In this new edition, the “Learning with CESAM” project explores how fish skins and crustacean shells, often treated as waste, can be transformed into valuable materials for medicine, agriculture, and food preservation. The sea is a vast source of resources that can contribute to health, environmental protection, and the creation of new products, using a zero-waste approach. In many factories, parts such as skins, scales, bones, and shrimp or crab shells are discarded, but scientific research shows they can be converted into fundamental substances like collagen and chitin, which yields chitosan.
These materials, known as biopolymers, are large, naturally occurring molecules that are biodegradable and compatible with both the human body and the environment. In the fields of health and cosmetics, collagen—which makes up about 30% of human body protein—is being studied for use in healing bandages, supplements, and skin hydration. Chitosan allows for the creation of tiny particles that transport drugs to specific parts of the body in a controlled manner. Beyond these applications, chitosan can be used in films to protect food, slowing down spoilage, or as a “sponge” to capture heavy metals and clean polluted water. In agriculture, it also functions as a growth stimulant and natural plant protector, which can help reduce the use of chemical pesticides.
The original article, written by researchers Mariana Almeida and Helena Vieira from CESAM/DAO, highlights that the valorization of this waste is a practical example of the circular economy and the blue bioeconomy, which promote the responsible use of ocean resources. Although Asian countries currently lead in patent registrations in this area, research in Portugal and Europe is significant and evolving toward more sustainable extraction methods, using enzymes and “green” solvents instead of harsh chemicals. By transforming what once seemed to be mere trash into useful solutions, these marine materials become allies in building a more sustainable future, contributing directly to various United Nations Sustainable Development Goals.
You can learn more and explore the proposed challenges at: https://www.cesam-la.pt/aprender-com-o-cesam/atividade-no-3/