Assessing the potential for invasive species introductions and secondary spread using vessel movements in maritime ports. (April 2022) - Costello, Katie E.
Abstract: Global shipping facilitates the introduction of invasive species and parasites via ballast water and hull fouling. Regional management of invasives may be strengthened by identifying the major routes in a network, to allow for targeted ship inspections. This study used cargo shipping records to establish the connectivity of shipping routes between ports in Ireland and other nations. 9291 records were analysed, investigating vessel residence and journey times. On average, vessels spent up to five days in port and less than five days at sea. However, there was strong variation, with general cargo ships recording up to 13 days in port. A horizon scan for species likely to invade in Ireland was incorporated for five species and their associated parasites: American razor clam, Asian shore crab, Brush clawed shore crab, Chinese mitten crab and American slipper limpet. Routes of concern are highlighted and a general framework for effective management is outlined. Highlights: Shipping can facilitate the introduction of invasive species via ballast water and hull fouling. Regional management and biosecurity can be strengthened by conducting targeted ship inspections. Inspections may be prioritised by enumerating connections to ports with confirmed invasives. Horizon scanning exercises may be also conducted to forecast the most likely invasive species. Secondary spread may be assessed by identifying the connectivity of ports within a region.