6 Synthesis: Filter feeder responses to dredging

Description

Coastal Western Australia 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, three-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. This project aimed to investigate the nature and thresholds of such risks.

Aims

• Investigate the nature and threshold of risks to local filter feeder communities through turbidity and light reduction, impediments to filtration organs and smothering by sedimentation.
• Provide critical insights into local filter feeder communities and their responses to dredging pressures.
• Identify relative impacts by different types of pressures in combination with thresholds and guidelines.
• Assist stakeholders and managers alike in reducing risks and severity of impacts from dredging developments.

Methods

• A review of available knowledge on sediment effects on sponges.
• A synthesis of northwest Australian sponge biogeographies.
• 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.
• Controlled aquarium experiments testing pressure: response effects and thresholds of stressor combinations (turbidity, sedimentation, temperature) on different growth forms. Response values to 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 have provided 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 in reducing risks and severity of impacts from dredging developments.

Outcomes

Project News

• New name for a tropical whip sponge

• Award goes to WAMSI sea sponge responses to dredging project

• Sponges show varying levels of tolerance and resilience to sediment stress

• Rare soft corals feature in Kimberley photographic field guide

• Effects of dredging on filter feeder communities, with a focus on sponges

• Sponges choose enigma over charisma

• Researcher Q and A – Mari Carmen Pineda

Reports

Schönberg C (2021) No taxonomy needed: Sponge functional morphologies inform about environmental conditions. Ecological Indicators https://doi.org/10.1016/j.ecolind.2021.107806

Abdul Wahab M.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

Fromont J, Abdul Wahab M.A, Gomez O, Ekins M, Grol M, Norman Ashby Hooper J. (2016) Patterns of Sponge Biodiversity in the Pilbara, Northwestern Australia Diversity 2016, 8(4), 21; doi: 10.3390/d8040021

Fromont J, Żółtowska-Aksamitowska S, Galli R, Meissner H, Erpenbeck D, Vacelet J, Diaz C, Tsurkan MV, Petrenko I, Youssef DTA, Ehrlich H (2019) New family and genus of a Dendrilla-like sponge with characters of Verongiida. Part II. Discovery of chitin in the skeleton of Ernstilla lacunosa. Zoologischer Anzeiger doi.org/10.1016/j.jcz.2019.03.002

Lafratta A, Fromont J, Speare P, Schönberg C (Feb 2016) Coral bleaching in turbid waters of north-western Australia Marine and Freshwater Research doi.org/10.1071/MF15314

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

Pineda M.C., Duckworth A, Webster N. (Jan 2015) Appearance matters: sedimentation effects on different sponge morphologies Journal of the Marine Biological Association of the United Kingdom DOI: http://dx.doi.org/10.1017/S0025315414001787

Schönberg C.H.L. (Sept 2015) Happy relationships between marine sponges and sediments – a review and some observations from Australia Journal of the Marine Biological Association of the United Kingdom DOI: http://dx.doi.org/10.1017/S0025315415001411

Schönberg C.H.L. (Dec 2014) Self-cleaning surfaces in sponges Marine Biodiversity DOI: 10.1007/s12526-014-0302-8

Strehlow BW, Pineda M, Duckworth A, Kendrick GA, Renton M, Abdul Wahab MA, Webster NS, Clode PL. (2017) Sediment tolerance mechanisms identified in sponges using advanced imaging techniques. PeerJ 5:e3904 doi: 10.7717/peerj.3904

Strehlow​ B.W., Jorgensen D, Webster N.S., Pineda MC, Duckworth A. Using a thermistor flowmeter with attached video camera for monitoring sponge excurrent speed and oscular behaviour PeerJ (2016) Dec DOI: 10.7717/peerj.2761

Vacelet J, Erpenbeck D, Diaz C, Ehrlich H, Fromont J (2019) New family and genus for Dendrilla-like sponges with characters of Verongiida. Part I redescription of Dendrilla lacunosa Hentschel 1912, diagnosis of the new family Ernstillidae and Ernstilla n. g. Zoologischer Anzeiger doi.org/10.1016/j.jcz.2019.03.001

Media

Presentations

Abdul Wahab M.A et al. Sponges of the Pilbara – a biodiversity hotspot. 2017 WAMSI Research Conference

Theme 6 Overview, Defining thresholds of filter feeder response to dredge pressures. (2015 WAMSI Research Conference)

Observations from pre-dredging surveys of filter feeders at Onslow, Western Australia. (2015 WAMSI Research Conference)

Identifying, characterising and quantifying the effects of dredging on sponges. (2015 WAMSI Research Conference)

Deriving pressure-response relationships of sponges to dredge pressures – a laboratory approach. 2015 WAMSI Research Conference