Thanks to Capt. Lawrence Bearse and the crew of R/V OCEANUS for helping us conduct the fourth safe and successful BroadScale Survey of 1998. The cruise offered few challenges because the ship was in good shape and was professionally operated. We had good weather, for which we are also grateful.
This report was prepared by Charles Miller, David Mountain, John Sibunka, Rebecca Jones, David Townsend, Amanda Hallbergh and James Brien. The entire scientific party contributed consistent work toward timely completion of the cruise, including an extra station. The chief scientist and PI's extend our thanks.
Oc322 was sponsored by the National Science Foundation and the National Oceanographic and Atmospheric Administration.
TABLE OF CONTENTS
Table of Contents 2
Trackline of Oc322 (Figure 1) 2
Brief Narrative 3
Personnel on Oceanus-322 4
Hydrographic Report - D. Mountain and C. Bascunan 5
Zooplankton and Ichthyoplankton Studies - J. Sibunka et al. 16
Summary of Zooplankton Findings - C. Miller 19
Summary of Ichthyoplankton Findings - R. Jones and J. Sibunka 20
Larval Fish Distributions - J. Sibunka and D. Mountain 21
Microzooplankton Analysis - A. Hallbergh and J. Brien 25
Summary of MOC-10 Samples - S. Brownell 26
Nutrient and Phytoplankton Studies - D. Townsend 29
Event Log - J. Sibunka and J. Gibson 37
Figure 1. Trackline of Oc322 showing Standard Station Numbers.
Our objective was the fourth running for 1998 of the Georges Bank BroadScale Survey. The survey aims to find the patterns and movement of developing Cod and Haddock larvae around and over Georges Bank throughout their development period in winter and spring. We also examine the distribution and changing stage distribution of food species for those larvae, specifically Calanus finmarchicus and Pseudocalanus spp. These four animals are the target species of the entire Georges Bank Program. The plankton data, principally from net tows, are supplemented with hydrographic (CTD), ADCP and chlorophyll distribution data. Specialized studies were also carried out on Oc322 of gonad development in late stage Calanus with the object of determining their life history direction and on microzooplankton abundance and distribution. We deployed three Lagrangian drifters.
The cruise track (Fig. 1) took us to the 41 standard and 40 intermediate (bongo only) stations of the BroadScale survey grid. On this cruise we did not do along track acoustic surveying. All stations were completed according to their standard assignment as "full" or "partial" stations, except that one MOC-10 haul had to be dropped due to large waves at the eastern end of the bank.
We departed Woods Hole at 1655 on 15 April. A delay from the desired morning departure was necessitated by late delivery from General Oceanics of a CTD after repair. The delay provided time to complete safety instruction and preliminary scientific meetings before sailing. The initial weather was good. The route chosen by Captain Bearse to Station 1 was around Martha's Vineyard to the west, then east south of Nantucket Shoal. We began work on Station 1 at 0400. From that point watches were kept: Group 1 ("Day"), John Sibunka leader - 0800 to 1200, 1600 to 0000; Group 2 ("Night"), James Gibson leader - 1200 to 1600, 0000 to 0800). Progress through the stations was steady, except for a day of gale force between stations 40 and 31. We were secured then from 1137 hr on 23 April until 20:02 hr on 24 April. On 18 April we paused in the vicinity of Station 19 to recover a malfunctioning mooring array for James Irish.
Apart from the excitement of recovering the "Irish buoy" and the boredom of the wait for weather north of Station 40, the cruise was a standard BroadScale survey in all respects. No daily summary is necessary. At the end of the cruise we added at station in Wilkinson Basin (consecutive station no. 82) to examine (1) the vertical distribution there of the C. finmarchicus population in detail, comparing night and day to look for vertical migration, and (2) the possibility that diapausing Calanus stocks are already established at depth by late April. We returned to Woods Hole, docking at 0900 on 27 April.
