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361.
José Fortes Lopes Ana Cristina Cardoso Maria Teresa Moita Alfredo C. Rocha Juan A. Ferreira 《Ecological modelling》2009
The main objective of this paper is to implement a coupled three-dimensional physical and ecological model for the Aveiro coast, and to apply it to study the temperature and the phytoplankton biomass spatial distributions along the coastal ecosystem. The Aveiro coast is located at Portugal within the upwelling system of the Atlantic Iberian coast, characterized by nutrients availability and phytoplankton biomass accumulation, from April to October. In order to implement the ecological model, its validation was assessed by comparing simulations to data relative to the horizontal and vertical distributions of the temperature, nutrients and phytoplankton biomass, obtained during the CICLOS I survey off the Portuguese coast [Moita, M.T., 2001. Estrutura, Variabilidade e Dinâmica do Fitoplâncton na Costa de Portugal Continental. PhD Thesis. Faculdade de Ciências da Universidade de Lisboa, 272 pp.]. A sensitivity analysis of the model has been performed in order to assess the influence of the main ecological model variables. The simulation results show that the model is capable of predicting realistic the temperature, the nutrients and the chlorophyll-a distributions for the study area. The scenarios evidence the setup of a thermal stratification pattern resulting from the upwelling of deep and rich in nutrients water to the surface layer and a chlorophyll-a maxima extending offshore, along the picnocline and the nutricline. The results confirm the crucial role played by the physical processes in the phytoplankton bloom along the Aveiro coast. They also evidence the close link between the surface phytoplankton distribution and the surface temperature distribution. 相似文献
362.
Anna Gagliardo Maria Savini Angelo De Santis Giacomo Dell’Omo Paolo Ioalè 《Behavioral ecology and sociobiology》2009,64(2):289-296
Some authors have proposed that homing pigeons are able to correct the error in orientation following a phase-shift treatment
by using the magnetic compass reference. They reported that clock-shifted pigeons bearing magnets display a greater deflection
compared to magnetically unmanipulated clock-shifted birds. However, this hypothesis tested by recording pigeons’ vanishing
bearings has led to contradictory results. The present study reports pigeons’ tracks recorded with a GPS and shows that clock-shifted
pigeons bearing magnets displayed a greater deviation through the whole route compared to the magnetically unmanipulated shifted
pigeons. Moreover, the analysis of the tracks shows that the birds belonging to both experimental groups stop in coincidence
with their subjective night. When re-starting their journey, the birds corrected the clock-shift induced error in orientation,
but the magnetically manipulated pigeons were less efficient in doing so. Our results are consistent with the hypothesis that
homing pigeons released from unfamiliar location re-orient after clock shift by using the magnetic compass. 相似文献
363.
Giovanni A. P. dos Santos Sofie Derycke Verônica G. F. Genevois Luana C. B. B. Coelho Maria T. S. Correia Tom Moens 《Marine Biology》2009,156(4):629-640
Accurate prediction of the biodiversity–ecosystem functioning relationship requires adequate understanding of the interactions
among species in a community. Effects of species diversity on ecosystem functioning are usually considered more pronounced
with increasing functional dissimilarity, although species within functional groups may also perform non-identical functions
and interact with each other. Here we present results of a laboratory experimental study aimed at elucidating whether interspecific
interactions among species within a single nematode trophic group, bacterivores, (1) affect population development and community
structure, and (2) depend on food availability. We studied the population growth of Rhabditis (Pellioditis) marina, a rhabditid nematode known to favour very high food densities when in monoculture, and of Diplolaimelloides meyli and D. oschei, congeneric Monhysteridae known to perform better in monocultures at intermediate food availability. Both Diplolaimelloides species showed significantly different patterns of food-density dependence in combination culture compared to monoculture.
