This report presents the results of a review on gaps in Baltic Sea monitoring based on two different information sources: peer-reviewed scientific articles, and BONUS and HELCOM project reports. The reviews are part of the BONUS project FUMARI. Our main questions are:

(1)    does the current monitoring of the Baltic Sea sufficiently address the requirements set by the Marine Strategy Framework Directive, the Water Framework Directive and the HELCOM´s Baltic Sea Action Plan?

(2)    what are the most critical shortcomings (gaps) in the current Baltic Sea monitoring programs?

We found that scientific articles dealing with Baltic Sea monitoring present a view on main monitoring gap occurrence, that differs from the view presented in reports dealing with the same topic. Both scientific articles and reports agreed that many thematic assessment categories are not monitored sufficiently, often due to insufficient spatial coverage. However, whereas articles often highlight both that a category is not sufficiently monitored, and that there is a lack of indicators, the reports focused more on gaps in data storage or handling, coordination of monitoring, or highlighted plans for new but non-operational indicators. Articles mainly mentioned gaps in relation to Eutrophication, Contaminants, Biodiversity, Commercial fish and shellfish, Food webs, Hydrographical conditions, and No alien species. Reports however indicated primarily Biodiversity gaps, followed by Contaminants and Healthy wildlife, Marine litter, and Sea-floor integrity. Our review also showed that certain categories are underrepresented in the scientific literature, i.e. with few scientists developing indicators or assessing data related to them, potentially indicating a knowledge gap in these fields.