# Presentation: 886811

## Tree-ring techniques for Pacific rockfish otoliths: 

**Tree-ring techniques for Pacific rockfish otoliths: **
**age validation, chronology development, and **
**effects of ocean variability**

**Bryan Black****1****, George Boehlert****1****, and Mary Yoklavich****2**
**         ****1. ****	****Hatfield Marine Science Center****	****2. NMFS Southwest Fisheries Science Center**
**	****	****Oregon State University****	****	****Santa Cruz Laboratory****	****	**
**	****	****Newport, Oregon ****	****	****Santa Cruz, CA**
**	****	**

**NOAA fisheries FATE program **

## The Concept: otoliths are environmental chronometers

**The Concept: **otoliths are environmental chronometers

## The Concept: otoliths are environmental chronometers

**	****1. Physiological and developmental status**
**	****	****(age, vigor, sex)**
**	****2. Physical environment**
**	****	****(temperature, upwelling)**
**	****3. Biological environment**
**	****	****(competition, food availability)**
**FATE goals: effects of environment on population**
**Important information for stock assessment**

**The Concept: **otoliths are environmental chronometers

## Original analytical approach

**(Boehlert, Yoklavich & Chelton. 1989, Fish. Bull.)**

**Otolith sections cut, animals aged to estimate birthyear**
**Measurement of first 6 years of growth back-calculated**
**New analysis: time series through 1994; additional sample depth**

## Target Species

**Target Species**

- 100

- 0

- 20

- 40

- 60

- 80

- 1880

- 1900

- 1920

- 1940

- 1960

- 1980

- 2000

**canary rockfish**
**growth increment sample depth**

**splitnose rockfish**
**growth increment sample depth**

## Chronology development

**	****- within each of the 6 age groups:**
**	****         ****GI – GI**

**Chronology development**

**std dev (GI)**

***z*****   =**

**Calculate average *****z***** for each calendar year; **
**yields 6 chronologies**

## Anomaly time series

**Anomaly time series**

***canary rockfish***

***splitnose rockfish***

**-1**

**0**

**1**

**-1**

**0**

**1**

**-1**

**0**

**1**

**-1**

**0**

**1**

**-1**

**0**

**1**

**-1**

**0**

**1**

**1920**

**1930**

**1940**

**1950**

**1960**

**1970**

**1980**

**1990**

**2000**

**1940**

**1950**

**1960**

**1970**

**1980**

**1990**

**2000**

**-1**

**0**

**1**

**-1**

**0**

**1**

**-1**

**0**

**1**

**-1**

**0**

**1**

**-1**

**0**

**1**

**-1**

**0**

**1**

- 1

- 2

- 3

- 4

- 5

- 6

## Anomaly time series

**Anomaly time series**

- -0.6

- -0.4

- -0.2

- 0

- 0.2

- 0.4

- 0.6

- 1920

- 1940

- 1960

- 1980

- 2000

- -0.6

- -0.4

- -0.2

- 0

- 0.2

- 0.4

- 0.6

- 1920

- 1940

- 1960

- 1980

- 2000

***splitnose rockfish***

***canary rockfish***

## Anomaly time series

**Anomaly time series**

- -1.5

- -1

- -0.5

- 0

- 0.5

- 1

- 1.5

- 1920

- 1940

- 1960

- 1980

- 2000

- yr1

- yr2

- yr3

- yr4

- yr5

- yr6

***splitnose rockfish***

- -1.5

- -1

- -0.5

- 0

- 0.5

- 1

- 1.5

- 1920

- 1940

- 1960

- 1980

- 2000

- yr1

- yr2

- yr3

- yr4

- yr5

- yr6

***canary rockfish***

## Interchronology correlations

**Interchronology correlations**

**Average correlation in 10-year moving windows**
**High frequency variability**
**	****splitnose: 1960 - 1994**
**	****canary: 1970 - 1994**

## Effects of environment

***coastal variables (38******°****** to 50******°****** N)******	******; Colbert & Schirripa***
**	****1. Sea surface temperature (1967 –1994)**
**	****2. Upwelling index (1946 – 1994)**
**	****3. Sea level pressure (1967 – 1994)**
***basin-wide variables***
**	****3. Pacific Decadal Oscillation (PDO) (1900 – 1994)**
**	****4. Northern Oscillation Index (NOI) (1948 - 1994)**

**Effects of environment**

## Effects of environment

**Correlate rockfish chronologies with seasonal averages**
**of environmental variables**

**Effects of environment**

**winter: Dec – Feb**
**spring: Mar – May**
**summer: June – Aug**
**fall: Sep – Nov**

## 1

***canary***

- SST

- PDO

- SLP

- UW

- NOI

***splitnose rockfish***

- -0.6

- 0

- 0.6

- -0.6

- 0

- 0.6

- -0.6

- 0

- 0.6

- -0.6

- 0

- 0.6

- -0.8

- 0

- 0.8

- -0.8

- 0

- 0.8

- summer (L)

