Report on the Invasive Species Component of the MEDA’s, TDA & SAP for the ASCLME Project

Invasive alien species (IAS) are now generally recognised as one of the greatest threats to global biodiversity. They also have serious economic, environmental and health impacts and, as a result, can place major constraints on development and natural resource use. In the marine realm there are examples of invasive species from all different taxonomic groups, ranging from plants, to vertebrates and even microbes.

Globally, the incidence of species invasion is increasing drastically, as ongoing development leads to growth in maritime and shipping sectors, and also other human-mediated activities involving species translocation, such as aquaculture. The impacts of invasions are similarly increasing as marine ecosystems weeken under the combined stresses of over-fishing, pollution and coastal development.

There are several significant vectors of transfer for marine organisms, including intentional introduction (e.g. for fisheries or aquaculture) and unintentional means, such as biofouling on ocean-going vessels, accidental release from aquariums, and discharge of ships’ ballast water, which is thought to be the most serious modern vector. Almost any type of organism can be transferred in situations where water is transported from one ecosystem to another, due to the planktonic life stages that most marine species experience. Ballast water is taken on by ships in order to stabilise them at sea when they are not fully loaded with cargo. Large vessels can carry over 150,000 tons of ballast water on one voyage. It is estimated that upwards of 10 million tons of ballast water are transferred around the worlds oceans each year, containing up to 7,000 species of aquatic organisms at any given time.

The International Maritime Organization (IMO) has developed the International Convention for the Control and Management of Ships’ Ballast Water and Sediments, adopted by member states in 2004, which remains the most pertinent of international legal instruments in the fight against marine IAS. The Convention on Biological Diversity (CBD) (1992) provides a comprehensive basis for protection of biodiversity from IAS generally, and the FAO has developed framework for the management of species deliberately introduced for fisheries and aquaculture purposes. Efforts to implement the provisions of these instruments are being made at local and regional levels. The ASCLME programme is aiming to help facilitate this process, and function as a medium for a collaborative partnership approach to building the appropriate capacity and networks to reduce the risk of serious impacts to the region’s marine biodiversity and resources.