Sustainability has become a fundamental pillar for the development and management of marinas. Among the most useful tools for assessing the environmental impact of their infrastructure and services is Life Cycle Assessment (LCA), which allows the environmental effects of a product or system to be quantified from its manufacture to its final disposal.

A recent LCA study focused on floating structures such as pontoons and fingers. The aim was to determine the carbon footprint of complete facilities and compare the emissions associated with different construction solutions. Two main types of structures were analysed: aluminium modules with polyethylene floats and composite decking, and reinforced concrete modules with galvanised steel and EPS core. Each of these presents different advantages and challenges from an environmental point of view.

The study was carried out following internationally recognised methodologies (ISO 14040, PAS 2050 and GHG Protocol), applying a cradle-to-grave approach that covers all stages of the life cycle: from the extraction of raw materials to dismantling and final treatment. It was found that the phase with the greatest environmental impact is the manufacture of materials, especially aluminium, steel and cement, which can account for up to 90% of the total footprint.

One of the main challenges was obtaining reliable data, especially in the early stages of the life cycle, such as the extraction or initial transformation of certain materials. This is particularly complicated in products such as EPS or some synthetic decking. Added to this is the lack of in-house studies by many suppliers and the complexity of identifying specific consumption in shared industrial processes.

Even so, tools such as Environmental Product Declarations (EPDs) or databases such as Ecoinvent help to fill some of these gaps. However, differences in data quality and format can make comparisons difficult, especially for elements such as flooring, where there is great variability between softwoods, tropical woods and composites.

As a practical example, an LCA study I carried out on pontoons that showed that transport and installation represent a very small part of the total carbon footprint. On the other hand, the final phase of the life cycle is key: aluminium structures have a high recycling capacity, while concrete modules can be reused as fill in construction projects. EPS, although not very polluting in its manufacture, poses an environmental risk if not managed correctly.

The comparison between aluminium and concrete structures showed a 30% difference in favour of aluminium (180 kg CO?/m² compared to 260 kg CO?/m²), although it is important to note that they do not offer the same technical performance. Aluminium models are lighter and easier to transport but can bear lower loads.

This type of analysis is also being applied to other elements of the port, such as water and electricity supply towers, where the type of surrounding structure has a significant impact on the final results.

A comprehensive LCA approach allows other indicators beyond carbon to be assessed, such as toxicity, resource scarcity and ease of recycling. 

In short, integrating LCA into the design and management strategy of marinas is essential to move towards more responsible models. Focusing on material selection and end-of-life planning will significantly reduce impacts and position the sector as a benchmark in coastal sustainability.