Effects of spilled oil on the tidal flat ecosystem - evaluation of wave and tidal actions using a tidal flat simulator

2001 ◽  
Vol 43 (2) ◽  
pp. 171-177 ◽  
Author(s):  
C. J. Cheong ◽  
M. Okada
Keyword(s):  
Tidal Flat ◽  
Tidal Flats ◽  
Fuel Oil ◽  
Benthic Organisms ◽  
Tidal Fluctuation ◽  
Controlling System ◽  
Wave Maker ◽  
Tidal Movement ◽  
Spilled Oil ◽  
Penetration Behaviour

The purpose of this study is to clarify the effects of wave and tidal actions on the penetration of spilled oil stranded on tidal flats and to evaluate the influence of the penetrated oil on seawater infiltration using tidal flat simulator. A simulator used was composed of tidal flat, wave maker, tide controlling device, temperature controlling system and computer controlling system. The infiltrations of seawater and fuel oil C into tidal flats were visualized using transparent glass beads as tidal flat sediments. Penetration behaviour of the spilled oil into the sediments was significantly different from that of seawater. Seawater infiltrated into the sediments both by wave action and tidal fluctuation, while fuel oil C penetrated by tidal movement only. The infiltration of seawater was reduced by penetrated oil. This result indicates that the penetrated oil diminishes infiltration of seawater into the sediments and thus results in the reduction in the supply of oxygen, nutrients, and organic matterto the benthic organisms in tidal flat.

Effect of non-aqueous phase liquid on biodegradation of PAHs in spilled oil on tidal flat

2003 ◽  
Vol 47 (7-8) ◽  
pp. 243-250 ◽  
Author(s):  
T. Kose ◽  
A. Miyagishi ◽  
T. Mukai ◽  
K. Takimoto ◽  
M. Okada
Keyword(s):  
Crude Oil ◽  
Tidal Flat ◽  
High Viscosity ◽  
Fuel Oil ◽  
Dissolution Rates ◽  
Decrease Rate ◽  
Oil Biodegradation ◽  
Polycyclic Aromatic ◽  
Phase Liquid ◽  
Spilled Oil

Biodegradation rates of polycyclic aromatic hydrocarbons (PAHs) in spilled oil stranded on tidal flats were studied using model reactors to clarify the effects of NAPL on the biodegradation of PAHs in stranded oil on tidal flat with special emphasis on the relationship between dissolution rates of PAHs into water and viscosity of NAPL. Biodegradation of PAHs in NAPL was limited by the dissolution rates of PAHs into water. Biodegradation rate of chrysene was smaller than that for acenaphthene and phenanthrene due to the smaller dissolution rates. Dissolution rates of PAHs in fuel oil C were smaller those in crude oil due to high viscosity of fuel oil C. Therefore, biodegradation rates of PAHs in fuel oil C were smaller than those in crude oil. Biodegradation rates of PAHs in NAPL with slow decrease rate like fuel oil C were slower than those in NAPL with rapid decrease like crude oil. The smaller decrease rate of fuel oil C than crude oil was due to higher viscosity of fuel oil C. Therefore, not only the dissolution rate of PAHs but also the decrease rates of NAPL were important factors for the biodegradation of PAHs.

1.  Toxicity of Fresh and Weathered Sunken Heavy Fuel Oil to the Early Life Stages of Rainbow Trout (Oncorhynchus mykiss) in Simulated Spawning Shoal Environments

2016 ◽  
Author(s):  
Julie Adams
Keyword(s):  
Rainbow Trout ◽  
Water Column ◽  
Aquatic Organisms ◽  
Fuel Oil ◽  
South American ◽  
Benthic Organisms ◽  
Heavy Fuel Oil ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Direct Exposure ◽  
Insight Into

Because the density of heavy fuel oil (HFO) is equal to or greater than that of freshwater, it behaves differently than lighter oils that float. Heavy fuel oil can sink to the bottom or be suspended in the water column and affect aquatic organisms that are not typically exposed to floating oils. Most research on oil spill technologies thus far examines the direct exposure of rainbow trout to floating or submerged oil droplets; there is little knowledge of the impacts of non‐floating heavy fuel oil on the water column and benthic organisms exposed to oil that accumulates in sediments. The toxicity of sunken HFO 6303 and Medium South American (MESA; reference) crude oil, as well as the effects of weathering on toxicity to embryos of rainbow trout were assessed using increasing concentrations of oil on gravel substrate in continuous‐flow desorption columns. Toxicity was assessed by measurement of the rates of mortality and growth, and the prevalence of blue sac disease, a hallmark sign of oil toxicity. The lower median lethal concentration for HFO compared to MESA indicated that HFO is more toxic. Interestingly, the LC50 values for fresh and weathered for both oils were similar, indicating little change in toxicity when the oil weathers naturally. Repetition of this experiment and analysis of PAH content in each treatment will provide more insight into the environmental and health risks associated with sunken heavy fuel oil.   

