Ballast Water Tanks Research Articles

Free-Living and Plankton-Associated Vibrios: Assessment in Ballast Water, Harbor Areas, and Coastal Ecosystems in Brazil

Ballast water (BW) is a major transport vector of exotic aquatic species and pathogenic microorganisms. The wide-ranging spread of toxigenic Vibrio cholerae O1 from harbor areas has been frequently ascribed to discharge of contaminated BW into eutrophic coastal environments, such as during the onset of the seventh cholera pandemic in South America in the early 1990s. To determine the microbiological hazards of BWs transported to Brazilian ports, we evaluated water and plankton samples taken from (i) BW tanks of recently arrived ships, (ii) port areas along the Brazilian coastline from ∼1 to 32°S and (iii) three coastal areas in São Paulo State. Vibrio concentration and toxigenic V. cholerae O1 occurrence were analyzed. Plankton-associated vibrios were more abundant than free-living vibrios in all studied environments. V. cholerae was found in 9.5% of ballast tanks and 24.2% of port samples, both as free-living and attached forms and, apart from the Santos harbor, was absent off São Paulo State. Toxigenic V. cholerae O1 isolates (ctxA+, tcpA+), involved in cholera disease, were found in BW (2%) and harbor (2%) samples. These results confirm that BW is an important carrier of pathogenic organisms, and that monitoring of vibrios and other plankton-attached bacteria is of paramount importance in BW management programs.

Effect of water treatment on the growth potential of Vibrio cholerae and Vibrio parahaemolyticus in seawater

In laboratory experiments we added Vibrio cholerae and Vibrio parahaemolyticus to bottles with seawater previously treated by filtration, UV, chlorine or ozone. The purpose was to investigate the influence of different treatment techniques on the growth potential of these bacteria in simulated ballast water tanks. Residual oxidants were removed before inoculation, and the bottles were incubated at 21 ± 1 °C. The growth potential of the vibrios was investigated in two different experimental setups, i.e. in presence and absence of added natural microorganisms. In general, V. cholerae and V. parahaemolyticus rapidly lost their culturability after inoculation and storage in untreated seawater, but showed increased survival or growth in the treated water. Highest growth was observed in water previously exposed to high concentrations of ozone. Addition of natural microorganisms reduced the growth of V. cholerae and V. parahaemolyticus.

Physico‐chemical variables determining the invasion risk of freshwater habitats by alien mollusks and crustaceans

The aim of this study was to assess the invasion risk of freshwater habitats and determine the environmental variables that are most favorable for the establishment of alien amphipods, isopods, gastropods, and bivalves. A total of 981 sites located in streams and rivers in Germany. Therefore we analyzed presence–absence data of alien and indigenous amphipods, isopods, gastropods, and bivalves from 981 sites located in small to large rivers in Germany with regard to eight environmental variables: chloride, ammonium, nitrate, oxygen, orthophosphate, distance to the next navigable waterway, and maximum and minimum temperature. Degraded sites close to navigable waters were exposed to an increased invasion risk by all major groups of alien species. Moreover, invaded sites by all four groups of alien species were similar, whereas the sites where indigenous members of the four groups occurred were more variable. Increased temperature and chloride concentration as well as decreased oxygen concentration were identified as major factors for the invasibility of a site. Species-specific analyses showed that chloride was among the three most predictive environmental variables determining species assemblage in all four taxonomic groups. Also distance to the next navigable waterways was similarly important. Additionally, the minimum temperature was among the most important variables for amphipods, isopods, and bivalves. The bias in the occurrence patterns of alien species toward similarly degraded habitats suggests that the members of all four major groups of freshwater alien species are a non-random, more tolerant set of species. Their common tolerance to salinity, high temperature, and oxygen depletion may reflect that most alien species were spread in ballast water tanks, where strong selective pressures, particularly temperature fluctuations, oxygen depletion, and increased salinity may create a bottleneck for successful invasion. Knowledge on the major factors that influence the invasion risk of a habitat is needed to develop strategies to limit the spread of invasive species.

