There are claims that 1/5 of all wild fish caught is used for production of fishmeal and fish oil. Most of this is used for fish farming. Most of the fish used to make fishmeal and fish oil is claimed to be suited for human consumption. What is the effect of this fishing on local food security? Does this kind of production effect your local fisheries?
https://storage.googleapis.com/planet4-africa-stateless/2019/06/6097170a-a-waste-of-fish-report-en-low-res.pdf?_ga=2.234381850.506020780.1599386218-1418741920.1599386218
Article Trends in Industrial and Artisanal Catch Per Effort in West ...
https://www.greenpeace.org/africa/en/press/7224/greenpeace-fishmeal-industry-stealing-regional-food-and-livelihoods-in-west-africa/
The demand for fish meal and oil is certainly high in the fattening of carnivorous fish species even though it seems that increased prizes have led to large-scale replacement by soya in feed formulae. Soya is not a perfect substitute as it misses some of the essential micronutrients in fish derived meals and oils.
Our non-profit has worked for years in West Africa and has witnessed the dramatic impact of increased industrial (and artisanal) fishing for small pelagics destined for reduction into fish meal and oil driven by massive expansion of the number of plants particularly in Mauritania, Senegal and to a lesser extent Gambia. We co-sponsored a film crew that worked for three years e.g. in the southern part of Senegal, Casamance, to familiarise with the conditions. Kafountine had become a refuge for the people from the entire sub-region deep into the Sahel countries. The fishers had moved south in pursuit of the fish which had become rare further north as a combined result of hydrographic (climate) change and overfishing stimulated through the voracious demand of fish meal plants. The locals had built up a regional economy around Sardinella spp. and bonga (Ethmalosa fimbriata) that fed literally millions of people with low income from Senegal to Mali, Burkina Faso and further east and south with valuable fish rich in protein and micronutrients
- see Hicks et al. 2019 in Nature about how Africa subsidises the "rest of the world" with essential micronutrients while part of its own population is undersupplied ( Hicks, C.C., P.J. Cohen, N.A.J. Graham, K.L. Nash, E.H. Allison, C. D'Lima et al., 2019. Harnessing global fisheries to tackle micronutrient deficiencies. Nature, 574:95-98. https://doi.org/10.1038/s41586-019-1592-6).
This regional hub had ensured thousands of jobs and valuable food. When the first fish meal factories arrived in Kafountine all this was destroyed in a very short period of time, which the film crew captured in a supplement to the original documentary. I gave a public lecture about the concerns at the University of Kiel earlier this year: https://www.mundusmaris.org/index.php/en/projects/projects-2020/2326-cau-en (you can click on the slides to get pictural evidence with stills from the documentary). It's now being turned into a book chapter about the series of public lectures to be published shortly.
This definitely holds for West Africa. It is a bit less pronounced in Peru and Chile where the historical cultures were built around the anchoveta, but current direct human consumption is not as pronounced. Having said this, the overextension of industrial fishing has led to the collapse of the seabird population and the guano production as valuable natural fertiliser. This in turn influenced the highly unsustainable "modern" artificial fertiliser production with the known desastrous effects in agriculture and coastal zones (high N3 in water tables, dead zones in the sea growing and growing). This is obviously short hand for more complex relations, but just to signal other largely unintended consequences.
So, the while your question asks about food safety (no food related disease), my answer relates to food security (access to sufficient and quality food to ensure a healthy and active life). And the answer is definitely affirmative in the sense that the demand for fish meal in wealthy societies is directly at the expense of financially weaker populations which would eat the fish directly and get a sufficiently varied food supply as a result.
Besides, from an energetic and ecosystem perspective the higher an organism is located in the food web, the lower the supply and the population of carnivores that can be sustained (think of the East African plains with millions of grazers and few lions). So fattening carnivores in aquaculture on a large scale (not small-scale using processing remnants) by definition destroys food that could sustain large numbers of organisms (incl. humans) feeding on lower trophic levels.
Cornelia E. Nauen Thank you for this long and insightful answer. I meant food security of course. I shall edit the question. As a Norwegian many of us feel unsettled about the fish farming industry and how it is ruining fisheries in Africa and other places. Thank you also for the lecture from Kiel.
For making fish meal and oil for using in pellets for high priced fish like salmon, protein enriched small and trash fishes are highly harvested and killed, which will hamper other fisheries (due to food chain disturbance) and at the same local food security in places like west Africa will be hampered.
Harvesting fish for meal creates a series of ecosystem issues. The first is that you remove a low food-chain consumer. If they are, for example, planktivorous, then that doesn't get eaten, multiplies, and may cause issues down the road. The example I have read of is that pre-industrial harvest, the Chesapeake Bay shellfish filtered the Bay every few days. Now, it is once a year due to reduced shellfish numbers. You get more phytoplankton as a result. Also, harvesting those fish takes them out of some other predators mouth. They, the predator, either starve or switch to some other food source and the dominos continue to fall. The predators include fish, birds, mammals. As they say, there is no free lunch.
Hal Michael Thank you for your input. Interesting about Chesapeak bay. As a child (1976-1977) i livet along the bay near Norfolk Virginia.
The impact of filter feeders on water quality can be seen in the Great Lakes following the invasion of Zebra and Quagga mussels. The water is way clearer. The whole ecosystem was disrupted because, originally, it did not have the benthic filter feeders. So, the mussels have made significant changes. But their action demonstrates what happens when you remove the filtering capacity from a system.
- Badges
- Science topic
- Similar topics
- Biological Science
- Zoology
- Ichthyology
- Vertebrates
- Fish