ARTi Team Member Jill Foreman Introduces Biochar to None Other Than Shrimp
ARTi Team member Jill Foreman has been working on a biochar project of her own and at first glance it may seem to be far outside the still wide realm of what biochar is known for. In this case, biochar’s effects on shrimp aquariums. Jill has been with ARTi for a number of years and fulfils many roles such as administration, shipping and lab work. Crucially, as biochar is a soil technology it can be a dirty business and Jill is in no way squeamish about getting biochar smudgings. Jill has a passion for water fauna like shrimps or fish and wanted to introduce a shrimp aquarium into the ARTi office. This quickly evolved into a chance for an experiment. In a project initiated by Jill, she wished to see if there was a notable difference with biochar being present in the aquarium’s plant bedding. There were two tanks with one having biochar and the other as a control with none. There was a striking difference observed. The tank with biochar present had much clearer water and less algae. In particular, the reduced algae was quite noticeable. One small bag of ARTi Biochar was used which is about 100 grams. The biochar was placed in the sand at the bottom of the tank.
Biochar has been in fact examined as a beneficial additive to aquaculture. In a paper titled Biochar: An Emerging Solution for Sustainable Aquaculture by Raul Et al. in India the researchers highlight seven possible positive uses for biochar in aquaculture:
- As a biofilter to remove pesticide, heavy metals and in particular as an effluent treatment system for shrimp farms.
- Acid neutralization.
- The reduction of leaching of nutrients.
- Enrichment of mineral nutrients.
- As a plant bed in an aquaponics system.
- Carbon Sequestration
- As a feed additive.
Jill Forman’s project centers around use as a plant bed in an aquaponics system. Raul Et al. note that biochar when used as plant bedding in an aquaponics system has the potential to retain nutrients from spent water as is the case in small aquarium settings. In this instance, the biochar’s focus is as a filter medium rather than as a soil or plant growth/health enhancement system.
Raul Et al. further cite work that has shown biochar as a feed additive increases growth rate in catfish. The authors also discuss ammonia absorption from fecal matter thereby reducing the ammonia toxicity in high-density larval rearing units. Shrimp fall into the category of high-density larval rearing and are candidates for examining the potential of biochar as a food additive. Nevertheless, as is so often the case in the biochar world, not every type of biochar made from every type of feedstock under every type of condition will make for good biochar as a food additive for shrimp.
Jill Forman’s experiment with biochar presence in a shrimp aquarium demonstrated that the most obvious positive benefits were clearer water and a notable reduction in algae. The experiment has been running for 8 months and over more time perhaps effects of the biochar presence on the shrimps themselves will be able to be seen. Again, Tank 1 has no biochar present. However, it has demonstrated plant growth. Nevertheless, the plants are not growing fast enough to replace the leaves being eaten by snails. Conversely, Tank 2 has biochar added and its plant growth is out-pacing the grazing done by the snails. Also note, there is a population of Neicaridina shrimps in tank 1, but they seem to have disappeared from tank 2. If the biochar addition is related has yet to be determined.
A number of cuttings of the plants were made from the tank with biochar. As a result, at least 3 adult shrimp were discovered to be “hiding in the jungle” thereby increasing their count. The tanks are unheated, and there is no soil or aquaponic planting medium. It is simple playground sand that was rinsed first to remove the tiny particles that cause cloudy water. No aquatic fertilizers were used, and water collected from the downspout during rains is the only source to replenish the small amount of evaporation. The water has never been changed. The shrimps get occasional feedings of shrimp food designed for helping the younger shrimp but that is added a pinch at a time every few weeks. Since some of the plant life has been culled, Jill considers this “hands-off” experiment to have drawn to a close. Instead of purging tanks and contents, the tanks will be given a good trimming, clearing away of the algae, and replacing the shared overhead light with one on a timer (perhaps controlled light will have an effect.) Jill does have a thing for the little shrimps and re-establishing their numbers in the biochar tank is a potential goal.
Biochar is present on the floor of the plant bed in the aquarium.
Two tanks used for the demonstration. Tank 1 is a control while tank 2 contains biochar.
Tank 2 on the left with biochar present shows markedly more plant growth.
Again, Tank 2 with Biochar present shows remarkable plant growth.