Title| Summary|Strategy|Impacts/Products|Collaborators/Clients|Task 1|Task 2 |Task 3|Task 4|Task 5|Task 6|Task 7

GEOLOGIC DIVISION CONTINUING PROJECT WORK PLAN - FL 2001

Task: 2
Task Leaders: Swarzenski, Peter W., Kindinger, Jack L.
600 4th Street South
St. Petersburg, FL 33701
Phone: (727)803-8747
Fax: (727)803-2030

Title: Sampling procedures/approach - Integrating our work with existing programs

Coastal and Marine Geology Programs

In this task the sampling strategy and approach are presented. Our proposed project is dovetailed into the existing NASQAN program, and will extend that dataset by including a series of sampling sites down-river in each delta. Much of the initial planning for this project was discussed with leaders of the Mississippi River NASQAN project (Hooper, Meade, Horowitz), and their guidance is reflected in the approach we have chosen. In addition to the obvious links to NASQAN, we also have discussed our planned efforts on the lower river with representatives from UNO (deltaic processes) and Tulane University, who have established a lower river monitoring station and who are planning to develop a large-scale NSF-funded effort (comparable to an LMER) on the lower Mississippi River. Our project would thus integrate and extend both academic and federal initiatives that are addressing long-term issues on the lower river. The objectives of this Task are to collect a series of uncompromised suspended sediment, water and bed load samples as per USGS protocol developed specifically for NASQAN. Year-1 samples will be used to derive not only a flux of sediment-hosted contaminants to the Gulf of Mexico, but will also address specific mechanisms and processes that are critical to the oceanic delivery of such contaminants/particles.

Work to be undertaken during the proposal year and a description of the methods and procedures:

Unlike Bob Meade's seminal effort that dealt with the entire Mississippi River, we have decided not to sample the river as Lagranian flow; instead we will focus on discrete sampling stations down river over time (low/high discharge) that will enable both flux determinations to the Gulf, and also will provide insight into fluvial processes/mechanisms that can modify the delivery of sediment-hosted contaminants. It is important to note that Meade's study focused primarily on the delivery of dissolved constituents in one coherent water parcel from the head waters of the Mississippi River down to Louisiana. In contrast, the underlying premise of this proposed project is the role of suspended sediments and bed-load sediments in the delivery of contaminants to the Gulf. Sampling will augment the seasonal NASQAN data runs in the lower Mississippi River and will include the following stations that have historically been a part of NASQAN, but that are no longer sampled due to budgetary constraints: 1) The Old River Control Structure, 2) St. Francisville, (already in the NASQAN net) 3) Plaquemine, 4) Union, 5) Lulling, 6) Belle Chase, 7) Pointe a la Hache, and 8) Venice. An additional set (~ 10) of samples will extend across the estuarine zone into the Gulf of Mexico. In addition, we will occupy a few river stations where seismic reflection data (TULANE coop and Kindinger) indicate sediment depo-centers. The Tulane group has recently confirmed seismic data by long barrel (Kasten) coring. Such sites will provide a detailed record of the fluvially-controlled geologic framework in regards to contaminant storage and sequestration in the lower river. At these sites we will determine geochronologic records (210Pb/137Cs) from which we will be able to derive long term contaminant inventories. About 25-33% of the flow of the Mississippi River is diverted at the Old Control Structure down the Atchafalaya River. In order to quantify the delivery of sediment-hosted contaminants in the lower river, a few stations in this river system need to be included, as follows: 1) Red River at Alexandria, 2) Atchafalaya at Melville (already in the NASQAN net, 3) Atchafalaya at Krotz Springs, 4) Atchafalaya at Wax Lake (distributary to relieve Morgan City) and 5) Atchafalaya at Morgan City. As for the Mississippi River, about 10 samples would also be collected across the estuarine zone of this system.

Planned Outreach:

This task describes the sampling approach of our project. Planned outreach includes the integration various state/federal and academic institutions. With scientists at LEAG, we intend on developing an interactive "layman's" display in New Orleans that protrays all USGS disciplines related to the Mississippi River.

Publications delivered/completed for this Task:

Publications planned for this task, to be submitted for publication in current or future fiscal years.

• Swarzenski and Horowitz, 2002, An integrated approach to study large rivers.

Geographic area of task:

United States, Gulf Coastal States, LA

Accomplishments

Current year nonpublication accomplishments and outcomes:
We had a very successful first cruise (March, 2001) during flood stage, in which at least 18 USGS and university scientists actively participated. The cruise window corresponded precisely to the peak discharge event.

Highlights - summary of the most significant outcome:
In spite of not be able to use our own research vessel, we were successful in acquiring undisturbed cores from the Mississippi and Atchafalaya River mouths. We were also fortunate in that several additonal scientists at Tulane and the USGS were able to participate in the field efforts, and in doing so expended the breadth of our project.

New Directions or Major Changes for Proposal Year:
The main new direction in regards to sampling procedures for Yr-2 is the addition of Scott Carr (BRD) and Jill Jenkins (BRD). Both offer a vital link to the toxicological effects of coastal contaminants. Orem and Swarzenski have shared the expense of a new piston corer, which will be available for the next cruise (Sept., 2001).

Title|Summary|Strategy|Impacts/Products|Collaborators/Clients|Task 1|Task 2 |Task 3|Task 4|Task 5|Task 6|Task 7