Studying on Shielding Effect in the Sacrificial Anode Cathodic Protection System

In order to study “shielding effect” problems of sacrificial anode cathodic protection system in the ballast water tanks, two sets of experiments, the “block-type shielding effect” and the “absorbed-type shielding effect” are carried out by changing the clapboard height and the distance from the upper surface of sacrificial anode to the copper tube, and corresponding numerical simulations are carried out. Both of the experimental data and the numerical simulation results illustrate the two kinds of “shielding effect” as mentioned above, and according to which, both the two kinds of “shielding effect” should be surely taken into account in sacrificial anode cathodic protection system for a ballast water tank.

Biological invasions: assessment of threat from ballast-water discharge in Patagonian (Argentina) ports

Between July 2007 and December 2008 we surveyed 194 commercial vessels for compliance with ballast water (BW) regulations at five Argentine ports (four of them along the Patagonian coast). Our survey included the inspection of the BW reporting forms and collection of BW samples for salinity and biological (plankton) analyses from 261 BW tanks. Most (77%) ships had some type of BW form on board, but the information in these forms was often unclear, incomplete or inconsistent and did not allow tracking the origin of the BW. Salinity of the BW was often in conflict with the reported geographic location of BW exchange, and the reported volumes of BW discharged in the ports surveyed appeared to be fictitious. Most (80%) BW tanks contained identifiable organisms, usually in very good state of preservation, totaling 408 plant and animal taxa, but only three of these had not been previously recorded in Argentina (two diatoms and one copepod). In spite of the fact that compliance with national and international regulations and guidelines on BW management is poor in the area, the number of recorded marine aquatic nonindigenous species (ANS) in Argentina is comparatively low (ca. 40). Several factors seem to buffer the Argentine coastline from ANS: (1) the low activity of most Patagonian ports; (2) the fact that most (61%) incoming ship traffic originates from domestic ports or areas unlikely to supply ANS; (3) the harsh environmental conditions (cold and turbulent, with few sheltered areas); and (4) the scarcity of hard substrates. In order to maintain its waters relatively free of ANS, Argentina needs to significantly increase its efforts at enforcing existing international and national legislation, and to revise and update its standards on BW management. We anticipate that the problems encountered are also characteristic of many other developing countries, both in South America and elsewhere, where compliance with IMO's BW guidelines is still seldom tested or enforced.

Determinación de Vibrio cholerae en tanques de aguas de lastre de buques internacionales que arribaron al Terminal Multiboyas de Ecopetrol y al Puerto de Tumaco

One of the prominent sources of aquatic invasive species to coastal regions, are the ballast waters discharged from ships, through which invading microorganisms can reach the bay regions, producing major contamination. For this reason, samples of the ballast water from the ships in international traffic that arrived in Tumaco were taken to identify the presence of microorganisms. The survey was conducted during the period from April to October 2010, in 48 ballast water tanks from the 18 ships that arrived at the Ecopetrol Buoyage Terminal in the Bay of Tumaco. In this universe, it was determined if there were Vibrio cholerae in these water samples and at the same time, it served to determine the physical-chemical conditions of the water ballast tanks of these ships. The result was that in 12 vessels the presence of Vibrio cholerae was confirmed, which means that 67% of the ships surpass the permissible level (absence/100ml), allowed by the International Maritime Organization (IMO).

USS New Orleans (LPD 18) Collision Repair-Divers and Dry Docks Unite to Return USS New Orleans to Deployment

On March 20, 2009, USS New Orleans (LPD 18) collided with USS Hartford (SSN 768) while transiting through the Strait of Hormuz and into the Arabian Gulf. Following the collision, USS New Orleans reported flooding in two ballast water tanks, flooding in one fuel oil tank, and fuel oil spilling from the starboard beam. Within hours of the casualty, numerous US Navy and contractor activities sprung into action to complete a damage assessment and coordinate an emergent voyage repair to allow USS New Orleans to return to deployment. Mid-Atlantic Regional Maintenance Center Detachment Bahrain coordinated the repair effort which included both a waterborne repair phase and a dry docking phase to permanently repair severe structural damage in the fuel oil and ballast water tanks. The waterfront repair team completed the waterborne repair phase on April 1, 2009 and the dry dock repair phase on May 12, 2009 and returned USS New Orleans to deployment.

