Impacts of global warming/ocean acidification to marine ecosystem around Japanese coastal area
It has been discovered that Japanese coral communities are migrating northward with a maximum speed of 14 km per year (Yamano et al., 2011). This estimate is drawing considerable attention due to being the fastest northward shift of living organism habitats caused by rising water temperature by global warming including terrestrial ecosystems reported so far. This discovery was made possible by the fact that monitoring survey results around Japanese coastal area had been accumulating for a long period of time since 1930s, and that the influences by global warming had been relatively large compared to local disruption factors. When assessing/projecting the impacts from global environmental changes such as global warming to coastal ecosystems, it is one of the major characteristics of Japanese coastal waters that local disruption factors such as sediment inflow from a continent is relatively small, or the factors can be easily identified. That is to say selecting Japanese coastal waters for a research subject in this study is extremely meaningful and this gives an advantage compared to other research communities from the rest of the world that are carrying out similar research within the framework of IPCC (Intergovernmental Panel on Climate Change). In addition, while the research into biological influences of ocean acidification has only been started in recent years, it has been pointed out that this global environmental change similar to global warming has a possibility that it can have serious and even faster impact to marine organisms than global warming (Yara et al., 2012).
Coastal ecosystems such as coral reefs and seaweed beds have high biological productivity and biomass: they perform the roles of forming marine environments, weakening waves and currents, absorbing nutrients, and purifying the sea, and providing exceedingly high ecological services. Considering the fact that the global demands for aquatic resources as a supply source for animal protein are expected to increase in the future, and that tourism industry is expected to become the largest single industry in the world by the middle of this century, one can expect the ecosystem services of coastal regions to increase progressively. In this research, we pay special attention to coastal marine ecosystem, to observe biodiversity and ecosystem services. However, for organisms such as Sargassum which is a class of temperate seaweed bed, when a part of that would become floating seaweed and functions as a spawning substrate by migrating fish such as flying fish, Pacific saury, or halfbeak, this would also connect to not only coastal but offshore ecosystems.
A large number of present day marine parks in Japan are those that were established in 1970s when the emphasis had been on locations with beautiful scenery. However, sometime in the future, they should be assessed and established from perspective of biodiversity and ecosystem services and future projection in response to climate change. Furthermore, since global warming and ocean acidification would also change the suitable regions for aquaculture of target species, adaptation measures by aquaculture and related regional industries are considered unavoidable as well. Our laboratory works with National Institute for Environmental Studies and others to provide objective and quantitative suggestions based on scientific backgrounds to the society regarding consensus building and initiatives towards marine ecosystem conservation and developing sustainable societies in coastal regions.
Updated on 2014/04/16