CRD 05-01 Tables

CRD 05-01 Table 1. List of cruise and gear information for the Cooperative surfclam survey in 2004.
Cruise code	200416
Cruise dates	June 26 – July 6, 2004
Total stations (Survey leg)	242
Survey area	NNJ, Hudson Canyon to as far south as 36.5 degrees (NMFS Surfclam strata)
Statistical design	Stratified random sampling in NMFS clam strata
Vessel name and length	FV Lisa Kim (115 feet)
Dredge width	120” (stern mounted dredge)
Dredge length	185”
Blade depth	3.5”
Pump type	Surface
Manifold nipples (outer diameter)	1”
Bar spacing	1.25” (up to 2” in some places)
Tow speed	3 knots
Tow duration	5 min
Differential Pump Pressure (at depth)	70 – 80 psi
Captain and Crew	Eddie Platter, Jeff, Seth, Alex
Scientists	Jim Weinberg, Eric Powell
	Chris Pickett, Vic Nordahl, Sara King
	Becky Marzec, Yungkul Kim, Jeff

Table 2. Surfclam depletion experiments conducted with the FV Lisa Kim. Table lists general location, date, station numbers and number of tows per experiment.
Experiment	Location	Date	Cruise or leg, stations	Total tows
sc04-1	NJ (mid-depth)	April 8, 2004	Shakedown, 15-38	24
sc04-2	NJ (shallow)	April 9, 2004	Shakedown, 49-68	20
sc04-3	DMV (mid-depth)	July 3, 2004	Survey, 146-165	20

Table 3. Specific locations (decimal degrees) and depths of three surfclam depletion experiments conducted by the FV Lisa Kim in 2004.

Table 4. Sensor information related to the three surfclam depletion experiments carried out by the FV Lisa Kim in 2004. “SSP” = NMFS survey sensor package. “WindPlot” = a GPS-based program, used by the Rutgers scientists, which collected vessel location information.
Experiment	Primary Lat/Lon Sensor	Sensor Logging Rate	Positions Interpolated for Patch Model?
sc04-1	SSP	2-sec (8-11 ft)	N
sc04-2	SSP	2-sec (8-11 ft)	N
sc04-3	WindPlot	10-sec (52-57 ft)	Y, to 10 ft

Table 5. Point estimates of dredge efficiency and surfclam density for three depletion experiments carried out by the FV Lisa Kim in 2004. Results are from the Rago model, assuming no indirect effects (as defined in Table 6 legend).
Experiment	Lisa Kim DredgeEfficiency	Surfclam density per square ft
sc04-1	0.797	0.104
sc04-2	0.825	0.026
sc04-3	0.753	0.165

Table 6. List of commercial clam dredge efficiency estimates from 2002 and 2004. Table also gives the region, bivalve species, and number of tows in each experiment. Estimates of efficiency are from the Rago model, assuming no “indirect” effects (i.e, a loss or addition of clams from/to the depletion site during the experiment caused by the repeated sampling of the area).

Table 7. List of surfclam catches at six stations that were sampled at the beginning and near the end of the 2004 surfclam survey. This was done to check for gross changes in gear efficiency over time within the survey.
Station #, NMFS Stratum #		# Surfclams/Tow
Time 1	Time 2	Time 1	Time 2
16, 21	209, 21	708	348
14, 21	211, 21	1161	1041
13, 25	212, 25	731	952
12, 25	217, 25	1265	1112
15, 21	218, 21	637	806
11, 25	219, 25	1089	724

Table 8. Gear selectivity data for Atlantic surfclams captured with the dredge on the FV Lisa Kim in 2004. See Table 1 for information on bar spacing. The table states whether individual surfclams could pass (yes/no) through the bars at three locations.

Table 9. Summary statistics for distance (nmi) sampled per tow by the FV Lisa Kim during the 2004 surfclam survey. Distances were calculated from sensor data (see text). Data only include the random survey stations.

Table 10. Efficiency corrected biomass estimates (‘000s mt meats), and confidence intervals, for fully recruited surfclams, by region and year. Catch per tow was standardized to 0.15 nmi based on computed tow distances (SENDIST_2004). Only good, random tows were included (RANDLIKE = 1 or 2).

Table 11. List of strata in the NNJ region, their areas, and the number of random stations sampled in the 2004 survey.

Table 12. Surfclam abundance per tow and meat weight per tow by stratum, for two size classes: A. 120mm + shell length, B. 88 – 119 mm. Catch per tow was standardized to 0.15 nmi based on computed tow distances (SENDIST_2004). Only good, random tows were included (RANDLIKE = 1 or 2). Meat weight – shell length parameters were based on data collected during the 2002 clam survey (LWSARCYR= 2003). Rank indicates which strata had the most clams per tow, on average.

Table 13. The percentage of random stations in Stratum # 9, off DMV, that captured no surfclams, by survey.

*= The proportion of zeros in 2004 is biased low relative to other values in the time series. Data from 1982 – 2002 were collected with the RV DE-II. In 2004, data were collected with the FV Lisa Kim commercial dredge, which is 2x the width of the dredge on the RV DE-II. The commercial dredge also has much higher clam capture efficiency than the dredge on the RV DE-II.

Table 14. List of survey strata, by region and depth zone. These zones were used to examine the proportion of surfclam biomass at depth over time. Strata are shown in Figure 1.

Table 15. Number of clam survey tows by region, depth category and year in the NEFSC clam survey during 1982-2002 and in the 2004 cooperative clam survey. Only successful, random tows were counted.

Table 16. Percent of surfclam biomass by region, depth category and year, based on the NEFSC clam survey during 1982-2002 and the 2004 cooperative clam survey. Data are from random tows completed successfully. Blank cells in the table are due to no (0) tows taken in “deep” depths (as defined in Tables 14 and 15) in the NNJ and SNJ regions during 1984.

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(Modified Jun. 18 2008)