Talking shells in Kiel

CACHE researcher, James Morris, who is looking at the potential applications of shell waste, reports from his recent visit to the company Coastal Research and Management (CRM) in Kiel, Germany:

“My first visit to Kiel and Northern Germany: sunshine and blue water. I was tirelessly informed that the three days I experienced were as atypical as they come, however my image of Kiel will be of glimmering sunshine until a future visit can prove otherwise.


Mussels and algae.

There are many fascinating potential applications of waste shells. From an academic perspective, it would be easy to shout about each from the rooftops and then wonder why such solutions are not commonplace!  In reality, the many environmental advantages of shell valorisation1, alone, are not enough of a driving force for those who generate shell waste. Economic incentives are much more tricky to underpin, and are likely case dependent. My trip to Kiel to visit CACHE partner Peter Krost and CRM’s aquaculture installation was to discuss the use of their farm as a case study for determining the economic ‘real world’ feasibility of a number of simple shell valorisation techniques in Northern Germany.

Further, I was keen to ‘pick’ Peter’s brain on his ideas for the sustainable future of aquaculture and the integrated multi-trophic aquaculture2 approach. It was great to see algae being grown in partnership with mussels at their farm, and I’m very excited for the day when seaweed is as common as iceberg lettuce (with the intensity of agricultural water, land, and energy use, and impending energy and water shortages, it could be sooner than we think!).

It was a stimulating couple of days with Peter discussing their farm, their current projects and production, as well as their plans for future expansion. I hope that my case study will throw up some economically viable shell applications that can convince them to keep and process some of their shells.”


1 Valorisation is act of assigning or giving value to something, where value can be economic, environmental, and/or social. In mollusc aquaculture, shells produced are often regarded as a nuisance waste product. In fact, shells are an incredible biomaterial that can be used in a variety of ways, many of which might provide environmental benefits, and some of which may provide economic incentives also. Shell valorisation is the drive to consider shells as a valuable resource rather than a bothersome waste product.

2 Integrated multi-trophic aquaculture (IMTA) is a complex term for a rather simple principle. Intensive production of a single species, common in aquaculture, can be bad for the immediate environment because that species will take up a specific set of nutrients and release others, creating artificial imbalance. In nature, complex food chains obtain and release nutrients which other species use in that given ecosystem. The IMTA approach produces several types of organism within a single system, typically finfish species mixed with shellfish and algal/seaweed species. By mimicking a simplified natural food chain, an IMTA system can have less detrimental effects on the surrounding environment than a single species system would.

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