CHESFIMS 2003 Sept./Oct. Shoal Survey Report
8 September 2003 – 3 October 2003
Survey Dates:
Boat Used:
20.0’ Maycraft with 130 HP engine
MD DNR Co-Principal Investigator:
Chief Scientist:
Phone Number:
E-mail:
Brandon Muffley
(410) 260-8284
BrandonM@dnr.state.md.us
Participating Scientists:
1. B. Muffley – MD DNR
2. T. Hershberger – MD-DNR
3. B. Sadzinski – MD-DNR
4. E. Pertain – MD-DNR
5. A. Sharov – MD-DNR
Objectives:
Alexei Sharov
6. C. Kennedy – MD-DNR
7. T. Jarzynski – MD-DNR
8. A. McCauley – MD-DNR (intern)
9. B. Pyle – MD-DNR
Obtain data on the 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/VA 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 biological, environmental and water quality variables at 111
stations in 9 different strata in Chesapeake Bay (Table 1, Figure 1).
Data / Specimens Collected: Collected 12,063 fish and crabs (over 150 kg) from 28
different taxonomic categories (Table 1). Preserved (EtOH)
samples from approximately 50 stations where targeted
species were present in the catch. Environmental and water
quality data recorded from each station.
Damage to Gear: We did not sustain any damage to the actual sampling gear (i.e.
trawls, YSI, scales etc.). However, due to engine failure on the last
day of sampling 3 October 2003, we were unable to sample 9 stations
in Tangier Sound (This is the reason why our total number of stations
sampled, 111, was lower than in May and July, 124 and 123
respectively).
Figure 1. ChesFIMS 2003 Sept./Oct. shoal survey station locations.
Cruise Summary:
We started the shoal portion of the survey on Monday, September 8 and finished
on Friday, October 3, 2003. This time period included 20 working days, 15 of which
were spent sampling. Hurricane Isabel and general windy conditions throughout the
survey postponed and/or cut short a number of sampling days. The strata were not
sampled in any pre-determined or systematic order but were sampled on any particular
day 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 Sept./Oct. survey was successful and all objectives were met. 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 111
stations (Table 1). As stated in the ‘Damage to Gear’ section, the boat engine died on the
last day of sampling and we were unable to sample 9 stations in Tangier Sound. Even
with the lower sampling effort, 12,063 fish and crabs were caught with a total weight of
approximately 150 kg (Table 1), our highest catch and biomass estimates to date (In both
total number and weight and catch and biomass per effort). We caught fish from 103 of
the 111 stations sampled (93%), and 3 of the 8 zero catches were from Calvert Cliffs.
Accounting for all species and all strata, the overall catch tow-1 was 108.6  191.8 fish
(mean  SD, range 0 – 1297). The Sept./Oct. 2003 catch rate was over 4 times as great as
Sept./Oct. 2002 (25.51 ± 38.77, mean ± SD) and more than 2 times as great as 2001
(43.24 ± 49.18). The Patapsco stratum, the northernmost stratum, had the highest catch
rate (mean 278.0 ± 228.3 SD), followed by the Pocomoke Sound, the southernmost
stratum (191.7 ± 235.0 SD) (Figure 2). The lowest catch rates were found in the Chester
(the highest catch rates in July) and Eastern Bay strata (mean 11.2 ± 16.2 SD, 17.3 ±
36.2, respectively) (Figure 2). The Patapsco, Pocomoke Sound, and Tangier Sound
combined, comprised 73% of the total biomass for the entire survey (Table 1). The total
number of different species caught, 28, was the highest among the three Sept/Oct surveys
(2001 – 21 species, 2002 – 25 species), but the number of species tow-1 was slightly
lower in 2003 (Figure 3).
