Spatial differences in the trace element concentrations of Irish Sea plaice Pleuronectes platessa and whiting Merlangius merlangus otoliths

Estimating connectivity between juvenile and adult fish habitats can provide an important contribution to effective fisheries management, through a better understanding of population resilience to harvesting pressure. Indirect methods for quantifying connectivity, such as geochemical or genetic techniques, allow us to assign adults from various sampling regions to their natal location, provided that natal origin data can be defined. The elemental composition of otoliths from juvenile sole Solea solea collected at 4 sampling locations in the Southern Bight of the North Sea was measured using laser-ablation inductively-coupled plasma mass spectrometry (LA-ICPMS), to determine elemental fingerprints indicative of distinct nursery grounds. Significant differences in elemental composition were detected among the 4 locations, with Na, Sr, Ba, Mn and Rb concentrations varying the most between groups. A discriminant model resulted in high assignment proportions of the juvenile fish to their respective nursery grounds with a total jackknife reclassification success of 88%. Even though some interannual variability in otolith chemistry was observed in juveniles from the Scheldt estuary, spatial patterns seemed to dominate. Our results constitute a firm basis for future investigations on nursery area contributions and quality, adult dispersal history and applications of population traceability.KEY WORDS: Connectivity · Juvenile fish · Nursery · Otolith microchemistry · Traceability · Solea solea Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 401: [211][212][213][214][215][216][217][218][219][220] 2010 provide insights into the spatio-temporal connectivity on an evolutionary time scale (in the order of hundreds of generations) (Hedgecock et al. 2007). In marine fish, however, the chances of detecting strong genetic structure, applicable to management decisions, are low because even few migrants suffice to prevent detectable differentiation , Hartl & Clark 2007. Since the 1980s, otolith elemental composition has increasingly been used to describe life histories of fish, study small scale variability in seasonal and within-generation migrations and identify the various environments fish have experienced. The use of trace elements in otoliths is based on the empirical evidence that fish incorporate elements from their environments and that these elements are permanently deposited in their continuously growing otoliths (Campana 1999, Thresher 1999. Consequently, the chemical composition of otoliths differs among fish from different geographical areas and constitutes a powerful multielemental signal reflecting the surrounding physical and chemical environment (Vasconcelos et al. 2007). Juvenile fish that have lived in different coastal environments or estuaries are often characterised by a distinct otolith composition, referred to as the elemental fingerprint. Analysis of otolith composition has been successfully applied in a wide range of flatfish species living in di...

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

Microchemical variation in juvenile Solea solea otoliths as a powerful tool for studying connectivity in the North Sea

Cuveliers¹,

Geffen²,

Guelinckx³

et al. 2010

“…In addition, the bioavailability of elements to the mother from ambient seawater may vary among sites (e.g. Geffen et al 2003) due to variation in the input (e.g. runoff, atmospheric deposition) and removal of elements in seawater (e.g.…”

Section: Egg-source Effectsmentioning

confidence: 99%

“…Multiple field studies have found Mn in calcified structures useful for discriminating among individuals from different sites (e.g. DiBacco & Levin 2000, Geffen et al 2003, and correlative studies on coral aragonite have found that Mn:Ca ratios are inversely related to upwelling intensity (e.g. Delaney et al 1993).…”

Section: Culture Seawater Effectsmentioning

confidence: 99%

Egg source, temperature and culture seawater affect elemental signatures in Kelletia kelletii larval statoliths

