In Italy, most of the actitivities of Posidonia oceanica transplantation activities are indicated, in the whole of the EIA, as a measure to compensate for damage caused to the seagrass by coastal works and infrastructures. The monitoring aims to verify the effectiveness of compensation measures during the time is not always included in the Environmental Impact Studies (EIS) and/or the Environmental Impact Assessment (EIA) requirements and, in the few cases where it appears, it is expected for short periods, rarely for no more than five years. That means that this kind of monitoring provide only partial information on the efficacy of transplants performed. For example, they can show the trend of growth dynamics of transplanted seagrass only in the short term, although it is known that the growth of P. oceanica prairies is very slow and can be only appreciated in the long term.
Therefore, considering long-term targets that characterize the compensation measures, such as the Habitats Directive (92/43/EEC), it is necessary to provide an implementation monitoring of the same measures before and after the achievement of the objectives set by these measures. In addition, the recent EIA Directive (EIA 2014/52/EU) introduces important changes related to the role, effectiveness and efficiency of environmental monitoring in the EIA, defining specific activities aimed at verifying the expected results from the entire EIA process, in order to avoid that the process is reduce to a mere administrative procedure. In this context, the collection of new and additional data, useful to better delineate the efficacy of existing P. oceanica transplants and the definition of optimal monitoring strategies are an important step to improve the governance process concerning the management and recovery of P. oceanica seagrass damaged for future research on transplantation activities.
Action B2: Monitoring the performance of the existing Posidonia oceanica transplantations
In the context of this action, new and additional data will be collected to assess the performance of Posidonia oceanica transplants existing in Italy and to define specific monitoring protocols to evaluate their effectiveness. The activities will take place with two underwater activities (Summer 2018 and 2019) in three sites, where have been carried out P. oceanica transplants following various anthropic impacts, Piombino (Tuscany), Ischia (Campania), Civitavecchia (Lazio) and Augusta (Sicily), where a transplant was carried out with the aim of recovering the pre-existing Posidonia habitat.
In these sites, various transplanting techniques have been used, selected according to the substrate type (sand or mat) and the extension of the transplant to be performed (from 1000 m2 to 10000 m2). Besides, transplants were carried out in different years and different were the monitoring plans (duration, frequency, investigated parameters) developed to evaluate their effectiveness. the monitoring activities will take place in each site so that each project partner can actively participate, sharing the planning, data collection and results obtained.
Each monitoring will be not destructive and planned according to the age of the transplant. Shoots will be counted, and assessing their survival and re-colonisation status will be performed. Data on the main phenological parameters will be collected in situ (for example: the length of the longest adult leaf) as well as ecological data, (for example: estimating the cover of the epiphytes community). These data will be compared with those obtained from surrounding natural meadows.