PERSONNEL on Oc322
Lawrence T. Bearse Master
Anthony D. Mello Chief Mate
Emily McClure Second Mate
Jeffrey M. Stolp Boatswain
Horace M. Medeiros AB
Ronald L. Trainor AB
Colin L. Walcott OS
Richard F. Morris Chief Engineer
Kevin Kay Junior Engineer
Alberto Collasius Junior Engineer
Hugh B. Dakers Steward
Jovinol J. Fernandes, Jr. Mess Attendant
Charles B. Miller Chief Scientist - Oregon State University
David Mountain NOAA/NMFS - Woods Hole
John Sibunka NOAA/NMFS - Sandy Hook
Rebecca Jones NOAA/NMFS - Narragansett
Stephen Brownell NOAA/NMFS - Narragansett
Cristina O. Bascunan NOAA/NMFS - Woods Hole
David Nelson Univ. Rhode Island - Narragansett
James Gibson Univ. Rhode Island - Narragansett
James Pierson Univ. Rhode Island - Narragansett
Neile Mottola Univ. Rhode Island - Narragansett
David Townsend Univ. Maine - Orono
Bruce Monger Cornell University - Ithaca, NY
James Brien Falmouth, Mass
Sonke Johnson Harbor Branch Foundation
Amanda Hallbergh Undergraduate student intern
Laura Stein SSSG Technician, WHOI
HYDROGRAPHIC REPORT - By David Mountain and Cristina Bascunan
The primary hydrographic data were collected using a Neil Brown Mark V CTD instrument (MK5), with a fluorometer, a transmissometer, and a rosette for collecting water samples. In addition a Seabird Electronics Seacat model 19 CTD (SBE19 Profiler) was used on each bongo tow to provide depth, temperature and salinity information during the tow.
The MK5 was deployed with 10 bottles on the rosette and samples were collected for various investigators. On each MK5 cast, samples were to be collected for chlorophyll/nutrient analysis (see Individual Report section below), for oxygen isotope analysis by R. Houghton (LDGO) and a sample was taken at the bottom for calibrating the instrument's conductivity data. Water samples were collected for micro-zooplankton analysis for S. Gallager (WHOI) and for phytoplankton species composition for J. O'Reilly (NMFS).
The data processing was done as described in previous cruise reports. Both the MK5 and SBE19 systems worked well, with no problems in operation or apparent quality of the data.
Figure 2 shows the locations of the MK5 casts made during the bank-wide survey, identified by the consecutive cast number. The surface and bottom temperature and salinity distributions are shown in Figures 3-4. Surface and bottom anomalies of temperature and salinity, were calculated using the NMFS MARMAP hydrographic data set as a reference. The anomaly distributions are shown in figures 5-6. An index of vertical stratification (sigma-t difference between 30 meters and the surface) and its anomaly from the MARMAP reference are shown in figure 7. The distributions of surface and bottom measured fluorescence are shown in figure 8. The volume average temperature and salinity of the upper 30 meters, and the associated anomaly, were calculated for the four sub-regions of the Bank and are shown in Figure 9. Profiles of each MK5 CTD cast with a compressed listing of the preliminary data are found in Appendix C.
The property distributions (figures 3-6) indicate that the southern and eastern flanks were cooler and fresher than other parts of the Bank, suggesting the influence of water from the Scotian Shelf moving westward across the Northeast Channel directly onto the Bank. A satellite image from April 14, 1998 did indicate a tongue of cooler water extending from the Scotian Shelf along the Bank's southern flank. Overall, the Bank was somewhat warmer than normal, except along the southern flank. The salinities were lower than normal throughout the region. The development of seasonal stratification appears to have begun normally (figure 7), although the highest stratification values along the southern flank appear more associated with influx of low salinity surface water than with the initiation of a thermocline by seasonal surface warming. The highest fluorescence values were observed in the south western part of the shallow, central part of the Bank.
The low salinity conditions observed in 1996 and 1997 have continued into 1998. The surface layer temperature and salinity values for the northwest region of the Bank for all Broad Scale surveys since 1995 are shown in figure 10, with the corresponding anomalies in figure 11. The properties in the northwest region reflect the waters coming onto the Bank through the whole Gulf of Maine system, rather directly across the Northeast Channel onto the southern flank. The decrease in salinity is believed due to a greater contribution of northern waters - certainly from the Scotian Shelf and probably from as far north as Labrador - to the Gulf of Maine/Georges Bank system, i.e., a large scale advective origin. The temperature anomalies, however, follow a different pattern, with highest values in 1995 and 1998, and lowest values in 1996. These are likely associated with variability in the local surface heat flux.
