Science Advisory Report 2021/039

Science advice on risk assessment methods for granting ballast water management exemptions

Summary

• The International Maritime Organization’s (IMO) Ballast Water Management Convention allows nations to grant exemptions from certain ballast water management requirements to ships travelling or exclusively operating between specified ports. Exemptions are based on robust risk assessments that indicate associated ballast water activities have low or no risk of introducing harmful aquatic organisms to the recipient port.
• Two risk assessment methods — i) Joint Harmonized Procedure and ii) Same Risk Area — previously considered by the IMO to grant exemptions from specific ballast water management requirements in Europe were evaluated to determine their suitability within Transport Canada’s regime for assessing exemption applications.
• Both the Joint Harmonized Procedure and Same Risk Area are suitable methods for use in Canadian ballast water management exemption applications, provided that the assessments are conducted following the modifications and minimum requirements recommended here to address the uncertainties of each method.
• Suitability of each risk assessment method depends on the context of the exemption request, including the spatial distribution and number of ports under consideration for an exemption, ship operational profile, and availability of robust biophysical models to estimate the unassisted dispersal of planktonic organisms.
• The original Joint Harmonized Procedure uses port survey data and a decision tree to assess risk based on differences in salinity between ports and the presence of species of concern at the source port that are not at the recipient port.
• Recommended modifications and additions to the Joint Harmonized Procedure include changes to the method of selecting species of concern, nodes in the decision tree assessing potential survival of species of concern in the recipient port, and minimum requirements for the environmental data informing the assessment.
• For the Joint Harmonized Procedure, it is recommended to use a stepwise approach that initially involves a comprehensive literature review prior to conducting detailed port surveys.
• The original Same Risk Area approach evaluates whether species of concern are likely to disperse unassisted via water circulation to recipient ports, regardless of their transport in ballast water.
• Recommended modifications to the Same Risk Area approach include setting the biological inputs of the model based on species of concern identified in the source port or region (when available), otherwise a general trait-based modelling approach should be used to represent a variety of nonindigenous species. Best practices must be used when conducting biophysical modelling to ensure the results are of sufficient quality to inform the exemption decision-making process.
• It is recommended that proponents be invited to submit a notice of intent before conducting port surveys (Joint Harmonized Procedure) or port connectivity modelling (Same Risk Area assessment) and that regional Fisheries and Oceans Canada experts be engaged for input on the methodology that will be used before significant effort is expended.
• After the risk assessment is completed, an independent peer review should be undertaken through a transparent process — such as the Canadian Science Advisory Secretariat science advisory process — to ensure that the risk assessment has been conducted in a thorough and objective manner.
• Regulation A‑4 may not be best suited for one‑time exemption requests, where ballast water exchange, ballast water treatment, or discharge to shore are alternative approaches to manage ballast water. These alternative approaches may also be used to manage the ballast water of ships that need to temporarily deviate from the exempted route.

This Science Advisory Report is from the February 23–25, 2021 National Advisory Meeting on the Evaluation of Existing Risk Assessment Methods for Granting Ballast Water Management Exemptions. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available.

Science Advisory Report 2021/039 (PDF, 630 KB)

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