Interreg
Baltic Sea Region
JROPEAN
Z6I0MAL
*VELOPMENT
aD.
1
Risk of species introduction (biosecurity risk)
7 COMPLETE PLUS
The growth and accumulation of aquatic organisms on vessels (biofouling) affects their
performance and can lead to a spread of aquatic organisms outside their natural range (biosecurity
risk).
The speed and intensity of biofouling growth varies depending on abiotic and biotic conditions
{table 1). Important abiotic conditions are water salinity and water temperature. With an
increasing salinity and/or temperature, the number of aquatic organisms increases and so does
the potential for them to attach to the ship.
Table 1: Factors affecting biofouling growth on a ship
Factors affecting
biofouling growth
Water salinity
Water temperature
Depth of the water and
distance to shore
Age and condition of
coating
ldle time and utilisation
rate of the ship
Ship’s speed
Maintenance history or
surface treatment at
last dry docking or
during the last IWC
procedure
Hull roughness
Trading area of a ship’s
voyage
Reasons for increasing probability of biofouling growth
Increasing salinity increases the number of aquatic organisms.
Increasing temperature increases the number of aquatic organisms.
The shallower the water and the closer to shore, the less species
typically disperse.
The older the coating or the worse the condition, the higher the
oprobability of fouling to attach to the ship.
The less a ship is moving, the less water friction will prevent fouling
from not attaching to the hull and niches.
The more the ship’s speed differs from the coating manufacturer’s
specifications on an accurate speed, the less biofouling growth is
prevented.
In general: The longer the time since last dry-docking or IWC and
the longer the period since the last surface treatment, the higher the
probability of heavier fouling attached to the ship.
The rougher the hull, the higher the probability of biofouling to
attach.
If the ship has travelled areas with different occurrence of biofouling
species, biosecurity risk increases.
