Hydromerd is a semi-enclosed pen system that has multiple areas of application. First and foremost, it is designed to be used as a holding pen. The pen is made from a composite material comprised of multiaxial fibreglass and thermoset plastic. It comes with ballast tanks that enable the pen’s entire volume to be raised above the surface of the water, which means it can be air dried and is simple to clean. Hydromerd reduces or eliminates the need for direct delivery by a fish carrier and therefore also the associated costs. The pen can be installed as a standalone unit or be integrated and anchored in an existing steel facility.