Ballast Water – Some issues and concerns

Ballast water and its impact across oceans, continents and countries is an extremely important area of concern. With the introduction of steel hulled vessels around 120 years ago, water has been used as ballast to stabilize vessels at sea. Ballast water is pumped-in to maintain safe operating conditions throughout a voyage.  This practice reduces stress on the hull, provides transverse stability that improves propulsion and maneuverability. This also compensates for weight lost due to fuel and water consumption.

While ballast water is essential for safe and efficient modern shipping operations, it may pose serious ecological, economic and health problems due to the multitude of marine species carried in it. This very disposal of water, when it takes place within ports and harbors is classed as a waste product as it may include bacteria, microbes, small invertebrates, eggs, cysts and larvae of various species. The transferred species may survive to establish a reproductive population in the host environment, becoming invasive, out-competing native species and multiplying into pest proportions. That in turn can cause extensive ecological and economic damage to aquatic ecosystems, along with serious human health issues including death.

Scientists first recognized the signs of an alien species introduction after a mass occurrence of the Asian phytoplankton algae Odontella (Biddulphia sinensis) in the North Sea in 1903. But it was not until the 1970s that the scientific community began reviewing the problem in detail to understand its seriousness and impact.

Ballast water discharges by ships can have a negative impact on the marine environment.

There are hundreds of organisms carried in ballast water that cause problematic ecological effects outside of their natural range. Some examples of serious impacts on ecology are:

New Zealand: The ballast tanks in New Zealand carry animals and plants that kill ecosystems. Ballast tanks are only used in cargo ships there. Ballast water is controlled under the Biosecurity Act 1993 in New Zealand.

Peru: A form of cholera, Vibrio cholerae, previously reported only in Bangladesh apparently arrived via ballast water in Peru in 1991, killing more than 10,000 people over the following three years.

United States: The zebra mussel, which is native to the Caspian and Black Seas, arrived in Lake St. Clair in the ballast water of a transatlantic freighter in 1988. Within 10 years it had spread to all of the five neighbouring Great Lakes.

Singapore: Among 818 ports in the Pacific region, Singapore alone accounts for an estimate of 26 percent of cross-region (long range) species exchange. Via targeted ballast management on Singapore and a few other important ports, cross-region species exchange to/from the Pacific region can be combinatorially reduced.

Invasive species and their cost implications

Since the Ballast Water Convention was adopted in 2004, almost all of the world’s seas and waterways have continued to be invaded by unwanted species. Global economic losses from the damage caused by harmful invasive aquatic species were estimated to have exceeded USD7 billion per year in  2004/05, making the total bill between the 2004 adoption of the Convention and end  of 2009 at least USD50 billion in present-day value. This sum reflects damage and repair costs to fisheries, aquaculture, water supply systems, industrial infrastructure and harbours. It does not include all of the indirect economic losses caused by changes to marine biodiversity and habitats, including impacts to and even near-extinctions of endemic species.

Reasons for the problem being on the rise

Merchant ships have increased dramatically in their number, average size and speed since the 1950s, with the sector currently estimated to grow at 8% per year until 2020 in response to widening world trade. Opportunities for spread and population increases of non-native species can also be expected to increase due to factors such as regional warming associated with global climate change, and increasing port and coastal water eutrophication in many areas.

The 2008 analysis of marine invasions found that marine invasive species have been reported for at least 84% of the world’s 232 marine eco-regions. The study also identified international shipping as being the major introduction pathway for these species. Studies of introduction records for particular ports, bays, countries or regions have yielded estimates of aquatic species invasion rates, including some alarmingly high rates for invasion-prone ports and estuaries. For example, introduction rates as high as two to three new species every year have been reported for Port Phillip Bay (Melbourne, Australia) and up to one species every nine weeks for San Francisco Bay (California, USA).

Shipping industry concerns

Until the Ballast Water Convention comes into force, ship owners and fleet managers cannot progress ballast water management in a consistent, business-predictable and safe manner, and without fear of their ships having to operate different procedures, equipments and performance standards when trading between different countries, or even different ports within a single country. Furthermore, the lack of a globally ratified Ballast Water Convention restrains the incentive for research and development of approved treatment systems.  

Way forward- finding a solution

Management practices and technological treatment systems that prevent invasions are a far more practical and cost-effective approach to the problem of invasive species transported in ballast tanks than clean-ups once a species has been discovered and may already be established in a new area.

Ballast water treatment systems in use

More than 80 manufacturing firms, water treatment companies and maritime businesses have undertaken research and development, testing and trialling work of ballast water treatment technologies since 2000. Having obtained type approvals by national administrations, and are thus ready for the market.

