Guidelines for sampling and determination of total phosphorus.

Abstract

While determination of dissolved phosphate gives information on the bioavailable pool of phosphorus, an assessment of the total amount of phosphorus is also essential. Total phosphorus includes all organic and inorganic forms of phosphorus present in seawater, particulate as well as dissolved. The dissolved organic phosphorus is also partly bioavailable, mainly when phosphate is exhausted. Also the particulate fraction can be used in part. 1.2 Purpose and aims Monitoring of nutrients in seawater is carried out to identify and quantify the amount of nutrients, which may cause eutrophication. The aim is to provide spatiotemporal information for detection of short-term status and long-term trends and to ensure that the data is comparable for the HELCOM core indicator ‘Dissolved inorganic phosphorus‘. The indicator description, including its monitoring requirements, is given in the HELCOM core indicator web site: http://helcom.fi/baltic-sea-trends/indicators/phosphorus-dip.