{"id":23354,"date":"2020-12-14T02:48:50","date_gmt":"2020-12-14T02:48:50","guid":{"rendered":"https:\/\/www.lifeandnews.com\/articles\/?p=23354"},"modified":"2020-12-15T12:36:35","modified_gmt":"2020-12-15T12:36:35","slug":"taking-fish-out-of-fish-feed-can-make-aquaculture-a-more-sustainable-food-source","status":"publish","type":"post","link":"https:\/\/www.lifeandnews.com\/articles\/taking-fish-out-of-fish-feed-can-make-aquaculture-a-more-sustainable-food-source\/","title":{"rendered":"Taking fish out of fish feed can make aquaculture a more sustainable food source"},"content":{"rendered":"

Pallab Sarker<\/a>, University of California, Santa Cruz<\/a><\/em><\/p>\n

The Research Brief<\/a> is a short take about interesting academic work.<\/em><\/p>\n

The big idea<\/h2>\n

Aquaculture, or fish farming, is the world\u2019s fastest-growing food production sector<\/a>. But the key ingredients in commercial fish feed \u2013 fishmeal and fish oil \u2013 come from an unsustainable source: small fish, such as anchovies and herring, near the base of ocean food webs.<\/p>\n

My colleagues and I have developed a high-performing, fish-free aquaculture feed<\/a> that replaces these traditional ingredients with several types of microalgae \u2013 abundant single-celled organisms that form the very bottom of the food chain in fresh and saltwater ecosystems around the world. To test this approach, we developed our feed for Nile tilapia<\/a> \u2013 the world\u2019s second-most-farmed fish<\/a>, exceeded only by carp.<\/p>\n

Our research showed that tilapia fed our fish-free diet grew significantly better, achieving 58% higher weight gain than tilapia fed conventional feed. The resulting cost per kilogram of tilapia raised on our feed was lower than for fish raised on conventional commercial feed. And our feed yielded a higher level of a key fatty acid that is important for human health<\/a>, DHA omega-3, in the resulting tilapia fillets.<\/p>\n

\"Infographic<\/a>
Small schooling species such as sardines, sauries, and smelt \u2013 commonly known as forage fish \u2013 play a critical role in sustaining the ocean. These species eat tiny plants and animals, in turn becoming an important food source for bigger fish, seabirds and marine mammals.<\/span>
\nPew Charitable Trusts<\/a>, CC BY-ND<\/a><\/span><\/figcaption><\/figure>\n

Why it matters<\/h2>\n

About 19 million tons of wild fish \u2013 some 20% of the total quantity caught around the world \u2013 are rendered into fish meal and fish oil every year, even though 90% of these harvested fish are fit for human consumption<\/a>. Analysts project that aquaculture feed demands for fish meal and fish oil could outstrip the supply of small forage fish<\/a>, also known as prey or bait fish, by 2037. If this happens, it could have disastrous consequences<\/a> for human food security and marine ecosystems.<\/p>\n

Aquaculture feeds can also contain soy and corn ingredients from industrial farms on land that generate large amounts of water pollution<\/a>. Fish can\u2019t fully digest these ingredients, so they end up in aquaculture wastewater<\/a>. Just like wastewater from cattle or poultry farms, effluent from fish farms can be a serious pollution source<\/a>. What\u2019s more, these crops could be used for direct human consumption.<\/p>\n

\"Handful<\/a>
Fish-free aquafeed made with two types of microalgae.<\/span>
\nDevin Fitzgerald<\/span>, CC BY-ND<\/a><\/span><\/figcaption><\/figure>\n

For all of these reasons, developing fish-free fish feed is a key leverage point for reforming aquaculture so that it helps to conserve natural ecosystems instead of damaging them. Reducing pressure on forage fish will strengthen global marine fisheries. Our work also shows that it is possible to improve the human health benefits of eating farmed tilapia by manipulating the fishes\u2019 diet.<\/p>\n

How we do our work<\/h2>\n

We developed our fish-free feed formula in a series of experiments over six years. First, we evaluated how well fish could digest specific varieties of marine microalgae<\/a>. Then we conducted separate experiments to see how well fish grew using these individual ingredients as replacements for either fish meal or fish oil.<\/p>\n

For this feed we used two types of marine microalgae. One is a waste product left over after another type of omega-3 fatty acid, called EPA, has been extracted from the microalga for use in human nutritional supplements. This is the first proof of concept for a tilapia feed that eliminates fish meal and fish oil while improving growth metrics and the resulting nutritional quality of the fish.<\/p>\n

Our feed is a substantial improvement over other commercially available feed products. There are some existing fish-free feeds that use soy, corn and other plant-based ingredients, but terrestrial vegetable oils within these feeds lack long chain omega-3 fatty acids. As a result, they produce fish fillets with lower nutritional value<\/a>.<\/p>\n

Microalgae ingredients don\u2019t have this problem. Researchers have been experimenting with using microalgae to replace either fishmeal or fish oil in aquaculture feeds<\/a>, but there haven\u2019t yet been any fully fish-free microalgae blend feeds available in the market. We hope that ours will be the first.<\/p>\n

The other major challenge in developing a commercially successful fish-free feed is achieving a competitive edge over conventional feed on cost and fish growth performance. Our research showed promising results for these factors as well.<\/p>\n

\"Farm<\/a>
Feeding pellets to tilapia in ponds in Northern Province, Zambia.<\/span>
\nKendra Byrd, Worldfish\/Flickr<\/a>, CC BY-NC-ND<\/a><\/span><\/figcaption><\/figure>\n

What\u2019s next<\/h2>\n

We currently have a patent pending for our formula and hope to work with the aquafeed industry, ingredient suppliers and sustainable aquaculture entrepreneurs to bring it to market. The major challenge will be achieving a consistent ingredient supply in order to produce large quantities on an industrial scale.<\/p>\n

We\u2019re also working now to develop fish-free feeds for other aquaculture species, including salmonids<\/a>, a group that includes trout and salmon. Unlike tilapia, which eat a primarily vegetarian diet, these species are predators, so farming them accounts for most of the fishmeal and fish oil used in aquaculture feeds. Successfully replacing fishmeal and fish oil with microalgae in salmonid feed would be a major advance toward more sustainable aquaculture.<\/p>\n

[Get our best science, health and technology stories.<\/em> Sign up for The Conversation\u2019s science newsletter<\/a>.]\"The<\/p>\n

Pallab Sarker<\/a>, Associate Research Professor of Environmental Studies, University of California, Santa Cruz<\/a><\/em><\/p>\n

This article is republished from The Conversation<\/a> under a Creative Commons license. Read the original article<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

Pallab Sarker, University of California, Santa Cruz The Research Brief is a short take about interesting academic work. The big idea Aquaculture, or fish farming, is the world\u2019s fastest-growing food production sector. But the key ingredients in commercial fish feed \u2013 fishmeal and fish oil \u2013 come from an unsustainable source: small fish, such as […]<\/p>\n","protected":false},"author":44,"featured_media":23355,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1862],"tags":[918,4613,2851,8281,9137,742,9136,4648,9135,2248,724,5511,1684],"_links":{"self":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/23354"}],"collection":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/users\/44"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/comments?post=23354"}],"version-history":[{"count":2,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/23354\/revisions"}],"predecessor-version":[{"id":23357,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/23354\/revisions\/23357"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media\/23355"}],"wp:attachment":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media?parent=23354"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/categories?post=23354"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/tags?post=23354"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}