Accuracy and Precision of Fish Ages - Northeast
January 05, 2021
It is important to ensure consistency in fish ages used in fish population assessments. The Fishery Biology Program in the Northeast conducts age and growth studies and completes regular testing to provide measures of consistency and accuracy.
Fishery Biology Program staff regularly test themselves to ensure their ages are precise and accurate. This table summarizes the results of precision testing for 2016–2020. Full information is linked above.
|
Species |
Number of Tests |
Number of Fish Aged |
Number of Fish Tested |
CV (%) |
Agreement (%) |
|---|---|---|---|---|---|
|
Bass, Black Sea |
27 |
15,617 |
2,154 |
2.40 |
86.6 |
|
Bluefish |
7 |
2,173 |
439 |
2.48 |
89.3 |
|
Butterfish |
15 |
8,237 |
993 |
4.32 |
88.1 |
|
Cod, Atlantic |
30 |
24,847 |
2,356 |
0.13 |
99.5 |
|
Flounder, Summer |
29 |
17,300 |
2,440 |
1.86 |
89.5 |
|
Flounder, Windowpane |
2 |
585 |
100 |
6.85 |
74.4 |
|
Flounder, Winter |
19 |
9,139 |
1,628 |
2.02 |
86.3 |
|
Flounder, Witch |
29 |
8,904 |
1,903 |
1.40 |
86.4 |
|
Flounder, Yellowtail |
38 |
15,771 |
2,663 |
1.79 |
90.7 |
|
Haddock |
28 |
35,182 |
2,611 |
0.42 |
97.2 |
|
Hake, Red |
10 |
7,658 |
906 |
2.82 |
87.2 |
|
Hake, Silver |
30 |
23,823 |
2,525 |
1.60 |
94.1 |
|
Hake, White |
20 |
5,561 |
1,076 |
2.29 |
92.7 |
|
Herring, Atlantic |
11 |
7,295 |
1,002 |
0.93 |
92.4 |
|
Mackerel, Atlantic |
19 |
7,618 |
1,400 |
0.77 |
97.5 |
|
Plaice, American |
25 |
13,888 |
2,195 |
4.10 |
67.3 |
|
Pollock |
23 |
9,551 |
1,681 |
0.39 |
96.2 |
|
Redfish, Acadian |
9 |
5,557 |
762 |
1.95 |
72.9 |
|
Scup |
19 |
10,524 |
1,628 |
3.73 |
79.1 |
|
Surfclam, Atlantic |
1 |
659 |
94 |
0.43 |
95.7 |
|
Tilefish, Golden |
11 |
5,823 |
915 |
3.01 |
75.5 |
Agreement: the percentage of fish where the two ages matched. A perfect result is 100 percent; over 80 percent is acceptable.
CV: a statistic which accounts for the relative difference between ages. A perfect result is 0 percent; under 5 percent is acceptable.