Emerging risks from ballast water treatment: The run-up to the International Ballast Water Management Convention

AbstractUptake and discharge of ballast water by ocean-going ships contribute to the worldwide spread of aquatic invasive species, with negative impacts on the environment, economies, and public health. The International Ballast Water Management Convention aims at a global answer. The agreed standards for ballast water discharge will require ballast water treatment. Systems based on various physical and/or chemical methods were developed for on-board installation and approved by the International Maritime Organization. Most common are combinations of high-performance filters with oxidizing chemicals or UV radiation. A well-known problem of oxidative water treatment is the formation of disinfection by-products, many of which show genotoxicity, carcinogenicity, or other long-term toxicity. In natural biota, genetic damages can affect reproductive success and ultimately impact biodiversity. The future exposure towards chemicals from ballast water treatment can only be estimated, based on land-based testing of treatment systems, mathematical models, and exposure scenarios. Systematic studies on the chemistry of oxidants in seawater are lacking, as are data about the background levels of disinfection by-products in the oceans and strategies for monitoring future developments. The international approval procedure of ballast water treatment systems compares the estimated exposure levels of individual substances with their experimental toxicity. While well established in many substance regulations, this approach is also criticised for its simplification, which may disregard critical aspects such as multiple exposures and long-term sub-lethal effects. Moreover, a truly holistic sustainability assessment would need to take into account factors beyond chemical hazards, e.g. energy consumption, air pollution or waste generation

Ballast water treatment techniques: review and suggestions regarding use in the Arctic and Great Lakes

The retreating ice cover opens up the opportunity for new shipping routes, and consequently shipping traffic in the Arctic region is increasing and with this the risk of introducing non-indigenous species (NIS) via ballast water. Ballast water must therefore be treated to prevent the transport of NIS in an environmentally friendly way to minimise the environmental impact of the treatment. There is, however, limited information on the suitability of different ballast water treatment methods for use specifically in Arctic conditions. A literature study was conducted to identify and summarise different ballast water treatment methods, evaluate their potential for use in the Arctic, and to identify gaps in the current knowledge on Arctic ballast water treatment for further investigation. As winter conditions on the Great Lakes present a useful analogue for Arctic operation, these conditions were also included in the scope of work. Three basic methods for ballast water treatment were addressed: mechanical systems, physical disinfection, and chemical treatments. In ballast water treatment systems often a combinations of these techniques is applied. From the literature, each technique was described and evaluated regarding key environmental conditions present in the Arctic and Great Lakes regions, such as salinity, temperature and turbidity

Marine bioinvasion prevention : understanding ballast water transportation conditions and the development of effective treatment systems

Man’s impact on the Earth is constantly increasing due to ever progressing technological developments. One of our major impacts is the transportation of organisms to new habitats, leading to alterations of existing ecosystems. Mechanisms responsible for the transportation of marine organisms are mainly associated with the shipping industry e.g. hull fouling, sea chests and ballast water. Ballast water has long been recognised as one of the major mechanisms by which aquatic organisms are transported to new environments. In 2004 the International Convention for the Control and Management of Ships’ Ballast Water and Sediments was adopted and measures were implemented to reduce and control the number of future invasions. This thesis has addressed aspects relevant to the future prevention of organism transport via ballast water. Firstly, during ballast water uptake organisms are exposed to potential damage whilst passing through a centrifugal pump. Upon reaching the ballast tanks they are stored in dark, confined conditions. These processes are not intended to damage individuals, but both could potentially kill organisms and reduce the discharge of live individuals. Both processes were examined in isolation to determine their effect on plankton survival. To manage ballast water introductions water treatment technologies have been investigated to determine their ability to kill plankton. This study assessed three technologies: a stainless steel 40μm screen filter, a UV light and a chlorine based chemical, for their potential in ballast water treatments. A further challenge facing researchers involved in developing ballast water treatment systems is accurately assessing the resulting mortality in plankton from treatments. Five common viability assessment methods were investigated and their application on test organisms and natural populations examined. This thesis concludes that no significant mortality was caused to plankton by a centrifugal pump, and phytoplankton are able to survive long periods in dark confined conditions. Thus these processes will not prevent viable organisms reaching new destinations. The three treatments assessed were all effective on two iii test species and could be utilised in large scale treatment systems on board vessels to minimise introductions. Finally, while viability is difficult to assess in plankton using viability stains it is possible to obtain accurate information if the methods used are properly optimised prior to use.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Inferential measurement and control of ballast water treatment system