The progressive shift from a warm to cold Slope Water at stations 7, 16 and 25 from January through March may be reversing, with a return to warmer Slope Water conditions. However the changes from March to April are not uniform through the water column at any of the stations, and the observations from the next cruise (May) will be needed to make a definitive statement about the duration of cold Slope Water conditions in the region.
Zooplankton and Ichthyoplankton Studies Based on Bongo and MOCNESS Tows.
by John Sibunka, James Gibson, James Pierson, Rebecca Jones, Stephen Brownell,
and Neile Mottola
(1) Principle objectives of the ichthyoplankton group in the broad-scale part of the U.S. GLOBEC Georges Bank Program were to study the composition of the larval fish community on Georges Bank, to define larval fish distribution across the Bank and within the water column, to determine those factors which influence their vertical distribution, and to determine bank-wide versus "Patch-Study" mortality and growth rates. Emphasis in this study is on cod and haddock larvae along with their predators and prey. This study also includes larval distribution and abundance, and age and growth determination. These objectives were implemented through use of bongo net and 1-m2 MOCNESS to make the zooplankton collections.
(2) The primary objective of the zooplankton group was to complete a bank-wide survey of Georges Bank to determine the distribution, abundance, and stage composition of the target species Calanus finmarchicus and Pseudocalanus spp. A second objective was to identify, quantify, and describe the occurrence of abundant non-target species in order to provide a description of the environment occupied by the target species. These objectives were implemented by using the 1-m2 MOCNESS, a vertically discrete, multiple opening and closing net system for sampling copepods and larger zooplankton, and submersible pumps for sampling the small, naupliar stages.
In addition to these objectives, the zooplankton group was responsible for obtaining
subsamples from the 1-m2 MOCNESS hauls for population genetic studies of Pseudocalanus spp. to be completed by Dr. A. Bucklin at the University of New Hampshire.
Finally, an additional 1-m2 MOCNESS tow was completed at Wilkinson Basin to collect live C. finmarchicus for Dr. William Macy at the Graduate School of Oceanography/University of Rhode Island for an ongoing herring feeding experiment and pteropods (Limacina sp) for Scott Gallager at the Woods Hole Oceanographic Institute.
Bongo tows were made with a 0.61-m frame fitted with paired 335 Ám mesh nets. A 45 kg ball was attached beneath the bongo frame to depress the sampler. Digital flow meters were suspended in the mouth of each net to determine the volume of water filtered. Tows were made according to standard MARMAP procedures, (i.e., oblique from surface to within five meters of bottom or to a maximum depth of 200 m while maintaining a constant wire angle throughout the tow). Wire payout and retrieval rates were 50 m/min and 20 m/min respectively. These rates were reduced in shallow water (<60 m) to obtain a minimum of a five minute tow or reduced due to adverse weather and sea conditions. A Seabird CTD was attached to the towing wire above the frame to monitor sampling depth in real time mode and to measure and record temperature and salinity. Once back on board, the 335 Ám mesh nets were rinsed with seawater into a 330 Ám mesh sieve. The contents of one sieve were preserved in 5% formalin and kept for ichthyoplankton species composition, abundance and distribution. The other sample was preserved in 95% ethanol and kept for age and growth analysis of larval fish. The same preservation procedure was followed as for the 1-m2 MOCNESS.
The 1-m2 MOCNESS sampler was loaded with ten nets. Nets 1-4 were fitted with 150 Ám mesh for the collection of older and larger copepodite and adult stages of the zooplankton. Nets 0, and 5-9 were fitted with 335 Ám mesh for zooplankton (nets 0 and 5) and ichthyoplankton (nets 6-9) collection. Tows were double oblique from the surface to within 5 m from the bottom. The maximum tow depth for nets 0, 1 and 5 was 500 m, and for net 6 was 200 m (if net 5 was sampled deeper than 200 m, it was returned up to 200 m and closed). Winch rates for nets 0-5 were 15 m/min and for nets 6-9, 10 m/min. For those nets fished >200m, the decent rate was increased so the maximum vertical velocity of the MOCNESS was 25m/min. This was providing the net angle did not go below 25 and the net horizontal speed did not drop below 0.5 kts. The depth strata sampled were 0-15 m, 15-40 m, 40-100 m, and >100 m. The first (#0) and sixth (#5) nets were integrated hauls. For shallow stations, with only 2 or 3 of the depth strata, not all nets were fished. The contents of nets 0-4 were sieved through 150 Ám mesh sieve, subsampled using a 2-L plankton sample splitter if the final biomass volume was too large for one quart jar, and then preserved in 10% formalin. Samples from nets 5-9 were sieved through 330 Ám mesh sieve and preserved in 95% ethanol. After 24 h of initial preservation, the alcohol was changed. The used ethanol was retained for disposal or recycling ashore. At priority 1 and 2 stations, 90-ml subsamples from the 150 Ám mesh nets were removed and preserved in 10% formalin for Dr. C. Miller (OSU). In addition, at priority 1 and 2 stations, 90-ml subsamples from these same nets were removed and preserved in 95% ethanol. These samples were collected for Dr. A. Bucklin for population genetic studies to distinguish the Pseudocalanus species found on Georges Bank.
