It might be rock hard, and look like tiny
knobbly stag’s antlers, but common maerl is actually a red seaweed
with a hard, chalky skeleton.
Unlike many other seaweeds, common maerl
does not need a hard surface to attach to, and so it can be found
across a variety of seascapes, from mud to sand and pebbles.
However, in common with all seaweeds, it needs sunlight to grow,
and so is usually only found in shallow water (above 10m depth) or
down as deep as light allows. Normally mauvish brown in colour, its
surface can be either smooth or flaky.
The live plants usually grow lying on top of
layers of dead maerl to form maerl beds. These beds are very
important for other marine creatures, which hide in amongst the
maerl, or use it as a hard surface on which to settle and grow.
Maerl is at risk from scallop dredging and other mobile fishing
gears, as well as from pollution.
Common maerl is recorded from the south and west coasts of
England, but is more abundant around the coasts of Scotland and
Ireland. It is the most widespread maerl species in Europe
and is found from Norway and Denmark in the north to Portugal in
the south, and into the Mediterranean Sea and in the Aegean.
- This is a UK BAP Priority Species (BAP
species are now Species of Principal Importance/Priority
- Species of principal importance for the purpose of conservation
of biodiversity under the Natural Environment and Rural Communities
- Listed on Annex V of the Habitats Directive
- Maerl beds are a UK BAP Priority Habitat and are listed in
Annex I of the Habitats Directive as a sub-feature of sandbanks and
on the OSPAR List of Threatened and/or Declining Species and
Life Information Network
JNCC - UK BAP Priority
Species and Habitats