- fall (L)

- winter

- spring

- summer

- fall

- summer (L)

- fall (L)

- winter

- spring

- summer

- fall

***splitnose***

- -0.6

- 0

- 0.6

- -0.6

- 0

- 0.6

- -0.6

- 0

- 0.6

- -0.6

- 0

- 0.6

- -0.6

- 0

- 0.6

- -0.6

- 0

- 0.6

- 2

- 3

- 4

- 5

- 6

## Applications of Dendrochronology

**Applications of Dendrochronology**

**Assign correct calendar year **
**Quantify effects of climate**
**on adults; population-wide**

## Applications of Dendrochronology

**	****(at least 15 or 20 years)**
**Must have more than just 6 increments per otolith!**

**Applications of Dendrochronology**

- many trees hundreds of
- years old; some thousands
- ex. Englemann spruce

- photo: H.D. Grissino-Mayer, Ultimate tree-ring web pages

## Extend otolith time series

**New Axis of Measurement:**

**Extend otolith time series**

- old axis (6 years)

## New axis of measurement

**New axis of measurement**

## Dendrochronology Procedures

**climate affects radial growth**
**-induces synchronous growth patterns**
**-growth patterns should match among samples**
**-if not: error likely**
**method: *****crossdating***

**Dendrochronology Procedures**

## Crossdating

**Photo credit: H.D. Grissino-Mayer, The Ultimate Tree-Ring Web Pages**

**Crossdating**

**direction of growth**

## Crossdating

**Synchronous growth in ponderosa pine**
***N***** = 10 trees**

**Crossdating**

## Crossdating

**Synchronous growth in ponderosa pine**
**example:***** N***** = 10 trees**

**Crossdating**

## Crossdating

**Crossdating**

## Crossdating

**Synchronous growth in splitnose rockfish**

**Crossdating**

## but  we only want the climate signal

**	****-correlate all otoliths with one another**
**	****-low correlation = potential errors**
**	**
***but*****  we only want the climate signal**
**otoliths growth increments also reflect**
**	****-age, vigor, sex, artifacts of **
**            ****preparation, error**

**Crossdating**

## Crossdating

**high frequency (year-to-year) variation**
**	****-due almost exclusively to climate **
**	****-statistically valid for correlations:**
**	****          ****independent**
**Isolate climate (high frequency) signal *****and***
**reduce autocorrelation via:**
**     ****	****DETRENDING**

**Crossdating**

## Detrending

**	**
**Divide the measurements by the fitted function**
**	****-reduces long-term trends (autocorrelation)**
**	****-stabilizes variance**
**	****-all otolith time series have a mean of 1**
**Thus, *****all otolith time series are equally weighted, ***
***also statistically valid for correlation*****	**

**Detrending**

## Detrending

**Detrending**

- 0

- 0.01

- 0.02

- 0.03

- 0.04

- 0.05

- 0.06

- 0.07

- 0.08

- 1930

- 1940

- 1950

- 1960

- 1970

- 1980

- 1990

**year**

**ring width (mm)**

## Detrending

**Detrending**

**ring width**
**measurements,**
**splines**

## Detrending

**all splitnose residual chronologies**
***N***** = 15**

**Detrending**

## Crossdating

**Correlate each otolith with sample-wide averages**

**Crossdating**

## Crossdating

**Step 1: select the first otolith time series**

**Crossdating**

**selected series**

## Crossdating

**Crossdating**

## r = 0.62 p < 0.001

**Step 3: correlate single series with average of others**

**Crossdating**

**average of remaining 14 series**

**r = 0.62 p < 0.001**

**selected series**

## r = -0.11

**If we overlooked 1983 (combined 1984 and 1983)**

**Crossdating**

**average of remaining 14 series**

**r = -0.11**

**selected series**
**with error**

## Crossdating

**Step 4: repeat for each of the series**

**Crossdating**

**selected series**

**r = 0.58**

## Crossdating

**Step 4: repeat for each of the series**

**Crossdating**

**selected series**

**r = 0.64**

## Crossdating

**Step 4: repeat for each of the series**

**Crossdating**

**selected series**

**r = 0.45**

## Crossdating

**Crossdating**

| sample 1 | r = 0.62 |
| --- | --- |
| sample 2 | r = 0.58 |
| sample 3 | r = 0.64 |
| sample 4 | r = 0.45 |
| sample 5 | r = 0.49 |
| sample 6 | r = 0.64 |
| sample 7 | r = 0.44 |
| sample 8 | r = 0.60 |
| sample 9 | r = 0.72 |
| sample 10 | r = 0.61 |
| sample 11 | r = 0.71 |
| sample 12 | r = 0.61 |
| sample 13 | r = 0.21 |
| sample 14 | r = 0.17 |
| sample 15 | r = 0.43 |
| average | r = 0.528 |