For the first time this year, bay anchovy (Anchoa mitchilli) was the most abundant
fish caught and comprised 72% of the total catch (Figure 4). Catch and biomass estimates
for anchovy were the highest in the survey to date. Bay anchovy was found in all strata,
and was most common in the Pocomoke, Tangier, and Choptank strata. White perch
(Morone americana) was the second most abundant species, and when combined with
bay anchovy, comprised 85% of the total Sept./Oct. catch. White perch was caught in all
but three strata (Little Choptank, Pocomoke, Calvert Cliffs), but 91% of all white perch
caught were from the Patapsco stratum. The blue crab (Calinectes sapidus) was the third
most abundant species and was found in all strata, however, blue crab abundance
declined for the second consecutive year in the Sept/Oct survey (Figure 5). Spot
(Leiostomus xanthurus), weakfish (Cynoscion regalis), and hogchoker (Trinectes
maculatus) were common in the more southern strata, such as Tangier and Pocomoke
Sound, while striped bass (Morone saxatilis) was common in the mid and northern strata
such as Severn/South and Chester. Atlantic croaker (Mircopogonias undulatus) and
northern kingfish (Menticirrhus saxatilis), usually common in the fall survey, were not
encountered during the 2003 Sept./Oct. survey. A summary of the biological
characteristics of all species caught during Sept./Oct. is provided in Table 2.
At the end of each trawl, surface and bottom YSI measurements (temp, DO, and
salinity) and secchi disk readings were taken at every station. Water temperature was
relatively uniform across all strata and very uniform between the surface (mean 23.1 C,
range 16.6 – 26.1) and bottom (mean 23.0 C, range 16.7 – 26.0). Salinities ranged from
a mean surface low of 3.1/ and mean bottom low of 2.8/ in the Patapsco
stratum, to a mean surface high of 14.4/ and mean bottom high of 14.6/ in
Pocomoke Sound. As in July, salinity readings in Sept/Oct. were, on average, 7 ppt lower
than salinities in 2002. For example, mean surface salinity in Patapsco was 3.1/ in
2003, compared to 12.2/ in 2002. DO readings (mg/L) were not only variable
between strata, but even within each stratum. The mean surface DO for all strata was 6.79
mg/L, with a high of 9.74 mg/L in the Choptank and a low of 5.23 mg/L in the
Severn/South. The mean bottom DO was only slightly lower than the mean surface
readings, 6.02 mg/L, and there was only one location in Tangier Sound where DO levels
fell below 4.0 mg/L. The mean water clarity depth for all stations was 1.16 m (range 0.45
– 2.00 m), which was in between the high in May, 1.22m, and the low in July, 0.99m. As
in May and July, Calvert Cliffs had the highest water clarity reading with a mean of
1.77m, and the Patapsco stratum had the poorest water clarity with a mean depth of
0.68m. The Little Choptank stratum had the second highest secchi depth, 1.37m, with
some readings as high as 2.00m, and we sampled the Little Choptank on the Monday,
September 22, two days after Isabel.
Sampling Dates
Stratum
# of Trawls
# of Fish Caught
Total Weight (kg)
# of Species
9/8/03 - 10/3/03
Chester
Eastern Bay
Choptank
Little Choptank
Tangier Sound
Pocomoke Sound
Patapsco
Severn/South
Calvert Cliffs
9
9
12
9
25
20
8
9
10
101
156
1913
704
2220
3834
2224
431
480
8.34
4.71
8.35
3.02
30.07
32.79
46.75
15.91
0.95
7
10
13
8
17
15
13
11
8
Total
111
12063
150.89
28
Table 1. Summary of the Sept./Oct. 2003 survey sampling intensity and catch results.