The 10-m2 MOCNESS was loaded with five 3.0 mm mesh nets. Tows were oblique from surface to ~10 m from bottom or a maximum depth of 500 m. The same depth strata were sampled as with the 1-m2 MOCNESS. The winch rate for retrieval varied between 5 and 15 m/min depending on the depth stratum. The slow winch rates were used in order to filter at least 4,000-5,000 m3 of water per depth stratum sampled. A stepped oblique tow profile during retrieval was used to achieve this, if needed. Catches were sieved through a 335 Ám mesh, and preserved in 10% formalin.
The Pacer high-volume pump was used to collect nauplii and younger, smaller copepodite stages of zooplankton. The intake hose was deployed off the starboard side hydro boom by connecting the intake end, fitted with a 1.7-L Niskin bottle cut in half lengthwise, to the winch wire. The boom winch meter block was zeroed at the surface and the wire out reading was used to determine the depth of the cast. A 70 kg weight was used to depress the array. Three or four 30-m sections of 7 cm diameter hose were connected to the pump (depending on the depth of the station), allowing the intake hose to attain a maximum depth of approximately 125 m. At shallow stations, the intake hose nozzle was lowered to 3 meters off the bottom. Integrated depth samples were collected with 35 Ám mesh nets, sieved through a 30 Ám mesh sieve and preserved in 10% formalin. At stations with a maximum sampling depth of more than 85 m, samples were taken from the maximum depth to 75 m, 75-40 m, 40-15 m, and from 15 m to surface. At stations with a maximum sampling depth of less than 85 m, samples were taken from the maximum depth to 40 m, 40-15 m, and 15 m to surface. Before samples were collected, water was diverted from the net and the hose was allowed to flush completely, to assure that the zooplankton from the desired strata were obtained. At the last depth interval, the intake section was held just below the surface for 51 or 88 s (when three or four hose sections were used, respectively) allowing the sample to pass completely through the hose. Wire retrieval rate was approximately 4 m/min. This rate was used to obtain volumes of 500 L per 5 m depth interval sampled.
Additional tows were made with the 1-m2 MOCNESS for collections of Calanus finmarchicus and pteropods in the southern portion of Wilkinson Basin. Two separate single oblique tows were made with the 1-m2 MOCNESS sampler. Net 0 was fished from surface to within 10 m of bottom and the remaining nets (nets 1 to 9) were each fished in approximately 20 m increments from ~200 m to the surface. Winch rates were 15 m/min for net 0 and 10 m/min for nets 1 to 9. Vessel speed was 1.5 kts. Samples were preserved in 10% formalin. The live tow was targeted to the depths that Calanus finmarchicus and pteropods were located in the previous 1-m2 MOCNESS haul. Multiple nets were fished in those depth strata to collect a large amount of these animals. Calanus finmarchicus were decanted off the top of the cod end collecting buckets and gently released into 30-gallon plastic trash cans previously filled with seawater using the Pacer pump system. The pteropods collected were pored into separate 30-gallon plastic trash cans also previously filled with seawater using the Pacer pump system.
