INTRODUCTION

Over 80 per cent of the world's cargo is moved over the ocean and billions of tonnes of ballast water are filled in one part of the ocean and discharged at another. In the process, large numbers of marine species enter or leave the ships ballast tanks, thus travelling large distances on a daily basis. These organisms range from microscopic bacteria to large plants and free- swimming fish. The introduction of marine organisms alien to local ecosystems through ship hulls and ballast water is referred to as marine bioinvasion and poses threats to human, animal, and plant life, as well as the marine environment. This has serious consequences for native biota, fisheries, and the overall coastal ecosystem, and can have harmful effects on local flora and fauna through their oxygenic, proliferate, and over-competitive characteristics. The introduction of new species can have a direct impact on society and human health by affecting fisheries and causing health hazards. Also, biodiversity may now be on the verge of collapse due to non-adherence of best practices for ocean governance. Regulations aimed at solving these problems are easily circumvented and ships continue to violate international laws with impunity.

The oceans and seas represent about 70 per cent of the earth's surface. These large bodies of water are intrinsically linked to human and organic life cycles on earth as they provide 15–20 per cent of the animal protein in the diet of people worldwide. Also, as the traditional raw material resources on land are depleted due to overexploitation, resources at sea have attracted great interest throughout the world. The pressures of population growth and food shortages have forced humankind to look towards the sea to meet the growing demand; thus, sea-based resources are now being increasingly exploited to support economic and industrial development. It would be significant to mention that in the long cycle exploitation of resources, the seas have become the last reservoir of resources, be it living or non-living. However, non-adherence to best practices in ocean governance has led to uncontrolled depletion of resources and that remains a cause for concern.