In Brief: What It's All About?
Can Aquaculture and Camelina Work Together for the South Dakota Economy and Global Ocean Health?
In the quest to sustainably feed the growing global population, aquaculture (the farming of fish and other aquatic organisms) has arisen as an important and increasingly profitable industry. However, availability and price of essential ingredients for aquaculture feeds are limitations to the growth and sustainability of fish farming. Aquaculture, especially fish and crustacean farming, relies on oil and meal made from ocean-harvested fish to supply the essential nutrients needed for seafood production. Overharvesting of the fish stocks used to produce aquaculture feeds has reached critical thresholds for ocean health, as well as presenting a costly bottleneck for the aquacultural supply chain. To overcome this challenge, researchers have worked to develop plant-based alternatives to fish oil and fish meal in aquaculture feedstuffs. Camelina (Camelina sativa), a crop that can thrive in South Dakota, shows tremendous promise for this market.
In addition to inclusion in aquaculture feeds, camelina has high potential for use in other animal feeds and for direct human consumption. Rich in omega-3s, anti-oxidants such as vitamin E, and other nutrients, camelina oil is attracting a culinary following. A high smoke point makes camelina oil a desirable choice for frying and sauteing, while its mild, nutty flavor makes it a pleasant addition to salad oil. An excellent biofuel resource, camelina has been developed for other beneficial uses including cosmetics, skin care products and industrial and medical applications.
Camelina, grown commercially in Europe and Canada, has also been grown successfully in Montana, North Dakota, South Dakota and elsewhere across the northern tier of the US. Its short growing season, cold tolerance and the availability of winter varieties make camelina suitable for use in the double-crop and relay cropping systems, which are gaining favor due to their contribution to soil health. During its crop production cycle, camelina provides ecosystem services in the agricultural landscape. Its nectar can provision pollinators including domestic honeybees and native beneficial insects. Its high fat content may also make it valuable to herbivorous wildlife wintering on farm fields.
Promoting the use of camelina in aquacultural feeds would provide the following benefits, both local and global:
● Provide a new market for northern-grown crops
● Increase diversity and sustainability in agriculture industry
● Provide a supply of oil for biofuels and other industrial uses
● Promote economic opportunity in these emerging industries
● Provide energized growth in a new aquaculture industry
● Help meet growing global food demand
● Provide a new source of healthful food meeting need for omega 3 lipids
● Decrease overfishing of ocean forage fish stocks, improving global ocean health
Omega 3's for health
As the science of nutrition has developed in recent years, we have learned that not all fats are created equal. Indeed, certain types of fats are crucial to the healthy functioning of our bodies. An important group of fats has emerged as particularly important: those containing Omega-3 fatty acids. These compounds differ from other fatty acids in their molecular structure, and are necessary to support a great number of processes within the body.
There are three main Omega-3 fats that are often discussed in relation to human nutrition: ALA (alpha-linolenic acid), DHA (docosahexaenoic acid), and EPA (eicosapentaenoic acid). DHA is the most important of these; it is a building block of many important body tissues including the brain and the retina of the eye, and fulfills many other essential functions. The body’s needs for DHA can be met by converting EPA into DHA. This is one important role for EPA, but this fatty acid is also important on its own and provides many benefits. ALA can also be converted into EPA and DHA; however, this process is very inefficient. Not enough of these fats can be derived from ALA, so the human body needs to bring these in from foods.
The average American diet is deficient in omega-3 oils, with recognized health consequences. This means that increasing the consumption of foods rich in these nutrients can provide benefits. This is an emerging area of research, but some recognized roles for dietary omega-3s include:
- Supporting pregnancy and infant development
- Improving brain and nervous system health
- Reducing inflammation
- Keeping joints healthy
- Promoting healing
- Improving cardiac health, reducing the risk of heart disease
Several other beneficial effects have been suggested by the research, and are currently being investigated, including helping manage anxiety and depression, and reducing the risk of age-related dementia. For further information on the current state of research on the effects of dietary omega-3 fats, please investigate our bibliography of relevant scientific literature.
Awareness of the importance of omega-3 fats is increasing, and so is the need to find better ways to include them in our diet. ALA is the most common of these fats, and is found in a variety of plant-based foods. Flax seed, flax seed oil, walnuts, chia seeds, soy products, and canola oil are all good sources of ALA. DHA and EPA are primarily found in certain types of animal-based foods. High quality oily fish such as tuna, salmon, and trout are good sources of these fats. They can also be found in meats and eggs that are specially grown to enhance the amount of these nutrients. Perhaps the most common way that people increase their dietary intake of DHA and EPA is simply taking a daily supplement.
