CRUISE DESCRIPTION:
2.0. OPERATIONS
SUMMARY OF ACTIVITIES:
A). Examine distribution and relative biomass of the midwater prey community
in areas of historically low and high bycatch. The midwater zone was sampled
with an Aleutian Wing Midwater Trawl into which a 20m, 1/2" stretch
mesh codend liner has been inserted prior to ship departure from Dutch
Harbor. Trawls were conducted as a diel series at three depths (0-250m;
-500m; -1000m) in two subareas. Two trendline CTD tracks were run and CTDs
were conducted at the equilibrium and end station for each trawl (Fig.
1). Trawls were conducted obliquely to depth (250m, 500m, and 1000m), with
one to two hours trawl time at depth at a vessel speed of 3kts. Vessel
speeds were increased up to 4.6 kts during. net deployment and retrieval
to reduce.bycatch from non-target depths. Trawl locations were adjusted
within the study area to take advantage of changing conditions such as
weather and density of fish sign (Fig. 2) otherwise, two to three days
were spent in each subarea allowing for a minimum of four trawls (two daylight,
two nighttime) at each depth. A total of 15 trawls were conducted throughout
the cruise. Drifters were deployed within each subarea as indicated (Fig.
3)
B) Examine distribution and feeding activity of marine mammal predators
in areas of historically low and high marine mammal densities. Marine mammal
surveys were conducted during daylight hours when the vessel was underway
(during nudwater trawl operations and between CTD stations). Observations
were conducted by one observer from the flying bridge.
C). Examine the physical mechanisms influencing the distribution of
the midwater nekton community and their predators. CTD readings were collected
along two transect lines to 1500m (or to the bottom), and at the equilibrium
point and end of each series of trawls (Fig. 1). Flourometer measurements
were taken along the same tracklines as CTDs, but the flourometer was removed
for casts deeper than 500m. The shipboard Seachest Flourometer was running
throughout the cruise. One satellite-tracked drifter was dropped at the
start of trawling on the first day of the cruise. The second and third
(color) drifter were dropped at the end of the first trawling set, and
the remaining drifter was dropped in the vicinity of trawl stations at
the end of the second series of CTDs (Fig. 3).
A standard oceanographic watch was utilized which consisted of a winch
operator, a scientific staff of three to five, and a survey tech on deck.
Operations were conducted 24 hours a day. A fishing crew assisted with
midwater trawls. A survey tech and winch operator were available for CTD
operations. The total number of trawls conducted were significantly reduced
from that originally proposed due to weather and a reduction in shiptime.
Additional adjustments were required in vessel operations as a result of
complications from drydock renovation. Nonetheless, the officers and crew
conducted operations in an exemplary fashion under ever-shifting conditions,
resulting in successful completion of this pilot study.
PROCEDURES FOR OPERATIONS:
The following operations were conducted on this cruise. The procedures
for these operations are listed in the FOCI Standard Operating Instructions
(SOI). Operations not addressed in the SOI and changes to standard procedures
are addressed below.
CTD(Water samples (SOI 2.2.1),
Midwater trawl (S012.2. 8)
Satellite tracked drifter buoy (SOI 2.2.11)
ADCP (SOI2.2.13)
EK500 monitoring (SOI 2.2.12)
Seachest and Uncontaminated Seawater (SOI 3.4)
3.0. FACILITIES AND EQUIPMENT
The following systems and their associated support services are essential
to the cruise. Sufficient consumables, back-up units, and on-site spares
and technical support must be in place to assure that operational interruptions
are minimal. All measurement instruments are expected to have current calibrations,
and all pertinent calibration information shall be included in the data
package.
