Fish in the Fields
SALMON
NOAA Fisheries has listed 28 population groups of salmon and steelhead on the West Coast as threatened or endangered under the Endangered Species Act. Threats to these wild Pacific salmon include illegal harvest, habitat destruction from development and mining activities, dams and other blockages in rivers, unregulated overharvesting, and a rapidly changing climate.
Salmon lead complex lives, which make them resilient to change but also make them vulnerable to a wide variety of threats. Salmon are born in freshwater, rear in streams, then head downstream to spend time in estuaries where they can grow large enough to survive in the ocean. Then they return home to spawn, beginning the cycle all over again. The collapse of their migratory ecosystem is a major threat to their survival.
RICE
Rice, a staple food for over half of the world’s population, also faces many challenges.
In its many shades and sizes, it is one of the world’s most important foods, recently surpassing wheat as the third largest crop in the world, providing one fifth of the calories consumed worldwide.
At the same time, rice is also a leading driver of habitat and biodiversity loss in wetland forests. Conventional rice farming significantly contributes to climate change, accounting for about 10% of global man-made methane emissions and consuming nearly 30% of the world's fresh water. The sustainability of rice is threatened and, with it, the world’s food supply.
FISH and RICE CO-CULTURE
There exists an ancient yet underutilized practice that offers a sustainable and eco-friendly alternative to contemporary farming practices. Rice-animal Co-culture (RAC) is an innovative agricultural practice that involves cultivating rice in paddies alongside various aquatic animals such as fish, shrimp, ducks, and crayfish. This symbiotic approach harnesses the synergies between rice crops and aquatic livestock.
The incorporation of fish into rice paddies initiates a symbiotic relationship. Fish excreta is a natural fertilizer, enhancing the soil and providing essential nutrients for rice growth. This nutrient cycling, further enriched by the organic matter of ducks and crayfish, creates a dynamic ecosystem within the paddies. Integrating fish and crayfish into rice paddies diversifies the farm’s output by providing an additional source of protein and income for farmers while contributing to a more sustainable and economically viable rice farming model.
Meanwhile, the presence of ducks in rice paddies serves as an ingenious pest management solution. With their voracious appetite for insects, ducks provide natural, chemical-free pest control, reducing the need for harmful pesticides. This ecological balance safeguards both the rice crop and aquatic life. While foraging for insects, ducks also assist in weed control. Their paddling movements help churn the soil, disrupting weed growth and other unwanted vegetation.
Another benefit of RAC is that the shared use of water resources among rice, fish, ducks, and crayfish maximizes the efficiency of water use. Water circulates through the system, benefiting each component and reducing waste. This integrated approach minimizes the environmental footprint and optimizes the farm’s productivity.
FISH in the FIELDS
The Resource Renewal Institute's Fish in the Fields program now integrates the practice of rice-fish co-cultivation into modern agricultural practices. It stemmed from the Nigiri Project, an initiative to restore threatened native salmon populations in California’s winter-flooded rice fields. The Nigiri Project demonstrated that these fields provided an abundant food source for salmon fingerlings. FIF launched in 2012 to create a sustainable alternative to threatened ocean forage fish and discovered that rice fields are 10 times more productive for raising fish than wild systems and require no additional expensive fish feed.
This initial experiment also showed that juvenile salmon who fed in the flooded rice fields grew many times faster than their counterparts in the river.
Now, thanks to nonprofit funding from Patagonia, the search for a solution to the methane pollution associated with rice production led to published research that documented the effect of small fish on methane emissions from a freshwater lake. By applying this research to rice field plots, an unprecedented scientific discovery was made—adding fish to fallow flooded rice fields naturally and dramatically reduced methane in the water column.
These days RRI personel travel up and down California, working with landowners, water agencies, conservation groups and government agencies on ways to reintegrate floodplain productivity into the way farms and rivers are managed in California.
