DOI: 10.5061/dryad.cn55b
title: Data from: Coupling biogeochemical tracers with fish growth reveals physiological and environmental controls on otolith chemistry

description: Biogeochemical tracers found in the hard parts of organisms are frequently
 used to answer key ecological questions by linking the organism with the
 environment. However, the biogeochemical relationship between the
 environment and the biogenic structure becomes less predictable in higher
 organisms as physiological processes become more complex. Here, we use the
 simultaneous combination of biogeochemical tracers and fish growth
 analyzed with a novel modeling framework to describe physiological and
 environmental controls on otolith chemistry in an upwelling zone. First,
 we develop increasingly complex univariate mixed models to describe and
 partition intrinsic (age effects) and extrinsic (environmental parameters)
 factors influencing fish growth and otolith element concentrations through
 time. Second, we use a multivariate mixed model to investigate the
 directionality and strength between element-to-element and growth
 relationships and test hypotheses regarding physiological and
 environmental controls on element assimilation in otoliths. We apply these
 models to continuous element (Na, Sr, Mg, Ba, Li) and growth increment
 profiles (monthly resolution over 17 years) derived from otoliths of reef
 ocean perch (Helicolenus percoides), a wild-caught, site-attached, fully
 marine fish. With a conceptual model, we hypothesize that otolith traits
 (elements and growth) driven by environmental conditions will correlate
 both within an otolith, reflecting the time dependency of growth and
 element assimilation, and among individuals that experience a similar set
 of external conditions. We found some elements (Sr:Ca and Na:Ca) are
 mainly controlled by physiological processes, while other elements (Ba:Ca
 and Li:Ca) are more environmentally influenced. Within an individual fish,
 the strength and direction of correlation varies among otolith traits,
 particularly those under environmental control. Correlations among
 physiologically regulated elements tend to be stronger than those
 primarily controlled by environmental drivers. Surprisingly, only Ba:Ca
 and growth are significantly correlated among individuals. Failure to
 appropriately account for intrinsic effects (e.g. age) led to inflated
 estimates of among individual correlations and a depression of within
 individual correlations. Together, the lack of among-individual
 correlations of otolith traits in properly formulated models and the
 biases that can be introduced by not including appropriate intrinsic
 covariates suggest that caution is needed when assuming multi-elemental
 signatures are reflective solely of shared environments.
description: Sr:Ca
 dataStrontium trace element
 data (Sr:Ca) from ocean perch otoliths for each discrete monthly time
 period extracted from laser ablation ICP-MS data. These data are used in
 the univariate mixed modeling analysis for the response variable of Sr:Ca.
 IDCode: unique identifier for each fish. Age.years.cap: age of the fish in
 years at date of capture. Age.month.cap: age of the fish in months at date
 of capture. Month.code.cap: month code for the date of capture, e.g. 75 =
 Dec 1996. FishID: = IDCode. SrCa: value of the Sr:Ca ratio for that
 discrete monthly time period (μmol/mol) extracted from the laser ablation
 ICP-MS data. Month: a code designating the specific month and year of each
 monthly resolved increment (i.e. 75 = Dec 1996, 76 = Jan 1997, etc.). Age:
 age when each monthly increment was formed (total months). fMonth = Month
 (as factor).SrCadata.txtNa:Ca dataSodium trace element data (Na:Ca) from ocean perch otoliths for each discrete monthly time period extracted from laser ablation ICP-MS data. These data are used in the univariate mixed modeling analysis for the response variable of Na:Ca. IDCode: unique identifier for each fish. Age.years.cap: age of the fish in years at date of capture. Age.month.cap: age of the fish in months at date of capture. Month.code.cap: month code for the date of capture, e.g. 75 = Dec 1996. FishID: = IDCode. NaCa: value of the Na:Ca ratio for that discrete monthly time period (μmol/mol) extracted from the laser ablation ICP-MS data. Month: a code designating the specific month and year of each monthly resolved increment (i.e. 75 = Dec 1996, 76 = Jan 1997, etc.). Age: age when each monthly increment was formed (total months). fMonth = Month (as factor).NaCadata.txtMg:Ca dataMagnesium trace element data (Mg:Ca) from ocean perch otoliths for each discrete monthly time period extracted from laser ablation ICP-MS data. These data are used in the univariate mixed modeling analysis for the response variable of Mg:Ca. IDCode: unique identifier for each fish. Age.years.cap: age of