The Kuroshio holds vast cultural, social-economic value to most of countries in the North Pacific. It transports large amounts of heat and salt from the tropics to mid-latitudes, interacting and exchanging energy with atmosphere along its path, and thus moderating the global and regional climate. The Kuroshio, together with its adjacent current systems and the topography, forms a unique environment for material exchange between the land, marginal seas, the Kuroshio and the pelagic ocean. The transportation of nutrients and organisms by the currents and associated ocean processes gives way to a high level of marine biodiversity along the path, and contributes to abundant marine fishery resources in the Western and North Pacific.

Despite its importance, most of our knowledge about the Kuroshio is still limited to those generated from the Cooperative Study of the Kuroshio and Adjacent Regions (CSK)- the first international ocean research project that the Intergovernmental Oceanographic Commission of UNESCO (IOC) conducted in the Western Pacific during 1965-1979.

Over the past decades, the Kuroshio region has been known as one of the most responsive areas to the global warming. Its drastic changes seem to directly affect the regional weather and climate patterns. Moreover, it is becoming evident that the distribution of many organisms is changing and some of them are even at risk of becoming endangered as a result of global warming and escalating human activities. These changes to the Kuroshio are affecting various marine ecosystem services our society has been dependent on.

In response to the demands of Kuroshio study and the UN Decade of Ocean Science for Sustainable Development (2021-2030), the IOC Sub-Commission for the Western Pacific established the CSK-2 as a large scale multidisciplinary and multinational research programme. There are two major high-level objectives formulated for its initial development, which are:

Objective 1: to understand the Kuroshio and its impact on global and regional weather and climate, with a societal outcome to achieve improved regional weather forecasts and climate predictions;

Objective 2: to understand the Kuroshio in relation to its marine ecosystem, with a societal outcome to achieve better management of regional fisheries and aquaculture along the Kuroshio and in its adjacent regions.