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The Louisiana State University College of the Coast & Environment (LSU CC&E) developed a multi-faceted strategic initiative to increase its diversity, equity, and inclusion. Elements of this initiative began one-by-one over the last decade and were aggregated into a comprehensive implementation plan--the 2020 CC&E Diversity, Equity, and Inclusion Action Plan. Based on best practices in the "physical sciences" (i.e., geosciences, including oceanography), the plan aims to augment recruitment and retention using limited resources and personnel. The long-range goal is to increase the number of PhD graduates from underrepresented groups by employing strategies that start at the 6-12th grade level. The plan involves a change in culture, clear communications about needs and goals, and active participation and engagement of CC&E faculty, students, staff, supporters, and partners. This plan is increasing the diversity of enrollment in our academic programs and will ultimately lead to more students with both undergraduate and graduate degrees. [ABSTRACT FROM AUTHOR]

Similar NH[SUB4,SUP+] and NO[SUB3,SUP-] uptake kinetic patterns were observed in Neoagardhiella baileyi (Harvey ex Kützing) Wynne & Taylor and Gracilaria foliifera (Forsskål) Borgesen. NO[SUB3,SUP-] was taken up in a rate-saturating fashion described by the Michaelis-Menten equation. NH[SUB4,SUP+] uptake was multicomponent: a saturable component was accompanied by a diffusive or a high K component showing no evidence of saturation (at ⩽50 μM [NH[SUB4,SUP+]). Nitrogen starved plants (CIN atom ratios >ca. 10) showed higher transient rates of NH[SUB4,SUP+] uptake at a given concentration than plants not N-limited. Only plants with high N content transient rates of NH[SUB4m,SUP+] uptake rates, and showed transient rates of NH[SUB4,SUP+] accumulation which did not greastly exceed the capacity to incorporate N in steady-state growth. NH[SUB4,SUP+] was preferred over NO[SUB3,SUP-], even in plants preconditioned on NO[SUB3,SUP-] as the sole N source. NO[SUB3,SUP-] uptake was suppressed at 5 μM [NH[SUB4,SUP+]. But simulataneous uptake occurred at unsurpressed rates at lower concentrations. Potential for N accumultion was greater via NH[SUB4,SUP+] uptake than via NO[SUB3,SUP-] uptake. Changing capacity for NH[SUB4,SUP+] uptake with N content appears to be a mechanism whereby excessive accumulation of N was abvoided by N-satiated plants but large accumulation was possible for N-depleted plants. [ABSTRACT FROM AUTHOR]

The Chesapeake Bay is a sink for much of the waste generated in the region's flanking the bay. The run-off contributes nutrients that encourage the proliferation of phytoplankton, which are in large part responsible for the decline of the bay. Scientists are studying these microscopic organisms and how best to check their growth. INSET: SELECTED HISTORY OF CHESAPEAKE BAY.

The authors critique the terminology used by political leaders to communicate about science, focusing on the words challenge, opportunity, restore, and sustainable. They argue that these terms are often used in an oversimplistic or dishonest manner to discuss issues such as environmental protection, energy policy, or anthropogenic climate change without providing any clarity or solutions. They call for a reevaluation of the vocabulary and goals for addressing environmental problems.

Flood control levees cut off the supply of sediment to Mississippi delta coastal wetlands, and contribute to putting much of the delta on a trajectory for continued submergence in the 21st century. River sediment diversions have been proposed as a method to provide a sustainable supply of sediment to the delta, but the frequency and magnitude of these diversions needs further assessment. Previous studies suggested operating river sediment diversions based on the size and frequency of natural crevasse events, which were large (>5000 m 3 /s) and infrequent (active < once a year) in the last naturally active delta. This study builds on these previous works by quantitatively assessing tradeoffs for a large, infrequent diversion into the forested wetlands of the Maurepas swamp. Land building was estimated for several diversion sizes and years inactive using a delta progradation model. A benefit-cost analysis (BCA) combined model land building results with an ecosystem service valuation and estimated costs. Results demonstrated that land building is proportional to diversion size and inversely proportional to years inactive. Because benefits were assumed to scale linearly with land gain, and costs increase with diversion size, there are disadvantages to operating large diversions less often, compared to smaller diversions more often for the immediate project area. Literature suggests that infrequent operation would provide additional gains (through increased benefits and reduced ecosystem service costs) to the broader Lake Maurepas-Pontchartrain-Borgne ecosystem. Future research should incorporate these additional effects into this type of BCA, to see if this changes the outcome for large, infrequent diversions. [ABSTRACT FROM AUTHOR]

