Characteristics of Marine Aggregates in Shallow-water Ecosystems: Implications for Disease Ecology

Abstract

Marine aggregates were evaluated for their potential role in the ecology of aquatic pathogens using underwater video surveys coupled with direct collection of aggregates in modified settling cones. Six locations, two each in New York, Connecticut, and Massachusetts, were surveyed over 8 months to explore differences in the characteristics of aggregates found in habitats populated by clams (Mercenaria mercenaria) and oysters (Crassostrea virginica). Microaggregate (<500 lm) concentrations were always greater than macroaggregate (>500 lm) concentrations, but peak concentrations of macroaggregates and microaggregates, mean size of particles, and volume fraction of aggregated material varied among the six shallow-water habitats. Concentrations (colonyforming units per ml) of total heterotrophic bacteria (THB) and total mesophilic pathogenic bacteria (MPB) from samples of aggregates were significantly different among the four locations bordering Long Island Sound (LIS). The highest concentrations and enrichment factors in aggregates were observed in August for THB and in June for MPB. Significant correlations were detected for salinity and the concentrations and enrichment factors of THB in aggregates and for the concentrations and percentages of MPB in seawater samples. Significant correlations were also detected for temperature and the concentrations of MPB in aggregates and the enrichment factors for THB and MPB (marginal significance). Bacterial species identified in association with aggregates included: Vibrio cholerea, V. parahaemolyticus, V. vulnificus, V. alginolyticus, Aeromonas hydrophila, Pseudomonas aeruginosa, Escherichia coli, and Mycobacteria sp. These results have important implications for the way in which aquatic pathogens are collected, quantified, and monitored for risk-based surveillance in shallow-water ecosystems.

Effects of Microbial and Heavy Metal Contaminants on Environmental/Ecological Health and Revitalization of Coastal Ecosystems in Delaware Bay

“…4) away from the discharge. These results agree with those of previous studies (Kelly, 1982;Singleton et al, 1982;O'neill et al, 1992;Hoi et al, 1998;DePaola et al, 2003;Pfeffer et al, 2003;Lyons et al, 2007;Froelich et al, 2012) that showed similar relationships between the water quality parameters and Vibrionaceae concentrations in oysters observed in our study.…”

“…Previous studies have shown that regardless of geographical location, Vibrionaceae bacteria are most abundant during the warmer months (DePaola et al, 1990(DePaola et al, , 2003Motes et al, 1998;Pfeffer et al, 2003;Randa et al, 2004;Warner and Oliver, 2008). So it is not surprising that the majority of findings indicate a positive correlation between temperature and Vibrionaceae populations in water and oysters as the water temperature increases (Kelly, 1982;DePaola et al, 2003;Pfeffer et al, 2003;Lyons et al, 2007;Warner and Oliver, 2008). It has been observed that Vibrionaceae can be found in water and/or oysters when spring approaches and water temperatures reach >10 • C (Wright et al, 1996;Motes et al, 1998;DePaola et al, 2003;Randa et al, 2004;Warner and Oliver, 2008).…”

Variability of planktonic and epiphytic vibrios in a coastal environment affected by <em>Ostreopsis</em> blooms

“…Tamplin et al 1990, Neogi et al 2012. However, in some recent studies both free-living lifestyles or communities associated with aggregates have been reported for Vibrio (Lyons et al 2007, Froelich et al 2013, Szabo et al 2013. A second hypothesis of our study is therefore that Vibrio is found more in particles than free-living in plankton.…”

“…Vibrios have been detected on a large variety of biological surfaces, especially animals (Thompson et al 2004, Baffone et al 2006, Main et al 2015, and are also associated with various types of organic particles of non-animal origin (Lyons et al 2007, Froelich et al 2013. Recently, there has been evidence that vibrios can remain free-living (Mourino-Perez et al 2003, Worden et al 2006, Eiler et al 2006, although little is known on the factors determining whether they remain free-living versus particle-attached (Takemura et al 2014).…”

Integration of Vibrio vulnificus into Marine Aggregates and Its Subsequent Uptake by Crassostrea virginica Oysters

“…2). In the environment, V. vulnificus and other vibrios have also been reported to be present in higher concentrations in natural marine aggregates than in the surrounding water (35,36). Marine aggregates are believed to increase bacterial survival when moving between hosts (35).…”