Right now, shrimp farmers in India are facing a “mystery” disease. From EMS in Thailand in 2012 to Whitespot in Ecuador in 2001, regional epidemics have shocked the shrimp world. As the popularity of Vannamei continues to rise (although we are seeing farmers turning back to Monodon), the widespread of this monoculture is always in jeopardy of falling to disease.
We want to explore how farmers are attempting to mitigate disease risk today and what it could look like in the future.
The Devastating Impact of Disease on Shrimp Farms
Disease is still the #1 concern of farmers, not only because it can significantly drive down profits, but when it comes, it can throw a farm and a region into a downward spiral of loss and increasingly desperate attempts to understand what the problem is and how to fix it.
Disease is introduced into a pond by some outside source: the PL themselves, the water, or birds or crabs carrying them into the pond. From these hosts they spread to infect the water. When the animals are stressed they then become highly susceptible to whatever pathogens may be present and the result is a diseased crop.
How Farms Handle Biosecurity Today
So, with disease coming from outside of the farm, farmers practice varying degrees of biosecurity today. The first is to ensure the PLs that arrive are not carrying a pathogen with them. If this is the case, the health of the environment will not have a great impact, positive or negative on the animal.
The next is to ensure that the water entering the pond is as free as pathogens as possible. Increasingly farmers are holding water in reservoirs and treating it with things like probiotics or other disease mitigation techniques to both remove harmful pollutants and mitigate the impact of disease.
The final is to stop airborne and human-borne pathogens from accessing the ponds. Some farmers put up bird and crab nets. Others go as far as to build greenhouses, and the most extreme case we have seen has been at Viet-Uc in Vietnam where in their greenhouses they have applied hatchery-level biosecurity like having all of their staff wear smocks, caps, and sanitize their boots before they enter.
In more remote areas with lower pond densities like Ecuador, biosecurity is handled by having farms generally not be that close to each other.
Will Farms Change Their Biosecurity Practices?
Likely yes. We are seeing a movement towards more investment by top producers in controlling the variables that can impact the health of their animals. It will take a while for such practices to trickle down to all farms. The pattern seems to be that farmers operate in a rather laissez-faire manner until an epidemic strikes the region. Then they put in measures (with varying degrees of success) to take action to prevent such a calamity from happening again.