the fish in years at date of capture. Age.month.cap: age of the fish in months at date of capture. Month.code.cap: month code for the date of capture, e.g. 75 = Dec 1996. FishID: = IDCode. MgCa: value of the Mg:Ca ratio for that discrete monthly time period (μmol/mol) extracted from the laser ablation ICP-MS data. Month: a code designating the specific month and year of each monthly resolved increment (i.e. 75 = Dec 1996, 76 = Jan 1997, etc.). Age: age when each monthly increment was formed (total months). fMonth = Month (as factor).MgCadata.txtBa:Ca dataBarium trace element data (Ba:Ca) from ocean perch otoliths for each discrete monthly time period extracted from laser ablation ICP-MS data. These data are used in the univariate mixed modeling analysis for the response variable of Ba:Ca. IDCode: unique identifier for each fish. Age.years.cap: age of the fish in years at date of capture. Age.month.cap: age of the fish in months at date of capture. Month.code.cap: month code for the date of capture, e.g. 75 = Dec 1996. FishID: = IDCode. BaCa: value of the Ba:Ca ratio for that discrete monthly time period (μmol/mol) extracted from the laser ablation ICP-MS data. Month: a code designating the specific month and year of each monthly resolved increment (i.e. 75 = Dec 1996, 76 = Jan 1997, etc.). Age: age when each monthly increment was formed (total months). fMonth = Month (as factor).BaCadata.txtLi:Ca dataLithium trace element data (Li:Ca) from ocean perch otoliths for each discrete monthly time period extracted from laser ablation ICP-MS data. These data are used in the univariate mixed modeling analysis for the response variable of Li:Ca. IDCode: unique identifier for each fish. Age.years.cap: age of the fish in years at date of capture. Age.month.cap: age of the fish in months at date of capture. Month.code.cap: month code for the date of capture, e.g. 75 = Dec 1996. FishID: = IDCode. LiCa: value of the Li:Ca ratio for that discrete monthly time period (μmol/mol) extracted from the laser ablation ICP-MS data. Month: a code designating the specific month and year of each monthly resolved increment (i.e. 75 = Dec 1996, 76 = Jan 1997, etc.). Age: age when each monthly increment was formed (total months). fMonth = Month (as factor).LiCadata.txtGrowth increment dataGrowth increment measurements from ocean perch otoliths for each discrete monthly time period. These data are used in the univariate mixed modeling analysis for the response variable of Growth. IDCode: unique identifier for each fish. Age.years.cap: age of the fish in years at date of capture. Age.month.cap: age of the fish in months at date of capture. Month.code.cap: month code for the date of capture, e.g. 75 = Dec 1996. FishID: = IDCode. Growth: measured value of the growth increment for a discrete monthly time period (μm). Month: a code designating the specific month and year of each monthly resolved increment (i.e. 75 = Dec 1996, 76 = Jan 1997, etc.). Age: age when each monthly increment was formed (total months). fMonth = Month (as factor).growthdata.txtEnvironmental dataEnvironmental (extrinsic) variables used in the univariate mixed modeling analyses to partition monthly variation of the response variables (Na:Ca, Sr:Ca, Mg:Ca, Ba:Ca, Li:Ca or Growth) between intrinsic and extrinsic drivers. Month: A code designating the specific month and year of each monthly resolved increment (i.e. 75 = Dec 1996, 76 = Jan 1997, etc.). BonneyUI: Monthly upwelling index for the Bonney Coast region of southern Australia (See Figure 2 and Table 1 for details). BottomTemp: monthly mean bottom temperature (C) for Bonney upwelling region (See Table 1 for details). Chl-a: levels of chlorophyll a (mg/m3) in the Bonney upwelling region (See Table 1 for details).AllEnviData.csvData for all response variablesData for all response variables (Na:Ca, Sr:Ca, Mg:Ca, Ba:Ca, Li:Ca and Growth) collected from ocean perch otoliths for each discrete monthly time period. Element:Ca data are extracted from laser ablation ICP-MS data and Growth data are growth increment measurements. These data are used in the multivariate mixed modeling analysis to estimate within and among individual correlations. Age.years.cap: age of the fish in years at date of capture. Age.month.cap: age of the fish in months at date of capture. Month.code.cap: month code for the date of capture, e.g. 75 = Dec 1996. FishID: = IDCode. Growth: measured value of the growth increment for a discrete monthly time period (μm). NaCa, SrCa, MgCa, BaCa, or LiCa: value of the Element:Ca ratio for that discrete monthly time period (μmol/mol) extracted from the laser ablation ICP-MS data. Month: a code designating the specific month and year of each monthly resolved increment (i.e. 75 = Dec 1996, 76 = Jan 1997, etc.). Age: age when each monthly increment was formed (total months). fMonth = Month (as factor).alldata.csv