Many human-mediated vectors – such as transportation of goods for consumption and movement of people – move species around the world, creating an opportunity for the establishment of invasive species. Ballast water from vessels has historically been one of the most important vectors for aquatic invasive species. Such species have contributed to the decline and disappearance of native ones and the collapse of local fisheries, caused damage to infrastructure, and cost billions of dollars per year in lost revenue and control costs.
To prevent the spread of harmful organisms the International Maritime Organization (IMO) adopted the International Convention for the Control and Management of Ships' Ballast Water and Sediments, which establishes standards and procedures for the management and control of ships' ballast water and sediments. The Convention has now been fully ratified and will enter into force on 8 September 2017, so there is a pressing need to plan its implementation into national legislation and Port State Control inspection programmes.
Monitoring compliance onboard RV Meteor
In preparation, 19 researchers from seven countries embarked on an ocean voyage from Mindelo, Cape Verde to Hamburg, Germany as a collaborative effort to assess sampling devices and analytic tools to evaluate their potential to monitor compliance with the standards laid down in the Convention. The researchers came from the areas of government, industry, and academia, with expertise in science, engineering, and maritime law. The work was led by the German Maritime and Hydrographic Agency (BSH) and Fisheries and Oceans Canada (DFO) and was carried out aboard the German research vessel, RV Meteor. The ICES Working Group on Ballast and Other Ship Vectors (WGBOSV) contributed to defining the trip objectives and participated as members of the voyage's scientific team.
Collection and analysis put to work
The experts looked at both parts of compliance monitoring: sample collection and sample analysis – where a number of tools and technologies are currently in development for each. Three methods for the former and nearly 20 different ones for the latter were examined, with the study being the first to concurrently test multiple analytic tools and sampling devices under operational conditions.
Analysis methods are categorized as either 'detailed' or 'indicative'. Detailed analyses, such as microscopy, provide a direct measurement of the number of viable organisms in a sample, but typically demand extensive expertise, costly equipment, and a time frame generally too long for a scenario where compliance can be enforced. In contrast, 'indicative' methods are rapid and easy to operate, but usually provide only an indication of potential non-compliance with the Convention, not a direct count of organisms. On the trip, water samples were collected using paired devices and analyzed in parallel by all methods to determine whether results were similar between sampling devices and whether quick, indicative methods offered comparable results to the more detailed testing methods and high-end scientific approaches.
Findings to help establish better methods
For sample collection, differences were observed in the number of viable organisms collected by the various devices (net, sampling skids in open and closed configurations), but these differences were not consistent across size classes. In the analysis, several promising indicative methods were identified which showed high correlation with microscopy results but allowed much quicker processing. The results offer insight into the benefits and limitations of each method, and support ongoing efforts to establish reliable analytic methods for compliance monitoring under the International Ballast Water Management Convention.
