Annulus Formation - Distant and River Recaps
LGCarlson
12/17/2019
Data processing
JoinID = ReleaseYear_TagNo
wrong_JoinID = RecaptureYear_TagNo
Batch_TagID = BatchNo_TagNo
Data Exploration and Visualization
Most fish in the dataset were presently 1SW fish (with 1 annulus) that were caught in Greenland, so they were destined to be 2SW fish. However, a few 2SW fish were caught at sea, and a few hundred were caught upon their river return.
Circulus deposition is not a linear process, neither over a single year (seasonally variable) nor over a lifetime (deposition rate decreases over a lifetime)
There is a large amount of variation in circulus deposition rate among individuals.
The average deposition rate is 11.4, but deposition rate varies by number of marine annuli
| Number of marine annuli | Mean circuli/day | SD circuli/day | n | Mean days at sea | SD days at sea |
|---|---|---|---|---|---|
| 0 | 9.43 | 2.92 | 37 | 84.73 | 27.67 |
| 1 | 11.05 | 1.42 | 1317 | 474.26 | 39.20 |
| 2 | 13.66 | 1.32 | 242 | 794.93 | 30.87 |
Calculate annulus formation date using individual average deposition rate
last.annulus - M1 if 1SW or M2 if 2SW
plus.growth - number of circuli after the last.annulus
afterm1 - number of circuli after the first marine annulus
The mean date of marine entry is May 3. The mean date of first annulus completion for 1SW (destined to be 2SW fish) is March 12.
With a constant individual average depsoition rate, the mean date of first annulus completion for 2SW fish is May 26. The second annulus completion date is May 2.
Annulus completion date by month of completion.
| Annulus Type | Recapture Month | Marker Month (mean) | Marker Month (mode) | n |
|---|---|---|---|---|
| firstannulus | 6 | 2.2 | 2 | 55 |
| firstannulus | 7 | 2.6 | 2 | 276 |
| firstannulus | 8 | 2.7 | 3 | 506 |
| firstannulus | 9 | 3.1 | 3 | 269 |
| firstannulus | 10 | 3.7 | 4 | 100 |
| firstannulus | 11 | 3.6 | 4 | 73 |
| firstannulus | 12 | 4.3 | 4 | 28 |
| noannuli | 7 | 4.8 | 5 | 24 |
| noannuli | 8 | 4.9 | 5 | 12 |
| secondannulus | 5 | 4.8 | 4 | 5 |
| secondannulus | 6 | 4.2 | 4 | 105 |
| secondannulus | 7 | 4.7 | 5 | 90 |
| secondannulus | 8 | 5.0 | 5 | 18 |
| secondannulus | 9 | 5.1 | 7 | 17 |
| secondannulus | 10 | 7.0 | 5 | 5 |