Climate change, current agriculture production, and consumption patterns have become the most significant problems of the food industry. Several studies proved the need to develop functional food as an alternative. Seaweeds are still not commonly used in Europe, but their several health benefits could improve food habits and essential mineral intakes. Lack of iodine has been documented as a global problem since the last century, and this mineral comprises a vital part of a healthy diet. The main objectives of this work were the development of a new and accessible food product rich in iodine and other essential minerals in order to fill the gap that the current European diet has but, also with appealing sensory characteristics. To achieve these main objectives, a canned mackerel enriched with seaweeds was developed. The selected edible macroalgae were: S. latissima, L. digitata, U. pinnatifida, and C. crispus. To quantify the minerals of interest (I, Se, Na, and K) and arsenic, the samples were digested by microwave-assisted acid digestion. The quantification of As, I and Se were performed by inductively coupled plasma - mass spectrometry; Na and K were determined by high-resolution continuum source flame atomic absorption spectrometer. All the characterized species exhibited high iodine levels: U. pinnatifida (64.02 ± 8.74 µg I/g ww), L. digitata (643.5 ± 13.0 µg I/g ww), S. latissima (211.6 ± 12.8 µg I/g ww) and C. crispus (239.2± 17.7 µg I/g ww). The impact of processing steps, such as rehydration and boiling, was assessed. Several canned fish samples were prepared, with and without the addition of algae, and comparisons between them were made. All samples revealed a satisfactory contribution to the recommended daily allowances of nutritionally essential minerals (K: 0.53-3.64%, I: 310.32-1780.8 %, Se: 71.1-99.9%). A sensory analysis was done after the canned samples production. The samples with macroalgae revealed the best textural aspect and aroma. Therefore, it was concluded that the sample with S. latissima has the best aroma, flavour, texture, and appearance. In conclusion, all the main objectives of the work were achieved, and a healthy product was developed. Some future work is needed to optimize the canned product and to explore further the total macroalgae and canned beneficial properties.