Samples Collected by the Zooplankton and Ichthyoplankton Groups:
Gear Tows Number of Samples
1. Bongo nets, 0.61-m 80 tows 82 preserved, 5% formalin
335-Ám mesh 82 preserved, EtOH
2. MOCNESS, 1-m2 43 tows
150-Ám mesh (Nets 1-4) 143 preserved, 10% formalin
335-Ám mesh (Net 0) 41 preserved, 10% formalin
335-Ám mesh (Nets 5-9) 178 preserved, EtOH
3. MOCNESS, 10-m2 21 tows
3.0-mm mesh 88 preserved, 10% formalin
4. Pump 20 profiles
35-Ám mesh 66 preserved, 5% formalin
Preliminary Summary of Zooplankton Findings - by Charles Miller
Zooplankton were not recurringly examined and characterized on Oc322. Throughout the circuit of Georges Bank the plankton were dominated by Calanus finmarchicus. Most of that stock was in fourth (C4) and fifth (C5) copepodite stages, which is expected for the end of April. Calanus were joined on the northeast peak by numerous Pseudocalanus spp., enough to make a modest addition to the overall plankton biomass. Up on the bank itself, inside the 60 meter isobath, Calanus were very few. The dominant plankton there were hydroids, mostly the now expected Clytia plus a few Sagitta. Clytia had not reached the densities seen other years in May and June, when MOC-1 cod end buckets can be packed solid with them. There were no shallow stations with numerous Centropages hamatus. There were a few specimens only, mostly younger copepodites, and the stock will doubtless increase by the May sampling.
I examined 450 individual Calanus from different stations for lipid sac fullness and gonad development. There were three gonad facies present: (1) a small tissue rudiment of 0.1-2 mm length, (2) a long, thin tubular format that seemed attached to the top of the usually full oil sac, and (3) various stages of active development toward maturation. Many of the last group were associated with very full oil sacs, and most of them were found in deep samples from stations off the bank. This opens the possibility that the G1 generation as well as the G0 generation matures near the bottom after a rest of some significant duration. That is, there may always be a rest phase in the life history, it just is broken after a short interval for some (or most) G1, while G2 (resting stock from which becomes G0 for the next year) requires a long time. There may be a hint in this as to how diapause is conditioned and broken in Calanus.
Observations ashore (May 1998) show that most of the maturing gonads were testes during Oc322, contrary to the impression gained at sea. High magnification observation of preserved, stained and cleared specimens showed that most enlarged gonads had a stout vas deferens rudiment bending left and down from the anterior end. Comparison to Nov. 1994 collections show that facies (1) is most common in the autumn resting stage, with an admixture of about 30% of facies (2). The significance of these two facies remains to be established.
A station in Wilkinson Basin was occupied after completion of the standard Broad-scale grid. It was heavily dominated by C. finmarchicus with the bulk of the stock (>80%) above 15m both day and night. Again, it was dominated by C5 with some C4 and a few adults. There was a secondary peak near the bottom, but we filtered much more water there, so it was hard to quantify by examining jars. Most of those individuals had large oil sacs. Individuals with enlarged, developing gonads were mostly found in the deep group. There were some Meganyctiphanes near the bottom as well.
Preliminary Summary of Ichthyoplankton Findings - by Rebecca Jones and John Sibunka
All samples from the Bongo and MOCNESS 1m2 (Nets 6-9) were subjected to a preliminary examination for eggs and larvae while on ship. The following qualitative observations of the larval size, abundance and egg abundance were made in the jars after preservation.
Cod (Gadus morhua):
Larval cod dominated the catches in both abundance and occurrence of larval fish collected during this cruise. Their distribution ranged across the entire survey area with the majority of larvae caught on the southwestern and central portion of the Bank (Figure ). Over all, the larval cod sizes ranged from 3-20 mm. The highest catches of larvae (~145) were observed at standard stations 3 and 4 respectively, and ranged in size from 3-15 mm. On the Northeast Peak there were larvae present in small numbers with lengths from 15-25 mm. Significant numbers of cod larvae were also found along the Northwest edge of the Bank (Figure ). Catches of cod larvae from this cruise closely resemble the observations from April cruises in 1996 and 1997 (refer R/V ENDEAVOR No. 282 and R/V OCEANUS No. 302 cruise reports). Observations from the March cruise (refer R/V OCEANUS No. 319 cruise report) showed the highest concentrations of cod larvae at standard station 18 (size range of 3-8 mm). The cod spawned on the Northeast Peak and are usually transported by the clockwise gyre as they develop; therefore, it is logical to find the concentration of fish from Station 18 in March (refer R/V OCEANUS No. 319 cruise report) transported to the general region of station 3 & 4 for this April cruise.
