460 research outputs found
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Characterization of plankton from the Galveston estuary
The purpose of this report is to summarize the published studies on phytoplankton and zooplankton in the Galveston Estuary. Before this project had begun, it was determined that there was insufficient long term data on plankton in the Galveston Estuary to attempt trend analysis. Information on phytoplankton species diversity, biomass and primary production, along with information on zooplankton species diversity and abundance, is summarized. This information is compared to similar data on other Texas and United States estuaries where available. Recommendations for a long term monitoring program are made. A bibliography of all Galveston Estuary plankton studies and an annotated bibliography of the major studies and publications are available in the GBNEP Information Center.Marine Scienc
The Many Meanings of Montgomery v. Louisiana: How the Supreme Court Redefined Retroactivity and Miller v. Alabama
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Recruitment of estuarine dependent species of commercial and recreational importance through the Aransas Ship Channel
Several species of shellfish and finfish of commercial or recreational importance in the Nueces and
Mission-Aransas Estuaries possess life history patterns that are dependent upon estuaries, whereby
juvenile members of these species live and mature in these estuary ânurseriesâ, then migrate to the Gulf of
Mexico as reproductive adults, releasing their eggs and planktonic larvae in the open ocean. The larvae
feed, grow and develop in the Gulf of Mexico, but must return back to these estuaries to complete their
life cycle. These planktonic larvae possess weak swimming skills and are too small to migrate directly
back into the estuaries under their own power, so they must depend on hydrodynamic and environmental
signals to selectively ride tidal and meteorologically driven currents back into the estuaries and avoid
being flushed back out when these currents reverse. Tides are relatively small in the Northwestern Gulf of
Mexico, and especially for estuaries in South Texas with little inflow of freshwater, meteorological
forcing over times scales of several days play a significant role in estuarine-shelf water exchanges (Smith
1978). The Aransas Pass connecting the Nueces and Mission-Aransas Estuaries to the Gulf of Mexico
was originally a shallow inlet between Mustang and San Jose Islands and it has been dredged to allow
access for ocean-going vessels to the Port of Corpus Christi. This deeper channel now delivers most of the
water exchange between the Nueces/Mission-Aransas Estuaries and the Gulf of Mexico, which has
reduced the flow through other shallow historical passes between these estuaries and the Gulf, causing
them to fill in with sediments and close unless maintained through dredging (e.g. Fish Pass, Cedar
Bayou). As a result of historical passes closing due to the already permitted deepening of the Aransas
Pass, this channel is now the main route available for larvae to recruit from the Gulf to local estuaries. It
is unclear how additional alterations to the depth of the Aransas Pass and adjacent waters will alter
hydrodynamics in this channel, or other remaining channels, and affect the recruitment of estuarine
dependent larvae. Below are several examples of important estuarine species that could be impactedMarine Scienc
Elevating Substance over Procedure: The Retroactivity of Miller v. Alabama under Teague v. Lane
This Article proposes a unique framework establishing that the United States Supreme Courtâs decision in Miller v. Alabama, which forbids states from automatically sentencing juveniles to life imprisonment without any meaningful opportunity for release, must apply retroactively to hundreds of juveniles whose convictions and life sentences were already final at the time of the decision. Such a framework is timely and critical. The lower state and federal courts are divided on the question, and the Supreme Court is likely to settle the issue within the next year. The Article reviews how, absent guidance from the Supreme Court, a host of states, led most recently by Michigan, have invoked the Miller majorityâs statement that it was merely requiring states to follow a âcertain processâ before sentencing a juvenile to life imprisonment without parole. By this reasoning, Miller is not retroactive under the Supreme Courtâs federal retroactivity doctrine established by Teague v. Lane. The Court has always applied new substantive rules retroactively under Teague, while it has never done so for a new procedural rule. The Article rejects this âprocessâ language as a basis for resolving