What ecological role do soft-substrate tide pools play for fishes? Difference in community structures between estuarine and coastal tidal flats in subtropical Japan

2020 ◽  
Vol 71 (7) ◽  
pp. 737
Author(s):  
Taiga Kunishima ◽  
Katsunori Tachihara
Keyword(s):  
Tidal Flat ◽  
High Tide ◽  
Tidal Flats ◽  
Individual Species ◽  
Nursery Ground ◽  
Ecological Role ◽  
Soft Substrate ◽  
Use Patterns ◽  
Habitat Value ◽  
Ecological Roles

Soft-substrate tide pools are considered important habitats for fishes from an ecological perspective. However, the ecological roles of such pools and use patterns by fish remain unclear, especially regarding differences between estuarine and coastal tidal flats. In this study, quantitative sampling using the quadrat method was performed in the estuarine and coastal tidal flats on Okinawa-jima Island of subtropical Japan during four seasons. Ecological roles of soft-substrate tide pools were classified as follows: (1) permanent habitat for residents; (2) nursery ground for transients; and (3) waiting area until high tide for accidental species. Within these classifications, the ecological role and value of tide pools for transient fishes varied between the tidal flat types. The habitat value of tide pools is higher for residents than for transient species because the habitat is not replaceable for residents because of their specific ability to survive there. By contrast, transient and accidental species use the tide pools as temporary habitats; however, their high diversity affects the variation in community structure on Okinawa-jima Island. Our results suggest that we should consider not only species diversity, but also habitat use patterns of individual species, together with their life history, when evaluating habitat value with regard to conservation and management of each tidal flat.

Drivers of nano- and microplanktonic community structure in a Patagonian tidal flat ecosystem

2019 ◽  
Vol 41 (5) ◽  
pp. 621-639
Author(s):  
Juan F Saad ◽  
Maite A Narvarte ◽  
Mariza A Abrameto ◽  
Viviana A Alder
Keyword(s):  
Tidal Flat ◽  
Tidal Flats ◽  
Size Spectrum ◽  
Spatial Gradient ◽  
Total Biomass ◽  
Total Density ◽  
Phytoplankton Structure ◽  
Tidal Transport ◽  
Sw Atlantic ◽  
Inshore Waters

ABSTRACT Tidal flats are exceptionally dynamic coastal ecosystems. Tides are their main source of energy, whose influence decreases landwards (as land elevation increases), thus shaping physical, chemical and biological gradients. In this study, we assess whether the structure of nano- and microplankton varies along a spatial gradient in San Antonio Bay (SAB, SW Atlantic), a semi-desert coastal ecosystem with a wide tidal flat and a macrotidal regime. We hypothesize that the tidal effect shapes SAB’s both taxonomical groups and size spectrum. The seasonal sampling of 9 sites revealed that diatoms and small flagellates were the most abundant groups, together accounting for over 75% of total density in practically all sites and seasons. High densities of meroplanktonic stages of Ulva lactuca were recorded in spring at the innermost sites, accounting for over 95% of all planktonic cells. Slopes of the size spectrum analysis were in line with highly productive inshore waters (mean, −0.64) and showed that larger phytoplankton was the main contributor to total biomass, despite its decreasing importance toward inner sites. The spatial and seasonal variations found for lower trophic web compartments provide evidence of the importance of tidal transport in ruling phytoplankton structure in tidal flats under strong macrotidal regimes.

CHEVRON MAIN PASS BLOCK 41 OIL SPILL: CHEMICAL AND BIOLOGICAL INVESTIGATIONS

1975 ◽  
Vol 1975 (1) ◽  
pp. 555-566 ◽  
Author(s):  
Clayton D. McAuliffe ◽  
Alfred E. Smalley ◽  
Robert D. Groover ◽  
W. Marvin Welsh ◽  
W. Stewart Pickle ◽  
...  
Keyword(s):  
Mississippi River ◽  
Water Surface ◽  
River Delta ◽  
Mississippi River Delta ◽  
Benthic Organisms ◽  
Water Emulsion ◽  
Number Of Species ◽  
Extractable Organic Matter ◽  
Number Of Individuals ◽  
Spilled Oil

