Social and economic drivers for activities affecting non-indigenous species
Growing global populations and the associated need for food and energy continue to increase the risk of the input and spread of non-indigenous species, especially through shipping, release via aquaculture, and marine littering. In addition, alterations in marine environmental conditions due to climate change will also affect the introduction and spread of NIS.
All social and economic drivers have the potential to influence the input and spread of non-indigenous species. Energy security, food security, climate change and the acquisition of resources and production of goods underpin political and economic stability.
Growing global populations increase the demand for food, and aquaculture will help to meet this growing demand. Aquaculture is a key pathway for the introduction and spread of non-indigenous species. In particular, non-indigenous species can contaminate aquaculture stock and be introduced into new locations as the stock moves about. Although the EU has regulated to prevent contamination by NIS between countries (Council Regulation (EC) 708/2007 of 11 June 2007 concerning the use of alien and locally absent species in aquaculture), NIS may still be introduced and spread within an EU country, through cultivation. The introduction of the hard substrate associated with aquaculture into the marine environment can provide the opportunity for colonisation by marine organisms. Moreover, aquaculture can also transfer NIS in “living wrappers” as part of the trade in aquaculture goods.
Growing populations increase societies’ demand for energy. The introduction of the infrastructure associated with renewable and non-renewable energy into the marine environment (e.g. offshore wind turbines, oil and gas platforms) provides hard substrate suitable for colonisation by marine organisms. Such structures may provide stepping-stones for the accelerated spread of NIS.
The movement of cargo, fishing, military and recreational vessels at sea is a major pathway for NIS introduction. As maritime traffic continues to increase, it may result in even more substantial transport of marine organisms between locations (e.g. in the ballast water or attached to ship hulls) and the introduction of novel NIS. The marine-built structures associated with increasing shipping and leisure boating, such as ports and marinas, offer suitable habitats for many NIS and are recognized introduction hotspots.
The increased demand for housing and utilities, for materials and their processing and for the manufacturing and processing of goods can introduce pollutants to the marine environment which alter habitat suitability for marine organisms, including NIS, as these are often opportunistic species (Piola et al., 2008). Associated with this driver is the thermal pollution related to power plants. Here, the localised temperature changes associated with power station outlets (e.g. discharge of coolant water at increased temperature) may alter habitat suitability in favour of heat-tolerant NIS.
Marine litter is another driver that alters habitat and favours new introductions of NIS (Miralles et al., 2018). While tourism and recreation contribute to societal health and wellbeing, their associated infrastructure may introduce substrate for colonisation by marine organisms.
Recreational activities including sailing and angling, and the collection of marine organisms for other purposes supporting societal health and wellbeing (e.g. medicinal, ornamental) can result in the translocation of marine organisms.
Policy responses to manage human activities need to consider all these driving forces to meet society’s needs while reducing the risks of the introduction and spread of non-indigenous species, and to facilitate societal change.