Environmental Engineering Reference
In-Depth Information
A number of physical, chemical and biological cues are involved in attracting spores
and larvae to a surface leading to their settlement and attachment and thus, causing
biofouling. The settlement is inluenced by surface properties including wettability
and microtopography, the microbial bioilms associated to the substrata, the presence
of conspeciic adults, or a speciic prey [30]. The bioilm forms an important cue for
spores and larvae settlement. Sudhakar and co-workers [31] observed that on high-
density polyethylene (HDPE), low-density polyethylene (LDPE) and polypropylene
(PP) strips immersed for six months in the Bay of Bengal sea (South India), attachments
of colonies were high on PP, followed by lesser colonisation on HDPE and LDPE
(
Figure 2.4)
. An average attachment on PP per month at Chennai Port (South
India) was 1100 and 1813 colony-forming unit (CFU)/ml of
Pseudomonas sp
., and
heterotrophic plate count, respectively. The values for HDPE were 560 and 450
CFU/ml and for LDPE were 540 and 240 CFU/ml, respectively. This shows that the
formation of bioilms is required for the easy deposition of macrofouling communities.
A
B
C
D
Figure 2.4
Biofouling on a polymer surface exposed to water of the Bay of Bengal,
South India for one month. A) LDPE; B) HDPE; C) PP;
and D) polycarbonate (PC). In image (D) the unexposed PC before exposure
is also shown
