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Introduction
Publications
Publications (78)
Chironomids have a number of characteristics that make them a useful group for investigating the impact of environmental and chemical stressors on their life cycle stages. It is crucial to first understand sensitivities to environmental factors and provide a basis for interpreting the results of toxicity tests. We focused on Chironomus riparius–one...
As sciences mature, they transition from observation and description to explanation and prediction. This transition is associated with qualitative changes in the way quantitative mathematical formulations are constructed and interpreted, resulting in a ‘theory’. Such transitions from phenomenology to theory are happening in biology but the heuristi...
Global warming has facilitated the invasion of several Red Sea species in the Mediterranean Sea; a phenomenon known as Lessepsian migration. In this work, two key Mediterranean herbivore fish, the native salema (Sarpa salpa) and the invasive marbled spinefoot (Siganus rivulatus) were studied via the lens of bioenergetic modeling based on Dynamic En...
Global warming and other climate change drivers have a significant impact on the life cycle of insects which in turn affect their population dynamics and geographic distribution. Among these insects are stink bugs (Hemiptera: Pentatomidae), which are hemimetabolous agricultural pests that cause major damage on crops in many countries. Their life cy...
Pinpointing thermal tolerance thresholds for commercially important species, such as aquaculture finfish, under acute and chronic thermal stress is becoming increasingly relevant in the context of climate change. While experimental research, traditionally quantified by the determination of the Critical Thermal Maximum ( C T m a x ), offers valuable...
Birds build up their reproductive system and allocate substantial energy to egg-production for each reproductive season. Energetic specifics of these this processes are still not completely clear, despite the increasing interest. Environmental risk assessment (ERA) of commercial pesticides is currently based on the statistical analysis of data coll...
Mechanistic modeling of chronic chemical exposure in birds is gaining traction in environmental risk assessment. Such models provide insight into physiological effects and can predict life-history traits in response to exposure to chemical stress under laboratory or realistic field conditions.
Lately, the new guidance document on risk assessment fo...
Parasitism is an energetically costly event for host species. Dynamic energy budget (DEB) theory describes the metabolic dynamics of an individual organism through its lifetime. Models derived from DEB theory specify how an organism converts food to reserves (maintenance-free energy available for metabolism) and allocates mobilized reserves to main...
Birds build up their reproductive system and undergo major tissue remodeling for each reproductive season. Energetic specifics of this process are still not completely clear, despite the increasing interest. We focused on the bobwhite quail-one of the most intensely studied species due to commercial and conservation interest-to elucidate the energy...
European sea bass is a species of great commercial value for fisheries and aquaculture. Rising temperatures may jeopardize the performance and survival of the species across its distribution and farming range, making the investigation of its thermal responses highly relevant. In this article, the metabolic scope, performance, and tolerance of juven...
To address challenges in management and conservation of fishes and fisheries it is essential to understand their life histories and energetics. The Add-my-Pet (AmP) collection of data on energetics and Dynamic Energy Budget (DEB) parameters currently contains 1150 of the 40000 extant species of fish. It gives 250-280 traits per species, depending o...
The Add-my-Pet (AmP) collection of data on energetics and Dynamic Energy Budget (DEB) parameters currently contains 200 out of over 1100 extant species of chondrichthyans. This milestone in the compilation of data for this group led us to investigate: (1) do the characteristics that we reported in 2014 for 20 chondrichthyan species, relative to oth...
The method of multidimensional scaling (MDS) has long existed, but could only recently be applied to animal traits in the context of dynamic energy budget (DEB) theory. The application became possible because of the following: (i) the Add-my-Pet (AmP) collection of DEB parameters and traits (approximately 280) recently reached 3000 animal species w...
In the oligotrophic, phosphorus (P)-limited Eastern Mediterranean Sea (EMS), grazing on heterotrophic bacteria (HB) by pigmented nanoflagellates (PNF) through mixotrophy is a significant source of bacterial mortality and is P-dependent. Heterotrophic nanoflagellates (HNF) are also important consumers of HB. However, there is still no conceptual fra...
This article reports on the thermal tolerance, metabolic capacity and performance of juvenile meagre (Argyrosomus regius) reared under three high water temperatures (24, 29 and 34 °C) for three months. The analysis includes the thermal effects on the growth performance, metabolism and physiology of meagre, including a range of molecular, haematolog...
Climate change poses increasing challenges to aquaculture, resulting in the need to develop appropriate tools to assess these challenges and support decision-making. We present ClimeGreAq, a software-based Decision Support System (DSS) co-created with stakeholders to support the adaptation of Greek aquaculture to climate change. The DSS is based on...