Haddock (Melanogrammus aeglefinus):
Haddock larvae were present only on the Northeast Peak and the southwestern portion of Georges Bank. The largest occurrence with ~140 larvae ( size range of 3-18 mm) was at standard station 3 (Figure ). Haddock larvae caught on the Northeast Peak area ranged from 1-2 fish per station at standard stations 26 & 30. The sizes of haddock larvae at these two stations ranged from 15-20 mm in length. Another area that haddock larvae were caught was on the Northwest edge of the bank for example,10 larvae at Standard station 37 (size range 5-15 mm). There were not a substantial number of haddock larvae found on the Bank during this cruise. A comparison of the larval haddock catches from this cruise to the catches obtained during the April 1996 & 1997 (refer R/V ENDEAVOR No. 282 and R/V OCEANUS No.302 cruise reports) GLOBEC surveys showed similar results of both low fish numbers and catches occurring in same general area on Georges Bank. The haddock spawned on the Northeast Peak and are generally transported by the clockwise gyre as they develop; so it is logical to find the concentration of fish from station 18 in March (refer R/V OCEANUS No. 319 cruise report) transported to the general region of station 3 for this April cruise.
Cod/Haddock/Witch flounder (Glyptocephalus cynoglossus) eggs:
Witch flounder are spring and summer spawners on Georges Bank. Their eggs are similar in size to that of cod and haddock, so microscopic observation is required to separate and positively identify the three species of eggs using embryonic development. Data results from previous surveys in April showed small and intermittent catches of Witch flounder eggs on the central and southern area of Georges Bank.
Cod/haddock/witch flounder eggs were distributed from the south central portion of Georges Bank eastward to the Northeast Peak area. Small and intermittent catches were made in the northern and western portion of the Bank The largest catches (estimated maximum catch of ~100-150 eggs/station) were made at stations occupied on the Northeast Peak Region. The distribution of these eggs is similar to that of the large gadoid eggs collected during the previous survey in March (refer R/V OCEANUS No. 319 cruise report) of this year. However, the large catches of gadoid eggs seen in the samples collected on the Northeast Peak area of the Bank during the previous two cruises (refer R/V OCEANUS Nos. 317 and 319 cruise reports) were no longer apparent during this April survey.
Miscellaneous Fish Larvae:
The following fish larvae were also identified in the ichthyoplankton samples collected during this broad-scale survey.
1. Sand lance Ammodytes sp.
2. Atlantic mackerel Scomber scombrus
3. Witch flounder Glyptocephalus cynoglossus
4. American plaice Hippoglossoides platessoides
5. Atlantic herring Clupea harengus
6. Sculpin Myoxocephalus sp.
7. Lightfishes Gonostomatidae
8. Rock gunnell Pholis gunnellus
9. Redfish Sebastes sp.
10. Sea snail Liparis sp.
Larval Fish Distributions - by John Sibunka and David Mountain
Figure 12 shows the general distributions of larval cod and haddock over Georges Bank as shown by sampling on Oc322, in April 1998. As stated in the larval fish report above, these are reasonable patterns to expect based on (1) the March distributions seen on Oc319 and (2) usual patterns of larval drift.
Locations of high abundance of both cod and haddock larvae in April are southwest of the locations observed in the March survey. To determine if the southwestward movement could be attributed to transport by the around Bank flow field, the March/April climatological mean flow field developed by the GLOBEC circulation modeling group (i.e., Lynch et al.), was used to advect the March observations to the time of the April survey. For both cod (Fig. 13) and haddock (Fig. 14) the locations of the advected larval concentrations (the bottom panel in each figure) are very similar to the observed locations (middle panel in each figure).
Microzooplankton Analysis: The Importance of Microzooplankton Motility
in Georges Bank. A Broad-scale Study for GLOBEC
by Amanda Hallbergh and James Brien for S. Gallager
The purpose of the microzooplankton analysis was to observe motility and general size within water samples. On Georges Bank there are three designated depths in the water column which are of interest; near bottom, the pycnocline region, and finally the upper well mixed region. Samples were taken at all priority #1 and #2 stations and most priority #3 and #4 stations.
