dated 1/22/96
Sproul 9602 Cruise Schedule

Monday Feb. 5, 1996
	Load R/V Sproul

Tuesday Feb. 6, 1996
	0730    All Aboard
	0800    Depart from Nimitz Marine Facility, San Diego.
		Proceed to Station 01 (32 52.4N  117 22.5W)
	1045   Arrive at ST01  32.873N  117.375W
		Bongo Cast (30 min)
		Test OPC/MOCNESS (1.5 hours)
	1245    Proceed to ST02  33.417N  117.917W  (CalCOFI Station 90.30)
	1830    Arrive ST02
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	2230    Proceed to ST03  33.183N  118.383W  (CalCOFI Station 90.37)

Wednesday Feb. 7, 1996
	0210    Arrive ST03
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
  	0610    Proceed to ST04  32.900N  118.930W  (CalCOFI Station 90.45)
	1300    Arrive ST04
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	1700    Proceed to ST05  32.750N  119.283W   (CalCOFI Station 90.50)
	1940    Arrive ST05
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	2340    Proceed to ST06  32.533N  119.500W  (CalCOFI Station 90.55)

Thursday Feb. 8, 1996
	0200    Arrive ST06		
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	0600    Proceed to ST07  32.367N  119.867W  (CalCOFI Station 90.60)
	0850   Arrive ST07
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	1250    Proceed to ST08  32.250N  120.300W  (CalCOFI Station 90.65)
	1455   Arrive ST08
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	1855    Proceed to ST09  32.067N  120.633W  (CalCOFI  Station 90.70)
	2135    Arrive ST09
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?

Friday Feb. 9, 1996
	0135    Proceed to ST10  32.667N  121.000W (CalCOFI Station 87.70)
	0700    Arrive ST10
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	1100    Proceed to ST11  ?? (CalCOFI Station 87.65)
	1330    Arrive ST11
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	1730    Proceed to ST12  33.000N  120.367W  (CalCOFI Station 87.60)
	2000    Arrive ST12
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?

Saturday Feb. 10, 1996
	0000    Proceed to ST13  33.167N  120.000W  (CalCOFI Station 87.55)
	0250    Arrive ST13
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	0650    Proceed to ST14  33.333N  119.667W  (CalCOFI Station 87.50)
	0930    Arrive ST14
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	1330    Proceed to ST15  33.500N  119.333W  (CalCOFI Station 87.45)
	1610    Arrive ST15
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?
	2010    Proceed to ST16  33.667N  119.000W  (CalCOFI Station 87.40)
	2250    Arrive ST16
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?

Sunday Feb. 11, 1996
	0250    Proceed to ST17  33.833N  118.633W  (CalCOFI Station 87.35)
	0540    Arrive ST17
		Bongo Cast (30 min)
		CTD Cast (15 min)
		MOCNESS/OPC, Plankton Pump, additional Bongos?	

If additional time is available:
Proceed to Channel Islands for attached kelp survey

	(This procedure will take place near the Channel Islands National Park.  Clearance has been given to sample in this area.  The ship will proceed to this region, and a skiff will be taken nearshore to sample attached kelp plants.  I do not have any further information at this time. All samples will be taken by hand at the surface.)

Proceed to Nimitz Marine Facility by 0600 2/13/96
Arrive 0600-0800 2/14/96		




Simultaneous Measurement of the Distribution of Pacific Hake, 
Merluccius productus, Larvae and Zooplankton Prey

Shannon L. Cass Calay

Scripps Institution of Oceanography
9500 Gilman Drive
La Jolla, California 92093-0218
scasscalay@ucsd.edu


 
INTRODUCTION
	
	The larvae of Pacific hake, Merluccius productus, are common in the California Current region.  
	Only the larvae of the northern anchovy are more abundant.  However, unlike the epipelagic 
	anchovy, adult Pacific hake generally spawn at depth over the continental slope. Whereas anchovy
	larvae are found in the upper 30 meters, hake larvae are distributed below the mixed layer
	at 50 to 200meters.  This strategy is surprising since hake larvae are known to consume small
	zooplankters which are relatively uncommon at this depth.  
	
	What tradeoffs make this mesopelagic habitat an appropriate nursery for hake larvae?  
	Possible explanations include refuge from predation and competition, minimal transport, and minimal 
	turbulence.  Perhaps the relative stability at depth allows patches of prey to persist.  
	LaskerÕs hypothesis suggests these patches would improve the ability of hake larvae to find an adequate 
	food supply.

