The spread of non-native species has been a subject of increasing concern since the 1980s when human-mediated transportation, mainly related to ships' ballast water, was recognized as a major vector for species transportation and spread, although records of non-native species go back as far as 16th Century. Ever increasing world trade and the resulting rise in shipping have highlighted the issue, demanding a response from the international community to the threat of non-native marine species. In the present study, we searched for available literature and databases on shipping and invasive species in the North-eastern (NE) and South-western (SW) Atlantic Ocean and assess the risk represented by the shipping trade between these two regions. There are reports of 44 species associated with high impacts for the NE Atlantic and 15 for the SW Atlantic, although this may be an underestimate. Vectors most cited are ballast water and biofouling for both regions while aquaculture has also been a very significant pathway of introduction and spread of invasive species in the NE Atlantic. Although the two regions have significant shipping traffic, no exchange of invasive species could be directly associated to the shipping between the two regions. However, it seems prudent to bring the exchange of ballast water between the two regions under control as soon as possible.

In 2005, Brazil addressed the environmental challenges posed by ballast water through a unilateral regulation, called the Maritime Standard Nº 20 (NORMAM-20), applied to all shipping in her waters. This world-leading decision was the culmination of a process that started during the 1990's. Here, we summarize how these ballast water regulations were brought in and adopted and present the findings of 10 years of enforcement (2005-2015) in 39 ports along the Brazilian coast. We show that compliance with the Brazilian standard has increased significantly since the regulations were implemented (p<0.001). After five years of implementation, non-compliance decreased probably reflecting an increase in awareness of the Brazilian Standard and a shift in the shipping industry commitment to minimize and control the spread of invasive species through ballast water. The Brazilian experience shows that very high levels (97%) of compliance with ballast water management regulations can be made to work in a region of global importance to the maritime industry. In the last decade, the rules governing ballast water in Brazil have evolved to address the demands from the maritime community and to provide updates such as imminent requirements for the use of ballast water management systems on board ships. These regulations are rarely cited when ballast water regulations are discussed internationally, yet there is much to learn from the proactive approach taken by Brazil such as what is feasible and enforceable.

Abstract. Biofouling is a major vector in the transfer of non-native species around the world. Species can be transported on virtually all submerged areas of ships (e.g. hulls, sea chests, propellers) and so antifouling systems are used to reduce fouling. However, with increased regulation of biocides used in antifoulants (e.g. the International Maritime Organization tributyltin ban in 2008), there is a need to find efficient and sustainable alternatives. Here, we tested the hypothesis that short doses of low salinity water could be used to kill fouling species in sea chests. Settlement panels were suspended at 1.5 m depth in a Plymouth marina for 24 months by which time they had developed mature biofouling assemblages. We exposed these panels to three different salinities (7, 20 and 33) for 2 hours using a model sea chest placed in the marina and flushed with freshwater. Fouling organism diversity and abundance were assessed before panels were treated, immediately after treatment, and then 1 week and 1 month later. Some native ascidian Dendrodoa grossularia survived, but all other macrobenthos were killed by the salinity 7 treatment after 1 week. The salinity 20 treatment was not effective at killing the majority of fouling organisms. On the basis of these results, we propose that sea chests be flushed with freshwater for at least 2 hours before ships leave port. This would not cause unnecessary delays or costs and could be a major step forward in improving biosecurity.