The role of the SW Atlantic burrowing crab in sequestering debris

O. IRIBARNE,; BOTTO, F; MARTINETTO P; GUTIERREZ, J.

MARINE POLLUTION BULLETIN

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2000 vol. 40 p. 1057 - 1062

0025-326X

The burrowing crab Chasmagnathus granulata is the most abundant macroinvertebrate on intertidal mud¯ats and salt marshes of the South Western Atlantic. This species excavates and maintains large semi permanent open bur- rows with a mouth opening that may reach 20 cm in di- ameter and a volume of up to 2 l. Areas populated by crabs retain a signi®cantly larger amount of debris (mainly plastics) on the surface and have larger amounts of buried debris in the sediment than areas without crabs. Field experiments showed that due to their hydrodynamic characteristics, burrows in the mud¯ats work as passive traps for debris enhancing their retention. Given the ex- tensive intertidal area inhabited by this species in SW Atlantic estuaries, crab bed areas should be considered as large areas that retain debris burying it in the soft bottom environment.