Lloyd¹,

Zacherl

Walker³

et al. 2008

Elemental signatures have been used as a tool to track individual organisms to their natal site in an attempt to understand stock structure and larval dispersal. However, factors that affect elemental signatures are not well understood. We conducted a factorial experiment using whelk Kelletia kelletii larvae from Salta Verde Point on Catalina Island, Los Angeles Harbor, and White Point, Palos Verdes peninsula, California, USA, to test the effects of egg source, temperature (10, 14 and 18°C) and culture seawater on the elemental composition of larval statoliths. Intra-capsular contents of newly laid capsules were also analyzed to explore whether maternal contributions might affect larval statolith chemistry. Using inductively coupled plasma mass spectrometry we quantified ratios of 7 elements to calcium in both intra-capsular contents and cultured statoliths and provided the first evidence of significant egg-source effects, independent of subsequently experienced environmental conditions, on statolith elemental signatures for Mg:Ca, Ba:Ca and Pb:Ca. Intra-capsular and statolith element ratios showed no clear relationship that might have indicated possible maternal transfer of elements to larvae. Culture seawater elemental concentration was positively related to statolith Ba:Ca and Pb:Ca, and temperature was negatively related to statolith Sr:Ca, Ba:Ca and Pb:Ca, while no significant effects were found for Mn:Ca or Zn:Ca. Effect-size estimates show that elements responded differently to factors within the variation measured in this study; the major effects for Ba and Pb were temperature and egg source, respectively. The significant effect of egg source on elemental signatures has potentially important implications for tracking free-spawned larvae. KEY WORDS: Statolith · LA ICP-MS · Dispersal · Egg source · Relative effects · Elemental signature · Kelletia kelletiiResale or republication not permitted without written consent of the publisher Mar Ecol Prog Ser 353: 115-130, 2008 natural signatures of stock structure (e.g. , as records of dispersal and migration pathways (e.g. Ikeda et al. 2003) and for identifying spawning and nursery grounds (e.g. Gillanders & Kingsford 2003).In particular, the elemental composition of the larval calcified structures of fish (Swearer et al. 1999), crabs (DiBacco & Levin 2000), bivalves (Becker et al. 2007) and gastropods (Zacherl 2005) has potential to elucidate much useful information about larval origin and dispersal trajectories. Many larvae begin forming their calcified structures at or near the site of production and, thus, potentially carry a permanent elemental signature of the site of origin. When larvae enter the water column and move through ocean masses with variable physical and chemical characteristics, these changes can be recorded in the elemental composition of calcified structures. In principle, not only can the site of origin be identified, but subsequent larval movement also can be tracked using statolith elemental signatures.To identify any particul...

“…isotopic analysis of the otoliths, in addition to trace element analysis; Thorrold et al 1998a). In the Bay of Biscay, up to 91% of Solea solea juveniles were correctly assigned to their origin (De Pontual et al 2000), but few other studies have used these techniques for European estuaries (Daverat et al 2004), or coastal areas (Gillanders et al 2001, Geffen et al 2003. It is of fundamental importance to address this issue for improvement of stock assessments and for common stock management, because these estuarine environments are significant nursery areas for several highly commercial species intensively fished within the European Union.…”

mentioning

confidence: 99%

Discriminating estuarine nurseries for five fish species through otolith elemental fingerprints

Vasconcelos

Patrick²,

Tanner³

et al. 2007

Chemical composition of otoliths may provide valuable information in establishing connectivity between nursery grounds and marine coastal stocks. Juveniles of the commercially important fish species Solea solea, S. senegalensis, Platichthys flesus, Diplodus vulgaris and Dicentrarchus labrax were captured in 8 estuarine nursery grounds along the Portuguese coast in July 2005. Concentrations of Li, Na, Mg, K, Mn, Ni, Cu, Zn, Sr, Cd, Ba and Pb were determined in whole juvenile otoliths using solution-based inductively coupled plasma mass spectrometry. Significant differences in the concentration of several elements were found between estuaries and species using ANOVA and MANOVA. Linear discriminant function analysis classified otolith fingerprints between estuaries for all species with good cross-validated results. Depending on the species, 70.2 to 92.0% of individuals were correctly assigned to their estuary of origin, with discrimination success varying with species, estuaries and number of estuaries in the analysis. Since accurate classification of juvenile fish to their nursery estuary was achieved, fingerprint analysis can be used as a natural habitat tag in assigning adult fish to their estuarine nursery. Ultimately the connectivity between Portuguese estuarine nursery grounds and coastal areas may be estimated, with possible implications for future fisheries and coastal management plans. KEY WORDS: Otolith microchemistry · Fingerprint · Juvenile fish · Estuary · Nursery · PortugalResale or republication not permitted without written consent of the publisher Mar Ecol Prog Ser 350: 117-126, 2007 (Kalish 1990, Tsukamoto & Arai 2001, (2) populations or stocks of fish (Campana 1999, Rooker et al. 2003 and (3) natal origin to near shore and estuarine habitats , Thorrold et al. 1998a, Dorval et al. 2005, Brown 2006a. This is possible due to some particular properties of otoliths reviewed by Campana (1999), Thresher (1999) and Elsdon & Gillanders (2003). Briefly, otoliths are metabolically inert and trace element uptake reflects the surrounding physical and chemical environment, although incorporation of some elements is affected by physiological regulation. Otoliths are deposited continually and contain daily and annual growth rings that can be used as life-history records reflecting habitat change through time, providing good natural tags of habitat use.Taking into account otolith properties, coastal fish that spent their juvenile period in estuaries are expected to have an otolith elemental composition which reflects their estuarine life period. The elemental composition of whole juvenile otoliths is commonly used to discriminate juvenile sites of origin as it is representative of the juvenile habitat (Thorrold et al. 1998a, Gillanders & Kingsford 2000, De Pontual et al. 2000, Dorval et al. 2005, Brown 2006b). Analysis of different regions of otoliths gives information on separate periods of ontogenetic development of the individuals. Point measurements done across daily or annual increments have be...