In the 1976-1986 period Branchiostoma lanceolatum was widely spread outside the near-coastal zone and reached densities of 600 ind./m2 maximally in that area. In the 1994-2001 period the distribution of the species was remarkably more limited and lower densities were observed: B. lanceolatum was exclusively found near the Hinder Banks in densities of maximum 120 ind./m2.