This second part of the Marine Strategy for the Netherlands, covering the period 2020-2026, provides for updating the monitoring programme, adopted in compliance with the provisions of the European Marine Strategy Framework Directive. This Marine Strategy defines the area and the waters of its application, including coastal waters, seabed and the subsoil on the seaward side of the baseline from which the extent of territorial waters is measured. The Strategy concerns the elaboration of criteria and indicators determining the status, the function and the processes of the marine ecosystem and the human activities resulting in disturbances of the marine ecosystem: biodiversity; demographic characteristics of marine mammals, birds, fish and cephalopods; distribution of habitats; introduction of alien species; commercial exploitation of fish species; sea floor integrity and extent of its physical loss; food webs and food chains; contaminants and pollutants in water, and their effects on the marine species; plastic in marine animals.
Concerning the monitoring programme, the Strategy provides for evaluating the environmental targets defined for each descriptor and indicator, summarising the requirements explained in the Marine Strategy Part I, the national and international benchmarks used, the monitoring survey adopted, and describing the proper assessment method for each indicator. Particularly, the assessment of marine food chain focuses on: the long-term abundance of the fish species and the retention of their full reproductive capacity; the size structure measured in relation to the fish community; determination of pelagic and demersal fish; eutrophication and its adverse effects, including: losses in biodiversity, ecosystem degradation, harmful algae blooms and oxygen deficiency in bottom waters; concentration of nutrients in coastal and offshore waters.