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Filter feeder responses to dredging

Description: 

Defining thresholds and indicators of filter feeder responses to dredging-related pressures

Other Details: 

Dredging Science Program: Theme 6
Location: Pilbara and Kimberley
Project Leader: Muhammad Azmi Abdul Wahab, AIMS
Telephone: 6369 4043
Email: m.abdulwahab@aims.gov.au

FINAL REPORTS

Effects_of_Dredging_on_Filter_Feeders_Review_WAMSI_DSN_Report_6.1_Schönberg_2016_FINAL

Sponge Biogeography of WA_a review_WAMSI DSN Project 6.2 Fomont et al 2017

Comparisons of benthic filter feeder communities before_after large scale dredging program_WAMSI DSN Project 6.3_Abdul Wahab et al 2017

Photo catalogue of marine benthic diversity off Onslow (Pilbara Region of WA)_WAMSI DSN Project 6.3.1_Abdul Wahab et al

SUMMARY:

Coastal Western Australia (WA) has unique communities of dense and diverse filter feeders that are comparatively understudied and are not found anywhere else in the world. They provide immense bioservices within their habitats, including bentho-pelagic coupling, nutrient cycling, purification of vast water masses, 3-dimensional habitats, and support for a multitude of other important organisms. These communities are often dominated by sponges, a difficult taxonomic group that in WA contains many endemic or undescribed species.

Extensive dredging projects pose an environmental risk to local filter feeder communities through turbidity and light reduction, impediments to filtration organs and smothering by sedimentation. The present project aims to investigate the nature and thresholds of such risks.

The approach will be 4-pronged:

6.1 A review of available knowledge on sediment effects on sponges.

6.2 A synthesis of NWA sponge biogeographies.

6.3 Field surveys by underwater video and SCUBA at Chevron’s Wheatstone Project describing local filter feeding communities before and after exposure to dredging pressures, allowing insights into which growth forms, common taxa and feeding strategies will be most affected, thus informing, but also in part validating proposed aquarium work.

6.4 Controlled aquarium experiments testing pressure: response effects and thresholds of stressor combinations (turbidity, sedimentation, temperature) on different growth forms). Response values will include monitoring of smothering (e.g. surface lesions), shading (effects on symbionts), clogging of feeding apparatus (e.g. pumping activity, histology), increased expression of stress genes and shifts in feeding strategies (photo- vs. heterotrophy).

Through fieldwork in addition to laboratory experiments we will provide critical insights into local filter feeder communities and their responses to dredging pressures. Identifying relative impacts by different types of pressures in combination with thresholds and guidelines will assist stakeholders and managers alike in reducing risks and severity of impacts from dredging developments.

Articles

Wahab M.A.A., Fromont J, Gomez O, Fisher R, Jones R. (2017) Comparisons of benthic filter feeder communities before and after a large-scale capital dredging program Marine Pollution Bulletin doi.org/10.1016/j.marpolbul.2017.06.041

Pineda MC, Strehlow B, Sternel M, Duckworth A, Jones R, Webster N.S. (2017) Effect of suspended sediments on the sponge holobiont with implications for dredging management. Scientific Reports. doi:10.1038/s41598-017-05243-x

Pineda MC, Strehlow B, Sternel M, Duckworth A, den Haan J, Jones R, Webster N.S. (2017) Effects of sediment smothering on the sponge holobiont with implications for dredging management Scientific Reports 7, Article number: 5156 doi:10.1038/s41598-017-05243-x

Pineda MC, Strehlow B, Kamp J, Duckworth A, Jones R, Webster N.S. (2017) Effects of combined dredging-related stressors on sponges: a laboratory approach using realistic scenarios Scientific Reports doi:10.1038/s41598-017-05251-x

Pineda MC, Strehlow​ B.W., Duckworth A, Doyle J, Jones R, Webster N.S. Effects of light attenuation on the sponge holobiont- implications for dredging management Scientific Reports (2016) doi:10.1038/srep39038

Presentations

Pineda MC, Strehlow B, Duckworth A, Jones R (2017) Pressure-response relationships of sponges to dredge pressures – a laboratory approach. 10th World Sponge Conference. Sponges & their Environment ABSTRACT

Strehlow B, Pineda MC,  Duckworth A, Clode P, Webster N (2017) Sub-lethal stress responses of sponges to dredging pressures. 10th World Sponge Conference. Sponges & their Environment. ABSTRACT

Wahab MAA, Fromont J, Gomez O, Fisher R, Jones R (2017) Effects of dredging on benthic filter feeding communities. 10th World Sponge Conference. Ecosystems & Environment. ABSTRACT

Posters

Fromont J, Wahab MAA, Gomez O, Ekins Merrick, Goverdina Geerruida Grol M, Hooper J.N.A. (2017) North-western Australia: a sponge biodiversity hotspot. 10th World Sponge Conference ABSTRACT