The modular treatment systems now coming on to the market are sufficiently compact to fit in or around most engine rooms and the majority involve pre-treatment and end-treatment as follows:

·         During  ballasting,  the  inflow  is  passed  through  filter/s  to  remove  larger organisms, sediments and other suspended solids.

·         The  filtered  water  is  then  subjected  to  the  main  treatment  which  kills  or inactivates the small organisms that had escaped filtration.

·         At the end of the voyage the ballast water is subjected to a repeat treatment prior to its discharge, so as to destroy any organisms that may have re grown in the tanks during the voyage.

There are three types of treatment systems available in the market:

1.    Systems that use filtration plus UV, oxygen stripping and pH reduction, and magnetic filtration.

2.    Systems  that  use  advanced  oxidation,  electrolysis  or  oxidative  chemical  dosing modules  to  produce  short-lived  radicals  (OH',  O3,  ClO-)  that  decay  without producing long-lived toxic end-products.

3.    Systems that generate chloride ions – typically by electro-chlorination – that can produce  long-lived  end-products  at  potentially  toxic  concentrations,  therefore requiring  adequate  decay  time  or  sulphite  treatment,  particularly  if  the  organic content is high.

 Additionally, the following steps can be followed for better BWM.

·         Clean ballast tanks regularly to remove sediments.

·         Rinse anchors and chains when the anchor is retrieved.

·         Remove fouling from the hull, piping and tanks on a regular basis.

·         Maintain a BWM Plan that includes the above in addition to ballast water management

·         Maintain records of ballast and fouling management.

The cost of ballast treatment systems

The operational costs of a ballast water treatment system will vary according to ship type and size, as well as the type of system that is selected. Capital cost estimates for installation onboard range between USD150,000 and USD500,000; extending to USD1 million for systems installed on very large carriers. However the total installation cost for a particular ship will also vary according to the number and arrangement of its ballast tanks and the difficulty of the retrofit.

The Cost of not treating ballast water

Using the estimated figure for direct global economic loss to society for damage caused by invasive species of USD7 billion per year  and the figure of 10 billion tonnes of ballast water used every year by international shipping, we can calculate a cost per tonne of untreated ballast water at 70 USD cents. Thus, the cost to society of not ensuring ballast water treatment is at least 350% higher than that of fitting adequate treatment onboard vessels, using the higher estimate for cost of treatment.

IMO convention

To react to the growing concerns about environmental impact of ballast water discharge, the International Maritime Organization (IMO) adopted in 2004 the "International Convention for the Control and Management of Ships' Ballast Water and Sediments" to control the environmental damage from ballast water. The Convention will require all ships to implement a "Ballast water management plan" including a ballast water record book and carrying out ballast water management procedures to a given standard. Guidelines are given for additional measures then the guidelines.

The spread of invasive species is now recognized as one of the greatest threats to the ecological and the economic well being of the planet. These species are causing enormous damage to biodiversity and the valuable natural riches of the earth upon which we depend. Direct and indirect health effects are becoming increasingly serious and the damage to environment is often irreversible

Means to avoid, minimise and address the potential impacts of wastes managed within ports and harbours

The main means of avoiding, minimizing and addressing the potential effects of port, harbour and ship generated wastes on the marine environment are provided by the following management practices:

·         the continued education and motivation of port and harbour users,

·         the production of waste management plans and provision of adequate reception facilities,

·         the preparation and implementation of oil and chemical contingency plans, and

·         the observation by ships of IMO guidelines to avoid introducing non-native species and contaminants in ships’ ballast waters.

Many of these management practices are regulated by other authorities and bodies, including the IMO, MCA, port state control, the environment agencies, MAFF, and local authorities, and not the port and harbour authorities themselves. The role of these bodies in waste management regulation and guidance is is to be described. The ports can, and should, support campaigns initiated by these bodies to ensure that measures to avoid, minimise and address environmental impacts are implemented effectively.

For example, it is the local regulations that require BWM to save their ecologically sensitive areas like the US, Australia, America, Brazil, Argentina to name a few. Usually, ballast exchange is carried out in open waters with minimum depth of over 200 meters and away from land at least 50 meters.  Even after BW is exchanged in open waters, Black Sea counties require Ballast to be exchanged once again in their Sea prior to making port calls. Argentina requires all tanks to be chlorinated and kept sealed for at least 12 hours prior to discharge being permitted. Shore reception facility for the discharge is also available at some places. 

Everyone needs to understand the seriousness of the BWM and contribute to making our planet safer and shipping a responsible trade.

Reference:

WWF for a living planet,- silent invasion.

IMO

Pictures are taken from Google for representational purposes, with due credits.