Objective:The purpose of this report is to give you an overview about my current research as part of my undergraduate thesis. The main objective of this work is to understand the hydrodynamics of Puyuhuapi fjord through the implementation of a program that adjust a model to explain the physics of the zone and be able about the influence of physical forcings in primary production. A brief description is given below. Puyuhuapi fjord and numerical model One of the largest estuarine zones on Earth is found in southern Chile. This region extend from 41 to 55◦S and from 72 to 74◦W, aproximately. Fjords in this zone has been affected by salmon aquaculture industry during the last decades, therefore, understanding how the ecosystem works becomes necessary. It is intented to understand how the hydrodynamics works in Puyuhuapi fjord, i.e., which are the physical forcings that have a major influence in estuarine circulation. Thus, research is based in the implementation of a model of the fjord. The Finite-Volume Coastal Ocean Model (FVCOM) is a three-dimensional coastal oceanic circulation model, free-surface, with finit-volume approach, triangular unstructured-grid, with complex irregular geometry and steep bottom topography. The source code is written in Fortran 90/95 and solves the momentum, continuity, temperature, salinity and density equations and is closed physically and mathematically using the Mellor and Yamada level 2.5 turbulent closure scheme for vertical mixing and the Smagorinsky turbulent closure scheme for horizontal mixing. The current research has focused in a calibration of the model and validation of the physical forcings in an idealized fjord (fig.1). At present, has been considered tides (with amplitudes of M2 and S2 tidal constituents), a freshwater input and wind (spatially uniformly distributed). Once the validation stage is completed, a mesh is constructed for Puyuhuapi fjord with data from ArcGis, in UTM coordinates. Some cases has been run with this mesh (fig.2), but in all examples it is necessary data from field campaigns. It is expected include tides with the major tidal constituents of the zone (M2 and S2); a river with monthly variations of volume discharge, temperature and salinity, and the last forcing is meteorological and will be just consider the wind (distributed spatially uniform). The model will be run for Summer and Winter, because running the full year is very expensive computationally and it is necessary to modify the source code of FVCOM. The goal to investigate how the different physical forcings works in Puyuhuapi fjord through a numerical model is to build a NPZ model to understand the biogeochemical processes and the influence of physical phenomena in primary production.FONDECYTFONDECYT