= 2 Introductory material: Ecopath = This chapter contains details of the theory underpinning the functioning of Ecopath: [EwEugMortalityForaPreyIsConsumptionForaPredator Mortality for a prey is consumption for a predator]; [EwEugTheEnergyBalanceOfaBox The energy balance of a box]; [EwEugOnTheNeedForInputParameters On the need for input parameters]; [EwEugDefiningTheSystem Defining the system]; [EwEugDealingWithOpenSystemProblems Dealing with open system problems]; [EwEugProduction Production]; [EwEugConsumption Consumption]; [EwEugOtherMortality Other mortality]; and [EwEugRepresentationOfMultiStanzaLifeHistoriesInEcopathEcoSimAndEcospace Representation of multi-stanza life histories]. See Ecopath inputs and [EwEugEcopathInputs#a6UsingEcopath.Part1:Ecopathinputs Ecopath outputs] for links to instructions for using Ecosim.