Finfish aquaculture in the Mediterranean Sea faces increasing challenges due to climate change, while potential adaptation requires a robust assessment of the arising threats and opportunities. This paper presents an approach developed to investigate effects of climate drivers on Greek aquaculture, a representative Mediterranean country with a lead...
Finfish aquaculture in the Mediterranean Sea faces increasing challenges due to climate change while potential adaptation requires a robust assessment of the arising threats and opportunities. This paper presents an approach developed to investigate effects of climate drivers on Greek aquaculture, a representative Mediterranean country with a leadi...
We compare parameter point and interval estimates based on the symmetric bounded loss function, as used in the Add-my-Pet collection on animal energetics, with the maximum likelihood method for number of surviving individuals as function of time. The aging module of Dynamic Energy Budget theory is used to generate Monte Carlo data sets. The simulat...
Mixotrophic nanoflagellates (MNF) play a key role in the carbon flux within aquatic ecosystems. They contribute significantly to primary production while, at the same time, they are important consumers of bacteria. MNF comprise a diverse assemblage with a whole range of photosynthetic and feeding potential and with various metabolic responses to en...
Population growth, and other population characteristics, have been computed and made available online for over 2000 animal species in the Add-my-Pet (AmP) collection, assuming constant food and temperature environments. The AmP collection – online database of Dynamic Energy Budget model parameters, implied properties and referenced underlying data...
We propose an extension of a parameter-free loss function for the estimation of Dynamic Energy Budget parameters for a set of related species that is symmetric in the role of data and predictions. The extension allows that particular parameters might vary, but not by much, among species, while the degree of variation is controlled by weight coeffic...
The abundance and grazing effect of small (< 5 μm) pigmented (PNF) and heterotrophic (HNF) nanoflagellates on prokaryotic picoplankton stock (i.e. heterotrophic bacteria (HB) and Synechococcus) were assessed during April 2016 at four stations along a longitudinal transect in the ultra-oligotrophic Eastern Mediterranean Sea and at two selected depth...
Linking organismal‐level processes to underlying suborganismal mechanisms at the molecular, cellular and organ level constitutes a major challenge for predictive ecological risk assessments. This challenge can be addressed with the simple bioenergetic models in the family of dynamic energy budget (DEB), which consist of a small number of state equa...
The effects of water temperature (15, 20 and 25 °C) on the stress response of European sea bass, Dicentrarchus labrax, were studied. Blood and water samples were collected prior and at 0.5, 1, 2, 4 and 8 h post-stress for hormonal and biochemical analysis. Water temperature affected the resting concentrations of all stress indicators examined, as w...
Extracellular release of dissolved organic matter (DOM) by phytoplankton is a significant process that drives the microbial loop, providing energy and nutrients to bacteria. A model based on Dynamic Energy Budget (DEB) theory is proposed for describing DOM release by phytoplankton under nitrogen-replete and nitrogen-limiting conditions. The model a...
Dynamic Energy Budget (DEB) theory constitutes a coherent set of universal biological processes that have been used as building blocks for modeling biological systems over the last 40 years in many applied disciplines. In the context of extracting parameters for DEB models from data, we discuss the methodology of fitting multiple models, which shar...
A working group at the National Institute for Mathematical and Biological Synthesis (NIMBioS) explored the feasibility of integrating two complementary approaches relevant to ecological risk assessment. Adverse outcome pathway (AOP) models provide “bottom‐up” mechanisms to predict specific toxicological effects that could impact an individual's abi...
Reserve capacity quantifies the ability of an animal to smooth out fluctuations in food availability. It is defined as the maximum reserve density, and can be quantified through the application of the Dynamic Energy Budget (DEB) theory. In this study, we analyze inter-specific patterns in DEB parameters of 1041 animal species, focusing on those tha...
We developed new methods for parameter estimation-in-context and, with the help of 125 authors, built the AmP (Add-my-Pet) database of Dynamic Energy Budget (DEB) models, parameters and referenced underlying data for animals, where each species constitutes one database entry. The combination of DEB parameters covers all aspects of energetics throug...
The framework provided by the Dynamic Energy Budget (DEB) theory allows the quantification of metabolic processes and the associated biological rates that are of interest for aquaculture, such as growth and feeding. The DEB parameters were estimated for farmed European sea bass (Dicentrarchus labrax), a species of major importance for the Mediterra...
Traditionally, the terms altricial and precocial are used to described the state at birth of birds and mammals. We suggest an explanation for why birds evolved from precocial to altricial and mammals from altricial to precocial. However, the concept is not confined to these groups alone and is an important pattern underlying all animal metabolism....
