Multiple Regression Models of δ¹³C and δ¹⁵N for Fish Populations in the Eastern Gulf of Mexico

Authors

Kara R. Radabaugh, University of South Florida
Ernst B. Peebles, University of South FloridaFollow

Document Type

Article

Publication Date

2014

Keywords

Dynamic model, Remote sensing, Carbon nitrogen stable isotope, Spatial variation, Isoscape, Continental shelf fish

Digital Object Identifier (DOI)

https://doi.org/10.1016/j.csr.2014.05.002

Abstract

Multiple regression models were created to explain spatial and temporal variation in the δ¹³C and δ¹⁵N values of fish populations on the West Florida Shelf (eastern Gulf of Mexico, USA). Extensive trawl surveys from three time periods were used to acquire muscle samples from seven groundfish species. Isotopic variation (δ¹³C_var and δ¹⁵N_var) was calculated as the deviation from the isotopic mean of each fish species. Static spatial data and dynamic water quality parameters were used to create models predicting δ¹³C_var and δ¹⁵N_var in three fish species that were caught in the summers of 2009 and 2010. Additional data sets were then used to determine the accuracy of the models for predicting isotopic variation (1) in a different time period (fall 2010) and (2) among four entirely different fish species that were collected during summer 2009. The δ¹⁵N_var model was relatively stable and could be applied to different time periods and species with similar accuracy (mean absolute errors 0.31–0.33‰). The δ¹³C_var model had a lower predictive capability and mean absolute errors ranged from 0.42 to 0.48‰. δ¹⁵N trends are likely linked to gradients in nitrogen fixation and Mississippi River influence on the West Florida Shelf, while δ¹³C trends may be linked to changes in algal species, photosynthetic fractionation, and abundance of benthic vs. planktonic basal resources. These models of isotopic variability may be useful for future stable isotope investigations of trophic level, basal resource use, and animal migration on the West Florida Shelf.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Continental Shelf Research, v. 84, p. 158-168

Scholar Commons Citation

Radabaugh, Kara R. and Peebles, Ernst B., "Multiple Regression Models of δ¹³C and δ¹⁵N for Fish Populations in the Eastern Gulf of Mexico" (2014). Marine Science Faculty Publications. 2271.
https://digitalcommons.usf.edu/msc_facpub/2271