Are they always bad? Assessing benefits of non-indigenous species in aquatic environment and their implications

Non-indigenous species (NIS), non-native, or alien species are any organisms living and spreading outside their natural habitat. Many of NIS spread to a new environment accidentally, while some other species are intentionally introduced by humans to a new habitat in many different pathways, as follows: 1) release; 2) escape; 3) contaminant; 4) stowaway; 5) corridor; and 6) unaided. Threaten native biodiversity may be the most problematic impact of NIS. They can also disrupt food-web organizations and affect the ecosystem structures. Additionally, the problem is exacerbated by disagreements regarding whether or not NIS should be permitted for aquaculture production. The likelihood of NIS escaping, being released from aquaculture, and establishing in its native habitat poses a significant threat to the ecosystem and biodiversity. NIS also have positive impacts as ecosystem engineers which may increase the biodiversity of native communities. Other benefits of NIS include providing an alternative food source and supporting fisheries and aquaculture sectors. Understanding the introduction process and the impacts of NIS should be supported by effective policy frameworks and management approaches, including risk assessment, prevention and control, pathway and vector management, early detection and rapid response, eradication, and mitigation and restoration. Furthermore, the crucial efforts would be raising public awareness, improving scientific research, and developing strategy regarding biosecurity issues as consequences of the emergence of interactions complexity among NIS and other global ecological change drivers.