whether Miller is retroactive. It concludes that Miller in fact has little to do with process and is instead primarily concerned with sentencing outcomes for youth. In striking down mandatory life without parole for juveniles, Miller adapted the individualized sentencing requirement from Woodson v. North Carolina, which invalidated the mandatory death penalty. This individualized sentencing requirement obligates states to always offer juveniles a sentencing outcome carrying the possibility of release and to consider the essential, mitigating fact of youth before imposing an irrevocable life sentence. These obligations are inherently substantive. By contrast, Millerâs alleged procedural component is undefined and collateral to its substantive altering of juvenile sentencing. Miller therefore announces a substantive rule that must apply retroactively
Changes in Herbaceous Plant Diversity in an Old-Growth Ohio Forest Before and After Emerald Ash Borer Invasion
The herbaceous layer of eastern North American deciduous forests is an important contributor to biodiversity in this region. One of the greatest threats to herbaceous plant diversity is the introduction of invasive species, which can suppress native species and alter local environmental conditions. Agrilus planipennis (emerald ash borer) is a non-native insect pest that has caused a mass death of ash trees (Fraxinus spp.) in North America since its introduction to the United States. The resultant changes in canopy structure may affect local conditions and thus have indirect impacts on herbaceous layer composition. Drew Woods State Nature Preserve is a 6-ha old-growth forest fragment in Darke County, Ohio that has recently experienced EAB-related ash mortality. Our goal was to understand how herbaceous layer diversity has been changing through time in response to this sitewide canopy disturbance. Annual surveys of herbaceous biodiversity were conducted across 32 1-m2 sampling plots from 2012 to 2017. Species richness, total cover, Shannon Diversity, and species evenness were calculated for each plot by year, and beta diversity (Bray-Curtis Dissimilarity) was used to assess community turnover through time. Repeated measures ANOVA was used to test for significant changes over this period, and regression analyses were used to understand relationships between diversity and environmental variables (canopy cover, soil moisture, and distance to forest edge). Species richness and herbaceous cover tended to be higher in more recent sampling years. There was a temporally consistent north-south gradient where diversity tended to be greater toward the southern edge of the stand. These results suggest that EAB-induced ash mortality is increasing light availability via canopy gap formation, which is a driving factor of herbaceous diversity. The full impact of EAB is not yet clear, but will likely extend beyond ash mortality and have important indirect effects on other parts of forest ecosystems
Keeping \u3cem\u3eGideon\u3c/em\u3e\u27s Promise: Using Equal Protection to Address the Denial of Counsel in Misdemeanor Cases
The Sixth Amendment of the U.S. Constitution guarantees criminal defendants the right to counsel, and the U.S. Supreme Court has made clear that right is applicable to all defendants in felony cases, even those unable to afford a lawyer. Yet, for defendants facing misdemeanor charges, only those defendants whose convictions result in incarceration are entitled to the assistance of counsel.The number of misdemeanor prosecutions has increased dramatically in recent years, as have the volume and severity of collateral consequences attached to such convictions; yet, the Courtâs right to counsel jurisprudence in this area has remained stagnant. Critics of the doctrinal and pragmatic problems created by the Courtâs actual incarceration standard have advocated for various reforms to better protect people accused of misdemeanors, including redefinition or expansion of the right to counsel and legislative changes that would cut back on incarceration and allow states to better apportion their limited resources among defendants.This Article offers a novel perspective, grounded in due process and equal protection and a line of Supreme Court cases that guarantee equal access to the courts. Viewed in that light, indigent misdemeanor defendants denied counsel may not suffer from a Sixth Amendment violation under the law as it stands, but they are deprived of meaningful access to the courts on the basis of wealth. It suggests that reconceputalizing the plight of misdemeanor defendants through the lens of due process and equal protection may help to identify the most effective judicial and legislative solutions to the crisis of âassembly line justice.
