Pelleted polychaetes

Feeding broodstock and shrimp with wild harvested worms has its downsides: for the environment, for the shrimp and ultimately also for profit margins. OddGeir Oddsen proposes a solution that modernises the way we feed broodstock, larvae and shrimp.

Worms on the wild side

Wild worms have been the shrimp feed of choice in the industry for many different (and valid) reasons. First and foremost, shrimp need polychaetes as a component in their food for spawning, and suitable worms are found in the areas where the shrimp are farmed. So we have easy access to a necessary protein. What could possibly go wrong?

Let’s start with how polychaetes are harvested in the wild. Currently, there are no rules or regulations that dictate where worms are to be harvested, or what constitutes a sustainable harvest. And since no-one regulates anything, areas that used to be rich in worms are now heading for depletion.

In addition, use of wild harvested worms has in several instances been associated with EMS (Early Mortality Syndrome) in shrimp farms. Wild harvested worms are likely to harbour parasites, viruses or bacteria which are transferred to broodstock and their offspring.

As I see it, these are the main problems facing the industry in relation to wild harvested shrimp feed. And I think there’s an alternative that may very well let businesses improve while at the same time modernising their practices, accessing new potential markets and being kind to the environment. Potential in polychaetes
Since we already know that worms constitute the optimal protein if one wants to ensure good maturation rates in broodstock, there really isn’t going to be a reason to try to make shrimp feed without including worms, at least not in the foreseeable future. In addition to good maturation rates, worms contain an important fatty acid profile that broodstock pass on to their offspring, and the inclusion of polychaetes in the shrimps’ diets is known to improve the health. Farmed polychaetes can be tested for parasites, bacteria and viruses in order to ensure a disease-free worm stock. The worms can be raised in facilities that do not hurt the environment around shrimp farms, a factor we all know has tarnished the industry for years. Polychaetes can be farmed in bio-secure ponds hundreds of miles away from open-water shrimp farms, thereby eliminating the potential for cross-contamination with shrimp disease. But switching to farmed worms doesn’t solve all problems: Shipping and handling wet feed requires a complex infrastructure, and it takes considerable time and effort both to freeze and thaw the polychaetes. In addition, wet feed disintegrates as soon as it enters the water, which means that many nutritional elements will go to waste. In turn, this means that shrimp farmers need to spend more money to feed their stock than necessary. So where does this leave us?

Sustainable shrimp feed

The solution is pellets. Or rather, the solution lies inside the pellets. By using farmed polychaetes as a component in pellets made especially for shrimps, many of the obstacles shrimp broodstock farmers face on a daily basis will become problems of the past. Today, the only manufacturer of pelleted feed with polychaetes as an active ingredient is the UK-based company Sea Farms Nutrition Ltd under the ProChaete brand. Using pellets instead of wet feed has obvious benefits. For one thing, storing and handling pellets is much easier than storing and handling wet feed. The same goes for feeding the shrimp, a process that can be automated when using pellets. In fact, pelleted feed is optimised for automatic feeding systems. In addition, the predictability with which pellets can be delivered is far greater than with wild harvested worms. And then there are the polychaetes. When the company manufacture feeds, they source their polychaetes from bio-secure farming units in Europe. In addition to lowering the risk of shrimp disease significantly, there are other benefits of using worms that have been tested for diseases and parasites. More and more retail chains look for transparency and corporate social responsibility throughout their entire supply chain. Big retailers will not consider using suppliers who impact their environment negatively. This means that using sustainably harvested, disease-free worms in pelleted feed could help shrimp farmers move into new era!

Modern maturation

So does pelleted feed work when the object is to mature broodstock as effectively as possible? The short answer is yes. Trials indicate both good maturation rates and good fertility. Food for the future I believe that hatcheries and shrimp farms need to adapt to an environmentfriendly future if they want to survive. Today’s harvest of wild worms is unsustainable, both on a farm-by-farm-basis and on an industrial scale. When we almost deplete the nearby environment of resources, the prices of those resources are going to skyrocket, as in every other industry. Thus switching to a predictable feed source has financial incentives as well. By using pelleted feed that contains polychaetes, hatcheries and shrimp farms are taking the first steps in building business models that can stand the test of time.