Marine Parasites as an Object and as a Factor in the Problem of Invasive Species in Marine Ecosystems: Reflections on the Topic

Abstract

The distribution of organisms in space is a natural function which ensures the spreading of genes and establishment of populations. The insertion of a new species into ecosystems is a process that has been occurring for centuries, and in many cases, is influenced by human interference, whom knowingly or unknowingly aids in spreading different species around the world. Marine parasites, in particular, can act as Invasive Species (IS) and also as environmental factors affecting the free living IS in the Recipient Ecosystem (RE). For Parasite Invaders (PI), there exists mechanisms that prevent its invasion in RE. The mechanisms of elimination of PI are very diverse, from grazing of parasites’ free-living stages by hydrobionts to the defense reactions of native organisms which PI will use as hosts. There are two possibilities to a successful introduction of PI. The first is the “soft” introduction of PI into the system interconnections of RE. The second variant can develop on the dysfunctional scenario for the recipient ecosystem. The result of the introduction depends on the individual characteristics of the PI. Marine parasites can be controlling factors which prohibit or prevent the establishment of free living IS at the invasion area. As a basis for logical constructions, we used the conception of Parasite Systems as normal component of ecosystems.