Affiliation:
1. University of Technology Sydney
2. Wavelength Reef Cruises
Abstract
Abstract
Coral propagation and out-planting based restoration approaches
are increasingly being applied as tools to assist natural recovery
and preserve resilience of coral reefs. However, many out-planting
and propagation methods rely on plastic zip-ties to fasten corals
to structures in coral nurseries, which is potentially problematic
and unsustainable for the marine environment. Plastic-free
biodegradable alternatives are becoming available but may pose
unique risks by impacting coral associated bacterial communities
that are integral to coral health. We therefore examined the
bacterial communities of Acropora millepora coral
fragments propagated in coral nurseries in two experiments on the
northern Great Barrier Reef to identify whether biodegradable
materials differentially impact coral associated bacterial
communities. In each study coral fragments were secured to nursery
frames with conventional plastic, metal and biodegradable
(polyester and polycaprolactone) ties, and both tie failure and
coral associated bacterial communities were characterised during a
six-month period. Minimal coral mortality was observed (3.6-8 %)
and all ties tested had low failure rates (0-4.2 %) with the
exception of the polyester biodegradable material (29.2 % failure).
No differences were observed between coral associated bacterial
communities of fragments secured in the coral nursery with
different tie types, and no proliferation of putatively pathogenic
bacteria was recorded for fragments secured with biodegradable
ties. Overall, our findings suggest that reducing reliance on
conventional plastic can be achieved through transitions to
biodegradable materials, without any notable impacts on
coral-associated bacterial communities, but we caution the need to
examine wider coral taxa of different morphologies and growth
dynamics, and any new plastic-free materials prior to
application.
Publisher
Research Square Platform LLC
Reference45 articles.
1. Commentary: Plastic waste associated with disease on coral reefs;Bidegain G;Science,2018
2. Coral restoration – A systematic review of current methods, successes, failures and future directions;Boström-Einarsson L;PLOS ONE,2020
3. Bruckner, A. W., Bruckner, R. J., & Hill, R. (2008). Improving restoration approaches for Acropora palmata: Lessons from the Fortuna Reefer grounding in Puerto Rico. In Proc. 11th Int. Coral Reef Symposium (1), 1199–1203.
4. DADA2: High-resolution sample inference from Illumina amplicon data;Callahan BJ;Nature Methods 2016,2016
5. Corals exhibit distinct patterns of microbial reorganisation to thrive in an extreme inshore environment;Camp EF;Coral Reefs,2020