Antarctic krill (Euphausia superba) are particularly susceptible to changes in their local environment. This can be due to a range of environmental, physical, chemical and biological factors, as well as by anthropogenic means. Fluctuations in these factors have been seen to affect crucial nursery habitats as well as feeding regions key to their survival (Flores et al., 2012).
Nonetheless, with the decline in populations of krill due to a variety of factors, the abundance of salps (a planktonic tunicate) (Figure 8) has been seen to rise over the last century. This has been due to the decline in krill richness, consequent changes in phytoplankton biomass and climate change (Atkinson et al., 2004).