## 1 Introduction  
Oceans cover up to 71% of the earth's surface, regulate the global climate system, supply more than half the biosphere's oxygen, and sustain the livelihood of billions of people worldwide [1; 2; 3; 4; 5; 6]. The ongoing decline in land-based resources is causing increased demand for marine resources such as food and energy and is expanding human marine activities including transportation and recreation, which ultimately threaten the ocean's health [6; 7; 8; 9]. Effective ocean management requires integrated and sustainable ocean observing systems, which enable us to better understand ocean processes and the impacts of human activities [6; 10]. Autonomous subsurface and surface vehicles, here collectively referred to as \({}^{1}\)\"gliders\", are advanced ocean observing systems providing high spatiotemporal resolution [11; 12; 13; 14; 15]. Equipped with energy-efficient sensors, innovative communication means, and data management systems, these vehicles are commanded remotely, and report results to land in near-real-time, providing a new set of tools to efficiently collect ecological and commercially relevant data from the open ocean and coastal areas. Through the project \"Unmanned ocean vehicles, a flexible and cost-efficient offshore monitoring and data management approach\", three different gliders were deployed from March to September 2018, along the Lofoten-Vesteralen (LoVe) shelf-slope-ocean system in Arctic Norway. This period covered the annual blooms of primary and secondary production, which in turn sustain high fish density aggregations in spawning grounds where cetaceans also feed [11; 16; 17; 18; 19]. The highly productive LoVe area is of prime interest to develop the national blue economy, with stakeholders including fisheries, offshore energy, aquaculture, shipping, and tourism. As such, the area is prone to increased anthropogenic pressure and concurrent environmental changes [20]. Current and future ocean-based value creation depends on sustainable use of the ocean's resources for which environmental monitoring and research are fundamental [20]. There is a need to gain knowledge about the LoVe ecosystem to develop appropriate management approaches to ensure environmental quality, business sustainability [12; 21], and good governance. Building this knowledge requires additional and persistent data collection that cannot rely solely on sampling by traditional vessels due to practical and economic reasons. Currently, autonomous continuous long-term in situ monitoring programs exist for the LoVe region thanks to an underwater observatory system that employs crawler and stationary platforms to study ecological processes in the deep sea ([[https://love.equinor.com/](https://love.equinor.com/)]([https://love.equinor.com/](https://love.equinor.com/))) (accessed on 7 October 2021) [12; 22; 23; 24; 25]. The deep sea, however, is a highly dynamic environment where benthic ecosystems are interconnected with the water column and the surface through the exchange of energy, mass, or nutrients [26; 27; 28]. Thus, knowledge of a wide variety of ecological and biological variables is needed to improve ecosystem monitoring, from the seabed to the surface. To achieve such monitoring capabilities of the entire water column across a wide spatiotemporal spectrum, a spatial hierarchy of clusters and networks should integrate various observation technologies [29; 30]. The goal of the GLIDER project was to test three gliders equipped with sensors capable of collecting physical, biogeochemical, and biological data simultaneously, performingan integrated ecosystem survey across different depths and a wide geographical area. At the same time, data collected by the gliders were incorporated in near-real-time into a data assimilative ocean circulation model to test whether the model forecast could be improved for the LoVe region, where geomorphological challenges are brought about by a complex coastline, the presence of fjords, and strong seasonal freshwater input.