Pathogen Filtration: An Untapped Ecosystem Service

Abstract

Marine pathogens present serious challenges to aquaculture, fisheries productivity, and marine conservation requiring novel solutions to identify, control, and mitigate their effects. Several ecological habitats, such as mangroves and wetlands can recycle waste and serve as aquatic filtration systems. While nutrient cycling and other ecosystem services of these habitats have been well-studied, their potential to remove pathogens and mechanisms of filtration remain largely unstudied. Here, we review how mangroves, shellfish beds, seagrasses, and constructed wetlands can reduce pathogen pressure in coastal ecosystems. Mangroves may inhibit bacterial growth through phytochemicals in their leaves and remove viruses through desalination in their roots. Some bivalves remove pathogens by excreting pathogens through their pseudofeces and others concentrate pathogens within their tissues. Seagrasses slow flow rates, increase sedimentation rates and may reduce pathogens through allelopathy. Constructed wetlands decrease pathogens through a combination of mechanical, biological, and chemical filtration mechanisms. Protecting and restoring coastal ecosystems is key to maintaining pathogen filtration capacity, benefiting conservation efforts of threatened host populations, and mitigating large disease outbreaks.

Seagrass canopy structure mediates putative bacterial pathogen removal potential

“…Given the decrease in the removal of putative bacterial pathogen potential in fragmented seagrass meadows, it could be argued that seagrass decline would lead to coastal-living humans and marine organisms suffering from high-risk diseases. Therefore, we suggest the recovery and protection of the declining seagrass meadows worldwide, which have important implications for human and marine organism health protection (Klohmann and Padilla-Gamiño, 2022).…”

“…At a global scale, more than 80% of domestic wastewater is discharged into rivers or ocean without any treatment (Programme, U.N.W.W.A 2017), thus introducing bacterial pathogens of human and marine organisms to coastal waters (Stewart et al, 2008;Perkins et al, 2014). Coastal-living humans can suffer diseases and other health-related effects when exposed to bacterial pathogens in the ocean (Graciaa et al, 2018;Klohmann and Padilla-Gamiño, 2022). Seagrass meadows, mainly distributed along the coastal areas, are recently highlighted for reducing seawater bacterial pathogens capable of causing diseases in humans and marine organisms (Lamb et al, 2017).…”

“…Seagrass meadows, mainly distributed along the coastal areas, are recently highlighted for reducing seawater bacterial pathogens capable of causing diseases in humans and marine organisms (Lamb et al, 2017). Although there is little information about the underlying mechanisms of seagrass meadows for removing putative bacterial pathogens, it is likely due to the mechanically trapped particles (Guan et al, 2019;Deng et al, 2021;Klohmann and Padilla-Gamiño, 2022). Therefore, seagrass meadows can help decrease bacterial pathogen pressure and improve human and marine organism health.…”

Cost-Effective and Scalable Solar Interface Evaporators Derived from Industry Waste for Efficient Solar Steam Generation

“…Desalination of seawater, brackish water, or industrial wastewater is an effective strategy to address this crisis and has drawn considerable attention . Currently, mature water desalination technologies such as the reverse osmosis process, , thermal distillation, , and chemical filtration − , have been used to produce fresh water mostly in the economically developed coastal areas. Traditional desalination is something of a controversial technology.…”

Non-linear effects of non-host diversity on the removal of free-living infective stages of parasites

“…In general, studies have shown that a multitude of non-host species can consume or obstruct infective stages of a large range of parasite groups from different environments (Thieltges et al 2008 ; Johnson and Thieltges 2010 ; Johnson et al 2010 ). Especially in aquatic environments, where vectors are much less common than on land and where transmission of parasites and pathogens mainly occurs via the water column, ‘pathogen filtration’ by non-hosts in form of physical obstructions by vegetation or filter feeding removal by bivalve beds has received increased interest as a potential ecosystem service and disease managing approach (Burge et al 2016 ; Lamb et al 2017 ; Klohmann and Padilla-Gamiño 2022 ). However, non-host species differ in their capability to consume or obstruct infective stages depending on the specific parasites or pathogens in question and some non-host species may not show an effect at all (e.g., Hopper et al 2008 ; Orlofske et al 2015 ; Welsh et al 2014 , 2020 ; Koprivnikar et al 2023 ).…”