Grand challenges in marine ecosystems ecology

INTRODUCTION The study of marine ecosystems has become a hot research topic in recent times. In fact, the number of manuscripts including the words “marine ecosystems” published since 1970 has immensely increased reaching between 1100 and 1500 articles per year in the past five years (Figure 1). Based on the keywords used in these manuscripts, the most frequent topics can be grouped into: (i) marine ecosystems (28.8% of the papers); (ii) biodiversity (26.6%), used as keyword at any level of organization, such as bacteria, phytoplankton, zooplankton, benthos, fishes, mammals, seabirds, etc.; (iii) functionality (10.7%), including aspects such as ecosystem function, biomass, foodwebs, primary and secondary production, etc.; (iv) environmental research (9.7%), including pollution, environmental monitoring, human pressures, impacts, etc.; (v) structural parameters (6.6%) such as abundance, richness, diversity; (vi) climate change (3.4%); (vii) ecology (3.4%); (viii) systems management (3.2%); (ix) genetic