Brine-induced mortality of non-indigenous invertebrates in residual ballast water

All transoceanic vessels entering the Great Lakes are required to manage ballast water and ballast tank residuals with ballast water exchange and tank flushing, respectively. While these management procedures effectively reduce the density and richness of biota in ballast waters and thereby reduce the risk of transferring non-indigenous species, some ships are unable to uniformly manage all tanks. Laboratory experiments were conducted to evaluate sodium chloride brine as an emergency treatment for ballast tanks with non-compliant residuals. Invertebrate communities collected from i) Detroit River, ii) exchanged ballast tanks arriving in the Great Lakes, and iii) North Sea ports, were exposed to a range of brine concentrations (15–115‰) until complete mortality was reached. Results indicate that a 1-h exposure to 115‰ brine is a broadly effective treatment (>99.9% mortality) regardless of treatment temperature, taxonomic group, or species’ source habitat salinity. A median of 0.00% (range 0.00–5.33) of individuals are expected to survive treatment and the expected number of viable individuals released after treatment is within Canadian and proposed international discharge standards. Before implementation, validation with ship-scale trials is recommended.

Shipboard trials of an ozone-based ballast water treatment system

Legislation introduced by the United Nations International Maritime Organization (IMO) has focused primarily on standards defining successful treatments designed to remove invasive species entrained in ballast water. An earlier shipboard study found that ozone introduced into salt water ballast resulted in the formation of bromine compounds, measured as total residual oxidants (TRO) that were toxic to both bacteria and plankton. However, the diffuser system employed to deliver ozone to the ballast water tanks resulted in patchiness in TRO distribution and toxicity to entrained organisms. In this follow-up study, the shipboard diffuser system was replaced by a single Venturi-type injection system designed to deliver a more homogeneous biocide distribution. Within-tank variability in TRO levels and associated toxicity to zooplankton, phytoplankton and marine bacteria was measured via a matrix of tubes deployed to sample different locations in treated and untreated (control) tanks. Three trials were conducted aboard the oil tanker S/T Prince William Sound in the Strait of Juan de Fuca off Port Angeles, Washington State, USA, between June and December 2007. Mortalities of plankton and bacteria and oxidant concentrations were recorded for treated and untreated ballast water up to 3days following treatment, and residual toxicity beyond this period was measured by bioassay of standard test organisms. Results indicated uniform compliance with current IMO standards, but only partial compliance with other existing and pending ballast water legislation.

Optimization of ship’s subdivision arrangement for offshore sequential ballast water exchange using a non-dominated sorting genetic algorithm

Ship’s subdivision arrangement is a multi-objective combinatorial optimization problem with multiple nonlinear constraints. This study focuses on finding a methodology for ship’s subdivision arrangement that can guarantee ship’s offshore sequential ballast water exchanging (SBWE) performances in the preliminary design stage. A mathematical model is built using minimizing trims and hull girder longitudinal bending moments and shearing forces occurred in the SBWE as the objectives, and the multiple safety criteria of the SBWE as the constraints. The longitudinal lengths of the ballast water tanks (BWTs) are taken as design variables that will alter within a reasonable length range. An elitist nondominated sorting genetic algorithm (NSGA-II) is utilized to perform the optimization, in which the nondominated sorting mechanism is employed to handle the multiple objectives, and the constraint-domination principle is utilized to handle the multiple constraints. A special crossover operator called the dispersion apportioned allelic (DAA) crossover is introduced to perform the reproduction of the special problem. A real case study of the subdivision arrangement based on the SBWE of a 50,000DWT double hull product tanker is conducted to demonstrate the feasibility and effectiveness of the proposed approach.

