In situ practice collector

An in situ benthic particle collector has been developed and constructed. The ultimate use of the collector is to provide seasonal rates for the input of particulates to the oceanic benthic enivronment. We plan to test the hypothesis that rapid, down-slope run-off of suspended organic-rich continental shelf sediments and offshore transport of organic detrital particles derived from the coastal upwelling ecosystem off Oregon provide the food source for the highly abundant slope-base benthic fauna. The particle collection system consists of three basic parts: 1) the particle collector with the capacity of three 4.5 m 2 collecting surfaces that sequentially roll up for storage, 2) duplicate electronically-timed explosive releases with anchor, and 3) the subsurface flotation unit with radio beacon, flashing stobe light, and radar reflector. The particle collector is designed to remain moored just above the sea floor for up to three months. During this time, three sequential samples can be collected. Exposure times are equal for each of the sample surfaces; however, the duration of the sample exposure period is easily adjusted from hours to months.