Ecological engineering: a field whose time has come

Sediment oxygen demand (SOD) is believed to be an important process affecting dissolved oxygen (DO) concentrations in blackwater streams of the southeastern coastal plain. Because very few data on SOD are available, it is common for modelers to take SOD values from the literature for use with DO models. In this study, SOD was measured in seven blackwater streams of the Suwannee River Basin within the Georgia coastal plain for between August 2004 and April 2005. SOD was measured using four in situ chambers and was found to vary on average between 0.1 and 2.3 g O2 ⁄m ⁄day across the seven study sites throughout the study period. SOD was found to vary significantly between the watersheds within the Suwannee River Basin. However, land use was not found to be the driving force behind SOD values. Statistical analyses did find significant interaction between land use and watersheds suggesting that an intrinsically different factor in each of the watersheds may be affecting SOD and the low DO concentrations. Further research is needed to identify the factors driving SOD dynamics in the blackwater streams of Georgia's coastal plain. Results from this study will be used by the Geor- gia Department of Natural Resources - Environmental Protection Division as model input data for the develop- ment and evaluation of DO total maximum daily loads in the Georgia coastal plain. (KEY TERMS: sediment oxygen demand; dissolved oxygen; coastal plain; Georgia; blackwater streams; watersheds; water quality.)

Factors affecting sediment oxygen demand dynamics in blackwater streams of georgia's coastal plain

Sediment oxygen demand (SOD) is considered a critical and dominant sink for dissolved oxygen (DO) in many river systems including blackwater streams and is often poorly investigated or roughly estimated in oxygen budgets. The purposes of this study are to (1) characterize and document the magnitude and variabil- ity of SOD in representative instream swamps found on the Georgia Coastal Plain; (2) predict SOD from more readily measured parameters such as soil, sediment, and litter organic carbon; and (3) obtain an accurate repre- sentation of SOD values within this understudied habitat to help improve water quality models and the contin- ued development of DO as an appropriate water quality standard. Results show SOD rates ranging from 0.491 to 14.189 g O2 ⁄m 2 ⁄day, up to 18 times higher than values reported for southeastern sandy-bottomed streams and suggest that instream swamps are repositories of large amounts of organic matter and are thus areas of intense oxygen demand and a major factor in determining the oxygen balance of the watershed as a whole. These areas of intense oxygen demand in relatively unimpacted areas indicate that low DO concentrations may be a natural phenomenon. SOD rates were significantly correlated (alpha = 0.05) with a number of sediment parameters, with organic carbon and total organic carbon being the best predictors of SOD rate. When develop- ing water quality models, managers should pay closer attention to the influence of SOD as it plays a critical role in determining DO levels within instream swamps and the river system.

High sediment oxygen demand within an instream swamp in Southern Georgia: implications for low dissolved oxygen levels in coastal blackwater streams.

The emergence of ecological engineering as a discipline

https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1001&context=laep_facpub

Ecological engineering in a new town development: Drainage design in The Woodlands, Texas

The lower reaches of the Arroyo Colorado have historically failed to meet their use under subsection 303(b) of the U.S. Clean Water Act due to fecal coliform bacteria and low dissolved oxygen (DO). Fish kills, especially at the tidal confluence at the Port of Harlingen, Texas, have been reported. Oxygen demand from sediment (SOD) for a river typically has two states-diffusion limited SOD (SOD) and potential SOD (pSOD), expressed when sediment is resuspended through increased flow or other disturbances. The objective of this research was to measure SOD in the Arroyo Colorado River in situ, estimate pSOD ex situ, and evaluate the relationship between SOD and the depositional environment. We measured SOD and pSOD in the Arroyo Colorado River at up to eight sites over three sampling events. We identified the sample sites based on a modified Rosgen geomorphic index for streambed stabilization. Sites with high sediment deposition potential had high SOD. The average values of SOD between sites were 0.62 g/m2/day (standard deviation 0.38 g/m2/day) and ranged from 0.13 to 1.2 g/m2/day. Potential SOD values ranged from as low as 19.2 to as high as 2,779 g/m3 sediment/ day. Potential SOD can serve as an indicator of the possible impact of SOD from resuspended sediment in stream systems.

Sediment oxygen demand in the arroyo colorado river

Ecological engineering: A rationale for standardized curriculum and professional certification in the United States

Sediment oxygen demand in the Arroyo Colorado River, by Marty D. Matlock, Kevin Ray Kasprzak, and G. Scott Osborn. Author's reply

As the impact of human activities expand to global proportions the demand for engineering solutions to ecosystem level problems has increased. The science of restoration ecology has developed to address many critical ecosystem management issues, yet the high degree of complexity and associated uncertainty demands a more quantitative approach. Ecological engineering is the science-based quantification of ecological processes to develop and apply engineering-based design criteria for sustainable systems, consistent with ecological principles that integrate human society with its natural environment for the benefit of both. There is little consensus on what distinguishes ecological engineering curricula from existing environmental, biosystems, or agricultural engineering curricula. We suggest that ecological engineering curricula should be offered only at the graduate level, and should require rigorous ABET-accredited (or equivalent) undergraduate preparation in the fundamentals of engineering. The graduate curriculum should provide the student with a core of courses in ecosystem theory including quantitative ecology, evolutionary ecology, community ecology, restoration ecology, trophodynamics, and ecological modeling, while strengthening the student’s mastery of engineering theory and application. This curriculum should have a significant component to provide students with practical experience and inter-disciplinary contact. Additional courses in limnology, environmental plant physiology, ecological economics, and specific ecosystem design should be provided to address specific professional objectives of the student. Finally, a professional engineering certification must be developed to insure the continuing credibility of this new engineering specialization. Several questions concerning acceptable standards of practice, codes of ethics, criteria for successful design, analysis of cost/benefit ratio, and safety factors must be addressed prior to development P ge 342.1 2 of professional certification. Ecological engineering is in its infancy; careful guidance and direction is critical for this exciting field to grow to its full potential.

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G. Scott Osborn

Papers

Sediment oxygen demand in the arroyo colorado river

Ecological engineering: A rationale for standardized curriculum and professional certification in the United States

Sediment oxygen demand in the Arroyo Colorado River, by Marty D. Matlock, Kevin Ray Kasprzak, and G. Scott Osborn. Author's reply

A Rationale For Standardized Curriculum And Professional Certification In Ecological Engineering