Physical versus biological control of element incorporation into biogenic carbonate: an in situ experiment in a New Zealand fjord

Abstract

We exploit the pronounced and persistent low salinity layer in Doubtful Sound, southwest New Zealand, as a natural experimental system with sharp environmental gradients in which to study physical versus biological control of element incorporation into biogenic carbonate. Mussels Mytilus galloprovincialis transplanted to cages in the low salinity layer and saline layer in inner, mid and outer fjord habitats were used as biological integrators of physico-chemical conditions in each water mass over a period of several months. We used solution inductively coupled plasma mass spectrometry (ICP-MS) to measure the concentrations of 15 elements (Li, B, Mg, P, S, Mn, Fe, Co, Cu, Zn, Rb, Sr, Cd, Ba, Pb) in the experimental shell growth and relate spatial trends to those in salinity and elemental sources. S concentrations were consistently below detection limits while Zn and Rb showed no spatial variability. The majority of elements were subject to environmental control, likely reflecting ambient concentrations and salinity. Sr incorporation showed evidence of strong biological mediation of environmental signals via the crystal shell growth rate. These findings are a valuable addition to the growing body of literature seeking to resolve physical versus biological controls of individual trace element incorporation into biogenic carbonates, and have important consequences for their use as environmental indicators or tracers for ecological studies. KEY WORDS: Trace elements · ICP-MS · Mussels · FjordResale or republication not permitted without written consent of the publisher

Otolith elemental evidence for spatial structuring in a temperate reef fish population

“…The same experimental fish displayed a transition in stable isotopic signatures after relocation, reflecting differences in the basal food web between habitats (Rodgers & Wing 2008). Physico-chemical conditions in inner and outer Doubtful Sound are markedly different (Gibbs et al 2000, Gibbs 2001 and mussels transplanted to cages in the inner, mid and outer fjord acquired discrete elemental fingerprints (Beer et al 2011).…”

Ocean acidification can interact with ontogeny to determine the trace element composition of bivalve shell

“…The trace elemental composition of biogenic calcium carbonate (CaCO 3 ) structures such as shells or otoliths reflect the physicochemical properties of the water in which they are formed (Beer et al 2011;Poulain et al 2015). Therefore, the trace elemental composition of CaCO 3 structures can provide valuable information on the water mass in which they were produced.…”

“…In addition to this change in the carbonate equilibrium reaction, the availability of ions will also be affected (Millero et al 2009). As the incorporation of trace elements into biogenic CaCO 3 is affected by both the availability of ions and a number of other environmental and physiological processes (Beer et al 2011), the composition of these carbonate structures is likely to be affected by changes in oceanic pH (Hoffmann et al 2012;Frieder et al 2014, Levin et al 2015.…”

Natural trace elemental markers for adult red rock lobsters Jasus edwardsii vary among replicate distinct water masses

“…Along these gradients, consistent patterns in larval dispersal and adult movement patterns likely result in a source−sink structure for populations of benthic invertebrates (Wing et al 2003, Perrin et al 2004) and fish (Rodgers & Wing 2008, Lawton et al 2010, as well as the red rock lobster Jasus edwardsii (Jack et al 2009. In addition, the strong physical gradients associated with the surface low-salinity layer influence distinct patterns in incorporation of trace elements into biogenic carbonate of mussels Mytilus galloprovincialis (Beer et al 2011). These characteristics result in an ideal testing ground for the use of natural tags for resolving geographic patterns in populations of J. edwardsii.…”

“…Influences on variability of trace elemental tags in biogenic carbonates are described by a growing body of experimental and field-based research (Thorrold et al 2007, Elsdon et al 2008, Beer et al 2011. Some elements are consistent indicators of spatial variability in environmental parameters, such as water chemistry, salinity and temperature, as they are incorporated into calcified structures via substitution for calcium (e.g.…”