Discovering marine biodiversity in the 21st century

We review the current knowledge of the biodiversity of the ocean as well as the levels of
decline and threat for species and habitats. The lack of understanding of the distribution
of life in the ocean is identified as a significant barrier to restoring its biodiversity and
health. We explore why the science of taxonomy has failed to deliver knowledge of
what species are present in the ocean, how they are distributed and how they are
responding to global and regional to local anthropogenic pressures. This failure pre-
vents nations from meeting their international commitments to conserve marine bio-
diversity with the results that investment in taxonomy has declined in many countries.
We explore a range of new technologies and approaches for discovery of marine spe-
cies and their detection and monitoring. These include: imaging methods, molecular
approaches, active and passive acoustics, the use of interconnected databases and cit-
izen science. Whilst no one method is suitable for discovering or detecting all groups of
organisms many are complementary and have been combined to give a more com-
plete picture of biodiversity in marine ecosystems. We conclude that integrated
approaches represent the best way forwards for accelerating species discovery, descrip-
tion and biodiversity assessment. Examples of integrated taxonomic approaches are
identified from terrestrial ecosystems. Such integrated taxonomic approaches require
the adoption of cybertaxonomy approaches and will be boosted by new autonomous
sampling platforms and development of machine-speed exchange of digital informa-
tion between databases.