Plant based feeding solutions for fisheries
Fish being fed plant based feeds
Due to the increasing population, and a need for new more efficient food sources, fisheries have become more popular in recent years. Aquaculture is one of the fastest growing forms of food production in the world, due to the high protein density of fish and low production costs. Unfortunately, as I discussed in a prior blog, many fish are carnivorous, and are often feed fishmeal which is made of smaller fish species. This has a plethora of negative environmental impacts, including depletion of wild fish and excessive waste. While there are many alternative options of fish feed, plant based diets are the most sustainable options. Switching fish to a plant based diet can also help to reduce contaminants in the fish, and make the fish healthier for human consumption (Fears, 2013).
(no this is not what vegetarian fish food actually would look like! This is just someone feeding a shark a snack!)
One solution to this is to feed fish vegetable or plant based feeds. While most carnivorous fish are not adapted to eating a vegetarian diet, vegetarian feeds often can have added vitamins, minerals and enzymes so that the fish can digest the food, and get all of the nutrients they need.
Photo of a Moringa Tree
Moringa and kikuyu meal has also been used to replace fishmeal. Moringa is a type of tree and kikuyu is a type of grass. Fish who ate the kikuyu diet actually had higher rates of growth than fish who were fed fishmeal. Fish who only ate moringa did not do as well, as fish who ate moringa as a supplement, instead of moringa as their sole source of food (Samkelisiwe, 2014). Regardless, these plants can be used as supplements, as well as the main source of food.
There are also other options such as using soybeans, barley or corn to feed fish, although these are not as sustainable, since farming these crops takes a lot of land. When cobia, a carnivorous fish species, were fed a combination of barley and soy protein they grew significantly larger, and absorbed less contaminants than they did when they were being fed fish meal (Fears, 2013). This is just one example of how switching to a plant based diet can help overall production in fisheries.
Some other more sustainable options include using agricultural waste as feed. There are also some fish feeds made from pistachios, which are a good alternative to fishmeal, because of their high protein content (Goldfarb, 2016).
While many of these options are more expensive currently, there are some low-cost solutions. Making the switch to feeding fish in fisheries vegetarian diets would ultimately save money, increase the quality of fish and help the environment. Educating fish farmers, and people whom live near fisheries about the positive impact that a vegetarian diet can have is one of the most important steps in making this change. Also ensuring that farmers have access to these vegetarian feeds is an important step. You can help make the change by volunteering or donating to Enhance a Village. Your donation or volunteering can help to make a positive impact in the Philippines, and in the world! To learn more about the organization click here.
Fears, D. (2013, August 11). Baltimore researchers turn some carnivorous fish into vegetarians. Retrieved October 20, 2017, from https://www.washingtonpost.com/national/health-science/baltimore-researchers-turn-carnivorous-fish-into-vegetarians/2013/08/11/46fc967e-0130-11e3-9711-3708310f6f4d_story.html?utm_term=.d06e81df7743%29
Goldfarb Jan. 6, 2016 Print Share Subscribe Donate Now, B. (2016, January 06). High Country News. Retrieved October 20, 2017, from http://www.hcn.org/articles/can-vegetarian-feeds-make-aquaculture-palatable
Samkelisiwe, H., & Ngonidzashe, M. (2014). Replacing Fishmeal with Kikuyu Grass and Moringa Leaves: Effects on Growth, Protein Digestibility, Histological and Haematological Parameters in Clarias gariepinus.Turkish Journal of Fisheries and Aquatic Sciences,14, 795-806. Retrieved October 20, 2017.