A 120‐year record of resilience to environmental change in brachiopods

Abstract

The inability of organisms to cope in changing environments poses a major threat to their survival. Rising carbon dioxide concentrations, recently exceeding 400 μatm, are rapidly warming and acidifying our oceans. Current understanding of organism responses to this environmental phenomenon is based mainly on relatively short- to medium-term laboratory and field experiments, which cannot evaluate the potential for long-term acclimation and adaptation, the processes identified as most important to confer resistance. Here, we present data from a novel approach that assesses responses over a centennial timescale showing remarkable resilience to change in a species predicted to be vulnerable. Utilising museum collections allows the assessment of how organisms have coped with past environmental change. It also provides a historical reference for future climate change responses. We evaluated a unique specimen collection of a single species of brachiopod (Calloria inconspicua) collected every decade from 1900 to 2014 from one sampling site. The majority of brachiopod shell characteristics remained unchanged over the past century. One response, however, appears to reinforce their shell by constructing narrower punctae (shell perforations) and laying down more shell. This study indicates one of the most calcium-carbonate-dependent species globally to be highly resilient to environmental change over the last 120 years and provides a new insight for how similar species might react and possibly adapt to future change.

Variation in brachiopod microstructure and isotope geochemistry under low pH–ocean acidification–conditions

“…The punctal pattern detected here is different from that observed by Cross et al (2018), who recorded no change in the punctal density of the ventral valve of C. inconspicua on specimens from the last 120 years. Also different is the trend in size of the endopunctae, which measured in the dorsal valve only by Cross et al (2018), seems to decrease in size. However, the environmental conditions of the natural ambient of 0.1 pH unit decrease and 2°C increase over the last two decades (refs.…”

“…This applies to calcium carbonate shell-forming species, such as brachiopods and mollusks, because they are considered excellent archives documenting how changes in environmental conditions can affect marine organisms (e.g., Kurihara. 2008;Comeau et al, 2009;Watson et al, 2012, Hahn et al, 2012Cross et al, 2015Cross et al, , 2016Cross et al, , 2018Crippa et al, 2016a;Milano et al, 2016;Garbelli et al, 2017;Jurikova et al, in review).…”

“…Overall, there appears to be little to no effect on brachiopod morphology or chemistry with lower seawater pH (Cross et al, 2015(Cross et al, , 2016(Cross et al, , 2018. Culture experiment a) pH 8.16, T 16.5, S 33.9, pCO2 465, Ω calcite 3.5 b) pH 7.79, T 16.9, S 33.9, pCO2 1130, Ω calcite 1.6 c) pH 7.62, T 16.6, S 33.9, pCO2 1536, Ω calcite 1.3 at pH 7.62 than the control conditions Calloria inconspicua (Sowerby, 1846) N = 389 (adults) Punctae width decreased by 8.26%, shell density increased by 3.43%, no change in shell morphology, punctae density, shell thickness, and shell elemental composition (Ca, Mg, Na, Sr and P) One specimen collected every decade from one locality Last two decades pH reduced 0.1 unit Temperature varied from 10.7-13.0 ℃ pCO2 varied from 320-400 Salinity and Ω of calcite not provided 120-year record Cross et al, 2018 Liothyrella uva (Broderip, 1833)…”

Variation in brachiopod microstructure and isotope geochemistry under low-pH–ocean acidification conditions

“…A limiting factor is the small database, but in general, the present observations agree with studies that show no or little impact of acidification on the growth rates of marine calcifiers (cf. Marchant et al, 2010;Thomsen et al, 2010;Range et al, 2011Range et al, , 2012Talmage and Gobler, 2011;Dickinson et al, 2012;Fernández-Reiriz et al, 2012;Liu and He, 2012;Hiebenthal et al, 2013;Cross et al, 2015Cross et al, , 2016Cross et al, , 2018, or even an increase in respiration, shell growth or metabolic rates after having experienced low-pH conditions (Wood et al, 2008;Cummings et al, 2011;Parker et al, 2012). We note however that a combined effect of multiple stressors, such as low pH, lower dissolved oxygen and higher temperature or scarce food availability is more complex and potentially detrimental.…”

A brachiopod biotope associated with rocky bottoms at the shelf break in the central Mediterranean Sea: Geobiological traits and conservation aspects

“…Global warming might be especially important, and could modify the water mass sustaining the brachiopod community by affecting nutrient content, current strength, and flow path. The effects of ocean acidification on brachiopod calcite are less likely to hinder the shell calcification process (Cross, Peck, & Harper, ; Ye et al, ). Thus, we do not foresee major concerns over the short to midterm for the continued survival of the Bb.…”