At very high food availability, the rhabditid nematode facilitated growth of both monhysterid species, probably as a result
of down-regulation of bacterial density. At the lowest food availabilities, the presence of even low numbers of monhysterid
nematodes lead to exclusion of the rhabditid, which at such low food availability has a very inefficient food uptake. At intermediate
food availabilities, abundances of both Diplolaimelloides species were strongly depressed in the combination culture, as a result of food depletion by the rhabditid, indirect inhibitory
interactions between the two congeneric species, or both. The complexity of the species interactions render predictions on
the outcome and functional consequences of changes in within-trophic-group diversity highly problematic. 相似文献
364.
Villy Christensen Carl J. Walters Robert Ahrens Jacqueline Alder Joe Buszowski Line Bang Christensen William W.L. Cheung John Dunne Rainer Froese Vasiliki Karpouzi Kristin Kaschner Kelly Kearney Sherman Lai Vicki Lam Maria L.D. Palomares Aja Peters-Mason Chiara Piroddi Jorge L. Sarmiento Jeroen Steenbeek Rashid Sumaila Reg Watson Dirk Zeller Daniel Pauly 《Ecological modelling》2009
We present a new methodology for database-driven ecosystem model generation and apply the methodology to the world's 66 currently defined Large Marine Ecosystems. The method relies on a large number of spatial and temporal databases, including FishBase, SeaLifeBase, as well as several other databases developed notably as part of the Sea Around Us project. The models are formulated using the freely available Ecopath with Ecosim (EwE) modeling approach and software. We tune the models by fitting to available time series data, but recognize that the models represent only a first-generation of database-driven ecosystem models. We use the models to obtain a first estimate of fish biomass in the world's LMEs. The biggest hurdles at present to further model development and validation are insufficient time series trend information, and data on spatial fishing effort. 相似文献
365.
366.
Parental care is a costly part of reproduction. Hence, natural selection should favor males which avoid caring for unrelated
young. However, the decision to abandon or reduce care requires cues which are evaluated to give information on potential
reproductive value of the offspring. The prediction that male sand gobies, Pomatoschistus minutus, care for foreign eggs as long as they were spawned in their own nest and at least some of such cues are fulfilled was tested.
Egg-guarding males that had recently taken part in a spawning event were given a clutch of eggs that was sired either by themselves
or another male, in either their own or another male’s aquarium. Males that had not taken part in a spawning event were used
as controls and were given eggs sired by another male. We measured the amount of filial cannibalism and nest building. Control
group males did not care for eggs and ate them all before rebuilding the nest. In the other treatments, there were no significant
effects of paternity, though males moved to another male’s aquarium increased their clutch area threshold and completely consumed
larger clutches than males that were not moved. There was no intermediate response in any treatment in the form of increased
partial filial cannibalism or less well-constructed nests. Our results suggest that egg-guarding males cannot distinguish
between eggs sired by themselves and those sired by other males but are able to react to cues indicating paternity state.
Males do not adopt eggs to attract females in P. minutus. 相似文献
367.
Hapry F. N. Lapian Marco Barucca Giorgio Bavestrello Maria A. Biscotti Marzia Bo Adriana Canapa Silvia Tazioli Ettore Olmo 《Marine Biology》2007,151(2):785-792
A phylogenetic analysis based on rDNA internal transcribed spacers (ITS) sequences was performed on 15 species of black corals assigned to the genera Antipathes, Stichopathes, Cirrhipathes, Rhipidipathes, Antipathella, Myriopathes and Cupressopathes recorded from the Messina Strait (Mediterranean Sea) and the Bunaken Marine Park (Celebes Sea, Indonesia). The phylogenetic analysis shows that the examined species are grouped in two main branches corresponding to the families Antipathidae-Aphanipathidae and Myriopathidae. While among the Myriopathidae species there is a very small genetic distance, the Antipathidae-Aphanipathidae clade shows a high degree of divergence between different genera. According to this study, the taxon Antipathes? sp. 3 characterised by a bush-like corallum without a well-defined axis, probably belongs to a new undescribed genus of the family Antipathidae. 相似文献
368.
