Compilation of processed and validated data of mesozooplankton along the St Helena Bay Monitoring Line (SHBML) (now under the Integrated Ecosystem Programme: Southern Benguela) on the Africana, Voyage 269, from 11 to 13 January 2011. This includes the validated flow, processed counts and validated ship`s information. This is ready for analysis by a user. The St Helena Bay Monitoring Line was initiated as a BENEFIT-driven project on "shipboard monitoring" which linked with similar lines run in Namibia and Angola. The aims are to obtain seasonal and interannual information on the hydrology and productivity of the area. Data on harmful algal blooms, low oxygen water and intrusions of Agulhas Bank water along the west coast are also collected. A long-term, multi-decadel time-series (from 1951 onward) of information already exists for this important region and has continued in the form of the IEP:SB to detect long-term changes in the hydrology and the plankton, which are important for...