The Fish Connection
Omega-3 supplements, especially those high in DHA, are almost exclusively derived from fish oil, which in turn is extracted from marine-caught fish. Because their bodies can do what ours mostly can't (make DHA and EPA from ALA), these fish are also the source of the feeds used to enhance the DHA and EPA content of eggs, meats and other foods marketed to meet this nutritional need. Farmed fish such as salmon and trout are fed large amounts of marine-based fish oil and fish meal. In most cases, several pounds of fish must be harvested from the ocean in order to produce one pound of farmed fish.
Camelina, like other plant sources of omega-3 fats, is rich only in ALA.. However, when used in feeds for farmed fish, it is converted at high rates int EPA and DHA. In fact, a complete substitution of camelina oil for fish oil in salmon diets enables the fish to produce healthy meat as though it had been fed on fish oil. Similarly, chickens fed camelina meal produce meat that contains these highly prized fatty acids. Therefore, camelina can be an important part of the effort to improve our diets and our health.
Applications for Sustainable Agriculture
Soil health is so important, for so many reasons. Soil provides the stage where the drama of agriculture takes place, literally feeding our bodies and spirits. For soils to sustain the plants we depend on for food, they must be healthy. This means several things. They must not be allowed to erode with wind and water; they must constantly build and replenish the organic matter and nutrients that can become depleted after years of producing crops; the physical structure of the soil must be maintained and supported; and the fantastic diversity of microscopic life must !flourish. Nurturing healthy soils is a complex endeavor, but certain principles form the basis for most successful programs. Camelina can contribute to the sustainability of an agronomic program in several important ways.
Soil is a living ecosystem, and the members of this complex community need to continuously live out their life cycles so that they can provide the functions of healthy soil. This means that plant growth is important throughout the year. Fall seeded crops, which are planted after harvesting an earlier crop, can help to extend the growing season into the winter. This winter growth focuses on early root development, which protects the soil from erosion, builds structural integrity, and feeds the microbes in the rhizosphere. Then, as soils warm in the spring, those winter crops are ready to resume growing and can capture the earliest part of the growing season. This early growth is important in many ways. As mentioned, it provides a living root zone where soil organisms can thrive. It also allows the plant to compete with undesirable weeds for sunlight and moisture, reducing the need for chemical weed control to protect crop yields. It can capture nutrients such as excess nitrogen, which can keep them from leaching into surrounding waters with the early spring runoff or even volatilizing as greenhouse gases. And of course, a growing crop builds a marketable commodity, helping keep the farm profitable.
Limited options exist for fall-seeded crops capable of surviving South Dakota’s challenging climate. Winter wheat is the predominant winter crop for the region. Camelina, having been cultivated over centuries in northerly climates in Europe and Asia, is well adapted to harsh conditions and has been successfully grown across the northern plains of North America. Its differences from winter wheat make it an attractive way to diversify the cropping options for the region.
The development of a diversified array of winter annual crops for South Dakota is increasingly important due to recent regional climate shifts. The spring growing season has become later, cooler, and more variable in recent years, leading to more uncertainty regarding the spring planting window. In some years, planting is prevented by excessive moisture (including late spring blizzards!) until late; ironically, late-seeded crops can then run the risk of inadequate moisture as summer progresses. It is frustrating when the fields finally dry out enough to get the planting done, and then it turns too hot and dry for the young plants to get established and survive. While spring has been uncertain in recent years, the fall weather conditions have recently extended longer, allowing for growth later in the season.
Often, the timing of a winter crop allows a second, warm-season crop to be grown during the height of the summer once the winter crop has been harvested. In some cases, these can crops overlap and share the field, one providing protection and weed control for the other during early growth. The suitability of camelina for these innovative rotations and cultural strategies has just begun to be explored. Although there are several studies suggesting good potential, much more work needs to be done to fully understand the role camelina can play in future farming. There are so any questions and opportunities!
We are excited to explore how camelina can contribute to the health of the soils on our farm!