Common Name
Total N
Total Weight (g) Mean Length (mm)
Alewife Herring
American Eel
Atlantic Menhaden
Atlantic Silverside
Bay Anchovy
Black Drum
Black Sea Bass
Blackcheek Tounguefish
Blue Crab
Brown Bullhead
Channel Catfish
Feather Blenny
Harvestfish
Hickory Shad
Hogchoker
Horseshoe Crab
18
1
2
17
8651
2
4
1
483
4
2
1
19
2
224
19
120.0
22.0
68.0
39.0
8737.5
147.0
283.0
30.0
49119.0
770.0
50.0
*****
187.0
6.0
5103.0
*****
Lizardfish
Naked Goby
Northern Pipefish
Northern Puffer
Northern Sea Robin
Oyster Toadfish
Spot
Striped Anchovy
Striped Bass
Summer Flounder
Weakfish
White Perch
9
14
4
3
14
3
336
78
204
5
314
1629
431.0
6.0
1.0
344.0
488.0
259.0
18549.0
375.0
3131.5
1104.0
4763.0
56769.0
S.D.
Range (mm)
94.8
243.0
153.0
69.0
52.1
172.0
166.3
146.0
121.5
238.3
148.0
50.0
65.8
82.5
100.9
*****
5.54
*****
9.90
8.78
10.33
5.66
17.46
*****
31.12
48.02
8.49
*****
26.79
3.53
15.79
*****
89 - 111
*****
146 - 160
50 - 83
23 - 95
168 - 176
149 - 190
*****
21 - 185
189 - 304
142 - 154
*****
19 - 116
80 - 85
58 - 162
*****
194.1
38.8
117.8
145.0
153.1
174.3
155.6
81.7
107.1
275.0
100.1
143.1
43.85
7.78
26.92
43.59
28.74
16.86
15.58
13.07
35.27
61.88
49.70
59.22
83 - 225
24 - 55
92 - 141
115 - 195
64 - 192
155 - 186
127 - 235
47 - 115
62 - 385
235 - 384
22 - 253
54 - 305
Table 2. Biological characteristics of all species caught during the Sept./Oct. 2003
survey.
Sept/Oct Catch Comparisons - By Strata
Mean Catch Tow
-1
400
350
300
250
200
150
100
50
C
ve
rt
Se
ll
ra
C
al
O
ve
lif
f
s
h
ou
t
ve
rn
/S
ta
ps
c
o
e
Pa
Po
co
m
ok
er
ng
i
ho
pt
Li
ttl
e
C
C
ho
Ta
an
k
nk
pt
a
B
er
n
st
Ea
C
he
s
te
r
ay
0
Figure 2. Strata comparison of the overall (all species) catch tow-1 for the Sept./Oct. 2003
sampling period.
Yearly Species Diversity Comparison - Sept./Oct.
2001
2002
2003
tC
lif
fs
O
ve
ra
ll
# of Species Tow
-1
7
th
8
6
5
4
3
2
1
C
al
ve
r
So
u
n/
co
Pa
ta
ps
ie
r
Ta
ng
co
m
ok
e
Po
Se
ve
r
Li
ttl
e
C
ho
C
ho
pt
pt
an
k
an
k
ay
B
Ea
st
er
n
C
he
st
er
0
Figure 3. Species diversity comparisons, measured as # of species tow-1, across survey
years.
Monthly Catch Comparisons - 2003
100
90
May
Mean Catch Tow -1
80
July
Sept/Oct
70
60
50
40
30
20
10
0
Anchovy
Blue Crab
Croaker
White
Perch
Hogchoker Weakfish
Striped
Bass
Spot
Yearly Sept./Oct. Catch Comparisons - All Strata
St
r
ip
ed
Sp
ot
2003
B
as
s
2002
ea
kf
is
h
W
H
og
ch
ok
er
rc
h
Pe
hi
te
W
C
ro
ak
er
e
C
ra
b
2001
B
lu
100
90
80
70
60
50
40
30
20
10
0
A
nc
ho
vy
Mean Catch Tow
-1
Figure 4. Monthly, i.e. seasonal, comparison of catch rates (catch tow-1) for a few of the
most common species found during the three surveys.
Figure 5. Figure 4. Yearly comparison of Sept./Oct. catch rates (catch tow-1) for a few of
the most common species found during the three survey years. 2001 – 107 trawls, 2002 –
120 trawls, 2003 – 111 trawls.