ABSTRACT During a three-week period in 1970 an estimated 65,000 barrels of 34° API gravity crude oil were discharged from the Chevron Main Pass Block 41C Platform, 11 miles east of the Mississippi River Delta. Two thousand barrels of chemical dispersants were sprayed on the platform and surrounding water surface. It is estimated that between 25–30% of the oil evaporated during the first 24 hours, 10–20% was recovered from the water surface, less than 1% dissolved, and less than 1% of the oil was identified in sediments within a 5-mile radius of the platform. The remaining oil emulsified and dispersed to undetectable levels, biodegraded, or photooxidized. The highest measured concentrations in water at the platform and at 1 mile were: oil-in-water emulsion, 70 to 1 ppm; dissolved hydrocarbons, 0.2 to 0.001 ppm; dispersant 1–3 to unmeasurable (<0.2ppm). Total extractable organic matter was highest in sediments near the Mississippi River Delta and in the inland bays. Spilled oil, identified in bottom sediments by gas chromatography, showed rapid weathering after 1 week to 1 month and at the end of 1 year was reduced to a few percent of the amount after the spill. Spilled oil was not found in the sediment below 1.5 inches. Over 550 species of benthic organisms were identified in 233 benthic samples. The number of species and number of individuals of benthic organisms showed low values in some samples near the platform. However, seasonal variations, bottom sediment type, and possibly other environmental parameters made it impossible to determine whether these locations had been affected by the spilled oil. There was no correlation of number of species, number of individuals, or other biological parameters with the hydrocarbon content of the sediments for samples from within a 10-mile radius of the platform. This lack of correlation suggests lack of significant effect of oil on benthic organisms. Extensive trawl samples showed no alteration in the annual life cycle of commercially important shrimp. Blue crabs were observed throughout the area, and the number of species of fish collected were comparable to a prior survey.

ARROW Oil Spill, 1970–90: Persistence of 20-yr Weathered Bunker C Fuel Oil

1994 ◽  
Vol 51 (4) ◽  
pp. 845-855 ◽  
Author(s):  
J. H. Vandermeulen ◽  
J. G. Singh
Keyword(s):  
Full Range ◽  
Inverse Function ◽  
Fuel Oil ◽  
Direct Function ◽  
Beach Sediment ◽  
Sediment Reworking ◽  
Oil Residue ◽  
Sediment Permeability ◽  
Spilled Oil

A full range of weathered petroleum residues persist in two beach sites in Chedabucto Bay, Nova Scotia, 20 yr after the ARROW Bunker C spill. Both sites contained ARROW bunker fuel residues (pentacyclic triterpane characterization). Residues from "tar pavement" and a tar deposit within a cobble spit retained many components of original ARROW Bunker C fuel. Results indicate that long-term persistence is a direct function of beach sediment permeability, and of the depth to which entrapped tar residues penetrate; persistence is an inverse function of the frequency and depth of sediment reworking during tidal incursions. Cobble beaches represent an extreme example, with the interstices acting as low-energy sinks for spilled oil. A revised model for oil stranding and fate proposes two distinct environmental reservoirs of stranded oil residue in these medium-grained beaches: the interstitual residue as the major long-term source and surface-stranded residue as the minor source, each with its own weathering rate, history, and persistence. Such in-beach sequestered oils undergo much slower weathering than surface-stranded residues, persist longer, and continue to be remobilized. However, actual transfer of hydrocarbons from such deposits to tidal waters is very low (ppb).

Soil genesis on hypersaline tidal flats (apicum ecosystem) in a tropical semi-arid estuary (Ceará, Brazil)

Soil Research ◽  
2014 ◽  
Vol 52 (2) ◽  
pp. 140 ◽  
Author(s):  
A. G. B. M. Albuquerque ◽  
T. O. Ferreira ◽  
G. N. Nóbrega ◽  
R. E. Romero ◽  
V. S. Souza Júnior ◽  
...  
Keyword(s):  
Tidal Flat ◽  
Coastal Wetland ◽  
Anthropogenic Activities ◽  
Analytical Data ◽  
Clay Fraction ◽  
Tidal Flats ◽  
Brazilian Coast ◽  
The North ◽  
North Eastern ◽  
Semi Arid