Kordiimonas lacus sp. nov., isolated from a ballast water tank, and emended description of the genus Kordiimonas

A Gram-negative, motile, rod-shaped bacterial strain, designated S3-22(T), was isolated from a sediment sample collected from a ballast water tank of a commercial ship and subjected to a polyphasic taxonomic characterization. The isolate formed small, light-yellow, semi-translucent and circular colonies on solid complex media. The strain was oxidase- and catalase-positive and metabolized a large number of carbon sources. Chemotaxonomic analysis showed ubiquinone Q-10 as predominant respiratory quinone, phosphatidylglycerol and an unidentified glycolipid as major polar lipids and iso-C(17 : 1)ω9c, iso-C(15 : 0), C(16 : 1)ω7c and/or iso-C(15 : 0) 2-OH, C(16 : 0), iso-C(17 : 0) and C(18 : 1)ω7c as major fatty acids and the hydroxy fatty acids iso-C(17 : 0) 3-OH and C(16 : 0) 3-OH. The genomic DNA G+C content was 54.9 mol%. 16S rRNA gene sequence analysis revealed that the isolate has 96.1 % similarity to the type strain of Kordiimonas gwangyangensis, the sole described species within the order Kordiimonadales, and less than 91.0 % similarity to other recognized species. On the basis of phenotypic and genotypic data, strain S3-22(T) represents a novel species of the genus Kordiimonas, for which the name Kordiimonas lacus sp. nov. is proposed, with the type strain S3-22(T) (=CGMCC 1.9109(T) =JCM 16261(T)). An emended description of the genus Kordiimonas is also presented.

Optimal ballast water exchange sequence design using symmetrical multitank strategy

The quality of the ballast water exchange scheme affects many aspects of a ship, including intact stability, structural strength, building and operational expenses, etc. This paper focuses on developing an optimization methodology for large-scale sequential ballast water exchange. The method of transversely symmetrical ballast water tanks being exchanged simultaneously is adopted, and the potentials of multiple tanks being exchanged at a time are explored. The mathematical model for the symmetrical ballast water exchange problem is built by minimizing the occurred maximum trims, maximum hull girder bending moments, and shearing forces as objectives, and the related safety assessment criteria as constraints. A multiobjective genetic algorithm with some operators specially designed for the problem is presented to obtain a set of approximate Pareto-optimal solutions for engineers to choose from. Finally, a real case study on the symmetrical ballast water exchange of a 176,000 DWT bulk carrier is conducted to illustrate the effectiveness of the proposed approach.

Two fatalities by hydrogen sulfide poisoning: Variation of pathological and toxicological findings

We report the simultaneous deaths of two individuals by inhalation of hydrogen sulfide (H 2S), produced either by the putrefaction of a large quantity of sweet corn or by heavy oil that flowed out of the fuel tank of a large stranded cargo vessel. Ten workers went into a water ballast tank of the vessel to remove remaining heavy oil and suddenly felt unwell. Two of the ten workers (patient A, a male in his early thirties, and patient B, a male in his early sixties) died. Autopsies of the two patients revealed a partial green discoloration of the skin and pulmonary edema. Toxicological analysis revealed high levels of thiosulfate in the blood (0.089 mmol/L in patient A and 0.142 mmol/L in patient B). From these findings, we concluded that the cause of death in both patients was H 2S poisoning. In addition, the autopsy of patient A revealed petechiae of the palpebral conjunctiva and the mucous membrane of the mouth and erosion of the respiratory tract. The autopsy of patient B failed to reveal these observations. We presumed that patient B may have been exposed to higher H 2S levels, and that the circulation and respiration of patient B may have arrested faster than patient A. Thiosulfate levels in the blood may reflect the levels of H 2S exposure. This case suggests that the pathological and toxicological findings of H 2S poisoning vary from case to case.

