The Eastern Oyster (
- Award ID(s):
- NSF-PAR ID:
- Date Published:
- Journal Name:
- Frontiers in Marine Science
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
The Eastern Oyster (
Crassostrea virginica) is a commercially important aquaculture species and food resource along the Atlantic and Gulf coasts of the USA. In addition to its economic value, oyster aquaculture provides ecological value such as water quality improvement. Oyster filtration is highly variable as filtration behavior is influenced by environmental conditions, oyster size, and oyster energetic demands. However, average rates generated in laboratory experiments are often used to estimate the ecological impact of oyster filtration, and there is a need for field-based, farm-specific estimates of filtration that account for this variation. In this study, field experiments were conducted between September 2020 and September 2021 to estimate seasonal oyster filtration physiology at oyster farms in three different bays in the Mid-Atlantic (Barnegat Bay and Delaware Bay in New Jersey and Rehoboth Bay in Delaware). The physiological activity of oysters at each farm varied such that oysters at Barnegat Bay were the most active and oysters at Rehoboth Bay were the least active. Seasonal physiological trends were observed such that filtration behavior generally increased in warmer months. An increase in physiological activity across all farms was associated with an increase in salinity and temperature, but physiological activity at each farm was associated with a different suite of environmental variables including total particulate matter and the organic content of seston. This study provides a robust dataset which can be incorporated into models estimating ecological filtration rates in the Mid-Atlantic and adds to the growing body of evidence supporting bivalve aquaculture as a nutrient reduction strategy.
This study collected summer meltwater runoff samples from several glacier watersheds of the northeast Tibetan Plateau during June-July 2017, and measured the concentrations of 17 trace elements (Li, Be, Sc, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Mo, Cd, In, Sb, Cs, Ba) in meltwater suspended particulate matter (SPM), in order to reveal the elemental concentration, spatial distribution, and water quality in remote glacier watershed under regional anthropogenic activities. Results showed that, the concentration of heavy metal elements was relatively high in Yuzhufeng Glacier basin, ranging from 0.57 μg/L (In) to 1,551.6 μg/L (Ba), whereas in Qiyi Glacier basin it was the lowest, ranging from 0.02 to 85.05 μg/L; and relatively medium in other glacier watersheds, with total elemental concentration varying from 1,503.9 to 1726.2 μg/L. Moreover, enrichment factors (EFs) of SPM heavy metals showed significantly higher value in the downstream than that of upper glacier region of the watershed. Most heavy metals with low EFs mainly originated from crust dust, while others with higher EFs (e.g., Cd, Sb) probably originated from anthropogenic sources. Spatially, the EFs of heavy metals were higher in Yuzhufeng and Laohugou Glacier basins; while in other regions the EFs were relatively low, which may be caused by regional land-surface and atmospheric environmental differences surrounding the various glacier watersheds. Compared with other remote locations in global range, heavy metals level (e.g., Cu, Ni, and Zn) in this region is relatively higher. Meanwhile, we find that, though the water quality of the glacier basin in northeast Tibetan Plateau was relatively clean and pollution-free, it is still obviously affected by regional anthropogenic activities. Mining activities, transportation and natural weathering and erosion processes in the study areas have important effects on the content of heavy metal pollutants of river-water SPM in the glacier watershed. Moreover, backward air-mass trajectories demonstrated the potential atmospheric pollutants transport from the surrounding cities and suburbs, to deposit in the snowpack and glaciers, and then melted out and released into meltwater runoff. This study provides a new perspective on more complete view of heavy metals distribution in glacier watershed, and new understanding for the cryosphere water environment evaluation in the Tibetan Plateau region.more » « less
Particle size greatly influences the fate of phosphorus (P) in estuaries as P adheres more readily to the larger surface area in smaller sized particles. Here, data on two size fractions of particulate matter, permanently suspended particulate matter (PSPM, ≤40 μm) and resuspended particulate matter (RSPM, >40 μm), from field and controlled laboratory erosion experiments were analyzed to determine their relative contribution to water column P in the mouth of the Susquehanna River in the upper Chesapeake Bay. Based on the composition of sequentially extracted P pools, C and N isotopes, and elemental data, all PSPM and the majority of RSPM are most likely derived from allochthonous sources through river transport. A minor fraction of particulate matter in the water column was derived from sediment resuspension, which had a dominant role above the sediment‐water interface in the river's mouth. The proportion of biologically available P pools to recalcitrant P pools in suspended particulate matter decreased with water column depth, indicating their preferential removal or biological utilization during settling. Suspended particulate matter (SPM) mobilized during sediment erosion experiments, regardless of particle size, was richer in biologically available P pools than SPM in the field, suggesting higher mobility of these pools in the field. These complementary results from field and field‐simulated laboratory erosion experiments provide unique insights into the composition of particulate matter under different hydrodynamic regimes in the river estuary.