Body size is not an independent variable, but an emergent property: the result of a number of inter-linked eco-physiological processes, like most other quantities that we can measure on organisms. Organisms do not have a particular body size. They are born small and grow to larger sizes during their life trajectory, while changing properties during...
Ecological risk assessment quantifies the likelihood of undesirable impacts of stressors, primarily at high levels of biological organization. Data used to inform ecological risk assessments come primarily from tests on individual organisms or from suborganismal studies, indicating a disconnect between primary data and protection goals. We know how...
Extracellular release of dissolved organic matter (DOM) by phytoplankton is a significant process that drives the microbial loop, providing energy and nutrients to bacteria. In this paper, a dynamic energy budget model is proposed for describing DOM release by phytoplankton under nitrogen and phosphorus limiting conditions. The model allows for the...
The recent finding that the Greenland shark, Somniosus microcephalus, reaches a life-span of almost 4 centuries and attains sexual maturity around 1.5 centuries, made us wonder what metabolic differences were responsible for these seemingly extreme values, compared to the related and better known spurdog Squalus acanthias. We studied this in the co...
Purpose
Web-based courses are a practical way to engage in meaningful discussions with learners from a diverse set of communities. By gathering online to learn about a topic, learners can form communities that transcend geographic and political boundaries. This paper aims to investigate a partnership between the University of Wisconsin-Madison (UW...
The effects of rearing volume on on-growing European sea bass performance and stress parameters were investigated for the first time in a pilot aquaculture farm. Fish were held under the same initial stocking densities in triplicate net-pen cages of different sizes (1.4, 45 and 252 m3) for a period of 8 months. Results showed significant difference...
The effects of different tank volumes (2000, 500 and 40 l) on European sea bass Dicentrarchus labrax larval rearing, relating to growth, survival, quality and stress variables, were investigated. A dynamic energy budget (DEB) model was used to analyse the results. The hydrodynamics of the tanks exhibited differences, with the water currents in the...
Larval stages are considered the most critical of fish development. During a very short period of time (2 to 3 months), larvae undergo major morphoanatomical and functional changes in order to transform into juveniles while remaining functioning (developing, eating, surviving). Depending on species and environmental conditions, patterns in larval d...
Organisms adopt different sets of physiological, behavioural and morphological trade-offs in order to cope with natural environmental fluctuations. This has consequential rebounds on ecological processes and population dynamics. Such aspects become crucial for sex-dimorphic species, where sex-specific growth variation could mirror different tactics...
The standard Dynamic Energy Budget (DEB) model assumes that food is converted to reserve and a fraction κ of mobilised reserve of an individual is allocated to somatic maintenance plus growth, while the rest is allocated to maturity maintenance plus maturation (in embryos and juveniles) or reproduction (in adults). The add_my_pet collection of over...
The standard Dynamic Energy Budget (DEB) model assumes that a fraction κ of mobilised reserve is allocated to somatic maintenance plus growth, while the rest is allocated to maturity maintenance plus maturation (in embryos and juveniles) or reproduction (in adults). All DEB parameters have been estimated for 276 animal species from most large phyla...
The eco-physiology of taxa in an evolutionary context can best be studied by comparison of parameter values of the energy budget that accounts for the inter-relationships of all endpoints of energy allocation. To this end, the parameters of the standard Dynamic Energy Budget (DEB) model have been estimated for 64 fish species from all 5 fish classe...
European sea bass, Dicentrarchus labrax L., groups reared under different conditions during larval stages (mesocosm and intensive rearing) were monitored during on-growing in sea cages until marketable size (350–400 g). Four caged groups were followed for a period of 17 months each at a pilot scale farm, where vertical distribution behaviour was mo...
An integrated cell-based dynamic mathematical model that take into account the role of the photon absorbing process, the partition of excitation energy, and the photoinactivation and repair of photosynthetic units, under variable light and dissolved inorganic carbon (DIC) availability is proposed. The modeling of the photon energy absorption and th...
The covariation method for estimating the parameters of the standard Dynamic Energy Budget (DEB) model provides a single-step method of accessing all the core DEB parameters from commonly available empirical data. In this study, we assess the robustness of this parameter estimation procedure and analyse the role of pseudo-data using elasticity coef...
The standard Dynamic Energy Budget (deb) model assumes that assimilates of an isomorphic individual are first added to reserve, a fraction κ of mobilised reserve is allocated to soma (somatic maintenance plus growth of structure), and therest to maturity maintenance and maturation or reproduction. Food, reserve and structure have constant chemical...
