Marine-coastal analysis

Marine-coastal analysis

ERSE carries out the following marine and marine-coastal analyses, both in Tuscany and the rest of Italy.

CARLIT Coastal Cartographic Method

The CARLIT method (CARtography of LITtoral and upper-sublittoral benthic communities) maps the composition and linear development of algal communities of microtidal environment on maps of suitable scale, in order to infer the magnitude of the human pressure, to which the superficial communities of rocky substratum dominated by macroalgae respond relatively quickly. It is a useful tool for a preliminary investigation on long coastal stretches, which at the same time guarantees sensitivity, ease of application and reduced analytical costs. Due to its simplicity of application and low impact on the community (non-destructive), the method is suitable for application in protected natural areas of conservation interest; the type of results produced is in accordance with Directive 2000/60/EC.

Analysis of Posidonia Oceanica meadows

The Study of Posidonia Oceanica not only provides data on the health’ status of this important Mediterranean biome, but it is also a reliable biological indicator of water quality and the ecological situation of the coastal area. This marine phanerogam is relatively sensitive to changes of environmental conditions, to which it responds by varying certain parameters (e.g. density, foliar coverage, phenological aspects, productivity, depth and aspect of the lower edge of the meadow). Among the many indexes developed for its monitoring, here are those most applied.

  • The estimation of meadows’ density measures the number of leaf bundles per square metre, defining a series of five Density Classes which, in turn, summarize the different levels of disturbance, from imperceptible (Class I: “extremely dense meadow”) to very intense (Class V: “demi meadows”).

  • The determination of the average number of leaves per tuft (Leaf Area Index: LAI) and the calculation of Coefficient A represent estimates of phenological parameters relating to the vegetative health’ status of individual orthotropic rhizomes, the actual foliar surface of the plant and the stress to which it is subjected (hydrodynamic or due to predation). These parameters are useful for a quick and precise comparison between the health’ status of different meadows, located in different geographical areas and/or subjected to different types of disturbances.

  • The lepidocronological analysis, providing an estimate of the number of leaves produced by each orthotropic rhizome during an annual vegetative cycle, allows to calculate the primary production per bundle (P). This method, properly paired with chemical analysis, also allows to evaluate the amount of pollutants absorbed by the plant during each cycle of vegetation, being very useful in the study of bioaccumulation.

  • The dynamics of meadows’ lower limit, that is ecologically more fragile and therefore more susceptible to regression and / or thinning in case of stress, is carried out through the balisage protocol, formulated by the Réseau de Surveillance Posidonies, which is based on the employment of dead bodies (balises) to be placed on the bottom. These represent the spatial reference on which to evaluate the progression or regression of meadows’ lower limit during subsequent monitoring campaigns. This study, together with the estimation of the parameters described above, allows to estimate the vegetative trend of the whole meadow, detecting any signs of stress.

Analysis of benthic communities (M-AMBI)

The M-AMBI index is used to define the health’ status of the water body through the analysis of macrobenthos. Benthic communities are successfully used as indicators of stress or pollution, as their species composition and inter-specific relationships reflect environmental conditions. They are also relatively static and act as a sort of biological memory as they are subject to all natural or anthropogenic changes occurring in the area where they live. For the evaluation of the index, the benthic community of each station is analysed by calculating the structural or community parameters (number of species, specific wealth, abundance, diversity and evenness), in order to describe the population qualitatively and quantitatively. The calculation of the index makes it possible to assess the status of the water body as required by European legislation.