Continuous flushing of contaminants from ballast water tanks

The transport of non-indigenous species (NIS) with ship ballast water is a major environmental problem. The International Maritime Organisation (IMO) have recommended that ballast tanks are flushed through with sea water to remove NIS contaminants. The flushing efficiency is studied using mathematical models and a scaled experimental model of a ballast tank. The density contrast between the ballast water and water used for flushing is important when the Froude number Fr w = U w / | g ′ | H ≪ 1 (defined in terms of average horizontal flow U w , reduced buoyancy g′, and H the vertical dimension in the tank). When denser water is used to flush a ballast tank, from below, it efficiently displaces lighter ballast water; but flushing through with light water creates a buoyant gravity current which effectively short circuits part of the tank. When Fr w ≫ 1, the density contrast between the ballast water and water used for flushing is not important and flushing is controlled by a bulk Péclet number, Pe w . For Pe w ≪ 1 perfect mixing occurs, while for Pe w ≫ 1 displacement flushing occurs. Laboratory experiments of flushing were performed using a model two-dimensional ballast tank employing dye attenuation to measure the whole concentration field and these experiments confirm the essential features of the mathematical models. The results of this study are discussed in the context of current IMO flushing protocols.

Macroalgal survival in ballast water tanks

Despite a large amount of research into invasive species and their introductions, there have been no studies focused on macroalgal transport in ballast water. To address this, we collected replicate samples of ballast water from 12 ships in two Mediterranean harbours (Naples and Salerno). Filtered samples were kept in culture for a month at Mediterranean mean conditions (18 °C, 12:12 h LD, 60 μmol photons m −2 s −1). Fifteen macroalgal taxa were cultured and differed according to the geographic origin of the ballast water. Most of the cultured algae were widely distributed species (e.g. Ulva spp. and Acinetospora-phase). However, Ulva ohnoi Hiraoka and Shimada, described from Japan, was hitherto unknown in the Mediterranean Sea. We show for the first time that ballast water can be an important vector for the transport of microscopic stages of macroalgae and that this can be a vector for the introduction of alien species.

프리징 현상을 고려한 발라스트 탱크 내 유동 및 열전달 해석

Several anti-freezing systems, such as heating coil system, hot air spray system, ballast water circulation system and air bubbling system, have been applied to the water ballast tanks for the vessels, operating in cold sea. In this study, numerical simulations were performed to investigate effectiveness of the air bubbling system used for winterization design concept for water ballast tank. Through the results of this study, it became clear that the air bubbling system equipped in each frame of water ballast tanks was effective to prevent freezing along the outer surface by promoting convective heat transfer.

Potential microbial bioinvasions via ships’ ballast water, sediment, and biofilm

A prominent vector of aquatic invasive species to coastal regions is the discharge of water, sediments, and biofilm from ships’ ballast-water tanks. During eight years of studying ships arriving to the lower Chesapeake Bay, we developed an understanding of the mechanisms by which invasive microorganisms might arrive to the region via ships. Within a given ship, habitats included ballast water, unpumpable water and sediment (collectively known as residuals), and biofilms formed on internal surfaces of ballast-water tanks. We sampled 69 vessels arriving from foreign and domestic ports, largely from Western Europe, the Mediterranean region, and the US East and Gulf coasts. All habitats contained bacteria and viruses. By extrapolating the measured concentration of a microbial metric to the estimated volume of ballast water, biofilm, or residual sediment and water within an average vessel, we calculated the potential total number of microorganisms contained by each habitat, thus creating a hierarchy of risk of delivery. The estimated concentration of microorganisms was greatest in ballast water ≫ sediment and water residuals ≫ biofilms. From these results, it is clear microorganisms may be transported within ships in a variety of ways. Using temperature tolerance as a measure of survivability and the temperature difference between ballast-water samples and the water into which the ballast water was discharged, we estimated 56% of microorganisms could survive in the lower Bay. Extrapolated delivery and survival of microorganisms to the Port of Hampton Roads in lower Chesapeake Bay shows on the order of 10 20 microorganisms (6.8 × 10 19 viruses and 3.9 × 10 18 bacteria cells) are discharged annually to the region.

