2.1. Sampling and Sediment Collection

Ballast tank sediment sample CN was collected from an empty ballast tank with a capacity of 747.0 m³ from Vessel A arriving at Jiangyin Port, China. Vessel A is a general cargo ship built in 1997. The ballast water log of the studied tank before sampling was present in Table 1. The sediment sample was collected on 10 November 2017 with a sterile trowel and sub-packaged into sterilized tubes, which were stored at 4 °C in darkness until further analysis.

The ballast water log for the studied ballast tank of Vessel A.

¹ BWX = Ballast water exchange.

A ballast tank sediment sample NA was collected from a double-bottom tank of Vessel B entering Windsor Port (Ontario, Canada) on 26 June 2002. This sample was related to a research program for assessing potential invasion vectors via overseas vessels arriving in the Great Lakes, with the information of ship, tank, and ballasting history provided by Johengen et al. (2005) [31]. In detail, this investigated ship was built in 1986. During the research program, the voyage of this ship was from Tampico (Mexico) to Toledo (USA), Windsor (Canada), and Detroit (USA). During the voyage, it was ballasted at Everglades (USA) with a total ballast capacity of 9000 m³ in May 2002. The sampled tank was not cleaned at the dry dock, and the number of total residuals was about 50 metric tons with sediments <25% when sampling.