Maerl

[10] In the British Isles maerl is composed of three species of coralline algae growing loose in beds of fragmented nodules in the sub-littoral.

The ecology of maerl habitats has received very little attention in contrast to other marine ecosystems such as kelp forests or sea grass beds.

[19] Maerl beds provide a complex habitat for a wide range of taxa[20] with a variety of niches that support high associated invertebrate and algal biodiversity.

[22] Maerl beds offer physical refuge and protection from predation as well as productive feeding grounds but are easily damaged by dredging and towed fishing gear.

[28] The slow growth of individual nodules and their accumulation in beds over a millennial timescale means that there is no possibility of maerl keeping up with dredging for this purpose.

Maerl should be considered as a non-renewable resource, and readily available alternative products (e.g., garden lime) make modern day exploitation controversial.