Primary and secondary production

On land as well as in the sea, plants or algae are the primary producers in the food chain. They are the “solar panels” that produce plant biomass (and also oxygen) from solar energy, water, CO2, and nutrients. Along our coastlines there is light (energy) sufficient for plant production down to 20-40 m depth, dependent on water visibility. Text: ©Hartvig C. Christie Photo: ©Erling Svensen