In the U.S. (and parts of Australia) Barramundi are farmed in re-circulating, closed systems (FOA 2008, Australis 2008). These systems involve biological and physical filtration, removing particulate matter such as faeces and uneaten food from the water. Clean filtered water can then be reused, with one U.S. Barramundi farm reusing the same water over 250 times before being replaced (Australis 2005). Filtering and recycling water greatly reduces any environmental impact. Re-circulatory systems also prevent the likelihood of fish escapes.

In Southeast Asia, Taiwan, and some parts of Australia, Barramundi are farmed in open ponds, or net pens in lakes or coastal marine areas. This farming method is considered high risk because of environmental concerns and the possibility of fish escapes. Open net pen farms are increasing in Southeast Asia to meet demand for export to the U.S. and Europe.

Although Barramundi farming systems or methods vary among countries, this ranking will focus on the re-circulatory, closed system used in the U.S. There is currently only one Barramundi farm operating in the U.S., located in Massachusetts.

Barramundi in the U.S. are farmed at moderate stocking densities, between 30-50 kg/m3 (Goldman 2008). In Australia, some Barramundi farms pump oxygen into the water to allow higher stocking densities. Although stocking density of U.S. farmed Barraumundi is moderate, there is a low number of farms (1) in the geographic region, thus points were added.

The use of high-tech re-circulatory systems, with biological and physical filtration, results in the farmed water being used and recycled for at least 250 times before being replaced (Australis 2005). Good filtration means that water released from the farm has very low levels of nutrients and organic compounds (Australis 2005). Waste material or effluent that is screened from the water is recycled and used as agricultural fertilizer (Australis 2005). The combination of these factors means that the farming operation used to grow Barramundi in the U.S. has minimal impact on the surrounding environment.

Barramundi in the wild are opportunistic predators feeding mostly on fish and crustaceans such as prawns (Allsop et al. 2006). Farmed-raised Barramundi are fed a diet of high energy pellets, consisting of essential amino acids, vitamins, carbohydrates and minerals (Glencross 2006). In the U.S, the diet of farmed Barramundi contains approximately 20% fishmeal and 5% fish oil, with one-third of the content produced as a by-product of the Canadian Herring roe fishery (Goldman 2008). The remaining two-thirds consist of Peruvian Anchovy and Icelandic Capelin. All three fish species are at good to high levels of abundance.
Barramundi larvae are generally fed on a diet of rotifers and brine shrimp, which in turn are cultured with microalgae (FOA 2008). However, microdiets enriched with essential nutrients are becoming more common when rearing Barramundi larvae (FAO 2008).
Although approximately 20% of the feed for adult Barramundi is sourced from wild fish populations, a significant proportion is a by-product for a human food fishery (roe), thus a ranking of 2 was chosen.

Canadian Herring and Icelandic Capelin, two of three seafood species used in Barramundi feed, are both ranked green (i.e. high score) on Blue Ocean Institute's wild-caught ranking system (BOI 2008). Peruvian Anchovy has not yet been ranked by BOI. In addition, the Herring component in the feed is a by-product from the Canadian Herring roe fishery, thus reducing waste in a human food fishery.

Research is currently examining ways to reduce the percent of fish products in farmed Barramundi diet, such as replacing fish meal with legumes or beans (Eusebio and Coloso 2000) or meat meal (Williams et al. 2003).

The FCR in many foreign commercial Barramundi farms is 1.6-1.8:1, and maybe be higher in winter when fished are farmed in open systems (FAO 2008). In contrast, Barramundi farmed in the U.S. have a relatively low FCR of 1.1:1 (Goldman 2008), achieved through feeding studies and tight control of environmental conditions promoting efficient conversion of 'food to fish'.

Barramundi farmed in the U.S. are raised in closed, re-circulatory system, where all water is screened through biological and physical filters (Australis 2005). Water that is released is first cleaned to remove nutrient and organic compounds and treated with ozone to remove micro-organisms. In the U.S., effluent or fish manure produced from farming Barramundi can be used as fertilizer for local farms (Australis 2005).

The one farming operation in the U.S. that cultures Barramundi does not add antibiotics or hormones (Australis 2008).

Treated effluent is discharged under a permit issued by the National Pollutant Discharge Elimination System, which is part of the U.S. Environmental Protection Agency. The discharged water is monitored weekly for suspended solids and biological oxygen demand, with the latter a good test to estimate the amount of micro-organisms in the water. A water quality report is submitted monthly to the Massachusetts Department of Environmental Protection and the U.S. Environmental Protection Agency (Goldman 2008).

Closed re-circulatory systems used to farm Barramundi in the U.S. promote the re-use of water, while fish effluent is recycled and used as agricultural fertilizer (Australis 2005).

Barramundi is a tropical species that lives in water temperatures from 20 to 28 oC (68-82 oF) (Fishbase 2008). In the U.S., Barramundi are farmed in Massachusetts, where water temperatures in summer are too cold for any escaped Barramundi to survive. In addition, the closed system used for farming Barramundi prevents escapes.

If Barramundi, which are a tropical warm-water species, did escape, they would not survive due to the cold water in the location (Massachusetts) where they are farmed.

The closed system used to farm Barramundi in the U.S. (FOA 2008) prevents fish escapes.

A closed system where waste water is passed through filters including an ozone treatment to kill micro-organisms before release (Australis 2005) reduces the chance of diseases escaping from the farm to the local environment.

The one operation in the U.S. commercially farming Barramundi is located in a small industrial park in Turner Falls, Massachusetts. Most of the land for the farming facility was previously developed (Goldman 2008); the remaining land was originally pine forest which is of low ecological sensitivity.

Barramundi farmed in the U.S. are grown in closed systems so there is no risk of predation, thus no predator deterrents are needed.

Juvenile Barramundi were initially imported from Australia, where they are cultured in hatcheries (FAO 2008). These imported Barramundi are certified disease-free by Australian fish health authorities (Australis 2005). Since January 2007, an on-site hatchery has been supplying juvenile Barramundi for grow-out (Goldman 2008).