Temperature: Average trend (increasing or decreasing) of sea surface temperature (°C) from pre-industrial times to present day.
Acidification: Carbon dioxide (CO2) absorption into the ocean affects the pH of the waters. The acidity of CO2 is neutralized by carbonates such as aragonite which is used by organisms such as corals and other shelled marine organisms for body structure. Increases in atmospheric CO2 have had influence on the ocean’s carbonate chemistry and absorptive capacity by rising the depth at which seawater is no longer saturated with aragonite.
Others: The latest version of the IUCN Red List (2010) was used to determine the number of marine species who were of least concern or who had some classification of concern (near threatened, vulnerable, endangered, critically endangered, extinct in wild, or extinct). The state of marine species was measured by comparing the number of species of least concern to those of concern.
Shipping/Ballast Water: Port activity in terms of total cargo shipped (tonnes) or total bulk carrier (tonnes) was used to assess the risk from invasive species introduced by ballast water exchange at the ports.