Exploring the role of fish in a lake ecosystem (Lake Kinneret, Israel) by coupling an individual-based fish population model to a dynamic ecosystem model

2011 ◽  
Vol 68 (7) ◽  
pp. 1265-1284 ◽  
Author(s):  
Vardit Makler-Pick ◽  
Gideon Gal ◽  
James Shapiro ◽  
Matthew R. Hipsey
Keyword(s):  
Population Model ◽  
Fishery Management ◽  
Coupled Model ◽  
Fish Population ◽  
Lake Kinneret ◽  
Trophic Levels ◽  
Management Tool ◽  
Lake Ecosystem ◽  
Ecosystem Research

To explore the role that fish play in aquatic ecosystems, a hydrodynamic–ecological model (DYRESM–CAEDYM) was coupled to a novel fish population model. The coupled model (DYCD–FISH) combined two modelling approaches: a complex dynamic model and an individual-based model. The coupled model simulates fish growth population dynamics and predicts fish impacts on various ecosystem components, including nutrients and lower trophic levels. The model was employed to explore the role of the dominant fish in Lake Kinneret (Israel), Acanthobrama terraesanctae (Kinneret bleak, or in Hebrew, lavnun ha’kinneret; hereafter lavnun). Model results suggested that the lavnun has a significant impact (p < 0.05) on the magnitude of output variables including its prey food (the predatory and microzooplankton), major nutrients such as ammonium (NH4) and phosphate (PO4), and on several phytoplankton species, but not on the seasonality of any of the output variables. Since the model incorporates trophic levels from nutrients to fish, it revealed the nonlinear dynamic impacts of fish on different ecosystem components and in particular has led to quantitative insights into the relative influence of top-down control on water quality attributes. Besides being an ecosystem research tool, DYCD–FISH can also be employed as a fishery management tool, and in particular facilitate ecosystem-based fishery management.

scholarly journals The ecosystem: research and practice in North America

Web Ecology ◽  
2013 ◽  
Vol 13 (1) ◽  
pp. 43-47 ◽  
Author(s):  
S. Bocking
Keyword(s):  
Environmental Governance ◽  
Atomic Energy Commission ◽  
Ecosystem Approach ◽  
Trophic Levels ◽  
Ecosystem Ecology ◽  
Ecosystem Research ◽  
Energy Transfers ◽  
Functional Components ◽  
Biological Program

Abstract. Since the early 1940s, the ecosystem approach has been developed in a variety of forms by North American ecologists. Lindeman established its foundation, with his focus on functional components and energy transfers between trophic levels; this view was developed further by several ecologists, including G. Evelyn Hutchinson, and H. T. and E. P. Odum. Ecosystem ecology eventually became closely associated with powerful American institutions, such as the Atomic Energy Commission, receiving ample support; in association with the International Biological Program it became known as "big ecology''. More recently, ecosystem ecology has exhibited strengthened interest in spatial patterns, the role of species in ecosystems, and global change. This history has encompassed various ontological, methodological, ethical and political claims regarding the place of this approach in the discipline of ecology and in environmental governance.

THE ROLE OF LOG MAT BIOFILM IN THE SPIRIT LAKE ECOSYSTEM AFTER THE ERUPTION OF MOUNT ST. HELENS

2018 ◽  
Author(s):  
Kena Fox-Dobbs ◽  
◽  
Emma Sevier ◽  
James Gawel ◽  
Avery L.C. Shinneman ◽  
...  
Keyword(s):  
Lake Ecosystem ◽  
Mount St Helens

scholarly journals The Role of Communication and Engagement in Airport Noise Management

2021 ◽  
Vol 13 (11) ◽  
pp. 6088
Author(s):  
Graeme Heyes ◽  
Paul Hooper ◽  
Fiona Raje ◽  
Ian Flindell ◽  
Delia Dimitriu ◽  
...  
Keyword(s):  
Research Priorities ◽  
Considerable Effect ◽  
Management Tool ◽  
Management Activity ◽  
Community Attitudes ◽  
Management Actions ◽  
Aviation Noise ◽  
Noise Management

Research suggests that non-acoustic factors can have a considerable effect on community attitudes and opinions towards aviation noise and that these can be influenced through processes of communication and engagement. This paper reviews literature from various fields to identify the key elements of effective practice, using them as a lens through which to assess case study noise management actions conducted at European airports. This analysis found that communication and engagement holds significant potential for noise management, but that this remains largely unfulfilled due to such methods being used as an ancillary management activity, rather than as a powerful tool to aid in the design and delivery of noise management actions. A series of recommendations and research priorities are proposed that could shape the future of noise management, including potential changes to European policy that more explicitly advocate for communication and engagement as a noise management tool in its own right.

