Aquatic ecology (Environmental Studies)

Size and structure of'footprints' produced by Daphnia: impact of animal size and density gradients

by Klaus Joehnk

Gries, T., Jöhnk, K.D., Fields, D., Strickler, J.R., 1999. Size and structure of "footprints" produced by Daphnia: impact of animal size and density gradients. Journal of Plankton Research 21: 509-523.

Fury, C.A. and Reif, J. (2012) Dolphin poxvirus-like lesions linked to flood events. Science of the Total Environment. 416:536-540

by Christine Fury

We report on the incidence of poxvirus-like lesions assessed by photographic identification in two estuarine... more We report on the incidence of poxvirus-like lesions assessed by photographic identification in two estuarine populations of bottlenose dolphins (Tursiops aduncus) in Australia over a 3-year period. Poxvirus infections of odontocetes are characterized by pinhole or ring-like skin lesions that appear as solitary or coalesced circular gray blemishes. Environmental and physiological stressors are believed to contribute to their manifestation (Van Bressem et al., 2009b). A total of 187 boat-based surveys were completed from October 2003 to September 2006 in the Clarence River (CR) and Richmond River (RR) estuaries, with 720 dolphins sighted. Forty-six individuals, including calves, were identified in the CR and 23 in the RR. We investigated the temporal relationship between four flood events that occurred in the region during the study period and the occurrence of poxvirus-like skin lesions. Dolphin poxvirus-like lesions were not observed in these populations prior to 2004. Following flood events in 2004, 2005 and 2006, a total of 10 new cases were observed, 6 in the CR and 4 in the RR. Our data suggest that the occurrence of dolphin poxvirus-like lesions may be an indicator for climatic events such as flooding. Long-term follow-up of these estuarine populations is required to further clarify the factors leading to ‘outbreaks’ of poxvirus infections.

Modelo conceitual de desenvolvimento espaço-temporal de macrófitas aquáticas

by Ligia Batista

Co-authored with Nilton Nobuhiro Imai, Edivaldo Domingues Velini
SBSR 2007 - Natal - RN

This paper describes a conceptual model created to represent the submerged aquatic vegetation growth and the... more This paper describes a conceptual model created to represent the submerged aquatic vegetation growth and the differential equations that are the product of the first phase of dynamic modeling process. This one is composed of four phases: formulation, verification, calibration and analysis and evaluation.
The problem of excessive macrophytes growth in reservoirs has caused many economic losses, since it is necessary to stop producing eletric energy to remove plants that obstruct turbines. Besides, it reduces the multiple uses of water body. The aim of this work is to present a model that can be used in spatio-temporal simulation to generate a geographic distribution of plants and their development during a period of time. The
state variables were selected based on previous works about modeling and limnology focused on submerged macrophytes, mainly Egeria najas and Egeria densa species. The diagram of conceptual model was designed with the energy language proposed by Odum, which allows to get the mathematical formulation in an easier way than writing it from scratch. The spatial dimension was described adoting the diffusion process and the cellular automata approach. The construction of a diagram to represent an abstraction of problem has the
advantage of facilitating the comprehension of interactions among related variables. Furthermore, it gives us a way of getting the equations that will be used in the next phase of modeling, when formulae will be implemented.

A STUDY ON WATER QUALITY PARAMETERS OF SANJAY SAGAR RESERVOIR, DISTT. - GUNA (M.P.)

by Pradeep Solanki

Biocatalysis of Matter Transfer in a Microcosm Is Inhibited by a Contaminant: Effects of a Surfactant on Limnea stagnalis

by Sergei Ostroumov

A new discovery: a new type of environmental hazards from chemical pollutants (contaminants) as exemplified by surfactants and detergents. Those chemicals inhibited the transfer of chemical elements which are part of the pellets produced by freshwater molluscs.
Important to: new vision of element fuxes in biocheochemistry;

S. A. Ostroumov and M. P. Kolesnikov. Biocatalysis of Matter Transfer in a Microcosm Is Inhibited by a Contaminant:... more S. A. Ostroumov and M. P. Kolesnikov. Biocatalysis of Matter Transfer in a Microcosm Is Inhibited by a Contaminant: Effects of a Surfactant on Limnea stagnalis. - Doklady Biological Sciences, Vol. 373, 2000, pp. 397–399. scribd.com/doc/49069985; Translated from Doklady Akademii Nauk, Vol. 373, No. 2, 2000, pp. 278–280.

