This work describes the conceptual basis of a modelling structure to simulate the growth and activities of plankton: Dynamic Resource Assimilation Modulated Activity (DRAMA). The conceptual base of DRAMA is that the physiology and behaviour of real organisms is strongly affected by their current physiological status. For example, an organism that is well fed behaves in a different way and grows faster than one that is less well fed, or is starving. In essence, an organism functions to maximise growth and reproduction through maintaining or optimising homeostasis. This document describes the conceptual basis of the model, and provides some example model outputs. Specific application of DRAMA, with their allied explanations and equations (model code) will be published separately. The history of this work lays in a series of models developed from Flynn et al. (1997), Flynn (2001) and Flynn & Mitra (2009) which have been deployed in various studies (e.g., Fasham et al. 2006; Mitra & Flynn 2010; Flynn et al. 2012; Mitra et al. 2014, 2016). Developments of the Perfect Beast
model of Flynn & Mitra (2009), targeted at describing mixoplankton (protist plankton that engage in phototrophy, osmotrophy and phagotroph - Flynn et al. 2019), such as in Leles et al. (2018, 2021) revealed the potential and also the need for developing a revised plankton model that was at once
computationally more efficient, but also a model that could provide an improved description of reality. Initial attempts lead to a model that was deployed for describing commercial algal production in bioreactors (SAPPM; Flynn 2021), and was also implemented for describing protist plankton (Schneider et al. 2021). Revisions from SAPPM, with a radical overhaul of the conceptual and mathematical basis, resulted in DRAMA. The conceptual core of DRAMA has potential to provide a common platform for describing all plankton functional types; bacteria through to mesozooplankton, as well as protist plankton including mixoplankton. DRAMA is based on concepts from medium/coarse -grain systems biology, and thus lends itself for
the development of digital twins of plankton