Two oceanographic cruises were completed in September 2016 and August 2017 to investigate the distribution of particulate organic matter (POM) across the northeast Chukchi Shelf. Both periods were characterized by highly stratified conditions, with major contrasts in the distribution of regional water masses that impacted POM distributions. Overall, surface waters were characterized by low chlorophyll fluorescence (Chl Fl < 0.8 mg m−3) and particle beam attenuation (
cp < 0.3 m−1) values, and low concentrations of particulate organic carbon (POC < 8 mmol m−3), chlorophyll and pheophytin (Chl + Pheo < 0.8 mg m−3), and suspended particulate matter (SPM ∼2 g m−3). Elevated Chl Fl and Chl + Pheo (∼2 mg m−3) values measured at mid‐depths below the pycnocline defined the subsurface chlorophyll maxima (SCM), which exhibited moderate POC (∼10 mmol m−3), cp(∼0.4 m−1) and SPM (∼3 g m−3). In contrast, deeper waters below the pycnocline were characterized by low Chl Fl and Chl + Pheo (∼0.7 mg m−3), high cp(>1.5 m−1) and SPM (>8 g m−3) and elevated POC (>10 mmol m−3). POM compositions from surface and SCM regions of the water column were consistent with contributions from active phytoplankton sources whereas samples from bottom waters were characterized by high Pheo/(Chl + Pheo) ratios (>0.4) indicative of altered phytoplankton detritus. Marked contrasts in POM were observed in both surface and middepth waters during both cruises. Increases in chlorophyll and POC consistent with enhanced productivity were measured in middepth waters during the September 2016 cruise following a period of downwelling‐favorable winds, and in surface waters during the August 2017 cruise following a period of upwelling‐favorable winds.
Oyster aquaculture is one of several methods for the restoration of Delaware Inland Bays; however, little is known about its potential impacts on the benthic community of the bays. In this study, water quality parameters were measured and polychaetes were collected from 24 sampling locations at Rehoboth, Indian River, and Little Assawoman Bays from July to October 2016 and 2017. We aimed to assess the impact of Eastern oyster farming under different stocking densities (50 and 250 oysters/gear) and distances away from the sites where the off-bottom gears are implemented (under gears, one meter, and five meters away). No significant impact was detected on polychaetes’ abundance and richness in regard to the presence of oyster gears. The number of polychaetes and species richness was significantly higher in Little Assawoman Bay in comparison to the Indian River and Rehoboth Bays. Results showed that the Ulva lactuca bloom that happened in 2016 could negatively impact the low abundance and richness observed in the polychaetes community. Similarly, the values of polychaetes abundance and species richness did not change significantly in samples that were taken far from the oyster gears. Dominant polychaetes families were Capitellidae and Glyceridae contributing to more than 70% of polychaetes’ number of individuals. Our results help to understand the role of oyster aquaculture in restoring the viability in the natural habitat of the Delaware Inland Bays.more » « less