VENN, C.*; LENIG, J.L.; Bloomsburg University of Pennsylvania; Bloomsburg University of Pennsylvania: Unique Pattern of Barnacle Settlement Associated with the 1997-1998 ENSO

The TAO/TRITON buoy array in the tropical Pacific is a network of 77 moorings that are deployed to measure and relay environmental conditions between 8 degrees north and 8 degrees south of the equator. The purpose of the array is to monitor conditions in real time and predict the onset and severity of ENSO events. The Pacific Barnacle Project has been monitoring settlement of pedunculate barnacles on buoys of the array since 1994. Barnacles are collected annually from the moorings when the moorings are replaced. In non-ENSO years, Lepas anatifera anatifera has been virtually the only barnacle to settle on the buoys at 8N, 95W. The buoy deployed at that location in October 1996, well before the onset of ENSO, and recovered in August 1997, during a fully-developed ENSO event, was populated with Lepas anatifera striata and Lepas hillii in addition to the normally-occurring L. anatifera anatifera. These groups evidently settled in three distinct pulses of settlement, as indicated by the different size structure of each group. Sequential settlement pulses are also indicated by the attachment of L. hillii individuals to shells of L. anatifera striata, and the attachment of individuals of L. anatifera striata to the shells of L. anatifera anatifera. This pattern of sequential settlement of three different cohorts may indicate unique current patterns associated with the 1997-1998 ENSO event.