NOTE Chittenden et al.: Spatial and temporal occurrence of Scomberomorus maculatus 



153 



CO 



LU 



X 



o 



m 



I 

 o 

 h- 

 < 

 o 



10-20 



5-10 

 1-5 



<1 — r 



A EASTERN SHORE 



° i ° 9° 



>20-i 



10-20 



5-10 



1-5 



<1 — - 



0-~ 



1 10 20 30 9 19 29 9 19 29 

 MAR APR MAY 



1 °-2°-|C REEDVILLE 



5-10 

 1-5- 



I 18 28 8 18 28 7 17 27 6 16 26 6 16 26 5 15 25 

 JUNE JULY AUG SEP OCT NOV 



-rfi <p O , Q 



1 10 20 30 9 19 29 9 19 29 8 18 28 8 18 28 7 17 27 6 16 26 6 16 26 5 15 25 

 MAR APR MAY JUNE JULY AUG SEP OCT NOV 



C 90 

 30 



20 



10 



1 10 20 30 9 19 29 9 19 29 8 18 28 8 18 28 7 17 27 6 16 26 6 16 26 5 15 25 

 MAR APR MAY JUN JUL AUG SEP OCT NOV 



DATES 

 Figure 2 



Estimates of daily Spanish mackerel Scomberomorus maculatus catches (no. of 22.6 kg boxes landed) in 1989 in 

 Chesapeake Bay: (A) Eastern Shore, (B) lower York River, (C) Reedville, and (D) Lynnhaven, with daily water 

 temperatures (E) at Kiptopeke and off the Chesapeake Bay Bridge-Tunnel. All data contacts are indicated. Zero 

 catches are indicated by open circles. One box = 22.6 kg fish. "First" and "Last" indicate dates when first and last fish 

 were captured; this is not specified when a long time-lapse in sampling occurred before the "First" or after the "Last" 

 record. 



effect on temporal trends, however, because the same 

 number of nets was generally used in a fishery through- 

 out the season. 



To make significance tests for differences between 

 areas, we converted the raw catch records to catch- 

 per-unit-effort (C/f) by using the nominal number of 



nets (Table 1) to estimate effort. The resulting C/f 

 records were then scored into the categories described 

 above. This procedure does not change the original 

 scores for records of "no catch" or "<1 box"; it does tend 

 to lower scores for larger catches, thereby making it 

 more difficult to declare significance. 