Ecosystem Services
Agriculture is a high-impact industry. Large amounts of land are highly modified for the production of crops, and this impacts landscape functions in ways that are only beginning to be understood. As unmanipulated ecosystems disappear, the need for deliberate replication of ecosystem processes on working landscapes grows. This highlights the need for crops capable of providing valuable products while also performing beneficial ecosystem services.
Food production around the world and here in South Dakota depends to an amazing degree on the work of pollinators, including bees and other insects. In nature, the relationships between plant species and their pollinators are amazingly diverse and important to the overall functioning of ecosystems. But as natural landscapes are increasingly converted to agriculture and other human uses, and the management of these lands becomes more intensive, the natural diversity of plants that pollinators depend on has decreased. Camelina, which flowers very early in the spring, provides food during the crucial period of emergence from winter, before other plant species begin blooming. This can provide benefit to native bees and other insects as well as domestic honeybees, adding to local biodiversity and boosting the potential profitability of the local honey industry.
Other animals may benefit from adding an early-flowering crop to the system as well. The potential for camelina to improve the habitat quality of agricultural landscapes for wildlife such as deer, pronghorn antelope, and birds is unknown but possibly significant.
In the case of fall-seeded varieties, the early spring emergence and growth of camelina is mirrored by its late fall germination and root development. As a cover crop actively growing during the early and late “shoulder seasons”, camelina increases the portion of the year with active plant growth, which confers a number of benefits for soil and ecosystem health.
Active root growth helps nourish the soil microbiotic community, which is extremely important in maintaining healthy soils. At the same time, above-ground living vegetation and post-harvest residue works to compete with weeds, and reduce the risk of soil erosion by both wind and water. Erosion prevention is of paramount importance not only for maintaining the health and value of the soil resource, but also for the protection of downstream waterways, where sediments and chemicals that wash in from upstream can cause many forms of damage.
By actively growing outside the season of other crops, camelina may help consume leftover inorganic nitrogen in the soil, preventing it from becoming an environmentally dangerous pollutant in streams, lakes or groundwater. In areas with heavy, poorly drained soils and where nitrogen fertilizers are used, excess nitrogen can also promote the emission of nitrous oxide, an extremely potent greenhouse gas. This means that “nitrogen scavenging” is not only a way to capture the value of expensive fertilizer before it leaches or volatilizes away, but is also a powerful tool in reducing the potential of these wastes to contribute to climate change.
The full potential of camelina to provide ecosystem services has yet to be discovered.
Global Environmental Benefit
Ocean Conservation from the Center of the Nation
The use of ocean-caught fish to produce fish oil and fish meal for use in aquaculture feeds is a vexing global problem. The fish used for this purpose consist of small pelagic species such as anchovies, sardines, herring and capelin. Called “forage fish”, these species form the base of many ocean food webs, supporting economically important fisheries such as cod, halibut, and tuna. They are also vital to the survival of many other forms of marine life, including sea birds, penguins, seals, sea lions, whales, and dolphins. Forage fish populations are under pressure from a variety of stresses including climate change and pollution, pushing marine ecosystems to the brink of collapse and making current harvest levels unsustainable. The increases needed to fuel projected growth in aquaculture creates an urgently precarious situation. This “fish trap” provides the impetus to identify alternative sources for the nutrients needed by the aquacultural sector.
The past few years have seen Americans eating more fish, partly to help meet the need for dietary omega-3 fatty acids. These lipids, especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are an important key to maintaining human health and unfortunately, most American diets are deficient in them. Fish, especially predatory species such as salmon and trout, are especially good sources of these healthful fats. To keep up with market demand, these fish can be farmed inland, but in order to provide optimally healthful meat, they must be supplied with food containing the necessary ratios of fatty acid types. While alternative ingredients such as soybeans, canola, and even insects have been developed to provide energy, protein and other nutrients for fish feeds, few sources compete with ocean-grown fish oil and fish meal for supplying the high-quality fats that are so sought after.
With a long agricultural history in Europe and a relatively recent rediscovery as an oilseed crop for biofuels, camelina has been shown to produce the necessary lipids to replace fish oil and fish meal in aquaculture feeds. Research has demonstrated that fish fed with camelina can perform well in terms of growth rate and health, and that the meat of camelina-fed fish (particularly salmon and trout, known for their healthy lipid composition) contain high levels of omega-3 fatty acids EPA and DHA. Camelina is the only known crop that can fully replace fish oil in diets for farmed salmon.
