Maerl is an unusual type of red seaweed. It forms hard, brittle nodule shaped structures and requires sunlight to grow. 

Maerl beds are formed of a complex tangle of fragments of live and dead maerl. 


What does maerl provide? 

  • Products from nature 
  • Nursery populations and habitats 
  • Cultural services 


What does maerl do for us? 


Maerl beds provide a home, place to reproduce and a safe nursery for many species, including some rare and endangered ones. 

Many species use maerl beds to reproduce and raise their young. 

Food from wild caught fish 

Healthy maerl beds support many commercial species, ensuring a continuing supply of the fish we eat. 

Maerl beds provide valuable nursery habitat for many of the fish we eat. In Cornwall’s Fal and Helford 26% of wild caught fish use maerl habitats. 

Human happiness and wellbeing 

Clear, clean seas rich in biodiversity provide greater opportunities for recreational activities and other benefits for people’s happiness and wellbeing. 


Threats and pressures 

Declining water quality 

  • Murky water 
  • Excess nutrients 

Recreational impacts 

  • Anchoring 
  • Swing moorings 

How can we help maerl? 

  • Reduce pollution 
  • Voluntary no anchor zone
  • Advanced mooring systems