Wetland soils, especially those under a semi-arid climate, are among the least studied soils in the tropics. The hypersaline tidal flats on the north-eastern Brazilian coast, locally named apicum, are coastal wetland ecosystems in the peripheral portions of semi-arid estuaries. Despite their great ecological importance, they have been highly impacted by anthropogenic activities. Morphological and analytical data of six soil profiles, representative of the different coastal compartments (mangroves, apicum and coastal tablelands) of the north-eastern Brazilian coast, were examined to better understand the pedogenesis of apicum soils. The hypersaline tidal flat soils were classified as Typic Fluvaquents and Typic Sulfaquents with the following main characteristics: predominance of sand fraction (62–77%); presence of high-activity clays (>24 cmolc kg–1 clay); clay fraction comprising kaolinite, illite, smectite and an interstratified smectite/illite; exchangeable complex dominated by Na+ (ESP ≥15%); elevated levels of salinity (electrical conductivity, EC 25–44 dS m–1); alkaline pH values (7.5–9.5). The sandy texture and quartz-dominated composition of the hypersaline, tidal flat soils indicate a pedogenesis associated with the superficial addition of mineral material. This upbuilding process would have lowered the watertable (relatively to the ground level) and decreased the flooding frequency by the tides, favouring salinisation and solonisation processes at the hypersaline tidal flats. Furthermore, the still-existing hydromorphism would have promoted the maintenance of gleisation and sulfidisation. The presence of pyrite on the hyper-saline tidal flat soils further corroborates the formation of apicum soils from/over buried mangroves.

scholarly journals The Spatiotemporal Characteristics and Dynamic Changes of Tidal Flats in Florida from 1984 to 2020

Geographies ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 292-314
Author(s):  
Chao Xu ◽  
Weibo Liu
Keyword(s):  
Tidal Flat ◽  
Gulf Coast ◽  
Atlantic Coast ◽  
Critical Role ◽  
Kendall Test ◽  
Tidal Flats ◽  
Dynamic Changes ◽  
Spatiotemporal Characteristics ◽  
Spatiotemporal Scales ◽  
Slope Estimator

Tidal flats are playing a critical role in the coastal environment, which mainly rely on satellite images to map the distribution on large spatiotemporal scales. Much effort has been made to monitor and analyze the spatiotemporal dynamics of tidal flats in order to provide worthwhile references for scientists and lawmakers. Instead of considering the dynamics of tidal flats only, this study implemented a series of comprehensive analyses on the tidal flats along the coast of Florida during the period 1984–2020. First, the analyses on the pixel level examined the spatiotemporal characteristics of tidal flat dynamics and the interactions with lands and permanent water. Second, the contiguous pixels of tidal flats were assembled as objects, and two geometric attributes were calculated and used to track the temporal patterns of tidal flat dynamics on this level. Finally, the Mann–Kendall test and Sen’s slope estimator were applied to identify and quantify the significant trends of tidal flat dynamics on the two levels. The results highlighted the differences in tidal flat distributions and dynamics between the Gulf Coast and Atlantic Coast, which further verified effective GIS representations and analyses that could be applied to other coastal studies.

scholarly journals The Impact of Reclamation on Tidal Flat Morphological Equilibrium

2021 ◽  
Vol 8 ◽  
Author(s):  
Zehua Zhong ◽  
Zhan Hu
Keyword(s):  
Tidal Flat ◽  
Dynamic Equilibrium ◽  
Anthropogenic Activities ◽  
Wave Climate ◽  
Tidal Flats ◽  
Sediment Supply ◽  
Tidal Range ◽  
The Mean ◽  
Comprehensive Framework ◽  
The Impact

Reclamation is one of the most prominent anthropogenic activities affecting tidal flat morphology and the related ecosystem service. Two representative types of reclamation are upper-flat enclosure and lower-flat enrockment. From a historical perspective, different type of reclamation was adapted in different areas in ancient China. As previous studies on reclamation are often site-specific, the reason that leads to such a difference is unclear. The intertidal dynamic equilibrium theory (DET) provides a comprehensive framework for this quest. Here, we extend the DET with additional effects of reclamation. A model based on DET (DET-ESTMORF) was applied to investigate the impact of reclamation on tidal flats. The model was validated by comparing our results against previous records and observations. Results show that both types of reclamation induce morphological adjustment by enhancing local accretion, which upset the previous equilibrium. Specifically, upper-flat enclosure drives tidal flats into evolution toward wave dominance, whereas lower-flat enrockment causes adjustment toward tidal dominance. Next, the impact of reclamation on tidal flats in different states (prograding or retreating) was investigated. We show that both enclosure and enrockment can induce accretion despite the varying wave climate and sediment supply, with the mean accretion rate raised by 1.8 cm/year and 1.2 cm/year, respectively. However, the resulting profiles are different in shape, especially on retreating flats. Finally, we point out that tidal range and sediment supply are the potential reasons affecting the choice of reclamation types in practices.

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