67 research outputs found
Direct Discharges of Domestic Wastewater are a Major Source of Phosphorus and Nitrogen to the Mediterranean Sea
Direct discharges of treated and untreated wastewater are important sources of nutrients to coastal marine ecosystems and contribute to their eutrophication. Here, we estimate the spatially distributed annual inputs of phosphorus (P) and nitrogen (N) associated with direct domestic wastewater discharges from coastal cities to the Mediterranean Sea (MS). According to our best estimates, in 2003 these inputs amounted to 0.9 × 10⁹ mol P yr-1 and 15 × 10⁹ mol N yr-1, that is, values on the same order of magnitude as riverine inputs of P and N to the MS. By 2050, in the absence of any mitigation, population growth plus higher per capita protein intake and increased connectivity to the sewer system are projected to increase P inputs to the MS via direct wastewater discharges by 254, 163, and 32% for South, East, and North Mediterranean countries, respectively. Complete conversion to tertiary wastewater treatment would reduce the 2050 inputs to below their 2003 levels, but at an estimated additional cost of over €2 billion yr-1. Management of coastal eutrophication may be best achieved by targeting tertiary treatment upgrades to the most affected near-shore areas, while simultaneously implementing legislation limiting P in detergents and increasing wastewater reuse across the entire basin
Sensor Selection and Optimization for Health Assessment of Aerospace Systems
Aerospace systems are developed similarly to other large-scale systems through a series of reviews, where designs are modified as system requirements are refined. For space-based systems few are built and placed into service. These research vehicles have limited historical experience to draw from and formidable reliability and safety requirements, due to the remote and severe environment of space. Aeronautical systems have similar reliability and safety requirements, and while these systems may have historical information to access, commercial and military systems require longevity under a range of operational conditions and applied loads. Historically, the design of aerospace systems, particularly the selection of sensors, is based on the requirements for control and performance rather than on health assessment needs. Furthermore, the safety and reliability requirements are met through sensor suite augmentation in an ad hoc, heuristic manner, rather than any systematic approach. A review of the current sensor selection practice within and outside of the aerospace community was conducted and a sensor selection architecture is proposed that will provide a justifiable, dependable sensor suite to address system health assessment requirements
Calcification response of planktic foraminifera to environmental change in the western Mediterranean Sea during the industrial era
The Mediterranean Sea sustains a rich and fragile ecosystem currently
threatened by multiple anthropogenic impacts that include, among others,
warming, pollution, and changes in seawater carbonate speciation associated
to increasing uptake of atmospheric CO2. This environmental change
represents a major risk for marine calcifiers such as planktonic
foraminifera, key components of pelagic Mediterranean ecosystems and major
exporters of calcium carbonate to the sea floor, thereby playing a major
role in the marine carbon cycle. In this study, we investigate the response
of planktic foraminifera calcification in the northwestern Mediterranean Sea
on different timescales across the industrial era. This study is based on
data from a 12-year-long sediment trap record retrieved in the in the Gulf
of Lions and seabed sediment samples from the Gulf of Lions and the
promontory of Menorca. Three different planktic foraminifera species were
selected based on their different ecology and abundance: Globigerina bulloides, Neogloboquadrina incompta, and
Globorotalia truncatulinoides. A total of 273 samples were weighted in both sediment trap and seabed
samples.
The results of our study suggest substantial different seasonal
calcification patterns across species: G. bulloides shows a slight calcification
increase during the high productivity period, while both N. incompta and G. truncatulinoides display a
higher calcification during the low productivity period. The comparison of
these patterns with environmental parameters indicate that controls on
seasonal calcification are species-specific. Interannual analysis suggests
that both G. bulloides and N. incompta did not significantly reduce their calcification between
1994 and 2005, while G. truncatulinoides exhibited a constant and pronounced increase in its
calcification that translated in an increase of 20 % of its shell weight.
The comparison of these patterns with environmental data reveals that
optimum growth conditions affect positively and negatively G. bulloides and
G. truncatulinoides calcification, respectively. Sea surface temperatures (SSTs) have a positive
influence on N. incompta and G. truncatulinoides calcification, while carbonate system parameters appear
to affect positively the calcification of three species in the Gulf of Lions
throughout the 12-year time series.
Finally, comparison between sediment trap data and seabed sediments allowed
us to assess the changes of planktic foraminifera calcification during the
late Holocene, including the pre-industrial era. Several lines of evidence
indicate that selective dissolution did not bias the results in any of our
data sets. Our results showed a weight reduction between pre-industrial and
post-industrial Holocene and recent data, with G. truncatulinoides experiencing the largest
weight loss (32 %–40 %) followed by G. bulloides (18 %–24 %) and N. incompta (9 %–18 %). Overall, our
results provide evidence of a decrease in planktic foraminifera
calcification in the western Mediterranean, most likely associated with
ongoing ocean acidification and regional SST trends, a feature consistent
with previous observations in other settings of the world's oceans.</p
Climate Influence on Deep Sea Populations
Dynamics of biological processes on the deep-sea floor are traditionally thought to be controlled by vertical sinking of particles from the euphotic zone at a seasonal scale. However, little is known about the influence of lateral particle transport from continental margins to deep-sea ecosystems. To address this question, we report here how the formation of dense shelf waters and their subsequent downslope cascade, a climate induced phenomenon, affects the population of the deep-sea shrimp Aristeus antennatus. We found evidence that strong currents associated with intense cascading events correlates with the disappearance of this species from its fishing grounds, producing a temporary fishery collapse. Despite this initial negative effect, landings increase between 3 and 5 years after these major events, preceded by an increase of juveniles. The transport of particulate organic matter associated with cascading appears to enhance the recruitment of this deep-sea living resource, apparently mitigating the general trend of overexploitation. Because cascade of dense water from continental shelves is a global phenomenon, we anticipate that its influence on deep-sea ecosystems and fisheries worldwide should be larger than previously thought
Are logging concessions a threat to the peatlands in DRC? (Les concessions d'exploitation forestière menacent-elles les tourbières en République démocratique du Congo?)
Faculty and administrator views of influences on professional programs
Administrators in professional programs perceive influences on the program from within the university as stronger than do faculty but the two groups do not perceive the strength of societal influences, professional community influences, or internal levels of curriculum debate differently. After controlling for program and institutional sizes and institutional types, these differences between faculty and administrator views regarding relationships between the program and the university appear characteristic of certain professional fields. The analysis was based on subsamples drawn from a data base of survey responses from 873 administrators and 849 faculty members in ten professional fields representing 732 programs in 346 colleges and universities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43601/1/11162_2004_Article_BF00992306.pd
A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience
PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern
European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good
Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary
approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge
gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal
areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also
independently performed. The comparison between meta-analysis results and IAs shows similarities
for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food
web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification
of additional research themes targeting research topics that are requested to the achievement of GES.
2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe
Animal performance and meat characteristics in steers reared in intensive conditions fed with different vegetable oils
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