Chesfims 2002 September Shoal Survey Summary Report
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- Participating Scientists
- Area of Operation
- Data / Specimens Collected
- Figure 1.
- Sampling Dates Stratum of Trawls of Fish Caught
- Total 120 3060 25
- Common Name Total N Total Weight (g) Mean Length (mm)
| ChesFIMS 2002 September Shoal Survey Summary Report
Sampling Dates: 17 September 2002 – 4 October 2002 Boat Used: 20’ Maycraft with a 130 hp engine MD DNR Co-Principal Investigator: Alexei Sharov Chief Scientist: Brandon Muffley Phone Number: (410) 260-8284E-mail: BrandonM@dnr.state.md.us Participating Scientists: 1. B. Muffley MD-DNR 8. K. Crawford MD-DNR 2. A. Sharov MD-DNR 9. M. Harlinski MD-DNR 3. J. Mowrer MD-DNR 10. E. Pertain MD-DNR 4. P. Genovese MD-DNR 11. K. Donaldson UMD–College Park 5. B. Sadzinski MD-DNR 12. H. Hornick MD-DNR 6. A. Bolinger MD-DNR 7. A. Jarzynski MD-DNR Objectives: Obtain data on relative abundance and biological characteristics of the bentho-pelagic fish community in the extensive shoal habitats (< 5m depth) in the Maryland portion of Chesapeake Bay. Collect and preserve a sub-sample of catch for dietary analysis. Area of Operation: From the MD line (approximately 37.5ºN) to just south of the Aberdeen Proving Grounds (39.15ºN). Type of Operations: Conducted 6-minute bottom-water trawls and recorded a number of environmental and water quality variables at 120 stations in 9 different strata in Chesapeake Bay (Table 1, Figure 1). Data / Specimens Collected: Collected 3,060 fish (over 117 kg) from 25 different taxonomic categories (Table 1). Preserved (EtOH) samples from approximately 14 stations where targeted species were present in the catch. Environmental and water quality data recorded at each station. Damage to Gear: The same trawl was used the entire sampling period without any damage to the gear. 
Figure 1. ChesFIMS 2002 September shoal survey station locations. Cruise Summary: We started the shoal portion of the survey on Tuesday, September 17 and finished on Friday, October 4, 2002. This time period included 14 working days, 12 of which were spent sampling. The strata were not sampled in any pre-determined or systematic order but were sampled on particular days based upon weather conditions and crew availability. Once at a particular location, the order in which the stations were sampled was not pre-determined but based upon weather conditions and tide state. Overall, the September survey was successful and all objectives were met or exceeded. Based upon survey design (random with allocation proportional to strata size), it was determined that 112 stations were required to be sampled and we were able to sample 120 stations (Table 1). We collected fish from 109 of the 120 stations (91%) sampled. Accounting for all species and all strata, the overall catch tow-1 was 25.50 ± 38.77 (mean ± S.D., range 0 – 254). As in July, these catch estimates are lower than the previous years estimates with an overall catch tow-1 of 43.24 ± 49.18 in September 2001. The Patapsco and Little Choptank strata had the highest catch tow-1 (mean 58.22 ± 61.03 SD, 50.67 ± 79.91, respectively), while the Severn/South and Chester strata had the lowest catch tow-1 estimates (mean 5.00 ± 5.89 SD, 5.56 ± 11.88, respectively). In total, 3,060 fish were caught from 25 different taxonomic categories with a total catch weight of more than 117 kg. Although not as dramatic as the July comparison, the total number of fish caught in September 2002 was lower than September 2001 (3,060 in 2002 compared to 4,627 in 2001), but the total biomass was higher in 2002 (over 117 kg) compared to 2001 (82 kg).As in May and July, bay anchovy (Anchoa mitchilli) was the most common fish encountered throughout the bay and accounted for over 1/3 of all the fish caught. The blue crab closely followed and was found in all strata but was dominant in Choptank Tangier Sound catches. Weakfish (Cynoscion regalis), spot (Leiostomus xanthurus), and the northern kingfish (Menticirrhus saxatilis) were common in the Pocomoke and Tangier Sound catches, while white perch (Morone americana) and striped bass were common north of the Bay Bridge in the Patapsco and Chester strata. A summary of the biological characteristics of all species caught during the September 2002 survey is provided in Table 2. We also compared mean catch tow-1 indices for a few common species between May, July, and September 2002 for a monthly comparison (Figure 2), and between September 2001 and 2002 surveys to provide some connection between last years results (Figure 3). At the end of each trawl, surface and bottom YSI measurements (temp, DO, and salinity) were taken at every station. Salinity ranged from a high of 20.8 in Pocomoke Sound, to a low of 11.8 in the Patapsco stratum. Even though this was our lowest reading for September, salinity in the Patapsco stratum has increased each sampling period and was much higher than readings found in May when salinity ranged from 0.9 to 4.3. and July with a range 8.2 to 9.4. Surface DO readings were variable between strata but within each strata DO was relatively consistent. On average, surface DO ranged from 5.0 – 8.0 mg L-1. The highest surface DO readings were found in the Patapsco stratum with a mean surface DO of 7.8 mg L-1, while lowest DO reading were found in the Tangier and Pocomoke Sound strata with a mean surface DO of 5.8 mg L-1. Bottom DO readings rarely fell below 5.0 mg L-1 (2 readings, both in Tangier Sound) and were usually greater than 6.0 mg L-1. Surface temperatures ranged from a high of 25.5 ºC to a low of 21.8ºC. The warmest mean temperatures occurred in the Pocomoke and Tangier strata, the first areas to be sampled.
Table 1. Summary of the September 2002 survey sampling intensity and catch results.
Table 2. Biological characteristics of all species caught during the September 2002 survey. Blue crab biomass based on a L-W relationship from May and July 2002 data of known length and weights 
Figure 2. Monthly catch rate comparisons (number tow-1) for a few of the more common species encountered during all sampling periods. Directory: cfdocs cfdocs -> Abundance, Distribution and Diversity of Chesapeake Bay Fishes: Results from chesfims Download 127.64 Kb. Share with your friends:
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