Water samples were obtained from Niskin bottles on a Neil Brown Mark V CTD at completion of the cast. A siphon was used to remove water from the top of the Niskin bottles keeping the zooplankton intact. Surface samples were taken in one of two ways, from the CTD or by lowering a dip bucket. The samples were placed into a 75 cm2 tissue culture flasks that have been dipped into soapy water and allowed to air dry. To further prevent fogging the recording unit resides in an incubator unit at 5oC.
Each flask, in turn, was placed in a holder across from a B/W high-res Pulnix camera fitted with a 50 mm macro lens and directly in front of a fiber optic ring illuminator fitted with a far-red filter. This apparatus was suspended within the incubator by a bungee cord to reduce vibrations produced by the ship. Recordings were made using a Panasonic AG1980 video recorder with SVHS formatted cassettes, a Panasonic TR-124MA video monitor, and a time code generator to record a period of 10 to 15 minutes for each sample. The flask was then replaced with the next sample from the present station and recordings continued. The field of view was calibrated for each new videotape by focusing on the front and back of the flask, and recording the width and height of the field of view in the record book as well as the F-stop in the log. All data noted was recorded on the video tape and in the log book containing latitude and longitude, times of recording and preserving, station numbers and priorities, time of day, and if any movement to the flask during recording. All information was recorded on videotape as a backup.
Priority #1 stations were analyzed; samples were recorded and preserved in 10% Lugols solution. Water samples from priority #2 stations were recorded but not preserved. Samples from priority stations #3 and #4 were recorded intermittently but no samples were preserved. Station #18, a priority #1, had only one surface sample collected and recorded. Since all standard stations were completed ahead of schedule, two Wilkinsons Basin's stations were added. A Mark V CTD cast was deployed on route to the Basin. The second cast was deployed within Wilkinsons Basin. Samples were recorded and preserved for further study.
Post Cruise Processing:
Samples will be delivered to Dr. Gallager and Phil Alatalo for further study. Motility patterns will be analyzed with the Motion Analysis EV system. The final output will be particle size distribution and a motility spectra associated with each particle. This will be compared with species composition in the microzooplankton fraction preserved in Lugol's solution.
Preliminary Summary of the 10-m2 MOCNESS samples.
by Stephen Brownell
The samples collected from the 10-m2 MOCNESS were examined on shipboard for a qualitative estimate of abundance, distribution, and size range of both the invertebrate and the fish community at station. The following observations are based on examination of the samples following preservation.
Sta.3 haul 1.
Fish Gadus morhua, Melanogrammus aeglefinus, Ammodytes sp.
Invert. Pleurobrachia, hydromedusae, Clione, Phronima sp., mysids, shrimp.
Sta.4 haul 2
Fish Gadus morhua, Melanogrammus aeglefinus, Ammodytes sp. Anarhichas lupus, Myoxocephalus sp., Scophthalmus aquosus, Ammodytes sp.
Invert. Euphausiids, Clione, benthic amphipods, shrimp, Polychaete worms
Sta.7 haul 3.
Fish Myctophid, Ammodytes sp., Gnathostoma.
Invert. Meganyctiphanes sp., Hydromedusae, Clione, benthic amphipods, shrimp, Phronima sp., squid.
Sta.9 haul 4.
Fish Gadus morhua, Anarhichas lupus, Nemichthys scolopaceus, Clupea harengus.
Invert. Benthic amphipods, Clione limacina, Pleurobrachia, hydromedusae, Phronima sp., mysids, shrimp, Euphausiids.
Sta.12 haul 5.
Fish Clupea harengus, Gadus morhua, Melanogrammus aeglefinus, Ammodytes sp. Anarhichas lupus, Myoxocephalus sp., Scophthalmus aquosus.
Invert. Hydroids, shrimp, benthic amphipods, Polychaete worms.
Sta. 13 haul 6.
Fish Gadus morhua, Melanogrammus aeglefinus, Ammodytes sp., Anarhichas lupus.
Invert. Euphausiids, Pleurobrachia, hydromedusae, hydroids, benthic amphipods, mysids.
Sta. 16 haul 7
Fish Myctophid, Gnathostoma, Nemichthys scolopaceus.
Invert Euphausiids, chaetognaths, Pleurabrachia, hydromedusae, shrimp, Phronima sp.
Sta. 17 haul 8
Fish Gadus morhua, Anarhichas lupus, Ammodytes sp., Nemichthys scolopaceus.
