B. Deployment of time- series sediment traps placed at 500 m and 50 m above the bottom on 

 the deep slope/rise moorings. Traps would be programmed to sample biweekly and would be 

 recovered and redeployed every 6 months. 



METHODS AND PLATFORMS 



A. Cruise-conducted, ROV (or submersible)-based, seasonal in-situ marine aggregate 

 measurements (size, sinking rates, etc.), and collections. Vehicle-based methods of aggregate 

 surveys and collection have been successfully developed and tested using an ROV off of 

 California from 1991-1993. 



B. Time-series particulate mass and POC fluxes will be obtained using high-resolution 

 time-series sediment traps (McLane Research Labs., Inc. MARK VI or VII traps) deployed on 

 subsurface, taunt-line moorings. The P.I. has had many years of experience with these trap 

 systems. 



STRENGTHS AND LIMITATIONS OF PROPOSED RESEARCH 



Strengths: Submersible vehicle-based aggregate measurements allow for the assessment of 

 horizontal as well as vertical variability in various aggregate parameters; also provides the 

 opportunity to collect marine aggregates in-situ. The time-series sediment traps represent the 

 "state of the art" as well as the recognized standard method for obtaining high-resolution 

 temporal data sets of POC fluxes. 



Limitations: The relatively high cost of conducting vehicle-based studies (due to vehicle leasing 

 and pilot fees) may limit the extent to which we will be able to provide in-situ aggregate data 

 sets throughout the study region. Key sites and/or transects for the vehicle-based aggregate 

 measurements may have to be selected depending upon where ship-board measurements of DOM, 

 POM and pC0 2 are concentrated, in addition to obtaining aggregate data sets from near the trap 

 mooring localities. The time-series sediment traps cannot be deployed in the shallow upper shelf 

 region due to the potential biasing of the particulate sampling by relatively high horizontal 

 velocities and resuspension activity in the shelf environment, as compared with the deep 

 slope/rise. 



STATUS OF RESEARCH 



A new ROV-based instrumentation for measuring aggregate size, abundance, and in-situ 

 sinking rates has been successfully developed and tested, with the final analyses to be completed 

 by spring- summer, 1995. Time-series aggregate size and abundance data sets and in-situ 



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