Brown shrimp

Systematic position: Crangon crangon belongs to the order Decapoda, family Crangonidae. This species is widely distributed in the coastal waters of the Atlantic, North Sea, and Baltic Sea, acting as a key component of the benthic ecosystem, though it may occasionally interact with agricultural infrastructure.

Impact on crops: While Crangon crangon is not a direct threat to terrestrial crops, it can affect coastal agriculture and halophytic crop cultivation. The species may cause damage when it enters irrigation systems fed by seawater or in areas where saltwater intrusion affects farmland, leading to potential clogging or direct consumption of soft plant tissues.

Biology and life cycle: The life cycle of the brown shrimp involves complex seasonal migrations between shallow estuaries and deeper waters. Females carry eggs on their pleopods, with larvae undergoing a planktonic stage before settling as juveniles on the seafloor. Their survival and distribution are highly dependent on water temperature and salinity levels.

Character of damage: Damage is largely related to the physical disruption of plant root systems in submerged or salt-affected coastal fields. Additionally, in aquaculture settings, high densities of Crangon crangon can lead to the deterioration of water quality due to high metabolic output, which can inadvertently affect the health of cultivated marine plants or crops.

Control measures: To manage the presence of these crustaceans near agricultural sites, several practices are recommended:

• Installation of fine-mesh screening at irrigation water intakes.
• Regular maintenance and dredging of irrigation canals to prevent organic accumulation.
• Monitoring of salinity levels to create unfavorable conditions for marine species in freshwater irrigation systems.
• Biological management by promoting local fish populations that act as natural predators of the shrimp.