Marine processes are observed with sensors from both the ground and space over large spatio-temporal scales. Citizen-based contributions can fill observational gaps and increase environmental stewardship amongst the public. For this purpose, tools and methods for citizen science need to (1) complement existing datasets; and (2) be affordable, while appealing to different user and developer groups. In this article, tools and methods developed in the 7th Framework Programme of European Union (EU FP 7) funded project Citclops (citizens’ observatories for coast and ocean optical monitoring) are reviewed. Tools range from a stand-alone smartphone app to devices with Arduino and 3-D printing, and hence are attractive to a diversity of users; from the general public to more specified maker- and open labware movements. Standardization to common water quality parameters and methods allows long-term storage in regular marine data repositories, such as SeaDataNet and EMODnet, thereby providing open data access. Due to the given intercomparability to existing remote sensing datasets, these tools are ready to complement the marine datapool. In the future, such combined satellite and citizen observations may set measurements by the engaged public in a larger context and hence increase their individual meaning. In a wider sense, a synoptic use can support research, management authorities, and societies at large.

A critical parameter to assess the environmental status of water bodies is the transparency of the water, as it is strongly affected by different water quality related components (such as the presence of phytoplankton, organic matter and sediment concentrations). One parameter to assess the water transparency is the diffuse attenuation coefficient. However, the number of subsurface irradiance measurements obtained with conventional instrumentation is relatively low, due to instrument costs and the logistic requirements to provide regular and autonomous observations. In recent years, the citizen science concept has increased the number of environmental observations, both in time and space. The recent technological advances in embedded systems and sensors also enable volunteers (citizens) to create their own devices (known as Do-It-Yourself or DIY technologies). In this paper, a DIY instrument to measure irradiance at different depths and automatically calculate the diffuse attenuation K_d coefficient is presented. The instrument, named KdUINO, is based on an encapsulated low-cost photonic sensor and Arduino (an open-hardware platform for the data acquisition). The whole instrument has been successfully operated and the data validated comparing the KdUINO measurements with the commercial instruments. Workshops have been organized with high school students to validate its feasibility.

Shelf waters near large cities, such as Barcelona, are affected not only by meteorological episodes but also by anthropogenic influence. Scientists usually use data from on-site coastal platforms to analyze and understand these complex water ecosystems because remote sensing satellites have low spatiotemporal resolution and do not provide reliable data so close to the coast. However, platforms with conventional oceanographic instrumentation are expensive to install and maintain. This study presents the scientific adaptation and initial measurements from a “patí a vela”, which is a very popular unipersonal catamaran in Barcelona. This versatile sailing vessel has been adapted to contain several low-cost sensors and instruments to measure water properties. Here, we describe the setup of a multi-parameter prototype, and then focus on results obtained using a low-cost temperature profiler. First, the temperature data are compared and validated with another conventional oceanographic instrument used in monthly oceanographic cruises. Then, field measurements between July and November 2021 are used to explore the relationship between air and water temperature in the Barcelona coastal area, showing the seasonal evolution of the temperature profile. We conclude that citizen sampling from fully sustainable sailing boats may turn into an effective strategy to monitor the urban coastal waters.

Traditionally, marine knowledge has been confined to specific sectors of society, such as marine research, fisheries, or maritime industries, resulting in a lack of integration into broader societal discourse. To reverse this trend, various education and outreach initiatives have been developed by multiple stakeholders, with marine research institutions playing a paramount role. This chapter presents a case study of a successful initiative developed by the Institut de Ciències del Mar (ICM-CSIC) in Barcelona, Spain. The main objective of this initiative was to bring Ocean ecosystems “into homes” by addressing the seven Ocean Literacy (OL) principles, aligning with the Sustainable Development Goals. Through a collaborative effort involving over thirty marine researchers, the initiative developed fifteen educational capsules and four seminars, creating a digital repository to engage the public in OL. This study examines the development and impact of this initiative, providing a potential model for similar institutions. Additionally, it introduces a survey, designed for the staff of marine research institutions, to identify the factors that influence their involvement in OL activities. A pilot test confirmed the tool’s reliability and validity. The study emphasizes the vital role of marine research institutions in educational and outreach initiatives, marking a significant step toward fostering a globally Ocean-literate society and promoting sustainability.

The ocean plays a vital role in sustaining life on Earth, yet its importance is often undervalued in public understanding and education. Achieving higher levels of ocean literacy and fostering public awareness requires tailored, inclusive approaches that respect the unique social, cultural, and administrative frameworks of each region. Spain’s decentralized educational system, where autonomous communities have authority over educational policies, presents both challenges and opportunities for cohesive ocean education. Our approach to ocean education involves not creating a single and centralized national network, but instead integrating efforts with existing local structures and resources to support schools and enhance “blue thinking” across the nation. Our model respects regional diversity while aligning with European standards, and highlights the collaborative network engaging schools, government bodies, NGOs, universities, and private companies to uplift local voices and increase ocean literacy.Each region’s distinctive network structure reflects diverse approaches: consortium-based networks, private companies, NGO, research centres, or University coordination or leadership. We aim to integrate these unique regional efforts under a shared framework, but also facilitating schools in acquiring the European Union’s Blue Schools certificate. This alignment supports the Network of European Blue Schools initiative, promoting unified objectives and standards across all Member States.Our bottom-up approach addresses the gap in official curricula, in which aquatic ecosystems are currently underrepresented. Embracing a multi-stakeholder model inspired by the Pentahelix framework, we bring together five key actors: educational institutions, research organizations, NGOs, government agencies, and the private sector. This collaborative model fosters a well-rounded understanding of marine environments by integrating diverse expertise and resources. Schools benefit from a robust support network, connecting them to vital resources, specialized knowledge, and materials for ocean education. Partnering with local stakeholders, we prioritize adapting existing resources to meet the unique needs of Spanish schools, ensuring accessibility in both Spanish and regional languages.A crucial aspect of this inclusive model is enhancing local actors’ voices and creating strong connections with students. Schools are informed and inspired about the concept of Blue Schools, guided through the certification process, given access to scientifically accurate resources, and empowered to implement ocean literacy initiatives that resonate within their communities. The primary objective is to embed blue literacy (ocean and freshwater) in a transversal way into the fabric of school teaching and ultimately into curricula across Spain, nurturing a generation that understands and values marine ecosystems. By fostering strong, regionally integrated networks, we can work at the local level while acting nationally through the education regional Ministry, establishing Spain as a collaborative model for inclusive ocean education. This approach not only uplifts local actors and diversifies public awareness but also contributes to the broader EU goals of sustainable development and marine conservation. Moreover, the model is designed to be adaptable and replicable in other countries, enabling a shared framework that can be tailored to the educational, cultural, and linguistic needs of various regions. By doing so, we support a unified, cross-border effort to elevate ocean literacy and foster a sustainable relationship with marine ecosystems across Europe.