Defining thresholds and indicators of coral response to dredging-related pressures
Dredging Science Program: Theme 4
Location: Pilbara and Kimberley
Project Leader: Ross Jones, AIMS
Telephone: 6369 4015
SUMMARY: In Australia, and especially in sub-tropical and tropical north-western Australia, there are many examples of current and planned major dredging projects where millions of cubic metres of sediments require removal. These volumes are significant by global standards and since the released sediments can reduce or block light, clog filtering and feeding apparatus and smother benthic organisms they carry a significant environmental risk. To manage this risk, there is a critical need to establish quantitative relationships between dredging-relating pressures and the responses for key biota, especially iconic and ecologically important groups such as corals.
The ultimate objectives of the proposed work are to:
- better understand the effects of dredging and dredge spoil disposal on corals by identifying the principle mechanisms by which suspended and settling sediments affect adult colonies in the short and long-term;
- establish pressure-response relationships for relevant pressure parameters that will provide water quality guidelines for dredging projects around coral reef environments; and
- produce protocols that describe how to incorporate this information into environmental impact assessment and monitoring programs. This will reduce uncertainty and environmental risks associated with large scale dredging projects and provide a mechanism for industry to ensure compliance with regulatory conditions.
Work is divided into four projects, with projects 1 and 2 involving analysis of existing data and reviews, project 3 involving laboratory manipulations and including project 4 involving field work. The work program is staggered and integrated, with projects 1 and 2 informing project 3. The field-work component (Project 4) is associated with recovery modelling [as opposed to deriving pressure-response relationships] as the latter was considered to be far too risky an approach given the uncertainty of field work.
Bessell-Browne P, Negri A.P., Fisher R, Clode P.L., Jones R (2017) Impacts of light limitation on corals and crustose coralline algae Scientific Reports doi:10.1038/s41598-017-11783-z
Fisher R, Walshe T, Bessell-Browne P, Jones R. (2017) Accounting for environmental uncertainty in the management of dredging impacts using probabilistic dose–response relationships and thresholds. J Appl Ecol. doi.org/10.1111/1365-2664.12936
Bessell-Browne P, Negri A.P., Fisher R, Clode P.L., Jones R, (2017) Cumulative impacts: thermally bleached corals have reduced capacity to clear deposited sediment Scientific Reports doi:10.1038/s41598-017-02810-0
Bessell-Browne P, Fisher R, Duckworth A, Jones R, (2017) Mucous sheet production in Porites: an effective bioindicator of sediment related pressures Marine Pollution Bulletin 2017 http://dx.doi.org/10.1016/j.ecolind.2017.02.023
Bessell-Browne P, Negri A.P., Fisher R, Clode P.L., Duckworth A, Jones R, (2017) Impacts of turbidity on corals: The relative importance of light limitation and suspended sediments Ecological Indicators 2017 http://dx.doi.org/10.1016/j.marpolbul.2017.01.050
Whinney J, Jones R, Duckworth A, Ridd P (Dec 2016) Continuous in situ monitoring of sediment deposition in shallow benthic environments Coral Reefs DOI 10.1007/s00338-016-1536-7
Fisher R, Stark P, Ridd P, Jones R (Dec 2015) Spatial Patterns in Water Quality Changes during Dredging in Tropical Environments PLOS DOI: 10.1371/journal.pone.0143309
Jones R, Bessell-Brownea P, Fishera R, Klonowskic W, Slivkoffc M (Dec 2015) Assessing the impacts of sediments from dredging on corals Marine Pollution Bulletin doi:10.1016/j.marpolbul.2015.10.049
Jones R, Fisher R, Stark C, Ridd P (Oct 2015) Temporal Patterns in Seawater Quality from Dredging in Tropical Environments PLOS DOI: 10.1371/journal.pone.0137112