Lake shrimp

Systematic position: The lake shrimp (Gammarus lacustris) belongs to the order Amphipoda, family Gammaridae. While often viewed as a beneficial element in natural aquatic ecosystems and aquaculture for feeding fish, it can become a significant pest in controlled agricultural environments such as hydroponics and aquaponics setups.

Crops damaged: This pest primarily affects plants grown in water-based systems, including lettuce, various herbs, and microgreens. The primary targets are the root systems, which provide both a substrate for attachment and a convenient food source for the shrimp, especially when other organic detritus is scarce in the system.

Biology and life cycle: The life cycle of Gammarus lacustris is entirely aquatic. They go through a series of molts and reproduce throughout the growing season. Females carry their eggs in a brood pouch, and the hatchlings are active immediately. They prefer environments with stable temperatures and sufficient organic material, which are common in many hydroponic installations.

Nature of damage and pest status: Damage is characterized by the consumption of root hairs and fine root tissue. This mechanical injury severely restricts the plant's ability to absorb water and nutrients, often leading to stunted growth, yellowing, and eventually plant collapse. Furthermore, the feeding wounds provide entry points for secondary bacterial and fungal pathogens.

Control measures: Effective management of lake shrimp involves physical barriers and system maintenance.

• Install fine mesh screens on all intake pipes to prevent the entry of shrimp and their larvae.
• Maintain system hygiene by removing dead plant matter and detritus that serves as their primary food source.
• Implement regular system flushing and deep cleaning protocols between crop cycles.
• In closed aquaponic systems, carefully manage fish predators that may keep shrimp populations in check naturally.