Submarine groundwater discharge: A previously undocumented source of contaminants of emerging concern to the coastal ocean (Sydney, Australia)

Tristan McKenzie; Ceylena Holloway; Henrietta Dulai; James P Tucker; Ryo Sugimoto; Toshimi Nakajima; Kana Harada; Isaac R Santos

doi:10.1016/j.marpolbul.2020.111519

Submarine groundwater discharge: A previously undocumented source of contaminants of emerging concern to the coastal ocean (Sydney, Australia)

Mar Pollut Bull. 2020 Nov:160:111519. doi: 10.1016/j.marpolbul.2020.111519. Epub 2020 Aug 8.

Authors

Tristan McKenzie¹, Ceylena Holloway², Henrietta Dulai³, James P Tucker², Ryo Sugimoto⁴, Toshimi Nakajima⁴, Kana Harada⁴, Isaac R Santos⁵

Affiliations

¹ Department of Earth Sciences, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, Honolulu, HI, USA. Electronic address: tristam@hawaii.edu.
² National Marine Science Centre, School of Environment, Science, and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia.
³ Department of Earth Sciences, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, Honolulu, HI, USA.
⁴ Research Center for Marine Bioresources, Fukui Prefectural University, Fukui, Japan.
⁵ National Marine Science Centre, School of Environment, Science, and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia; Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden.

PMID: 32781267
DOI: 10.1016/j.marpolbul.2020.111519

Abstract

Submarine groundwater discharge (SGD) is rarely considered as a pathway for contaminants of emerging concern (CECs). Here, we investigated SGD as a source of CECs in Sydney Harbour, Australia. CEC detection frequencies based on presence/absence of a specific compound were >90% for caffeine, carbamazepine, and dioxins, and overall ranged from 25 to 100% in five studied embayments. SGD rates estimated from radium isotopes explained >80% of observed CEC inventories for one or more compounds (caffeine, carbamazepine, dioxins, sulfamethoxazole, fluoroquinolones and ibuprofen) in four out of the five embayments. Radium-derived residence times imply mixing is also an important process for driving coastal inventories of these persistent chemicals. Two compounds (ibuprofen and dioxins) were in concentrations deemed a high risk to the ecosystem. Overall, we demonstrate that SGD can act as a vector for CECs negatively impacting coastal water quality.

Keywords: Contaminants of emerging concern; Micropollutant; Pharmaceuticals; Radium; Risk assessment; Submarine groundwater discharge.

MeSH terms

Australia
Ecosystem*
Environmental Monitoring
Groundwater*
Oceans and Seas