national quarantine policy on ballast water discharges, long-term multidisciplinary research on ballast water invaders is crucial to enhance our understanding of the biodiversity and functioning of the ecosystem. Copyright © 2005 John Wiley & Sons, Ltd. [source] Decimal reduction times of Pyrodinium bahamense var. compressum and Escherichia coli in chlorine- and ultraviolet-treated seawaterLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2001M.P.V. Azanza Aims:,Decimal reduction times (D -values) of the vegetative cells of Pyrodinium bahamense var. compressum and Escherichia coli in ultraviolet- and chlorine-treated seawater were established. Methods and Results:,The cells of the test organisms were exposed to ultraviolet- and chlorine-treated seawater and maintained at 20,35 ppt salinity and 20 to 35°C. The dinoflagellate cells which cause Paralytic Shellfish Poisoning (PSP) were found to be more resilient than the bacterial cells. Ultraviolet treatment was found to be more effective than chlorine to both test organisms. Irreversible morphological changes in the treated dinoflagellate cells were noted, including protoplast discoloration, cellular membrane leakage and damage to the thecal armour. Conclusions:,The vegetative cells of both test organisms in seawater were more sensitive to ultraviolet treatment than to chlorine exposure. Generally, the dinoflagellate cells were less susceptible than bacterial cells to both disinfection treatments. Significance and Impact of the Study:,Results of this study may have significant implications in depuration procedures for molluscs and cleaning protocols for ballast waters of ships. [source] | ||||||||||