Interactions between Zooplankton and Crude Oil: Toxic Effects and Bioaccumulation of Polycyclic Aromatic Hydrocarbons
We conducted ship-, shore- and laboratory-based crude oil exposure experiments to investigate (1) the effects of crude oil (Louisiana light sweet oil) on survival and bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) in mesozooplankton communities, (2) the lethal effects of dispersant (Corexit 9500A) and dispersant-treated oil on mesozooplankton, (3) the influence of UVB radiation/sunlight exposure on the toxicity of dispersed crude oil to mesozooplankton, and (4) the role of marine protozoans on the sublethal effects of crude oil and in the bioaccumulation of PAHs in the copepod Acartia tonsa. Mortality of mesozooplankton increased with increasing oil concentration following a sigmoid model with a median lethal concentration of 32.4 ml L21 in 16 h. At the ratio of dispersant to oil commonly used in the treatment of oil spills (i.e. 1:20), dispersant (0.25 ml L21 ) and dispersant- treated oil were 2.3 and 3.4 times more toxic, respectively, than crude oil alone (5 ml L21 ) to mesozooplankton. UVB radiation increased the lethal effects of dispersed crude oil in mesozooplankton communities by 35%. We observed selective bioaccumulation of five PAHs, fluoranthene, phenanthrene, pyrene, chrysene and benzo[b]fluoranthene in both mesozooplankton communities and in the copepod A. tonsa. The presence of the protozoan Oxyrrhis marina reduced sublethal effects of oil on A. tonsa and was related to lower accumulations of PAHs in tissues and fecal pellets, suggesting that protozoa may be important in mitigating the harmful effects of crude oil exposure in copepods and the transfer of PAHs to higher trophic levels. Overall, our results indicate that the negative impact of oil spills on mesozooplankton may be increased by the use of chemical dispersant and UV radiation, but attenuated by crude oil-microbial food webs interactions, and that both mesozooplankton and protozoans may play an important role in fate of PAHs in marine environments.Zoe Wambaugh was supported by the National Science Foundation (NSF) Research Experiences for Undergraduates (REU) program (grant OCE-
1062745). This research was made possible by a grant from BP/The Gulf of Mexico Research Initiative through the University of Texas Marine Science Institute
(DROPPS consortium: âDispersion Research on Oil: Physics and Plankton Studiesâ). The funders had no role in study design, data collection and analysis, decision to
publish, or preparation of the manuscript.Marine Scienc
A study of the potential effects of deepening the Corpus Christi Ship Channel on hurricane storm surge
publishedVersio
How much crude oil can zooplankton ingest? Estimating the quantity of dispersed crude oil defecated by planktonic copepods
AbstractWe investigated and quantified defecation rates of crude oil by 3 species of marine planktonic copepods (Temora turbinata, Acartia tonsa, and Parvocalanus crassirostris) and a natural copepod assemblage after exposure to mechanically or chemically dispersed crude oil. Between 88 and 100% of the analyzed fecal pellets from three species of copepods and a natural copepod assemblage exposed for 48 h to physically or chemically dispersed light crude oil contained crude oil droplets. Crude oil droplets inside fecal pellets were smaller (median diameter: 2.4â3.5 Όm) than droplets in the physically and chemically dispersed oil emulsions (median diameter: 6.6 and 8.0 Όm, respectively). This suggests that copepods can reject large crude oil droplets or that crude oil droplets are broken into smaller oil droplets before or during ingestion. Depending on the species and experimental treatments, crude oil defecation rates ranged from 5.3 to 245 ng-oil copepodâ1 dâ1, which represent a mean weight-specific defecation rate of 0.026 Όg-oil ÎŒg-Ccopepod1 dâ1. Considering a dispersed crude oil concentration commonly found in the water column after oil spills (1 Όl Lâ1) and copepod abundances in high productive coastal areas, copepods may defecate âŒ1.3â2.6 mg-oil mâ3 dâ1, which would represent âŒ0.15%â0.30% of the total dispersed oil per day. Our results indicate that ingestion and subsequent defecation of crude oil by planktonic copepods has a small influence on the overall mass of oil spills in the short term, but may be quantitatively important in the flux of oil from surface water to sediments and in the transfer of low-solubility, toxic petroleum hydrocarbons into food webs after crude oil spills in the sea
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