Biological Invasion of Seas and Oceans

Abstract

Biological invasion is the entry of invasive species. Species are considered invasive when they become established in natural habitats, are agents of change, and threaten native biological diversity. Most invasive organisms from other ecosystems are transported around the world in the ballast water of ships.

In this paper for the Journal of Maritime Research, it will be explained to the audience which is the problem with these organisms transported in ballast water of ships, as well as prevent their invasion in other ecosystems and how to choose the right equipment to remove such species. 

These invasive species densities are up to several thousand individuals per square meter, which can cause significant damage to hydraulic infrastructure such as hydropower centrals. Also in aquatic ecosystems can cause major disruptions in the food chain or food web dynamics, leading to displace native species. As is well known, the ballast is needed for many functions related to stability, manoeuvrability and propulsion of ships. The problem is that ballast water contains a soup of organisms. These organisms are composed of plankton (microscopic plants and animals), bacteria and viruses. This movement of organisms is now seen as one of the greatest threats to coastal ecosystems in the world. The ballast water organisms have a great environmental and economic impact. If ignored, a marine species could invade a new environment somewhere in the world every nine weeks. To combat this problem there are different solutions, each belonging to one of the largest companies in the marine sector. In the present circumstances of technological development, it is estimated that new generation of ballast water treatment systems, based on physical processes (such as in this paper presented) are the safest and most reliable to avoid transporting and unloading of organisms that ballast water contains.

This article concludes that a more suitable to fit onboard systems based on physical removal than those based on chemical, aggregations and storage of chlorine products and / or other chemicals where, if there is any leakage, may pose a risk to the safety of crew and vessel. Among the solutions discussed in this article for the Journal of Maritime Research, have been identified a number of disadvantages in each. The first is the unit cost and maintenance, in the case of using Ultra-Violet or inert gas is very high. The size and footprint are important determinants from the design point, and something that in practice all units showed. The simplicity of design, elimination of chemical additives, the small size and low maintenance costs are the parameters that should determine the adoption of a system or another.