Moon DH Dermatas D Wazne M Sanchez AM Chrysochoou M Grubb DG 《Environmental geochemistry and health》2007,29(4):289-294
Several million tons of Chromite Ore Processing Residue (COPR) were deposited at two sites in New Jersey and Maryland, USA,
and over time they exhibited extensive heaving phenomena. Ettringite, a needle-shaped mineral and an expansive mineral commonly
recognized in the literature concerning cement- and soil, has been identified extensively in numerous COPR samples collected
from these sites. It was therefore believed that ettringite formation and its crystal growth are strongly associated with
COPR heaving. We investigated the correlation between ettringite and the heaving phenomena in COPR materials that contained
no initial ettringite. Two identical COPR samples were exposed to a 4% w/w sulfate solution (25°C, 50°C) in a confined swell
test apparatus. Both swell test samples were analyzed by means of X-ray powder diffraction. The peak intensities of newly
formed ettringite were more pronounced in the sample tested at 50°C, and swell development was only observed in this sample.
Scanning electron microscopy analyses revealed well-crystallized ettringite needles exceeding 40 μm in length for this sample,
while ettringite crystals less than 15 μm in length formed in the sample tested at 25°C. Therefore, the results suggest that
the quantity of ettringite and the extent of crystallization play a key role in the heave of COPR. 相似文献
369.
Eutrophication is an ongoing process in most parts of the Baltic Sea. This article reports on the changes during recent decades of several eutrophication-related variables in the open sea areas surrounding Finland (wintertime nutrient concentrations, wintertime nutrient ratios, and summer time chlorophyll alpha concentrations at the surface). The sum of nitrate- and nitrite-nitrogen ([NO3+NO2]-N) was observed to increase nearly fourfold in the Northern Baltic Proper and the Gulf of Finland and almost double in the Bothnian Sea from the 1960s until the 1980s or 1990s. The increase was followed by a decrease, which was modest in the two former subregions. Phosphate-phosphorus (PO4-P) concentrations followed a similar pattern in the Northern Baltic Proper (threefold increase and subsequent slight decrease) and Bothnian Sea (30% increase and subsequent decrease), but increased throughout the study in the Gulf of Finland, with the present concentration being threefold to the measurements made in the early 1970s. The PO4-P concentration decreased throughout the study in the Bothnian Bay. Silicate-silicon (SiO4-Si) concentrations decreased 30-50% from the early 1970s to the late 1990s and increased 20-40% thereafter in the Northern Baltic Proper, the Gulf of Finland, and the Bothnian Sea. Chlorophyll alpha showed an increase of over 150% in the Northern Baltic Proper and the Gulf of Finland from the 1970s until the early 2000s. In the Bothnian Sea the chlorophyll alpha concentration increased more than 180% from the late 1970s until the late 1990s, and decreased thereafter. According to these long-term observations, the Gulf of Finland and Northern Baltic Proper show clear signs of eutrophication, which may be emphasized by hydrographical changes affecting the phytoplankton communities and thus the algal biomass. 相似文献
370.
da Silva LI de Souza Sarkis JE Zotin FM Carneiro MC Neto AA da Silva Ados S Cardoso MJ Monteiro MI 《Chemosphere》2008,71(4):677-684
In this work, 24-h PM10 samples were collected in Rio de Janeiro, Brazil, and analysed for trace elements (Cd, Ce, Cu, La, Mo, Ni, Pb, Pd, Rh, Sb and Sn). The sampling was carried out at five locations (Bonsucesso; Centro, downtown city; Copacabana; Nova Igua?u and Sumaré) with different traffic densities and anthropogenic activities. An analytical method based on the EPA method for the determination of trace elements in airborne particulate matter (PM), using ultrasonic-assisted extraction and inductively coupled plasma mass spectrometry (ICP-MS) was applied. Our results suggest that vehicular traffic is the most important source of environmental pollution at the studied sites. The presence of Mo, Pd and Rh in the analysed filters reflects an additional source of pollution caused by the erosion and deterioration of automotive catalytic converters. 相似文献