The Centre for the Environment, Fisheries and Aquaculture Science (Cefas), as one of the world's longest-established marine research organisations, has provided advice on the sustainable exploitation of marine resources since 1902. Today Cefas works in support of a healthy environment and a growing blue economy providing innovative solutions for the aquatic environment, biodiversity and food security. The Cefas Data Portal provides access to over 2125 metadata records, with over 6402 data sets available to download and connect to in support of commitments to Open Science. Datasets available are increasingly diverse and include many legacy datasets including those from fish, shellfish and plankton surveys from the 1980's to the present day. Other increasingly international datasets made available include species migration data from tagging activities and data on habitat and sediment, ecosystem change, human activities including marine litter, otolith sampling and fish stomach contents, oceanography, acoustics, health and water quality. Data is provided under UK Open Government License by default where feasible.