Copepods—tiny creatures that can help reduce the need for soya imports

Posted by Nutramar Staff on January 31, 2024

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In the quest for sustainable fish farming practices, there is potential to establish a new feed industry based on species lower in the marine food chain. Ingrid Ellingsen, a research scientist at SINTEF, suggests that utilizing resources from the sea, where fish naturally find their food, can be an alternative to the current reliance on imported agricultural products like soya for salmon feed. By sourcing raw materials from the marine food chain, such an industry could reduce dependence on imports and contribute to a more sustainable and ecologically sound approach to aquaculture.

The challenge lies in the limited understanding of the ecological impact of harvesting species from the mesopelagic zone (depths between 200 and 1,000 meters). In efforts to address this knowledge gap, researchers, including Ingrid Ellingsen from SINTEF, are working on projects like SFI Harvest to investigate the potential of utilizing mesopelagic species for fish feed. While the biomass in the mesopelagic zone is vast, its ecosystems are among the least explored. For example, the copepod Calanus finmarchicus, a crucial part of the diet of commercial fish like cod and mackerel, is one species identified in the Norwegian economic zone that requires further study. The goal is to harness the abundant marine resources sustainably to reduce reliance on traditional feed sources.

The copepod Calanus finmarchicus is noted for its high fatty acid composition, exceeding 60%, making it a potentially valuable feed resource. While commercial fishing for C. finmarchicus is ongoing, the catch quota is currently minimal compared to the estimated biomass in the Norwegian Sea. In order to determine the sustainability of increasing the extraction of biomass, more data is required. One challenge is that the quality of copepod feed deteriorates rapidly once on board a vessel due to enzymatic processes breaking down fatty acids. Researchers at the SFI Harvest center are exploring more efficient and energy-friendly technologies to preserve the quality of harvested copepods for fish feed.

Eva Chamorro Garrido, a Ph.D. student at the Arctic University of Norway, is researching Calanus finmarchicus in collaboration with Ingrid Ellingsen at SFI Harvest. C. finmarchicus has a one-year life cycle, hatching in spring and spending the summer in the upper water column. To reduce predation risk, it ascends at night to feed and descends to greater depths during the day. As autumn approaches, it migrates to even greater depths for hibernation (diapause), relying on accumulated fat reserves. In spring, it returns to shallower depths, reproduces, and dies. The vertical migration behavior varies in regions with the midnight sun, suggesting food access is crucial.

Ingrid Ellingsen's work involves providing advanced models describing the physics and biology of the marine environment to understand where and when marine copepods, like Calanus finmarchicus, are most likely to be found. This depends on ocean current movements, which can be simulated using models. The collaboration with SFI Harvest aims to enhance the model with biological input to unveil secrets of the marine ecosystem. The model predicts optimal locations for commercial catches with minimal fuel consumption, considering copepods' inability to swim against strong horizontal currents. Eva Chamorro Garrido compiles a database for geographical and depth distribution using vessel measurements and sampling at different depths.

In the quest for ecologically sustainable copepod exploitation, researchers are investigating whether increased catch quotas are viable. The model developed by Ingrid Ellingsen helps predict optimal locations for commercial catches with minimal fuel consumption, aiding in the potential expansion of a sustainable copepod fishery. This is crucial for the Norwegian aquaculture sector's goal of achieving an annual production volume of five million tons by 2050, requiring substantial protein sources, with copepods emerging as a promising solution to reduce reliance on soya imports. Go to Guro Kulset Merakerås’ article at Phys Org to learn more