## Crossdating

**Crossdating**

| sample 1 | r = 0.62 |
| --- | --- |
| sample 2 | r = 0.58 |
| sample 3 | r = 0.64 |
| sample 4 | r = 0.45 |
| sample 5 | r = 0.49 |
| sample 6 | r = 0.64 |
| sample 7 | r = 0.44 |
| sample 8 | r = 0.60 |
| sample 9 | r = 0.72 |
| sample 10 | r = 0.61 |
| sample 11 | r = 0.71 |
| sample 12 | r = 0.61 |
| sample 13 | r = 0.21  potential problems |
| sample 14 | r = 0.17  potential problems |
| sample 15 | r = 0.43 |
| average | r = 0.528 |

## Crossdating

**remeasure, drop, or**
**keep problematic **
**series**
**typical eastern forests**
**hemlock: 0.3 – 0.4**
**oaks: 0.5 – 0.6**

**Crossdating**

| sample 1 | r = 0.62                   r = 0.69 |
| --- | --- |
| sample 2 | r = 0.58                   r = 0.59 |
| sample 3 | r = 0.64                   r = 0.66 |
| sample 4 | r = 0.45                   r = 0.45 |
| sample 5 | r = 0.49                   r = 0.50 |
| sample 6 | r = 0.64                   r = 0.62 |
| sample 7 | r = 0.44                   r = 0.45 |
| sample 8 | r = 0.60                   r = 0.54 |
| sample 9 | r = 0.72                   r = 0.72 |
| sample 10 | r = 0.61                   r = 0.63 |
| sample 11 | r = 0.71                   r = 0.70 |
| sample 12 | r = 0.61                   r = 0.61 |
| sample 13 | r = 0.21                   r = 0.42 |
| sample 14 | r = 0.17                   r = 0.55 |
| sample 15 | r = 0.43                   r = 0.43              |
| average | r = 0.528          r = 0.570 |

***N***** = 15****                   *****N***** = 15**

## Chronology development

**Average of 15 time series**

**Chronology development**

## Full data set: 50 otoliths

**Splitnose captured in 1989 and 1995;  ISC = 0.512**
**Average of all 50 time series**

**Full data set: 50 otoliths**

- splitnose master chronology

## Effects of environment: splitnose

**Effects of environment: splitnose**

- -0.8

- -0.6

- -0.4

- -0.2

- 0

- 0.2

- 0.4

- 0.6

- 0.8

- summer (L)

- fall (L)

- winter

- spring

- summer

- fall

**correlation coefficient**

**SST**

**PDO**

**SLP**

**UW**

**NOI**

- *

- *

- *

- *

- *

- *

- *

- *

- *

- * if *p* < 0.05

## Crossdating in canary rockfish

***N***** = 43 canary otoliths measured**
**Chronology timespan: 1945-1994**
**interseries correlation:  *****r***** = 0.412**
**(compare to 0.512 for splitnose)**

**Crossdating in canary rockfish**

## Canary chronology

**Canary rockfish;  ISC = 0.412**
**Average of all 43 time series**

**Canary chronology**

## Effects of environment: canary

**Effects of environment: canary**

- -0.6

- -0.4

- -0.2

- 0

- 0.2

- 0.4

- 0.6

- summer (L)

- fall (L)

- winter

- spring

- summer

- fall

**SST**

**PDO**

**SLP**

**UW**

**NOI**

- *

- *

- * if *p* < 0.05

## Chronology comparison

**Chronology comparison**

## Effects of environment: comparison

**Effects of environment: comparison**

**SST**

**PDO**

**SLP**

**UW**

**NOI**

- -0.8

- -0.6

- -0.4

- -0.2

- 0

- 0.2

- 0.4

- 0.6

- 0.8

**correlation coefficient**

- splitnose rockfish

- canary rockfish

## Conclusions

**Dendrochronology: improved accuracy **
**	****- will become more widely used in fisheries**
**	****- establish effects of environment**
**	****- puts contemporary growth in context **
**	****  ****of past growth**
**BA Black, GW Boehlert, MM Yoklavich. 2005. Using tree-ring crossdating techniques to validate age in long-lived fishes.  *****Canadian Journal of Fisheries and Aquatic Sciences.***** In Press**

**Conclusions**

## Future Directions

**	****and competition**
**Yelloweye: ideal for exploring spatial variability**
**	****- Gulf of Alaska to California Current**
**	****- trees: stand specific chronologies, what ****	****  ****	****   about fish?**

**Future Directions**

## Contact Information

**Hatfield Marine Science Center**
**Newport, OR 97365**
**(541) 867-0283**
**Bryan.Black@oregonstate.edu**

**Contact Information**