Taxonomy in times of the taxonomic impediment – examples from the community of experts on amphipod crustaceans

The term "taxonomic impediment" is widely used in the biodiversity literature. The taxonomic impediment consists of several problems: the incomplete knowledge of the largely unknown global biodiversity, the insufficient number of experts and their unbalanced distribution across the globe and the taxonomic infrastructures that are not meeting the demands yet. It is difficult to examine how severe the problem in the development of taxonomic knowledge is, because there might be big taxonomic gaps in knowledge in some groups, like many invertebrates, but small in some vertebrate taxa. As an example of an invertebrate taxon, the online WoRMS database was queried for amphipod crustaceans, and data for the cumulative increase of species numbers, species description rates and data from the taxonomic community were extracted. The increase of species numbers over time is strong and the species description rates are high since the 1960s. Within the group of 30 most productive amphipod taxonomists during the past 15 years, 9 are retired, 2 are on temporary contracts, 1 is a freelancer, 8 stopped working on amphipods leaving 9 out of 30 permanently employed. There is a strong geographical bias with 21 of the 30 taxonomists originating from Australia, Europe, North-America and Japan especially within the group of highest productivity. The taxonomic effort of amphipodologists was compared with the situation in Cumacea and Mysidacea.