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Dataset: Impact of early Danian environmental perturbations on mid-latitude planktic foraminiferal assemblages from the ODP Site 1262 (South Atlantic Ocean)

<div> <div> <div> <p><span>After the mass extinction at the Cretaceous/Paleogene (K/Pg) boundary (~66 Ma), life forms quickly radiated to occupy ecological niches in the world’s oceans. Nevertheless, the aftermath of the Chicxulub impact, the massive volcanism of the Deccan Traps and climatic perturbations endured during the early Danian. The impact of consequent carbon cycle perturbations on nascent plankton communities, such as the Dan-C2 event (~65.80 to ~65.71 Ma), is still poorly known. In this work, we present a detailed study of planktic foraminiferal assemblages from Ocean Drilling Program (ODP) Site 1262 (Walvis Ridge, South Atlantic Ocean), spanning the first ~400 kyr of the Danian. No relevant perturbations in planktic foraminiferal assemblages and carbonate preservation indices have been identified at Site 1262 during the Dan-C2 event. Approximately 50 kyr before the beginning of the Dan-C2 event, a Hg-rich interval, potentially linked to the emplacement of the Ambenali Formation of the Deccan Traps massive volcanism, is recorded between ~65.95 and 65.82 Ma. It coincides with an increase in aberrant planktic foraminifera (~65.93 to ~65.82 Ma), allowing to establish a cause-effect relationship. Additionally, a bloom of triserial guembelitriids was recognized between ~65.87 and ~65.78 Ma, also preceding the Dan-C2 event but lagging the Hg-rich interval and the bloom of aberrant planktic foraminifera. The lag time between the first volcanic episode and ecosystem response may be due to factors such as an inefficient biological pump and increases in temperature, microbial activity and food supply at the ocean surface. A second Hg-rich interval identified between ~65.70 and ~65.65 Ma has been tentatively tied to the Mahabaleswar Formation of the Deccan Traps. Neither the second volcanic episode nor the Dan-C2 event resulted in relevant environmental perturbations at Site 1262. This suggests that, although volcanism may have had an impact on early plankton communities in the early Danian through metal contamination, marine ecosystems likely became progressively more stable and resistant to changes in volcanic emissions and the carbon cycle. </span></p> </div> </div> </div>

F I G U R E 6 in Variation in the post-smolt growth pattern of wild one sea-winter salmon (Salmo salar L.), and its linkage to surface warming in the eastern North Atlantic Ocean

F I G U R E 6 Back-calculated mean body length (±95% confidence interval) of Salmo salar at the midpoint of the winter annulus, following the conclusion of the post-smolt growth period

F I G U R E 1 in Variation in the post-smolt growth pattern of wild one sea-winter salmon (Salmo salar L.), and its linkage to surface warming in the eastern North Atlantic Ocean

F I G U R E 1 Hierarchical cluster analysis of intercirculus spacing for scales of Salmo salar. (a) The dendrogram for k = 20 using Euclidean distance and Ward linkage for z-scored and interpolated data. The five major sub-branches (A–E) and the 20 clusters are ordered sequentially from the left. (b) The standardized intercirculus spacing plots for the 20 clusters. Clusters are colour-coded and ordered as in (a). The LOESS fits for each cluster are shown as a black line and the number of fish per cluster (n) is also shown

F I G U R E 2 in Variation in the post-smolt growth pattern of wild one sea-winter salmon (Salmo salar L.), and its linkage to surface warming in the eastern North Atlantic Ocean

F I G U R E 2 Tabulation of significant under- and over-representation of the 10 most frequent growth pattern categories (and "Others") for Salmo salar scales amongst the 20 dendrogram clusters. Proportions of growth pattern frequency were compared to the overall population proportion of scales for k = 20 with Ward linkage, and clustering of the z-scored and interpolated data. Light shading (−) indicates significant under-representation and dark shading (+) indicates over-representation. Sample sizes (n) for each growth pattern across the time-series are shown

F I G U R E 4 in Variation in the post-smolt growth pattern of wild one sea-winter salmon (Salmo salar L.), and its linkage to surface warming in the eastern North Atlantic Ocean

