Sea lamprey found in the northern and western Atlantic Ocean along the shores of Europe and North America, in the western Mediterranean Sea, the Black Sea, and in the shores of the Great Lakes. They have been found at depths to 4000 m and tolerate temperatures between 1.0 and 20 °C. The largest European populations of sea lampreys are located throughout the south-western areas of Europe (north-central Portugal, north-northwest of Spain, and west–south-west of France). These countries also support the main fisheries of the species. Sea lampreys are anadromous. From their lake or sea habitats, they migrate up rivers to spawn (followed
Europe Cyprus and the Transcaucasian countries. A century ago, Europe had nearly a quarter of the world's population. The population of Europe has grown in the past century, but in other areas of the world (in particular Africa and Asia) the population has grown far more quickly. Among the continents, Europe has a relatively high population density, second only to Asia. Most of Europe is in a mode of Sub-replacement fertility, which means that each new(-born) generation is being less populous than the older. The most densely populated country in Europe (and in the world) is the microstate of Monaco. Pan