The essential role of early-spring westerly wind burst in generating the centennial extreme 1997/98 El Niño

2021 ◽  
pp. 1-38
Author(s):  
Tao Lian ◽  
Dake Chen
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Low Frequency ◽  
Coupled Model ◽  
Early Spring ◽  
Strong Nonlinearity ◽  
Westerly Wind ◽  
Enso Dynamics

AbstractWhile both intrinsic low-frequency atmosphere–ocean interaction and multiplicative burst-like event affect the development of the El Niño–Southern Oscillation (ENSO), the strong nonlinearity in ENSO dynamics has prevented us from separating their relative contributions. Here we propose an online filtering scheme to estimate the role of the westerly wind bursts (WWBs), a type of aperiodic burst-like atmospheric perturbation over the western-central tropical Pacific, in the genesis of the centennial extreme 1997/98 El Niño using the CESM coupled model. This scheme highlights the deterministic part of ENSO dynamics during model integration, and clearly demonstrates that the strong and long-lasting WWB in March 1997 was essential for generating the 1997/98 El Niño. Without this WWB, the intrinsic low-frequency coupling would have only produced a weak warm event in late 1997 similar to the 2014/15 El Niño.

Finite element analysis of hydrogen effects on superelastic NiTi shape memory alloys: Orthodontic application

2018 ◽  
Vol 29 (16) ◽  
pp. 3188-3198 ◽  
Author(s):  
Wissem Elkhal Letaief ◽  
Aroua Fathallah ◽  
Tarek Hassine ◽  
Fehmi Gamaoun
Keyword(s):  
Finite Element ◽  
Coupled Model ◽  
Element Model ◽  
Orthodontic Wires ◽  
Niti Wire ◽  
Element Analysis ◽  
Finite Element Software ◽  
Orthodontic Wire ◽  
Niti Shape Memory Alloys

Thanks to its greater flexibility and biocompatibility with human tissue, superelastic NiTi alloys have taken an important part in the market of orthodontic wires. However, wire fractures and superelasticity losses are notified after a few months from being fixed in the teeth. This behavior is due to the hydrogen presence in the oral cavity, which brittles the NiTi arch wire. In this article, a diffusion-mechanical coupled model is presented while considering the hydrogen influences on the NiTi superelasticity. The model is integrated in ABAQUS finite element software via a UMAT subroutine. Additionally, a finite element model of a deflected orthodontic NiTi wire within three teeth brackets is simulated in the presence of hydrogen. The numerical results demonstrate that the force applied to the tooth drops with respect to the increase in the hydrogen amount. This behavior is attributed to the expansion of the NiTi structure after absorbing hydrogen. In addition, it is shown that hydrogen induces a loss of superelasticity. Hence, it attenuates the role of the orthodontic wire on the correction tooth malposition.

scholarly journals A review on macrobenthic trophic relationships along subtropical sandy shores in southernmost Brazil

2014 ◽  
Vol 14 (3) ◽  
Author(s):  
Raphael Mathias Pinotti ◽  
Diogo Marroni Minasi ◽  
Leonir André Colling ◽  
Carlos Emílio Bemvenuti
Keyword(s):  
Surf Zone ◽  
Fish Assemblages ◽  
Trophic Levels ◽  
Trophic Relationships ◽  
Intermediate Type ◽  
Sandy Shores ◽  
Macrobenthic Assemblages ◽  
High Species Richness ◽  
Asterionellopsis Glacialis

Main trophic relationships that occur along the exposed sandy shores in southernmost Brazil (∼33° S) are established taking into account several biological compartments operating at morphodynamically distinct environments. Beaches are predominantly of the intermediate type but some stretches of coastline are truly dissipative (Cassino Beach) or tending-to-reflective (Concheiros Beach), presenting thus diverse biological compartments and inhabitant macrobenthic assemblages. Dense concentrations of the surf-zone diatom Asterionellopsis glacialis are responsible - at least for the intermediate shorelines - for the most year-round primary production, sustaining several consumers up to tertiary level. Among them, bivalves Amarilladesma mactroides, Donax hanleyanus and the hippid crabEmerita brasiliensis can account for more than 95% of all the surf-zone secondary production, in addition to the elevated biomass of the suspension-feeder polychaete Spio gaucha and the scavenger isopod Excirolana armata. Crabs, whelks, carnivorous polychaetes, seabirds and surf-zone fishes may also be present and occupy superior trophic levels depending on the beach morphodynamics. Based on the high species richness, abundance and the role of macrobenthic fauna in transferring matter and energy to seabirds and the surf-zone fish assemblages, we address this important issue on the Southwestern Atlantic ecology. Conservation efforts should be implemented for the southernmost Brazilian sandy shores, at least for those non urbanized areas.

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