F I G U R E 4 Time-series changes in ocean surface temperature and Salmo salar scale growth pattern. (a) Changes in monthly SST anomaly for the 250 and 500 km standard deviation spatially weighted kernels in the Norwegian Sea (April 1992 – March 2011). (b) Changes in frequency (proportion within years) of selected growth patterns. The three selected pattern groupings illustrate fish showing persistent Fast growth (F) throughout the post-smolt growth season, Slow growth followed by Fast growth (SF), and all patterns pooled that displayed one or more growth Checks. The growth pattern data for each capture year (b) are aligned with the SST anomaly in April of the previous year (a), coinciding with the commencement of annual smolt emigration

F I G U R E 5 in Variation in the post-smolt growth pattern of wild one sea-winter salmon (Salmo salar L.), and its linkage to surface warming in the eastern North Atlantic Ocean

F I G U R E 5 Monthly correlations between the SST anomalies throughout the post-smolt Salmo salar growth period and annual frequency of the Fast (F) and All Check growth patterns. The salmon data were lagged by -1 year to match the annual post-smolt growth seasons to the SST anomalies. Significant correlations (P <0.05; following adjustment of d.f. to allow for autocorrelation) are shown by the filled circles

Figures 2 and 3 in Variation in the post-smolt growth pattern of wild one sea-winter salmon (Salmo salar L.), and its linkage to surface warming in the eastern North Atlantic Ocean

Figures 2 and 3 summarize the under/over-representation of the more common growth patterns and years, respectively, amongst the k = 20 clusters. The SF growth pattern was over-represented for four of the five clusters of sub-branch A, in association with general underrepresentation of patterns showing an initial Fast (F) sequence (Figure 2). Sub-branch B revealed an essentially inverse structure to sub-branch A, with sporadic over-representation of patterns commencing with a Fast sequence and under-representation of those with an initial Slow sequence. Sub-branches C and D were heterogeneous

F I G U R E 3 in Variation in the post-smolt growth pattern of wild one sea-winter salmon (Salmo salar L.), and its linkage to surface warming in the eastern North Atlantic Ocean

F I G U R E 3 Tabulation of significant under- and overrepresentation of the 20 dendrogram clusters amongst years of capture of return adult Salmo salar. Details as for Figure 2

Figure 4b in Variation in the post-smolt growth pattern of wild one sea-winter salmon (Salmo salar L.), and its linkage to surface warming in the eastern North Atlantic Ocean

Figure 4b shows that there was (a) a decrease in the frequency of fish showing consistently Fast growth throughout the post-smolt period, (b) an increase in the frequency of the SF growth pattern and (c) an increase in the frequency of growth patterns including one or more Check sequences. Furthermore, these time-series changes in circulus pattern were linked significantly to contemporaneous and anomalous warming of the Norwegian Sea (Figure 5). As shown in Figure 6, one proximate consequence of these changes is manifest in the backcalculated mean length of fish at the midpoint of the winter annulus, following the completion of the post-smolt growth season. This showed a marked and significant decrease across the final six capture years of the time series.

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Figure 4. P in Description of Pseudoameiropsis suphankaraytugi sp. nov. (Copepoda: Harpacticoida: Ameiridae) with the first report of the genus Pseudoameiropsis Pallares, 1982 outside of the South Atlantic Ocean

Figure 4. P. suphankaraytugi sp. nov., holotype, ♀, swimming legs, anterior: a) P1, b) P2, c) P3, d) P4.

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Figure 3. P in Description of Pseudoameiropsis suphankaraytugi sp. nov. (Copepoda: Harpacticoida: Ameiridae) with the first report of the genus Pseudoameiropsis Pallares, 1982 outside of the South Atlantic Ocean

Figure 3. P. suphankaraytugi sp. nov., holotype, ♀: a) A1, b) A2, c) labrum, d) mandibular gnathobase, e) mandibular palp, f) maxillule, g) maxilla, h) maxilliped.

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Figure 2. P in Description of Pseudoameiropsis suphankaraytugi sp. nov. (Copepoda: Harpacticoida: Ameiridae) with the first report of the genus Pseudoameiropsis Pallares, 1982 outside of the South Atlantic Ocean

Figure 2. P. suphankaraytugi sp. nov., holotype, ♀: a) urosome, ventral; b) anal somite and caudal rami, dorsal; c) P5.

