This criterion is focused on identifying highly productive regions that support abundant producers and consumers. In marine ecosystems, primary producers include not only photosynthetic organisms, but also chemosynthetic organisms that drive the ecosystems in hydrothermal vents and methane seeps. Highly productive areas such as fronts of upwelling currents or river mouths are considered major candidates. In this research program, the primary productivity of fundamental species is quantified by direct/indirect measurements as well as fisheries statistics (e.g., for kelps). Furthermore, productivity learn more can be represented by the area of distribution

in the case of kelp beds by assuming positive relationships with area and productivity. In the case of seagrass ecosystems, productivity can be calculated according Selleckchem Fulvestrant to area and primary production using a model used in previous studies. The scale of the development of a reef can be used to represent productivity in coral reef ecosystems. In the offshore pelagic plankton community, chlorophyll A concentration can be estimated using satellite images and used as proxy for productivity. Zooplankton biomass obtained by several research cruises can also be used as a good indicator of productivity.

In the deep sea, the biomass of Calyptogena clams and Bathymodiolus mussels living symbiotically with chemosynthetic bacteria are candidates for representing productivity. Data on productivity are generally available for most types of ecosystems. Spatial estimation of the variation of primary productivity is also possible using remote-sensing and GIS techniques. Among habitat comparison methods, the integrated use of quantitative indices for this criterion is plausible. Nevertheless, further studies on the accuracy of the estimation of productivity as well as methods for the extrapolation and evaluation of geographical variation are required for more precise evaluation. This criterion is defined as an “area containing comparatively higher diversity

of ecosystems, habitats, communities, or species, P-type ATPase or higher genetic diversity,” [5]. There is no scientific consensus regarding the definition of biological diversity or biodiversity [40] and [41]. Therefore, this criterion must be considered according to multiple aspects including the absolute number of elements such as richness, popular biodiversity indices representing relative abundance (e.g., evenness), and differences in variables (e.g., taxonomic distinctness). In this research program, species richness and diversity indices are calculated on the basis of the database on species occurrence in major ecosystem types. This time, the species diversity of focal fundamental species was considered. For example, for kelp forest ecosystems, the number of kelp species can be used to rank this criterion for kelp beds.