Accurate prediction of species distributions based on sampling and environmental data is essential for further scientific
analysis, such as stock assessment, detection of abundance fluctuation due to climate change or overexploitation, and to underpin
management and legislation processes. The evolution of computer science and statistics has allowed...
The accurate representation of species distribution derived from sampled data is essential for management purposes and to underpin population modelling. Additionally, the prediction of species distribution for an expanded area, beyond the sampling area can reduce sampling costs. Here, several well-established and recently developed habitat modellin...
Temperature tolerance and sensitivity were examined for some North Atlantic marine species and linked to their energetics in terms of species-specific parameters described by dynamic energy budget (DEB) theory. There was a general lack of basic information on temperature tolerance and sensitivity for many species. Available data indicated that the...
Phenols represent a group of organic pollutants frequently found in many near-shore marine systems. The microbial degradation of phenols, mainly by bacteria and fungi, has been extensively studied both experimentally and theoretically, but only relatively recently the capabilities of some algae for phenols biodegradation gained interest. The biodeg...
Aim To propose a new approach to the small island effect (SIE) and a simple mathematical procedure for the estimation of its upper limit. The main feature of the SIE is that below an upper size threshold an increase of species number with increase of area in small islands is not observed.
Location Species richness patterns from different taxa and i...
Aim To test the performance of the choros model in an archipelago using two measures of environmental heterogeneity. The choros model is a simple, easy-to-use mathematical relationship which approaches species richness as a combined function of area and environmental heterogeneity.
Location The archipelago of Skyros in the central Aegean Sea (Greec...
We have developed a mathematical model based on the underlying mechanisms concerning the responses of the photosynthetic apparatus of a microalga cell which grows under constant incident light intensity and ambient CO(2) concentration. Photosynthesis involves light and carbon-fixation reactions which are mutually dependent and affect each other, bu...
An organism's feeding rate is governed by constraints imposed by processes associated with consumption. We present a general feeding model that incorporates encounter, successful pursuit, handling, and digestion in one functional representation where we treat digestion as a parallel process. The model produces type II functional response curves. Ho...
We compare the implications of determinate vs. indeterminate growth of a parthenogenetic iteroparous ectotherm at constant food density in the context of the dynamic energy budget theory, which specifies the tight links between life history traits, such as feeding, aging, growth and reproduction. We do a comparative analysis using, as measure of fi...
Aim To propose a model (the choros model) for species diversity, which embodies number of species, area and habitat diversity and mathematically unifies area per se and habitat hypotheses.
Location Species richness patterns from a broad scale of insular biotas, both from island and mainland ecosystems are analysed.
Methods Twenty‐two different data...
1. Dynamic energy budget (DEB) models describe how individuals acquire and utilize energy, and can serve as a link between different levels of biological organization.
2. We describe the formulation and testing of DEB models, and show how the dynamics of individual organisms link to molecular processes, to population dynamics, and (more tenuously)...
We formulate a Dynamic Energy Budget (DEB) model for the growth and reproduction of individual organisms based on partitioning of net production (i.e. energy acquisition rate minus maintenance rate) between growth and energy reserves. Reproduction uses energy from reserves. The model describes both feeding and non-feeding stages, and hence is appli...
We establish the existence of traveling wave solutions for a nonlinear partial differential equation that models a logistically
growing population whose movement is governed by an advective process. Conditions are presented for which traveling wave solutions
exist and for which they are stable to small semi-finite domain perturbations. The wave is...
The relationships between the dynamics of environmentally and chemically stressed populations and indicators of the effects
of the stressor are explored in a model framework. The physiologically structured population, represented by a system of McKendrick–von
Foerster hyperbolic partial differential equations, includes the dynamics of numerous indi...
The recruitment to the adult stock of a fish population is a function of both environmental conditions and the dynamics of juvenile fish cohorts. These dynamics can be quite complicated and involve the size structure of the cohort. Two types of models, i-state distribution models (e.g., partial differential equations) and i-state configuration mode...
Accurate modelling and prediction of fish spatial distributions, based on sampled data, provide essential information for management purposes and stock monitoring. This study compares current and novel modelling techniques, in order to justify their suitability and accuracy on acoustic data. Ten different Resource Selection Functions were tested, a...
Accurate techniques that are able to identify potential distributions of small pelagic fish in any spatial or temporal scale are essential tools for fisheries management purposes. Additionally, knowledge on small pelagic species distribution could be used for the proper sampling strategy designation and decision making for effective management. In...
