scholarly journals Linear decline in red snapper (Lutjanus campechanus) otolith Δ14C extends the utility of the bomb radiocarbon chronometer for fish age validation in the Northern Gulf of Mexico

2018 ◽  
Vol 75 (5) ◽  
pp. 1664-1671 ◽  
Author(s):  
Beverly K Barnett ◽  
Laura Thornton ◽  
Robert Allman ◽  
Jeffrey P Chanton ◽  
William F Patterson
Keyword(s):  
Gulf Of Mexico ◽  
Red Snapper ◽  
Lutjanus Campechanus ◽  
Age Validation ◽  
Data Set ◽  
Northern Gulf Of Mexico ◽  
Significant Difference ◽  
Bomb Radiocarbon ◽  
Relationship Of ◽  
Age Estimates

Abstract Radiocarbon (Δ14C) was analyzed in northern Gulf of Mexico (nGOM) red snapper (Lutjanus campechanus) otolith cores (n = 23), otolith edge samples (n = 12), and whole age-0 otoliths (n = 9), with edge samples and whole age-0 otoliths constituting known-age samples. There was no significant difference in the linear relationship of Δ14C versus year of formation between regional corals and known-age otolith samples, and a linear regression fit to the combined data from 1980 to 2015 extends the utility of the bomb radiocarbon chronometer for age validation. The entire regional coral and known-age otolith data set (1940 to 2015) was then utilized as a reference series to validate otolith-derived red snapper age estimates for cored otolith samples. A loess regression was fit to the reference data and then the sum of squared residuals (SSR) was computed from predicted versus observed birth years for cored adult otolith samples. This process was then repeated for ages biased ±1–4 years. Ages with no bias applied had the lowest SSR, thus validating red snapper age estimates and demonstrating the utility of the combined regional coral and known-age red snapper otolith Δ14C time series for age validation of nGOM marine fishes.

Otolith Microchemical Fingerprints of Age-0 Red Snapper, Lutjanus campechanus, from the Northern Gulf of Mexico

1998 ◽  
Vol 16 (1) ◽  
Author(s):  
William F. Patterson ◽  
James H. Cowan ◽  
Elizabeth Y. Graham ◽  
W. Berry Lyons
Keyword(s):  
Gulf Of Mexico ◽  
Red Snapper ◽  
Lutjanus Campechanus ◽  
Northern Gulf Of Mexico

Red Snapper: Ecology and Fisheries in the U.S. Gulf of Mexico

2007 ◽  
Keyword(s):  
Time Series ◽  
Gulf Of Mexico ◽  
Mississippi River ◽  
Red Snapper ◽  
Survey Area ◽  
Lutjanus Campechanus ◽  
Data Set ◽  
Stock Size ◽  
Central Texas ◽  
The U.S

<em>Abstract.</em>—Eleven taxa of snappers were found among the 20,301 snapper larvae examined from over 14,000 bongo and neuston samples collected during SEAMAP surveys, 1982 to 2003. During that time series, a total of 639 red snapper <em>Lutjanus campechanus </em>larvae were identified in bongo samples and 1053 larvae in neuston samples. Red snapper larvae first appeared in May and were present as late as November. Months of highest occurrence and abundance were July and September when larvae were taken in 12.7% and 11.0% of bongo samples, and in 7.6% and 8.4% of neuston samples. Mean abundance in those months was 1.18 and 0.82 larvae under 10 m<sup>2</sup> of sea surface for bongo samples and 0.36 larvae per 10 min for neuston samples. By November, percent occurrence was less than or equal to 0.2% and mean abundance was less than 0.01 larvae in samples from either gear. Larvae identifiable as red snapper ranged in body length from 2.4 to 19.2 mm (mean = 5.12, median = 4.60) in bongo net samples; and 2.7–24.0 mm (mean = 4.37, median = 4.00) in neuston net samples. Over 95% of larvae in bongo samples were less than or equal to 8.3 mm and in neuston samples were less than or equal to 5.6 mm. Larvae were captured throughout the survey area but were consistently observed in greatest abundance at stations on the mid-continental shelf west of the Mississippi River, especially off western Louisiana and central Texas. This time series of observations is the data set from which annual estimates of larval red snapper abundance were derived for use as a fishery independent index of adult stock size.

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