Encapsulation as a biosecurity tool for managing fouling on recreational vessels
Date
2020
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Abstract
Hull fouling is a dominant vector in marine systems, with recreational vessels playing
an important role in intra-regional transfer of biota. Encapsulation (i.e. the wrapping
of a structure in plastic to deprive biota of oxygen and food, ultimately causing
their death), offers promise as a tool for treating vessel fouling in situ. However, there
is currently no standardised approach with detailed field application recommendations.
In recognition of this gap this study aimed to: 1) use laboratory experiments to
establish a timeframe for the effective encapsulation of yachts, 2) test this approach
in the field and 3) consider the practicalities associated with implementing an
encapsulation program. Laboratory experiments exposed the ascidian Ciona robusta,
the mussel Semimytilus algosus and fouling communities to four treatments:
aerated control in seawater, encapsulation in seawater, aerated seawater with 4%
acetic acid and encapsulation in seawater with 4% acetic acid. All biota in acetic
acid died in 24 hours regardless of encapsulation, while in encapsulated seawater
mortality of all taxa occurred within three days. In the field four yachts and five
pontoons with high (80–100%) and low (30–50%) fouling cover were encapsulated.
It took more than three days to achieve mortality on all structures (pontoons high
cover 3.7 days (± 0.48 SD); pontoons low cover 3.8 days (± 0.42 SD) and yachts
4.3 days (± 0.5 SD)). The discrepancy between laboratory and field results likely
reflects an unavoidably higher water to fouling biomass ratio in field systems.
These results suggest that five days may be sufficient for successful encapsulation
of yachts. However, in recognition of the limited sample size of yachts in this
study, it is recommended that these findings be used as a basis for further developing
region specific protocols through adaptive management. Logistical considerations
around the implantation of national encapsulation programs are also discussed.
Description
CITATION: Keanly, C. & Robinson, T. B. 2020. Encapsulation as a biosecurity tool for managing fouling on recreational vessels. Aquatic Invasions 15(1): 81–97, doi:10.3391/ai.2020.15.1.06.
Keywords
Ciona robusta
Citation
Keanly, C. and Robinson, T.B. (2020). Encapsulation as a biosecurity tool for managing fouling on recreational vessels. In: Proceedings of the 10th International Conference on Marine Bioinvasions. Puerto Madryn, Argentina. (eds. Fowler, A., Blakeslee, A., Tepolt, C.et al). Aquatic Invasions. 15, pp. 81-97.