Getting sorting right
‘De Juiste Sortering’ (‘Getting sorting right’) was a research project in which machine builder De Boer RVS, the Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), and the crews of the WR9 and the WR289 worked together on a study of an innovative onboard processing line for shrimp fishing vessels.
Innovative processing line
The innovative processing line was developed by De Boer RVS in partnership with RayTec and optimised on board the WR9 and WR289 during the course of the project. The system separates saleable shrimp from bycatch by means of pre-sorting (singulation), camera images and automatic image recognition. The innovative system is designed to improve the sorting and grading of saleable shrimp, increase bycatch survival and improve working conditions for fishermen.
Successful sorting
The results of the field tests led ILVO researchers to conclude that the innovative processing line successfully separates saleable shrimp from the rest of the catch. The processing line is also equipped with a vibrating grader that accurately sorts saleable shrimp into three commercial size categories. This eliminates the need for manual removal of bycatch and foreign objects such as shells and feathers after cooking.
The innovative processing line lands the same total amount of shrimp as a traditional processing line. It also cooks fewer undersized shrimp and bycatch than a traditional processing line. Most of the undersized shrimp are discarded during the pre-sorting process prior to optical sorting. This pre-sorting process, which singulates the catch, has been shown to play an important role in preventing overloading of the optical sorter and ensuring accurate sorting.
Better hope of survival
During one field trip, ILVO researchers monitored the short-term survival of shrimp and bycatch species (72 hours after capture). While the survival rates of bycatch species were the same for the innovative and traditional processing lines, undersized shrimp showed slightly better survival after being sorted with the innovative processing line and more undersized shrimp were released back into the water alive. However, as the researchers state in their report, it is not possible to determine the impact of the innovative processing line on survival throughout the year on the basis of a single field trip. Survival might be further increased by, for example, increasing the capacity of the optical sorter so as to reduce or eliminate pre-sorting. The researchers also recommended further study of shrimp pulse trawling.
>> You can download the final scientific report HERE.
This report is only available in Dutch
VIDEO – Getting sorting right: a study of an innovative shrimp processing line
