A low number of introduced marine species in the tropics: a case study from Singapore

Fred Wells

doi:10.3391/mbi.2019.10.1.03

Abstract

Non-indigenous marine species (NIMS) are being transported around the world by anthropogenic mechanisms, particularly by vessels in ballast water or as biofouling. A small subset of NIMS become invasive marine species (IMS) and can cause considerable damage to local marine ecosystems. Understanding where NIMS originate, how they are transported, and their effects in the new environments are crucial to the management of IMS. As one of the busiest ports in the world that handles tens of thousands of high invasion-risk vessels annually, Singapore is regarded as being at very high risk for the introduction of NIMS and IMS. However, a compilation of 3,650 marine invertebrates, fishes and plants revealed that only 22 species have been confirmed as NIMS. The results are consistent with a growing dataset that suggests biodiverse marine ecosystems in the tropical Indo-West Pacific are less susceptible to introductions than previously thought.

Highlights

The number of non-indigenous marine species (NIMS) being introduced into new areas as a direct result of human activities—such as global shipping and canal construction, and by deliberate or inadvertent release of species used in aquaculture, fisheries and aquarium trade—has received the attention of the general public (Willan et al 2000) and caused increasing concern to scientists, agencies and managers who are working with the marine enviroment (Dommissee and Hough 2004)
Singapore lies in close proximity to the megadiverse coral triangle that stretches from Malaysia and the Philippines east to Papua New Guinea and the Solomon Islands (Hoegh-Guldberg 2009), evidenced by the high number of macroscopic marine invertebrates, plants and fish species reported in its territorial waters
Increasing coastal urbanisation, coupled with intensification of maritime activities, will continue to exert considerable pressure on tropical coastal marine ecosystems that may result in further introductions and invasions in the future

Summary

Introduction

The number of non-indigenous marine species (NIMS) being introduced into new areas as a direct result of human activities—such as global shipping and canal construction, and by deliberate or inadvertent release of species used in aquaculture, fisheries and aquarium trade—has received the attention of the general public (Willan et al 2000) and caused increasing concern to scientists, agencies and managers who are working with the marine enviroment (Dommissee and Hough 2004). A low number of introduced marine species in the tropics and Port Philip Bay, Melbourne, Australia (99 species; Hewitt et al 2004). There have been a number of surveys of ports and adjacent habitats in Australia that have recorded introduced species (Hewitt and Martin 2001; Hewitt 2002). It is not a coincidence that marine hotspots of introduced species are often in and around ports, as shipping movements are a primary vector of NIMS, either through ballast water (Carlton 1985) or biofouling (Carlton 1996; Hewitt 2002; Hewitt et al 2004; Yeo et al 2010; Jaafar et al 2012)

Methods

Results

Discussion

Conclusion