Água de lastro e bioincrustação como vetores de espécies não-nativas mediadas por embarcações: uma perspectiva da Autoridade Marítima Brasileira

Abstract

The present thesis addresses the topic of ballast water and biofouling as vectors for the introduction of non-native species by vessels and the role of the Brazilian Maritime Authority (BMA) in this context. These vectors are responsible for most introductions of aquatic organisms worldwide. And under certain circumstances, the introduced organism can survive in the new environment, generate offspring, and establish a population. When causing problems of economic, social, and/or environmental order, it can be said that a bioinvasion event has occurred. To tackle this problem, the International Maritime Organization (IMO) has adopted conventions and guidelines aimed at maritime transport, with each state's maritime authorities being responsible for its regulation and enforcement. The first study of this thesis evaluated the compliance of Ballast Water Reports, used as a tool for monitoring ship ballast water management, since its implementation, in 2005, until 2022. It was demonstrated that compliance was significantly higher after the entrance into force of the IMO International Ballast Water Convention in 2017. However, it was noted that some regions of the country presented few reports relative to the volume of discharged ballast water, indicating the need for a greater sampling effort in these areas. Finally, the study highlights recent BMA initiatives to better meet the Convention's objectives. In an experimental study with low salinity water as a biosecurity tool for preventing the introduction of non-native organisms via biofouling, exposure of assemblages developed in Guanabara Bay-RJ to salinities below 7 for two hours proved to be promising. One month after treatment, the fouling panels presented a higher abundance of dead organisms, open spaces, and biofilm compared to panels subjected to salinities of 15 and 35 (control). Salinities below 7 also showed a lower biofouling thickness, indicating that this treatment also has the potential to improve ship energy efficiency by reducing hull drag against the water, which can reduce fuel consumption and greenhouse gas emissions. Since the IMO Biofouling Guidelines are voluntary instruments, South Africa, New Zealand, and the United States have implemented their mandatory rules to prevent the introduction of organisms through this vector. In order to suggest a mandatory rule for ships and recreational crafts in Brazil, a comparative study of the main topics of these documents was conducted and used as the basis for outlining requirements for biofouling management in Brazilian Jurisdictional Waters. The study's appendix provides a base text in the form of Chapter 4 of NORMAM-20/DPC. Among the suggested requirements, highlights include: differentiated treatment between vessels larger and smaller than 24 meters in length, the subdivision of the Brazilian coastline into 3 marine biogeographic regions, and the non-adoption of a "clean hull" requirement. The present thesis addresses monitoring, prevention, and regulation tools with impacts on vessel-mediated bioinvasion. A topic that permeates these studies is biosecurity risk assessment. This thesis presents important parameters in defining the risk of a ship in introducing exotic aquatic species into Brazilian Jurisdictional Waters, and provide suggestions to the Brazilian Maritime Authority for a more assertive surveillance.