Over 25% of Mississippi River delta plain (MRDP) wetlands were lost over the past century. There is currently a major effort to restore the MRDP focused on a 50-year time horizon, a period during which the energy system and climate will change dramatically. We used a calibrated MRDP marsh elevation model to assess the costs of hydraulic dredging to sustain wetlands from 2016 to 2066 and 2016 to 2100 under a range of scenarios for sea level rise, energy price, and management regimes. We developed a subroutine to simulate dredging costs based on the price of crude oil and a project efficiency factor. Crude oil prices were projected using forecasts from global energy models. The costs to sustain marsh between 2016 and 2100 changed from $128,000/ha in the no change scenario to ~$1,010,000/ha in the worst-case scenario for sea level rise and energy price, an ~ 8-fold increase. Increasing suspended sediment concentrations, which is possible using managed river diversions, raised created marsh lifespan and decreased long term dredging costs. Created marsh lifespan changed nonlinearly with dredging fill elevation and suspended sediment level. Cost effectiveness of marsh creation and nourishment can be optimized by adjusting dredging fill elevation to the local sediment regime. Regardless of management scenario, sustaining the MRDP with hydraulic dredging suffered declining returns on investment due to the convergence of energy and climate trends. Marsh creation will likely become unaffordable in the mid to late 21st century, especially if river sediment diversions are not constructed before 2030. We recommend that environmental managers take into consideration coupled energy and climate scenarios for long-term risk assessments and adjust restoration goals accordingly. [ABSTRACT FROM AUTHOR]

Currently the Mississippi delta stands as a highly degraded and threatened coastal ecosystem having lost about 25% of coastal wetlands during the 20th century. To address this problem, a $50 billion, 50-year restoration program is underway. A central component of this program is reintroduction of river water back into the deltaic plain to mimic natural functioning of the delta. However, opposition to diversions has developed based on a number of perceived threats. These include over-freshening of coastal estuaries, displacement of fisheries, perceived water quality problems, and assertions that nutrients in river water leads to wetland deterioration. In addition, growing climate impacts and increasing scarcity and cost of energy will make coastal restoration more challenging and limit restoration options. We address these issues in the context of an analysis of natural and artificial diversions, crevasse splays, and small sub-delta lobes. We suggest that episodic large diversions and crevasses (>5000 m 3 s −1 ) can build land quickly while having transient impacts on the estuarine system. Small diversions (<200 m 3 s −1 ) that are more or less continuously operated build land slowly and can lead to over-freshening and water level stress. We use land building rates for different sized diversions and impacts of large periodic inputs of river water to coastal systems in the Mississippi delta to conclude that high discharge diversions operated episodically will lead to rapid coastal restoration and alleviate concerns about diversions. Single diversion events have deposited sediments up to 40 cm in depth over areas up to 130–180 km 2 . This approach should have broad applicability to deltas globally. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "The High Cost of Coming to America," by A. Teich and W.D. White in the May 5, 2006 issue.

Gracilaria foliifera (Forsskål) Borgesen and Neoagardhiella baileyi (Harvey ex Kützing) Wynne & Taylor were grown in continuous-flow culture under cocentration of nitrogen enrichment supplied to the plants. Growth rate appeared to follow saturation-type nutrient uptake kinetics for plants receiving ammonium, nitrate, urea or sewage effluent enrichments. Ammonium enrichment produced higher growth rates than nitrate or sewage enrichment. The lowest growth rates occurred in the chambers receiving unenriched seawater or urea. Half saturation constants (K) for growth were in the range of 0.2-0.4 μM N for all N enrichments examined. The low estimated values of K compare closely with those found for microalgae and indicate that both species possess the ability to utilize very low concentrations of N. [ABSTRACT FROM AUTHOR]