Fisheries Research 159 (2014) 95–104 Contents lists available at ScienceDirect Fisheries Research j ourna l ho me page: www.elsevier.com/locate/fishres Connectivity of capelin (Mallotus villosus) between regions and spawning habitats in Newfoundland inferred from otolith chemistry Gail K. Davoren a,∗ , Norman M. Halden b a Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada b Department of Geological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada a r t i c l e i n f o Article history: Received 20 March 2014 Received in revised form 15 May 2014 Accepted 19 May 2014 Handling Editor Prof. George A. Rose Available online 20 June 2014 Keywords: Capelin Mallotus villosus Otolith microchemistry Connectivity Spawning habitat a b s t r a c t Capelin (Mallotus villosus) is an important, highly migratory marine forage fish in many northern marine ecosystems. During 2009, spawning capelin were collected from beach and nearby deeper water (15–40 m) spawning habitats in two regions of Newfoundland ∼200 km apart (Bellevue, Trinity Bay; Lumsden, Notre Dame Bay). We used otolith chemistry to investigate connectivity by testing if age- specific chemical signatures differed between fish from different regions or spawning habitats. Trace element concentrations (strontium, barium) did not differ between regions but did between spawning habitats. Otolith strontium and barium during the larval period (i.e. pre-metamorphosis) resulted in suc- cessfully classifying fish spawning in each habitat (71–77%). This suggests that beach and deep-water spawning fish experienced different environmental conditions during the larval period and, thus, pos- sibly represent different behavioral types or contingents within the broader capelin population. These findings are in contrast to previous studies showing a lack of population structuring between beach and deep-water spawning fish using life history, morphometric and molecular markers (i.e. microsatel- lites). Fisheries management should aim to maintain this intraspecific complexity to buffer against future climate change and shifting fishing practices. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Connectivity refers to the degree to which organisms from spa- tially separated groups within a species mix during their lifespan. Understanding connectivity in marine fish provides insight into the level of gene flow (e.g. local adaptation) among subsets of the population and the degree of self-recruitment within sub- sets either due to larval retention near natal habitat (e.g. Swearer et al., 1999) or natal homing (e.g. Thorrold et al., 2001). Identi- fying population structure allows predictions about the ability of population subsets to occupy new habitats, the long-term stability of population dynamics (e.g. Schindler et al., 2010) and effec- tive protected area design (Di Franco et al., 2012). Connectivity is often difficult to determine in marine fish that have a high dis- persal potential as planktonic larvae and/or are highly migratory as adults. To overcome this challenge, scientists have used the chem- istry and structure of otoliths, or ‘earstones’, as natural tags of ∗ Corresponding author at: Department of Biological Sciences, 212B Biological Sciences Building, 50 Sifton Road, University of Manitoba, Winnipeg, MB R3T 2N2, Canada. Tel.: +1 2044747497. E-mail address: gail.davoren@ad.umanitoba.ca (G.K. Davoren). habitats experienced as well as life history patterns (e.g., age- specific growth, metamorphosis, spawning), because otoliths are metabolically inert once formed (Campana, 1999). Incorporation rates of some trace elements (e.g., Sr, Ba) into otoliths are in direct proportion to ambient concentrations (Bath et al., 2000; Elsdon and Gillanders, 2004; Walther and Thorrold, 2006), but rates can be modified under varying environmental conditions, such as tem- perature and salinity (Elsdon and Gillanders, 2003; Elsdon et al., 2008), the degree to which may be physiologically-determined (e.g., Kalish, 1991; Sadovy and Severin, 1992; Walther et al., 2010). Regardless of these complexities, age-specific growth and chemical patterns in otoliths have revealed the degree of connectivity within and among life stages of marine fish species (e.g. Fowler et al., 2005; Steer et al., 2009; Aldanondo et al., 2010; Di Franco et al., 2012). Capelin is a small, short-lived (3–6 years) forage fish that many top predators rely on as prey in northern marine ecosystems (Carscadden and Vilhjálmsson, 2002). In the center of their dis- tribution off the east coast of Newfoundland (NAFO Divs. 3K and 3L, Fig. 1), capelin larvae hatch from coastal spawning areas in the summer/fall and begin to disperse to offshore nursery areas near the shelf edge (i.e. 500 m depth contour; Carscadden et al., 2013a). After a possible short retention period near natal habi- tat (weeks to months; Frank and Carscadden, 1989; Pedersen http://dx.doi.org/10.1016/j.fishres.2014.05.010 0165-7836/© 2014 Elsevier B.V. All rights reserved.