Marine invasive species, also known as non-native species, non-indigenous species, or alien species, are organisms that have been introduced into ecosystems where they do not historically or naturally occur. These introductions can occur either intentionally, such as through the release of ornamental species or aquaculture, or accidentally as a result of shipping activities or recreational pursuits. Once introduced and established into new environments, they have the potential to cause significant harm to local ecosystems and economies. Here we will provide a comprehensive understanding of marine invasive species, their impacts, and how they are managed.
There are many varying definitions on what constitutes an invasive species in marine waters. However, marine invasive species will typically share one or more of the following characteristics, each of which represent a significant threat to the biodiversity, stability, and overall health of the ecosystems they invade. It is essential to identify and understand these characteristics to develop effective management strategies and minimize the impacts of these species on native ecosystems.
- Lack of natural predators: In their new environment, marine invasive species may not have any natural predators, which allows their populations to grow unchecked. Without predators to keep their numbers in balance, invasive species can rapidly multiply and dominate their new surroundings.
- Ability to outcompete native species: Marine invasive species often possess traits that give them a competitive edge over native species, such as a higher reproduction rate, greater tolerance to environmental stress, or more efficient resource utilization. This enables them to outcompete native species for food, habitat, and other resources, leading to a decline in native populations and potentially even the loss of entire native species.
- Rapid adaptation: In some cases, marine invasive species can quickly adapt to new environmental conditions, which allows them to thrive and spread in their new habitats. This adaptability can make them even more successful than native species, further exacerbating their impacts on local ecosystems.
- Habitat alteration: Certain marine invasive species can physically alter their new habitats, changing the structure and function of ecosystems. For example, some invasive species may create new habitats by constructing extensive burrows or reef-like structures, while others may release toxins or other chemicals that can harm native species and disrupt ecosystem functioning.