Estimation of models for durability of epoxy coatings in water ballast tanks

Estimates of the expected life (durability) of protective (organic) coatings for ships are increasingly desired for the rational management of maintenance practices and the setting of asset policies. The life of coatings also has an influence on the prediction of safe remaining structural life, particularly for ships already subject to coating deterioration. Methods for estimating the life of organic protective coatings are briefly reviewed. It is concluded that despite attempts to develop mathematical models of coating deterioration, there is still insufficient unbiased data obtained from actual field experience for sufficiently well-defined vessel areas such as ballast tanks, known to be particularly prone to coating breakdown and poor inspection. Herein a preliminary survey to obtain initial estimates of models for coating durability for water ballast tanks in commercial vessels is described. The survey was conducted using experts from vessel users, coating contractors and suppliers, and an independent expert. As might be expected, the users tended to be more pessimistic and the contractors/suppliers more optimistic in their estimates compared with those of the independent expert. The collective estimates are reasonably consistent with a normal distribution. It was also found that coating life, described as percentage area breakdown, is approximately normal distributed with both increasing mean deterioration and variance.

Investigation of coating failure on the surface of a water ballast tank of an oil tanker

The current crude oil tanker is constructed as a double-hull structure which consists of an oil tank and a water ballast tank whose surface is coated with epoxy paint to prevent corrosion. Since the cracks that developed in the epoxy coating have caused corrosion of the interface of the water ballast tank, the identification of the parameters for crack development is important. In addition, the moisture absorption by the epoxy coating can cause deterioration of bond strength, which results in delamination of the coating and accelerates the corrosion at the interface. In this study, after the mechanical and thermo-mechanical properties of epoxy paints were measured, the residual stresses induced by the temperature change and cure shrinkage were calculated by the finite element analysis, which were compared with the experimental results. Also, the pull-off tests were performed to investigate the deterioration of the bond strength of epoxy coatings due to moisture absorption. It was found that the thermo-mechanical properties such as the coefficient of thermal expansion and glass transition temperature of the coating materials had dominant effects on the crack resistance rather than the cure shrinkage; the moisture penetration to the bonding interface caused interfacial failure and a significant deterioration of bond strength.

Dinámica planctónica, microbiológica y fisicoquímica en cuatro muelles de la Bahía de Cartagena y buques de tráfico internacional

During the second and third quarter of 2004 four Cartagena Bay quays and international traffic vessel ballast tanks were monitored to determinate physical and chemicals characteristic, microbiological and planctonic diversity present at sea environmental and international traffic vessels tanks. The objective was to establish zooplanctonic, fitoplanctonic composition and environmental characteristic mostly present at sea. The purpose was to establish if through international vessel ballast water have arrived new invading species that effects the natural sea environmental conditions. Likewise, 422 fitoplantonic species were registred as natural bay species. The monitoring determinated 116 fitoplantonic species presence, 23 of them founded at ballast water, 78 zooplantonics taxa, being seven of them inside the vessels tanks. Also Aeromonas hydrophila, Serratia sp., Pantoea sp., Providencia rettgeri, Yersinia sp., Enterobacter sp., Pasteurela sp., Proteusmirabilis y P. vulgaris, Citrobacter sp., Vibrio parahaemolyticus, y V. algynolyticus microbiological species were registred. In the other hand, during summer times chemical and physical parameter showed the highest salinity, transparece, pheophytin-a and wind speed levels, as the nutriment transition epochs (PO4, NO2, NH4) and rainy seasons showed the highest chlorophylls a, b, and c., oxygen, pH and temperature. Besides, registred values for surface station were superior than sea bottom stations, values that comes together with some other bay studies showing bottom aerobics hidrochemical conditions still. Ballast water tanks reported the lowest values more than the bay stations during the three year seasons. During the rainy and transition epochs surface stations as CONTECAR, Néstor Pineda, And Muelles El Bosque, reported the highest levels of faecal contamination, as well derby howlers values oscillate between 500- 16000 NMP/ml fecal coliformes and 1766-17000 UFC/100ml of fungus. Microbiological vessel tanks reports were considered acceptable, nevertheless, under a sanitary point of view, one of these ships represent a potential contamination factor, wich it means that it’s necessary to increase control levels to prevent contamination risk shy patogenos.