3.1 Equipment and Capabilities Provided by the Ship:
Oceanographic winch with slip rings and 3-conductor cable terminated
for CTI),
Wire-angle indicator and readout for oceanographic winch,
Oceanographic winch for bongo net (and other nets when used) with slip
rings and 3-conductor cable terminated for the SeaCat,
Sea-Bird 911 plus CTD system to be used with PMEL stand (primary system)
(The underwater CTD unit should have mounts compatible with the PMEL CTD
stand),
Sea-Bird 911 plus CTD system with stand (back up system),
Sea-Bird SBE-19 SeaCat system (primary system) (Each CTD system should
include underwater CTD, weights, and pinger and there should be one deck
unit and tape recorder for the two systems),
10-liter sampling bottles for use with rosette (10 plus 4 spares),
For CTD field corrections:
IAPSO water and AUTOSAL salinometer,
Wire speed indicators and readout for quarterdeck,
Rowe and Marco winches,
For meteorological observations:
2 anemometers (one R. M. Young system interfaced to the SCS),
calibrated air thermometer (wet-and dry-bulb) and a calibrated barometer
and/or barograph,
Freezer space for storage of biological and chemical samples (blast
and storage freezers),
Simrad EQ-50 echo sounder,
JRC JFV-20OR color sounder recorder,
RDI ADCP written to SCS and Iomega Zip drives,
Bench space in DataPlot for PCS,
monitor, printer and VCR to fly MOCNESS,
Use of Pentium PC in DataPlot for data analysis,
SCS (Shipboard Computer System),
Aft Rowe winch,
Electrical connection between Rowe winch and DataPlot,
Laboratory space with exhaust hood, sink, lab tables and storage space,
Sea-water hoses and nozzles to wash nets (quarterdeck and aft deck),
Adequate deck lighting for night-time operations,
Navigational equipment including GPS and radar,
Safety harnesses for working on quarterdeck and fantail,
NOTE: Stern platform was removed and stored prior to departure as requested.
3.2 Equipment Provided by the Project:
PMEL PC with SeaCat and SEASOFT software for CTD data collection and
processing,
Fluorometer to be mounted on CTD,
CTD stand modified for attachment of fluorometer,
Conductivity and temperature sensor package to provide dual sensors
on the primary CT, and one for the backup system,
CTD rosette sampler,
60-cm bongo sampling arrays,
20-cm bongo arrays,
WestMar (third wire),
Two MBTs (bathythermographs),
Two Aleutian Wing Midwater Trawls (AWT),
Two AWT codend liners (2" stretch)
Fishbuster doors (2750 lbs)
Argos tracked drifter buoys with optical sensors,
EK500 monitoring system,
Miscellaneous scientific sampling and processing equipment, Sorting
tables and baskets for processing trawl catches,
Discrete Sample DataBase forms
3.3. Ship's Computer System (SCS)
The ship's Scientific Computer System (SCS) operated throughout the
cruise, acquiring and logging data from navigation, meteorological, oceanographic,
and fisheries sensors. See FOCI Standard Operating Instructions for specific
requirements. The ship uses the NT version of SCS. The VAX was available
for data processing. An upgraded version of the NT SCS software was installed
on the transit to Ketchikan in April. Contact CST Wm. Floering for further
information.
4.0 DATA AND REPORTS
Biological samples are in freezer storage aboard the Miller Freeman
and will be offloaded and analyzed when the vessel returns to Seattle in
October. Preliminary data has been organized in a format compatible with
the public fisheries database at the Alaska Fisheries Science Center. A
cruise description with preliminary cruise results is currently being prepared
for posting on the PMEL/FOCI Bering Sea webpage. .
Milestones:
1999 April - May Shipboard - data collection
October Summary of preliminary analysis of: drifter data, trawl samples,
marine mammal observations
2000 October Synthesis and publication of results from 1998 retrospective
studies and 1999 field studies
5.0 ADDITIONAL INVESTIGATIONS AND PROJECTS
5.3 Piggyback projects:
There were no formal piggyback projects however, 18 bongoes were conducted
for Art Kendall (FOCI) in conjunction with CTD transects.
6.0 MISCELLANEOUS
6.5. Hazardous Materials:
The Chief Scientist was for complying with NC Instruction 6280A, Hazardous
Waste; policy, guidance, and training, dated February 4, 1991, paragraph
7.g and paragraph 9. By federal law, the ship may not sail without a complete
inventory of MSDS, and appropriate neutralizing agents, buffers, and/or
absorbents in amounts adequate to address spills of a size equal to the
amount aboard.
The following hazardous materials were provided and controlled by the
scientists with the Chief Scientist assuming responsibility for the safe
handling of such substances:
Hazardous Materials:
Buffered Formalin
Isopropyl Alcohol
Additions to FOCI/AFSC chemical manifest -- none
8.0 APPENDICES
Figure 1.-- CTD sample locations. Marine mammal/bird
observations, were at cruising speed in tracklines between CTD stations.
Figure 2.--Midwater trawls were conducted within
three depth categories (0-250m; 250- 500m; and 500 -1000m) at the two primary
sampling locations near Unimak Pass and Bogoslof Island.
Figure 3.-- Drifter activity as of 7/15/99.
