The rocky intertidal plankton trap RIPT2: A modified device

Abstract The paper describes a modification (RIPT2) of an earlier described, passive Rocky Intertidal Plankton Trap (RIPT1) to be used in exposed rocky shores. The trap is light, simple to build, easy to install, and inexpensive. It aims to evaluate and integrate over time the mero- and holoplankton arriving to the rocky shore. A set of 3 RIPT2 and 3 RIPT1 traps were tested, over a period of 3 days, on an exposed horizontal rocky platform at El Eden, Antofagasta, Chile. RIPT-flowmeters permitted an approximation of the rate of water filtering, which was about 3 times greater (ranging from 1.48 to 1.69 m3 24 h−1) through the RIPT2 trap than the RIPT1 trap. Maximum water velocities on the intertidal platforms, determined with the use of an intertidal dynamometer, ranged between 1.64 and 3.28 m s−1. The RIPTs collected a total of 21–22 major plankton items belonging to 7–8 phyla. The individuals ranged between approximately 100 µm (bivalve larvae) and 2720 µm (Isopoda). The cumulative (over 72 h) number of p...