<p>A complete understanding of past El Niño-Southern Oscillation (ENSO) fluctuations is important for the future predictions of regional climate using climate models. Reconstructions of past ENSO dynamics use carbonate oxygen isotope ratios (δ<sup>18</sup>O<sub>c</sub>) and trace metal geochemistry (Mg / Ca) recorded by planktonic foraminifera to reconstruct past spatiotemporal changes in upper ocean conditions. We investigate whether planktonic foraminifera-based proxies offer sufficient spatiotemporal continuity with which to reconstruct past ENSO dynamics. Concentrating upon the period of the instrumental record, we use the <i>Foraminifera as Modelled Entities</i> model to statistically test whether or not δ<sup>18</sup>O<sub>c</sub> and the Temperature signal (T<sub>c</sub>) in planktonic foraminifera directly records the ENSO cycle. Our results show that it is possible to use δ<sup>18</sup>O<sub>c</sub> from foraminifera to disentangle the ENSO signal only in certain parts of the Pacific Ocean. Furthermore, a large proportion of these areas coincide with sea-floor regions exhibiting a low sedimentation rate and/or water depth below the carbonate compensation depth, thus precluding the extraction of a temporally valid palaeoclimate signal using long-standing palaeoceanographic methods.</p>