Scientific Reports
Scientific Reports
X-Sender: ksmith@popmail.ucsd.edu
Date: Tue, 29 Dec 1998 13:35:58 -0800
To: shipsked@ucsd.edu
From: Ken Smith <ksmith@ucsd.edu>
Subject: Weekly Report - New Horizon
Weekly Science Report: R/V New Horizon
Station M , located 220 km west of Point Conception, is a long time-series
abyssal site (4100 m depth) we have occupied for the past nine years to
study the cycling of carbon primarily in the benthic boundary layer. This
cruise marked the end of this time-series study and the weather was
inhospitable as usual with winds gusting to 45 knots and swells up to 20
feet. Now well accustomed to such sea conditions at this station, we made
the last free vehicle deployments and recoveries in knee deep waters
crashing over the deck while holding on to any available permanent
structure for safety. Large volume water samples were taken from the
surface to abyssal depths for analysis of uranium-daughter isotopes by Dr.
Shaw (U. South Carolina). A long-term mooring of sediment traps was
recovered and the samples of sinking particulate matter collected at 600
and 50 m above bottom will be processed for carbon and other chemical
constituents for comparison with our previous time-series results over the
past 9 years. Hourly photographs of the sea floor taken with a time-lapse
camera will provide us with a record of changes at the sediment-water
interface for comparison with similar monitoring over the past 9 years. A
free-vehicle grab respirometer was deployed to measure sediment community
oxygen consumption as an estimate of the organic carbon consumed by the
sediment community. Grenadier fish, apex predators in the benthic boundary
layer, were caught on free-vehicle set lines and will be analyzed
biochemically to detect temporal changes in their energetic state. With
great sadness, we leave behind this station with its inclement weather for
the last time after 36 cruises spanning almost a decade. The Captain, crew
and Resident Technician did an outstanding job supporting our scientific
program, making this last cruise a total success. Our homeward journey is
blessed by a strong tailwind and quartering swell which previously plagued
us while on station.
Ken Smith
This cruise is being funded by a grant from the National Science Foundation.
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