Invert. Pleurobrachia, Clione, shrimp, chaetognaths, hydromedusae, Phronima sp., benthic amphipods, Euphausiids.
Sta. 18 haul 9
Fish Gadus morhua, Anarhichas lupus, Nemichthys scolopaceus.
Invert. Benthic amphipods, Clione, hydromedusae, Pleurobrachia, chaetognaths, shrimp, Phronima sp., Euphausiids.
Sta. 20 haul 10
Fish Gadus morhua, Myoxocephalus sp.,
Invert. Pleurobrachia, Phronima sp., mysids, Limacina sp., Clione, hydromedusae, Euphausiids.
Sta. 23 haul 11
Fish Gadus morhua, Melanogrammus aeglefinus, Ammodytes sp., Anarhichas lupus.
Invert. Benthic amphipods, Phronima sp., shrimp, Clione, hydromedusae, Euphausiids, Limacina sp., Pleurobrachia, hydroids,
Sta. 25 haul 12
Invert. Meganyctiphanes sp., Euphausiids, chaetognaths, Pleurobrachia, Phronima sp., hydromedusae.
Sta.39 haul 13
Fish Ammodytes sp..
Invert. Meganyctiphanes sp., Phronima sp., Clione, shrimp, Pleurobrachia, hydromedusae, Euphausiids.
Sta. 27 haul 14
Fish Gadus morhua, Melanogrammus aeglefinus, Myoxocephalus sp., Clupea harengus.
Invert. Limacina sp., Pleurobrachia, Clione, Polychaete worms, Phronima sp., chaetognaths.
Sta.29 haul 15
Fish Anarhichas lupus, Myctophid.
Invert. Shrimp, benthic amphipods, Meganyctiphanes sp., Phronima sp.
Sta.30 haul 16
Fish Gadus morhua, Melanogrammus aeglefinus, Clupea harengus, Ammodytes sp. Anarhichas lupus.
Invert. Pleurobrachia, benthic amphipods, Clione limacina, shrimp, Limacina sp., Meganyctiphanes sp., Euphausiids, squid.
Sta. 40 haul 17
Fish Gadus morhua, Melanogrammus aeglefinus, Ammodytes sp.
Invert. Meganyctiphanes sp., Euphausiids, Clione, hydromedusae, Pleurobrachia sp., Chaetognaths, benthic amphipods, mysids.
Sta. 32 haul 18
Fish Gadus morhua, Ammodytes sp.
Invert. Benthic amphipods, shrimp, mysids.
Sta. 34 haul 19
Fish Gadus morhua, Anarhichas lupus, myctophids, Macrozoarces sp.
Invert. Meganyctiphanes sp., Limacina sp., Clione, Pleurobrachia sp., Chaetognaths, hydromedusa, benthic amphipods, shrimp, mysids.
Sta. 38 haul 20
Fish Gadus morhua, Melanogrammus aeglefinus.
Invert. Meganyctiphanes sp., Limacina sp., Clione, Euphausiids, shrimp, Phronima sp.
Sta.WB haul 21
Fish Gadus morhua, Anarhichas lupus.
Invert Euphausiids, Phronima sp., Clione, shrimp, Limacina sp.
Nutrient and Phytoplankton Studies
by David W. Townsend, University of Maine
[see also http://grampus.umeoce.maine.edu/globec/globec.html]
Overview: We are collecting water samples on five of the Broad-scale cruises of 1998 (February to June) to analyze for a suite of nutrients and phytoplankton biomass. During this cruise, water samples were collected for analyses of
dissolved inorganic nutrients (NO3+, NO2, NH4, SiO4, PO4);
dissolved organic nitrogen and phosphorus;
particulate organic carbon, nitrogen and phosphorus;
phytoplankton chlorophyll-a and phaeophytin, and
phytoplankton species composition
Methods: Water collections were made at various depths at all of the regular hydrographic stations (Stations 1-41) sampled during the April 19098 Broad-scale survey cruise aboard R/V OCEANUS, using the 1.7 liter Niskin bottles mounted on the rosette sampler. Additional near-surface water samples were collected at positions between the regular stations (Station numbers > 41) using the ship's underway flow-through sea water system (Fig. 15).
Event Log - R/V OCEANUS Cruise Oc322, GLOBEC Georges Bank Broad-scale Survey Cruise for April 1998. Compiled by John Sibunka and James Gibson