The results of this report (period 2017-2021) are based on the integration of numerous scientific field observations and 6,123 catch diaries, collected through the voluntary reporting by marine recreational anglers. This valuable data set demonstrates the importance of cooperation between citizens and science. The local nature of marine recreational fisheries means that this fine-grained data can contribute to the national evaluation of environmental and fisheries-related policies. In addition, the strict spatial delimitation of the programme (i.e. the Belgian part of the North Sea) means that marine recreational fisheries data can serve as an early warning when worrying local trends are observed that are not (yet) reflected in the general North Sea figures.The biggest challenge in the programme is the continuity of the involvement of marine recreational fishermen. Despite the fact that data collection supports the interests of the sector, the number of diaries received on an annual basis dropped to just under 700, whereas in 2017 this was still over 2,000. A stabilisation occurred over the last two or three years, with even a limited increase in the last year. In general, angling boats accounted for the bulk of the fishing effort. Annually, the 8,000 boat movements provided more than 100,000 fishing hours (on an individual level), the majority of which took place within the 3 nautical miles off the coast (73%). With the exception of passive beach fishing (60,000 fishing hours), the other techniques ranged between 15,000 and 35,000 fishing hours on an annual basis. Total fishing activity resulted in an average catch of 1.3 million fish (excluding shrimp) per year, of which about half were kept for consumption (45- 53%). Overall discarding of fish that meets the minimum size was limited to 4-11%, indicating that marine recreational fisheries from a catch and release perspective is currently low. The total recreational landings of fishery products (including shrimp) have fluctuated between 185.7 (2020) and 265.8 ...