New experiments on how aquatic biota functions as a catalyst of migration of matter and chemical elements: ecology, geochemistry
scribd.com/doc/49069985;

The key role of this discovery is explained here:
http://www.scribd.com/doc/61251644/; New Discovery:Pollutants Inhibit Fluxes of Chemical Elements.

Main discoveries made by the same author:
Публикации того же автора. Основные результаты. Main Results: http://www.scribd.com/doc/59437439/;
On the author / Об авторе (С.А.О.):
http://www.famous-scientists.ru/3732/;

Seasonal changes on two different spatial scales: response of aquatic invertebrates to water body and microhabitat

by Wilco Verberk

Insect Science (2005) 12: 263-280.

Knowledge about the spatial and temporal scales of both habitat use and the functional significance of different... more Knowledge about the spatial and temporal scales of both habitat use and the functional significance of different adaptations is essential for an understanding of the population dynamics of invertebrate assemblages. This fundamental knowledge is not only interesting from an academic point of view, but is sorely lacking and needed in the field of restoration ecology. Many species are threatened due to degradation. Knowing what
environmental conditions are needed during the life cycle of these species is important in the design of restoration measures which aim to lift existing bottlenecks for threatened species.

To assess the relative importance of water type and microhabitat in structuring the invertebrate assemblage during different seasons, invertebrates were sampled in three water bodies differing in trophic level and acidity. Different parts within a water body (microhabitats) were sampled separately and each water body was sampled in all four seasons.

Results show that water body is an important factor structuring the invertebrate assemblage early in the season, whereas microhabitat became more important later in the season. Structural complexity of microhabitats was related to the type of locomotion employed by invertebrates. Seasonal differences could be related to population dynamics (reproduction, mortality). Moreover, fluctuations in resource availability were expected to differ between the water bodies, with highest fluctuations in the eutrophic water body and with fluctuations becoming less predictable later in the season. This was confirmed by the data: species synchronization to pulses in food availability was strongest in the eutrophic water body. Moreover, synchronization was strongest in summer, while in autumn waters were invaded by dispersive species.

Based on these results a synthesis is presented on the functioning of the different waters during the different seasons.

A paleozoological perspective on unionid (Mollusca: Unionidae) zoogeography in the upper Trinity River basin, Texas Read More: http://www.esajournals.org/doi/abs/10.1890/09-1425.1

by Steve Wolverton

Randklev et al. 2010

In north central Texas, USA, the zoogeography of unionids in the Trinity River is thought to consist of upland and... more In north central Texas, USA, the zoogeography of unionids in the Trinity River is thought to consist of upland and lowland biogeographic components reflective of differences in upstream and downstream hydraulic conditions. Historical and modern surveys from a limited number of localities were used to delineate these zoogeographic provinces based on the absence of several species thought to occur only in the lower Trinity River drainage. Available zooarchaeological data indicate that at least one species considered absent from the upper Trinity River basin was present during the late Holocene (roughly the last 2500 years), suggesting that both biogeographical provinces shared similar mussel fauna in the recent geological past. The discrepancy between historical and zooarchaeological data is probably the result of inadequate sampling and of an extirpation gradient related to impoundments that have been constructed in this drainage during the last century. The presence of lower Trinity species during the late Holocene in the upper Trinity drainage challenges interpretations drawn from modern biogeographic studies.

Read More: http://www.esajournals.org/doi/abs/10.1890/09-1425.1