	I propose to examine the distribution and abundance of Pacific hake larvae and the fine scale 
	distribution of prey in the California Current region.  These measurements will be made using a 
	combined optical plankton counter (OPC), multiple opening and closing net system (MOCNESS) package 
	which enables simultaneous measurement of the concentration of zooplankton-sized particles and hake
	larvae. This will permit investigation of the relationship between fine-scale food distribution, 
	and the distribution and gut content of Pacific hake larvae.

	These methods were employed successfully during the 1995 HAKE I cruise aboard the David Starr Jordan.  
	The results were quite exciting.  Analyses indicate that the horizontal distribution of Pacific hake 
	larvae is positively correlated with the concentration of particles of the size appropriate for 
	consumption by those larvae (see Figures 1 and 2).  The proposed cruise will allow rigorous testing 
	of this hypothesis, as well as others outlined below.  At this time, the vertical distribution of hake 
	larvae and the fine-scale distribution of particles is unknown.  
	

HYPOTHESES

	HA:  The number of particles counted by the OPC is positively correlated with the number of 
	zooplankters captured by the MOCNESS.

   	HA:  The number of hake larvae per stratum is positively correlated with the concentration 
   	of particles in that stratum, as measured by the OPC.

	HA:  The average gut content volume of hake larvae in a given stratum is positively 
	correlated with the concentration of particles in that stratum, as measured by the OPC.

	HA:  The number of hake larvae per stratum is positively correlated with the degree of 
	aggregation of particles in that stratum, as measured by the OPC.

	HA:  The average gut content volume of hake larvae in a given stratum is positively 
	correlated with the degree of aggregation of particles in that stratum, as measured 
	by the OPC.
	
CRUISE SCHEDULE

	Eight days of ship time on the R/V Sproul are requested.
	
	Departure: R/V Sproul departs from San Diego 6 Feb 1996.
	Returning:  14 Feb 1996 to San Diego.

Procedure	Casts	Time Required
		
OPC/MOCNESS Casts	10	20  hours
Bongo Casts (minimum #)	20	20  hours
Kelp Net Tows	10	10  hours
Plankton Pump	5	20  hours
Transit Time  	N/A	87.5 hours
Weather Days etc.	N/A	34.5 hours
		
		Total = 192 hours
		          = 8 days

	Cruise Plan:  The proposed cruise track is shown in Figure 3.  A bongo net will be deployed at each station.
	Each bongo sample will undergo immediate microscopic analysis.  All hake larvae will be removed, enumerated 
	and measured.  Following this procedure, the larvae will be preserved in 95% ethanol for later otolith analysis.  
	The hake larvae from the second bongo sample will be quick-frozen in liquid nitrogen.  This process will enable 
	future examination of the health of the larvae. 

	An OPC/MOCNESS cast will take place at the discretion of the chief scientist based upon the relative number
	of hake larvae collected.  The following ten strata will be sampled , 
	300-250, 250-200, 200-150, 150-125, 125-100, 100-75, 75-50, 50-25, 25-0, and 0-300.  
	The MOCNESS net samples will be preserved in 95% ethanol for later otolith analysis. 

	
ADDITIONAL SCIENTIFIC PROJECTS: 

	 Several other students and scientists have expressed an interest in space aboard this cruise.  At this time, 
	 the following additional work is proposed.

	Scott Rumsey:  Bongo tows to examine the distribution of Euphausia pacifica in the California Current region.

	Alistair Hobday:  A kelp net (provided by A. Hobday) will be used to sample drift kelp.  These samples will 
	allow A. Hobday to continue his examination of the evolution of  community structure in drift kelp epizoa.

	Dr. Mike Mullin:  Continuing to examine the fine-scale distribution of macro-zooplankton and phytoplankton 
	using a plankton pump.  This study was initiated during the HAKE I cruise.
	
	NOAA:  Dr. Paul Smith and Dr. John Hunter have expressed an interest in receiving samples collected during
	 this cruise.  They are tentatively planning to provide the 1M MOCNESS and a MOCNESS technician.  Confirmation
	  is pending.


Analysis Performed	Time Required	Total
		
Sproul Ō96 MOCNESS samples	4 h/sample * 100 samples	 400 hours
		

	This cruise, if funded, will provide three advanced graduate students with valuable experience 
	and critical thesis data.  It is also an excellent opportunity to provide ship time and training 
	for several first and second year graduate students.  These students can expect to have first hand 
	experience performing bongo, OPC, and MOCNESS casts, sorting, identifying, and analyzing zooplankton 
	and fish larvae, as well as planning cruise execution. Much of the data collected will be available to 
	all who participate.  It is hoped that some of this data will be valuable to students working on separately 
	funded projects.