Transboundary pathogen transfers can hamper shrimp industry

Close look up of blue pathogen. Photo: Claudio Ventralla

Transboundary animal diseases are potentially epidemic, highly contagious illnesses that can spread quickly. They could have detrimental effects on public health and the socioeconomic system.

The industry’s explosive growth also posed a threat to shrimp producers all around the world. It was believed that the rise of intensive aquaculture was responsible for the appearance of new illnesses. Early Mortality Syndrome (EMS), later known as Acute Hepatopancreatic Necrosis Disease (APHND), was responsible for a large number of fatalities in various emerging nations. While the White Spot Syndrome Virus (WSSV), which has been linked to severe economic loss in the Philippines, was discovered to have its origins in China. In addition to the harmful bacteria already described, environmental conditions and nutritional deficits can also contribute to diseases in shrimp.

A number of factors led to the importation of P. vannamei into Asia, but the primary one was P. chinensis in China and P. monodon almost everywhere else’s poor performance, slow growth rate, and disease susceptibility. Additionally, there can be marketing benefits and a desire to develop, intensify, or diversify aquaculture systems. Over the past ten years, the culture industries of the majority of Asian nations have suffered considerable losses as a result of a string of illness outbreaks brought on by viral infections that affect Asia’s cultured shrimp output. These illnesses have not only spread across international borders but also throughout shrimp farming regions, ostensibly as a result of stock trades involving diseased animals.

The importation of P. vannamei has drawbacks as well, including its capacity to act as a carrier of various viral pathogens exotic to Asia, a lack of knowledge of culture techniques in Asia (particularly for broodstock development), a smaller final size and price compared to P. monodon, the need for high-tech intensive ponds, competition with Latin America for markets, and a lack of support for farmers due to their frequently unpaid work.

Using exotic aquatic organisms like P. vannamei has the primary drawback of possibly spreading dangerous infections. In newly imported species, transboundary pathogen transfers frequently result in the establishment of infections in naturally susceptible local hosts and may trigger the diseases’ adaptation to a new range of hosts. The transmission of viral pathogens is of special concern because of their inherent genetic heterogeneity, quick rate of replication, and frequent occurrence as low-level latent infections in animals that appear to be in good condition.

The widespread introduction of this species to Asia, mostly by commercial farmers, is the result of encouraging trial results, benefits perceived by the industry, including superior disease resistance, growth rate, and other advantages. These factors were combined with difficulties in controlling imports from other countries. Sadly, the importation of less expensive, non-disease-free stock has led to the introduction of dangerous viral infections (especially TSV) into a number of Asian nations, including Mainland China, Taiwan, Thailand, Indonesia, and potentially other places. Though the origins of the stocks and their current state of health are largely unknown, there are already numerous hatcheries operating in Asia that are generating PL for stocking.

It is realistic to believe that many of the hatcheries are unable to keep their stocks as SPF, and as a result, they frequently contract local viral illnesses and, quite potentially, illnesses that are common to the species in Latin America (such TSV). Due to the increased demand for postlarval P. vannamei, private-sector hatcheries have begun to cut corners and are thus not adhering to the standards for maintaining clean stocks.

It is safe to believe that many of the hatcheries are unable to keep their stocks as SPF, and as a result, they frequently contract local viral illnesses and, quite potentially, illnesses that are common to the species in Latin America (such TSV). Due to the increased demand for postlarval P. vannamei, private-sector hatcheries have begun to cut corners and are thus not adhering to the standards for maintaining clean stocks.

Since it is obvious that P. vannamei shrimp has a well-established culture and is expanding quickly in the Asian Region, it is crucial that judgments about these benefits and drawbacks are well-informed and that the proper steps are taken. The best way for this to happen is through close communication between the public and private sectors as well as other interested organizations.

By SEAFOOD NETWORK BANGLADESH

Reference: https://seafoodnetworkbd.com/transboundary-pathogen-transfers-can-hamper-shrimp-industry

DOMESTICATED SHRIMP POSTLARVAE – THE KEY TO SUCCESS

See more:

• Is EHP now the key health concern for Asian shrimp producers?
• AI Chatbots and Aquaculture Professionalism
• Inhibition of Vibrio biofilm formation by ginger extracts