Biomass Variation Phytoplanktons Using Agent-Based Simulation

2004

Coastal lagoons ecosystems are very complex to model and its global behaviour it’s hard to simulate. This com-plexity is even greater if the simulation model includes the intelligent entities like decision-makers involved in the system. Typical ecological simulations include only models of entities that have a very easy to predict behav-iour (using mathematical equations and/or simple logical rules). However, in real ecological systems, man is heavily involved and his decisions are not based on fixed mathematical equations or simples rules but con-trarily they are based on an in-depth analysis of the environment using his knowledge. This paper introduces an approach to intelligent ecological systems simulation using the agent-based approach. Intelligent entities are modelled as agents that have perception of their envi-ronment, reason using their knowledge and are able to change the simulated environment by using a given set of configurable actions.

Austral Ecology, 2003

Lagoon is a computer simulation aimed at allowing users to investigate the principles controlling equilibria in complex systems by carrying out virtual experiments. This conceptual tool was developed to provide students with an interactive learning experience that demonstrates the importance of complexity in ecosystems. The simulation represents a 'coastal embayment or estuary' governed by biological dynamic equilibria. Users can manipulate the model parameters to explore eutrophication, competition for limiting nutrients, predator-prey relationships, and food chains. Well, so much for the synopsis. A PDF manual on the CD-ROM describes how Lagoon can be used. The software is easy to install, and has modest system requirements (minimum: Windows 95, Pentium 100 MHz, 16 MB RAM, CD-ROM drive 4 ϫ). The program interface is colourful, pleasing to the eye, and user-friendly. The software is largely mouse driven, with controls consisting of buttons and scroll bars, and pop-up menus giving descriptions of the controls. For someone with a childhood love and professional interest in the tidal parts of estuaries, but currently dryfooted research-wise, the opportunity to review this program provided a most pleasant diversion. In this regard though, the name Lagoon is deceptive. The program consists of a relatively simple closed system that more closely resembles a coastal embayment than an estuary, with parameterization of riverine inflow (and equivalent oceanic outflow) rate, but no parameterization of tidal fluxes or salinity. Two types of physical variables can be altered: (i) the rate of oxygen transfer from the atmosphere; and (ii) the rate and concentration of nitrate inflow. The presence and growth of each of a range of organisms is governed by Michaelis-Menten kinetics and can be manipulated by changing: (i) their maximum resource uptake (or growth) rate and half saturation constant; (ii) the efficiency of conversion of resources consumed into biomass; and (iii) the background biomass loss (or death) rate. The organisms, forming a linear food chain, consist of primary producers (green algae), grazers (zooplankton eats green algae), carnivores (shark eats fish eats krill eats zooplankton), and decomposers (bacteria regenerate nitrogen). Competition between green algae and blue-green algae can also be simulated.

Progress in Oceanography, 2006

Realistic modelling of marine ecosystems is necessary for improving our understanding of the ocean's biogeochemical state and for predicting their response to anthropic perturbations. An essential step in achieving this task is the use of mechanistic formulations to describe the biogeochemical processes involved in the dynamics of marine pelagic ecosystems. This study provides a review on some modelling strategies for some of the key processes involved in the dynamics of phytoplankton. It encompasses the most advanced work in terms of mechanistic understanding and, therefore, mainly deals with photosynthesis (including photoacclimation and photoinhibition), respiration, and nutrient uptake (including multilimitation of algal growth by nutrients). We highlight, that in many ecosystem models, phytoplankton processes are still described more or less empirically, mainly due to a lack of biochemical knowledge, or if a mechanistic formulation exists, the parameters are often difficult to assess experimentally. As a result of this investigation, a preliminary structure for a generic phytoplankton model is delivered in the last section of this paper. This model includes a mechanistic representation of photosynthesis/photoinhibition based on photosystem II status, as well as new formulations for photoacclimation and dissolved organic matter exudation processes. The model sensitivity analysis with regard to its parameters and a comparison with chemostat experimental data are presented in a companion paper . Investigation and sensitivity analysis of a mechanistic phytoplankton model implemented in a new modular numerical tool (Eco3M) dedicated to biogeochemical modelling. Progress in Oceanography]. Finally, this new class of multi-element, multi-species phytoplankton models will provide the basis for future studies on ecosystem modelling.

Freshwater Reviews, 2010

Twenty years after model equations describing the in situ growth rates of phytoplankton were first devised and eight since their successful incorporation into a computer simulation was first published, we set out to affirm the general validity and utility of PROTECH (Phytoplankton

Agent-Based Simulation, 2004

Management and operation of reservoirs require knowledge of cause–effect relationships which influence water quality. In this work, spatial and temporal patterns of phytoplankton in the Tucuruí reservoir, Pará State, Brazil, were studied by following a computer modeling approach. A water quality model was coupled to a 3-D hydrodynamic model. Simulations were carried out in low and high rainfall periods, by using MOHID, a process-oriented modeling system. Modeling results were compared to field data over a 1-year period (1 July 2010–1 July 2011). Field data included water and air temperature, wind, relative humidity, radiation, cloud cover, nitrate, ammonia, phosphorus, and dissolved oxygen. Water flow data were used at the reservoir's inlet and outlet as forcings for simulations. The results indicated that Tucuruí reservoir is a phosphorus limited system, and that phytoplankton growth is limited by hydrodynamics, due to the different nutrients load in low and high rainfall periods over the year. Moreover, modeling results showed that the chlorophyll a is a key factor to define the system's trophic status, since the nutrients may be in excess in the system and can trigger algal blooms. The model enabled a comprehensive understanding of system for developing the best management policy for algal blooms in Tucuruí reservoir.

Limnology and Oceanography, 1975

of phytoplankton growth dynamics and nutrient assimilation by a computer simulation model are consistent with studies of field and laboratory populations. The model simulates population dynamics and gross physiology of phytoplankton species in

INTEGRANTES TORRES JESUS C.I.:16.755.466 OBISPO LUIS C.I.:17993622 Punto Fijo; mayo 2011

Vimarśana; Journal of Junior Staff Development Programme, FSS, 2021 ISSN 2806-5077iii

Greek civilization holds paramount importance in the history of civilized man. Greek pottery is one of the most important resources in examining the significance of Greek civilization as they reveal many important pieces of evidence which help to gather important facts about Greek culture, art and human society. The main objective of this study is to examine the important facts about classical Greek society depicted in ancient Greek pottery. Greece is the birthplace of Western Civilization. Therefore, an important tool for archaeologists and historians in determining the chronology of ancient Greece. The study is based on secondary data collected from different reliable sources of published books, journals, reports and websites, the study was conducted under the qualitative research method based on textual studies. Pottery is a valuable archaeological resource in exploring the history of mankind and also a cultural expression that depicts hidden facts of a civilization. On the other hand, pottery is considered an example of the characteristic of the artistic movement in civilization. Ancient Greeks had given a respectable value to making pottery & pottery Paintings. Black-figure pottery, red-figure pottery and white pottery are the main types of pottery that we found from the Greek civilization and they contain remarkable evidence of the contemporary mythical beliefs and cults. These Greek pottery Paintings express various social activities and social movements in Greek society. In conclusion, then, We can say that through the study of ancient Greek pottery we can examine the Technology, values and social activities in ancient Greek society, which had contributed much to the Technology, art, philosophy, medicine, logic and science of the world civilization.