Umeå Marine Sciences Centre (UMF) is a research centre at Umeå University, organised under the Faculty of Science and Technology and situated in Norrbyn, 40 kilometres south of Umeå. UMF supports marine research and education, and performs environmental analysis on commission of swedish environmental monitoring. We also provide information about research and environmental status, with a particular focus on the Gulf of Bothnia. One of the two mesocosm facilities at UMSC consists of 12 indoor cylindrical mesocosms with water columns 4.86m high and 74cm in diameter. The temperature is controlled at three different sections on each mesocosm. This means that they can be used in projects that require thermoclines or convective stirring, or even both simultaneously. The rate of convective stirring can be controlled.Methal halogen lamps of 150W are used as light sources. Equipment is available to allow for studies that require intact sediment at the bottom of each mesocosm. This includes a semi-automatic sediment sampler. The intake water can either be pumped in directly from the sea, or transported from elsewhere. There is equipment to filter the intake water down to 1 micron.There are also a facility that consist of 24 outdoor mesocosms. These are cubic and carry 946 liters each. The mesocosms are placed in four different pools with running, temperature controlled water. A plastic light-dispersing roof is placed over the pools and mesocosms. Both mesocosm facilities are open to the scientific community.