Related Experiment Video
Updated: Dec 29, 2025
10:11
The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations
Published on: August 3, 2016
10.3K
Invasive ecosystem engineers threaten benthic nitrogen cycling by altering native infaunal and biofouling communities
L W Tait1, A M Lohrer2, M Townsend2,3
1National Institute of Water and Atmospheric Research, 10 Kyle St, Riccarton, Christchurch, 8011, New Zealand. leigh.tait@niwa.co.nz.
Scientific Reports
|February 2, 2020
Summary
The physical structure created by invasive fanworms (Sabella spallanzanii) significantly alters marine sediment, increasing nitrogen fluxes and reducing denitrification. These physical impacts, rather than biological interactions, drive ecosystem changes, predicting widespread effects of bio-engineers.
Area of Science:
- Marine Ecology
- Invasive Species Biology
- Biogeochemistry
Background:
- Predicting the ecological impact of invasive ecosystem engineers is challenging, partly due to difficulties in distinguishing physical from biological mechanisms.
- Understanding these mechanisms is crucial for predicting and mitigating potentially damaging bioinvasions.
Purpose of the Study:
- To test the hypothesis that invasive ecosystem engineers negatively influence benthic ecosystem function primarily through autogenic (physical) mechanisms.
- To compare the effects of the fanworm Sabella spallanzanii against artificial mimics on gas and nutrient fluxes in marine sediments.
Main Methods:
- Experimental manipulation of marine soft-bottom sediment plots in Hauraki Gulf, New Zealand.
- Comparison of sediment plots containing Sabella spallanzanii versus inert worm-like structures (mimics).
- Measurement of gas and nutrient fluxes, community metabolism, and denitrification rates.
Main Results:
- Both Sabella and mimics significantly increased nitrogen fluxes, community metabolism, and reduced denitrification.
- Denitrification was reduced to zero at densities greater than 25 individuals/m².
- Sabella plots exhibited higher respiration, ammonium (NH₄) release, and nitrate (NO₃) release compared to mimics, indicating secondary biological effects.
Conclusions:
- Autogenic (physical) mechanisms dominate the impacts of the fanworm Sabella spallanzanii on benthic ecosystem function.
- The physical structure created by invasive bio-engineers is a key driver of ecosystem change, with predictable consequences regardless of recipient region or engineer identity.
- Compromised denitrification by Sabella spallanzanii can exacerbate eutrophication and ecological degradation in marine systems.
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