Material resources are scarce and should be dealt with carefully. Ports can play a vital role in this for several reasons. Ports are typically built to handle large volumes of materials. Secondly; port construction also requires substantial volumes of materials (breakwaters, quaywalls, roads, railways). Thirdly; capital and maintenance dredging also involves large volumes of materials. And last but not least, ports are often situated  in the midst of urban regions in need for places to regenerate materials (noisy, dusty) for reuse, industrial areas like port areas are one of the few places where such activities can take place. In other words; ports are excellently positioned to play a leading role in a circular economy. Closing material loops requires cooperation between companies to detect (waste) material streams they can exchange. Therefore, companies must have some kind of forum to exchange information, experiences and good practice examples. Ports can play a role in this, helping out these actor and at the same time supporting their own business as well.