Exotic creatures The rivers Wye and Usk are host to wide range of aquatic species. Some, such as Atlantic salmon and otters are iconic, household names. Others are less well known. Sea lamprey (Petromyzon marinus) are pre-historic looking creatures that enter both rivers in late spring and early summer to spawn (otherwise known as an anadromous species). They are highly protected and, like all fish species, rely on water that is free of pollution and excess sediment. Please help us to ensure the water quality in the Wye and Usk is good enough for them. By supporting the Foundation’s work you will be helping not only Sea lamprey but a broad range of aquatic flora and fauna to overcome serious threats to their existence.