Abstract
This report presents the Deliverable 6.2 – Report on Environmental Impact Assessment and Mitigation Strategies. The first and essential step for an evaluation of potential effects on the environment was the collection of available information on the existing environments at the three sites: (i) off Gran Canaria (Spain), (ii) off Crete (Greece), and (iii) off Liuqiu Island (Taiwan). In the second step we developed an appropriate methodology for the environmental impact assessment (EIA) of floating multi-use offshore platforms that may serve as a guideline for future EIAs. The third step involved the identification and summary of potential impacts of the three selected TROPOS scenarios, Leisure Island (Gran Canaria), and Green & Blue Scenario (Crete and Liuqiu Island), on the particular environments. In the fourth step we evaluated the significance of each identified effect to estimate overall magnitude of consequences. The fifth and final step was the development of appropriate negative impact mitigation measures. In total, a multitude of potential impacts were identified for each scenario, most of them of only minor or moderate significance. The Green & Blue Scenario off Crete is not expected to have major detrimental effects on the environment, because the existing environment is not of high sensitivity. However, the waters are phosphorous limited and the deposits and remains from the fish aquaculture may result in a boost of local primary production due to phosphorous input. For the Leisure Island scenario off Gran Canaria, noise from vessel traffic and operation of leisure facilities, as well as artificial lighting from bars and restaurants have been identified as the most critical effects. The Green & Blue scenario in Taiwan involves aquaculture, OTEC and some leisure facilities, i.e. noise and artificial lighting are impacts to consider here, too. Additionally, solid and liquid wastes from leisure facilities and the fish aquaculture may in combination significantly affect water quality and the living community. Some of the identified negative effect can be efficiently mitigated, e.g. appropriate waste and waste water treatment and management will avoid or at least significantly reduce negative impacts of wastes on the environment. Other negative effects, such as noise generated by mooring installation, vessel traffic and leisure facilities or artificial lighting can be reduced, but not completely removed. Effects of these stressors on the environment will need comprehensive monitoring and appropriate management. An EIA of a 4th TROPOS concept, the so-called Sustainable Service Hub, will be included in a future deliverable; nevertheless, a first short introduction of the concept and a preliminary summary on environmental aspects are already provided, here.