As a result of interaction with the surrounding environment, shipping has become one of the vectors of bio-invasion across the globe. Ballast water is one of the means of bio-invasion from shipping through which microorganisms break through natural barriers and establish in a new location. Shipboard treatment systems are predominately considered as mitigating measures for bio-invasion via a ballast water system. Currently shipboard performance monitoring of ballast water treatment systems, and thus assessment of discharge quality of ballast water as required by the Convention, depends on off-line laboratory assays with long delay analysis. Lack of online measurement sensors to assess the viability of microorganisms after treatment has made monitoring and thus control of ballast water treatment systems difficult. In this study, a methodology was developed, through a mathematical algorithm, to provide an inferential model-based measurement system in order to monitor and thus control non-observable ballast water systems. In the developed inferential measurement the primary output of the treatment system is inferred by using easy to measure secondary output variables and a model relating these two outputs. Data-driven modeling techniques, including Artificial Neural Networks (ANN), were used to develop an estimator for the small scale UV treatment system based on the data obtained from conducted experiments. The results from ANN showed more accuracy in term of Root Mean Squared Error (RMSE) and Linear Correlation Coefficient (LCC) when compared to the other techniques. The same methodology was implemented to a larger scale treatment system comprising micro-filter and UV reactor. A software-based inferential measurement for online monitoring of the treatment system was then developed. Following monitoring, inferential control of the treatment setup was also accomplished using direct inverse control strategy. A software-based “Decision Making Tool” consisted of two intelligent inverse models, which were used to control treatment flow rate and maintain the effective average UV dose. The results from this study showed that software-based estimation of treatment technologies can provide online measurement and control for ballast water system.EThOS - Electronic Theses Online ServiceEuropean funded project “BaWaPla”GBUnited Kingdo

Biology and Control of Invasive Fishes

This book is a collection of 12 peer-reviewed articles on freshwater invasive fish and is the first on this topic. It focuses on real-world lessons learned from managing common carp, bigheaded carp, sea lamprey, northern pike, and lake trout in different parts of the world. Articles also discuss damage caused by invasive fish, environmental DNA as means to measure spawning carp, and CO2 as a fish deterrent. Detailed critical evaluations of the possibility of using koi herpes virus to control common carp, market-driven fishing (invasivorism), as well as changes in lock and dam operating protocols to control bigheaded carps are also presented. Several important commonalities are noted between successful management efforts, including the simultaneous use of multiple integrated strategies, a focus on suppressing reproduction, and a deep local knowledge in an introductory article that provides context for the discipline

What Works in Conservation 2021

This book provides an assessment of the effectiveness of 2526 conservation interventions based on summarized scientific evidence. The 2021 edition contains substantial new material on bat conservation, terrestrial mammal conservation and marine and freshwater mammals, thus completing the evidence for all mammal species categories. Other chapters cover practical global conservation of primates, amphibians, bats, birds, forests, peatlands, subtidal benthic invertebrates, shrublands and heathlands, as well as the conservation of European farmland biodiversity and some aspects of enhancing natural pest control, enhancing soil fertility, management of captive animals and control of freshwater invasive species. It contains key results from the summarized evidence for each conservation intervention and an assessment of the effectiveness of each by international expert panels. The accompanying website www.conservationevidence.com describes each of the studies individually, and provides full references. This is the sixth author-approved edition of What Works in Conservation, which is revised on an annual basis