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FIG. 1. — Orygmatobothrium schmittii n in A new Orygmatobothrium Diesing, 1863 (Eucestoda, Tetraphyllidea) parasite of Mustelus schmitti Springer, 1939 (Carcharhiniformes, Triakidae) from the southwestern Atlantic Ocean

FIG. 1. — Orygmatobothrium schmittii n. sp.; A, scolex; B, gravid proglottid (ventral view); C, cross section throught proglottid at level of ovary; D, detail of terminal genitalia with everted cirrus (lateral view); E, egg. Abbreviations: d, dorsal; v, ventral; o, ovary; od, oviduct; dod, dorsal osmorregulatory duct; vod, ventral osmoregulatory duct; mg, mehlis glands; va, vagin; vf, vitelline follicles; u, uterus. Scale bars: A-C, 0.2 mm; B, 1 mm; D, 0.05 mm; E, 0.01 mm.

Fig. 46 in The Mollusca of Galicia Bank (NE Atlantic Ocean)

Fig. 46. Percentage of the different trophic groups, in number of live-taken individuals (left) and species represented by at least one live-taken specimen (right).

Fig. 48 in The Mollusca of Galicia Bank (NE Atlantic Ocean)

Fig. 48. Number of Galicia Bank species shared with other distant regions of the Atlantic (Bay of Biscay, Ibero-Moroccan region, seamounts of Lusitanian region and Western Atlantic).

Fig. 42. Cuspidariidae. A–C in The Mollusca of Galicia Bank (NE Atlantic Ocean)

Fig. 42. Cuspidariidae. A–C. Rhinoclama teres (Jeffreys, 1882), BANGAL 0711, V5, 1631 m, 12.8 mm and 10.6 mm. D–F. Rhinoclama semistrigosa (Jeffreys, 1882), BANGAL 0711, V7, 1462 m, 9.1 and 8.7 mm. G–I. Cuspidaria cf. rostrata (Spengler, 1793), BANGAL 0711, V3, 818 m, 14.6 and 15.2 mm. Scale bars = 1 mm.

Fig. 49 in The Mollusca of Galicia Bank (NE Atlantic Ocean)

Fig. 49. Similarity between Galicia Bank and other areas of the North Atlantic, based on presence/ absence data of molluscan species and on the Bray-Curtis similarity index. Areas as on Fig. 48.

Fig. 44. Scaphopoda. A–C in The Mollusca of Galicia Bank (NE Atlantic Ocean)

Fig. 44. Scaphopoda. A–C. Fissidentalium capillosum (Jeffreys, 1877), shell and soft parts, BANGAL 0711, V2, 1706 m, shells 80 and 74 mm. D–F. Antalis agilis (M. Sars in G.O. Sars, 1872), ECOMARG 0709, V5, 876 m, 32.8 mm and details of the posterior end. G–H. Bathoxiphus ensiculus (Jeffreys, 1877), BANGAL 0711, V5, 1631 m, 14.0 mm. I–J. Cadulus monterosatoi Locard, 1897, BANGAL 0711, V9, 1671 m, 7.2 mm. K. Cadulus artatus Locard, 1897. BANGAL 0711, V2, 4.3 mm. L. Pulsellum lofotense (M. Sars, 1865), BANGAL 0711, V2, 7.1 mm. Scale bars: A–D = 10 mm; E–L = 1 mm.

Fig. 47. A in The Mollusca of Galicia Bank (NE Atlantic Ocean)

Fig. 47. A gastropod of the genus Colus Röding, 1798 (probably C. gracilis (da Costa, 1778)), roaming a sedimentary bottom of the summit platform where there are abundant brittlestars and small bivalves of the genus Limopsis Sasso, 1827 (probably L. minuta (Philippi, 1836), white dots in the photograph). Photo: Indemares project; Bangal_E09L1_0080.

Fig. 45. Similarity between samples from the BANGAL 0711 in The Mollusca of Galicia Bank (NE Atlantic Ocean)

Fig. 45. Similarity between samples from the BANGAL 0711 campaign, based on presence/absence data of living specimens for molluscan species and on the Bray-Curtis similarity index (A, all samples; B, beam trawl samples only). Sample labels with depth in brackets. A similar topology was obtained using the abundance data transformed to fourth root.