Discarded marine Eel fish skin has essential properties of biomaterials for potential use in tissue engineering application. Processing and preparation of eel fish for edible purpose requires the removal of skin due to its thick size, which is treated as a waste. A huge amount of Eel skin is dumped as a waste material which leads to marine environmental pollution. To overcome this issue, we have isolated collagen from the discarded marine Eel skin as a potential blue biomaterial. Further, the isolated collagen was incorporated into alginate hydrogel to fabricate scaffolds using extrusion-based 3D printing technology. Swelling, degradation and biocompatibility were evaluated for lyophilized scaffolds. Biocompatibility studies were performed on hUMSCs (Human Umbilical cord Derived Mesenchymal Stem Cells) by live/dead staining using FDA (fluorescein diacetate)/PI (Propidium Iodide). The quantitative evaluation of metabolic activity was performed using Alamar Blue (AB) dye reduction assay. All the hydrogels with collagen show enhanced metabolic activity and cell proliferation compared to alginate hydrogels without collagen. The utilization of Eel skin derived collagen for 3D printing application was not yet reported. Moreover, sustainable utilization of renewable marine Eel skin discard as a novel blue biomaterial is of immense value due to its low cost and has great potential for further tissue engineering applications. © 2019 Elsevier Ltd