- Testing all sizes of ballast water organisms identified by the IMO is important to remain compliant.
- IMO has specified the type and size of organisms that treatment is needed for.
- Organisms are broken down into bacteria, organisms between 10-50µm (phytoplankton) and organisms greater than 50µm (Zooplankton).
- Can’t conclude monitoring only the 10-50µm fraction.
- Zooplankton can survive in the ballast tank without light, but phytoplankton dies or is eaten.
- B-QUA ballast water monitoring system is scientifically validated to measure ballast water readings across all three fractions.
LuminUltra highlights the importance of testing all sizes of ballast water organisms identified by the IMO to remain compliant, writes Malcolm Latarche for an article published in Ship Insight.
LuminUltra, a Microbiological monitoring equipment specialist advised the shipping industry the importance of testing all sizes of ballast water organisms that are identified by the IMO. They urge testing all sizes of organisms to,
- prevent the spread of aquatic invasive species and
- to remain compliant.
Organism carried in ballast water
There are more than 4,000 species of organisms that are carried in ballast water. They range in size and resilience to treatment. The IMO has specified the type and size of organisms that treatment is needed for.
The three fractions
These organisms are broken down into three fractions. They are
- into bacteria,
- organisms of between 10-50µm and
- organisms greater than 50µm.
All the above mentioned three sizes are to be measured and assessed under Regulation D2 of the Ballast Water Management Convention (and Circ.42/Rev1).
About the organisms
- Organisms found in the 10-50µm range are typically phytoplankton and some micro-zooplankton.
- Organisms found in the >50µm range are typically zooplankton.
Can’t conclude monitoring only the 10-50µm fraction!
Bacteria and phytoplankton are considered easier to treat, while zooplankton has proven more difficult.
Monitoring just 10-50µm fraction therefore should not be considered as the most suitable group for base compliance or system performance verification.
Carine Magdo, Business Development Manager for Ballast Water Monitoring Solutions, LuminUltra, said, “It is important that all three fractions and especially those greater than 50µm are considered when testing ballast water, as experience proves that if a system fails it is most likely in this category.”
Difficulties with zooplankton
- Zooplankton is the most difficult fraction to treat for compliance with D2 discharge requirement.
- Blooms of zooplankton can also clog up BWTS filters.
- If filters fail, they can pose a significant challenge to system performance.
Phytoplankton and bacteria
The presence of phytoplankton and bacteria is seasonal and dependent on the region. So checking for these organisms alone is not a fair indicator of a BWMS’s effectiveness.
Difference between ports
The ballast tank ecosystem can change between ports, with the >50µm fraction potentially increasing and the 10-50µm fraction potentially decreasing.
One of the reasons is that Zooplankton can survive in the ballast tank without light, but phytoplankton dies or is eaten.
IMO in regulating ships’ ballast water
Magdo said, “IMO has made remarkable progress in regulating ships’ ballast water. The Ballast Water Management Convention, still fairly new to the industry, continues to evolve as more technology and expertise is developed. A number of next steps have been identified, which LuminUltra is involved with, including verification of the indicative analysis instruments required to measure the different levels across the fractions.”
System scientifically validated
The company’s B-QUA ballast water monitoring system has been scientifically validated to measure ballast water readings across all three fractions.
LuminUltra believes that greater emphasis should be placed on detecting and treating zooplankton in ballast water to minimise the spread of invasive aquatic species.
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Source: Ship Insight