Goose barnacle

Systematic position: Scalpellum scalpellum belongs to the phylum Arthropoda, subphylum Crustacea, class Maxillopoda, order Cirripedia, and family Scalpellidae. It is a sessile marine crustacean that acts as a significant biofouling agent in marine environments, often colonizing artificial substrates within aquaculture installations.

Biology and life cycle: The life cycle involves planktonic larval stages (nauplius and cyprid). The cyprid larva is responsible for selecting a suitable hard substrate to settle on. Once it attaches, it undergoes metamorphosis into its adult form, encased in a series of calcareous plates. These organisms are hermaphroditic and can form dense clusters in favorable marine conditions.

Nature of damage: The primary concern regarding Scalpellum scalpellum is biofouling. When these barnacles attach to nets, floating pens, and mooring lines, they significantly increase the drag and overall weight of the equipment. This causes structural stress, potential sinking of flotation systems, and a drastic reduction in water flow, which is vital for the oxygenation of farmed fish or shellfish.

Economic impact: The economic damage is largely indirect but costly. Biofouling by goose barnacles leads to increased labor costs for cleaning, shorter lifespan of expensive gear, and potential losses due to reduced animal health caused by restricted water circulation. In high-density aquaculture areas, managing these populations is an essential part of facility maintenance.

Control measures: Management strategies focus on both deterrence and removal. Key methods include:

• Application of marine-grade antifouling paints that inhibit larval settlement.
• Installation of ultrasonic transducers on submerged structures to disrupt settlement.
• Manual or high-pressure water cleaning schedules during the peak spawning season.
• Regular inspection and proactive replacement of colonized equipment to prevent excessive weight build-up.