Biodiversity of Spongosorites coralliophaga (Stephens, 1915) on coral rubble at two contrasting cold-water coral reef settings

The authors would like to thank Bill Richardson (Master), the crew of the RRS James Cook, Will Handley and the Holland-I ROV team. We also thank all the specialists in taxonomy that provided important help with identification of species: Professor Paul Tyler (ophiuroids), Dr. Tammy Horton (amphipods), Dr. Graham Oliver (bivalves), Dr. Rob van Soest (sponges), Susan Chambers, Peter Garwood, Sue Hamilton, Raimundo Blanco Pérez (polychaetes). Also we would like to thank Val Johnston (University of Aberdeen) for her contribution to cruise preparations and John Polanski (University of Aberdeen) for his help onboard the RRS James Cook. Special thanks to Dr. Alexios P. Lolas (University of Thessaly, Greece) for all the artwork. Funding for the JC073 cruise was provided by the Natural Environment Research Council (NERC) UK Ocean Acidification (UKOA) research programme’s Benthic Consortium project (NE/H017305/1 to JMR). JMR acknowledges support from Heriot-Watt University’s Environment and Climate Change theme. GK was funded by a Marine Alliance for Science and Technology for Scotland (MASTS) Ph.D. scholarship.Peer reviewedPublisher PD

Hidden structural heterogeneity enhances marine hotspots’ biodiversity

Studies in terrestrial and shallow-water ecosystems have unravelled the key role of interspecific interactions in enhancing biodiversity, but important knowledge gaps persist for the deep sea. Cold-water coral reefs are hotspots of biodiversity, but the role of interspecific interactions and “habitat cascades” (i.e. positive effects on focal organisms mediated by biogenic habitat formation) in shaping their biodiversity is unknown. Associations between macrofaunal hosts and epifauna were examined in 47 stations at the Mingulay Reef Complex (northeast Atlantic). In total, 101 (group level) and 340 (species level) unique types of facultative associations formed by 43 hosts and 39 epifaunal species were found. Molluscs and empty polychaete tubes had higher values for the type and number of host-epifaunal associations, the Shannon–Wiener (H) and Margalef (d) indices of the epifauna than the rest of the taxonomic groups (p < 0.05). Hosts’ body size, orientation, surface smoothness, and growth form explained a significant amount of variability (32.96%) in epifauna community composition. Epifaunal species richness (S), H and d were 27.4 (± 2.2%), 56.2 (± 2.8%) and 39.9 (± 2.3%) of the respective values for the total sessile communities living on coral framework. This is intriguing as coral framework is orders of magnitude larger than the size of macrofaunal hosts. It is suggested that bivalves, tunicates and empty polychaete tubes increase habitat heterogeneity and enhance biodiversity through “habitat cascades”, in a similar way that epiphytes do in tropical rainforests. Most macrofaunal habitat suppliers in the studied cold-water coral reef are calcified species and likely susceptible to ocean acidification. This indicates that the impacts of climate change on the total biodiversity, structure and health of cold-water coral reefs may potentially be more severe than previously thought

Listening to limericks: a pupillometry investigation of perceivers’ expectancy

What features of a poem make it captivating, and which cognitive mechanisms are sensitive to these features? We addressed these questions experimentally by measuring pupillary responses of 40 participants who listened to a series of Limericks. The Limericks ended with either a semantic, syntactic, rhyme or metric violation. Compared to a control condition without violations, only the rhyme violation condition induced a reliable pupillary response. An anomaly-rating study on the same stimuli showed that all violations were reliably detectable relative to the control condition, but the anomaly induced by rhyme violations was perceived as most severe. Together, our data suggest that rhyme violations in Limericks may induce an emotional response beyond mere anomaly detection

Ecohydrodynamics of Cold-Water Coral Reefs:A Case Study of the Mingulay Reef Complex (Western Scotland)

Ecohydrodynamics investigates the hydrodynamic constraints on ecosystems across different temporal and spatial scales. Ecohydrodynamics play a pivotal role in the structure and functioning of marine ecosystems, however the lack of integrated complex flow models for deep-water ecosystems beyond the coastal zone prevents further synthesis in these settings. We present a hydrodynamic model for one of Earth's most biologically diverse deep-water ecosystems, cold-water coral reefs. The Mingulay Reef Complex (western Scotland) is an inshore seascape of cold-water coral reefs formed by the scleractinian coral Lophelia pertusa. We applied single-image edge detection and composite front maps using satellite remote sensing, to detect oceanographic fronts and peaks of chlorophyll a values that likely affect food supply to corals and other suspension-feeding fauna. We also present a high resolution 3D ocean model to incorporate salient aspects of the regional and local oceanography. Model validation using in situ current speed, direction and sea elevation data confirmed the model's realistic representation of spatial and temporal aspects of circulation at the reef complex including a tidally driven current regime, eddies, and downwelling phenomena. This novel combination of 3D hydrodynamic modelling and remote sensing in deep-water ecosystems improves our understanding of the temporal and spatial scales of ecological processes occurring in marine systems. The modelled information has been integrated into a 3D GIS, providing a user interface for visualization and interrogation of results that allows wider ecological application of the model and that can provide valuable input for marine biodiversity and conservation applications

Environmental Variability and Biodiversity of Megabenthos on the Hebrides Terrace Seamount (Northeast Atlantic)

We present the first remotely operated vehicle investigation of megabenthic communities (1004–1695 m water depth) on the Hebrides Terrace Seamount (Northeast Atlantic). Conductivity-temperature-depth casts showed rapid light attenuation below the summit and an oceanographic regime on the flanks consistent with an internal tide, and high short-term variability in water temperature, salinity, light attenuation, aragonite and oxygen down to 1500 m deep. Minor changes in species composition (3–14%) were explained by changes in depth, substratum and oceanographic stability, whereas environmental variability explained substantially more variation in species richness (40–56%). Two peaks in species richness occurred, the first at 1300–1400 m where cooler Wyville Thomson Overflow Water (WTOW) mixes with subtropical gyre waters and the second at 1500–1600 m where WTOW mixes with subpolar mode waters. Our results suggest that internal tides, substrate heterogeneity and oceanographic interfaces may enhance biological diversity on this and adjacent seamounts in the Rockall Trough

Sensitivity of a cold-water coral reef to interannual variability in regional oceanography

Aim: We assessed the effects of regional oceanographic shifts on the macrofaunal biodiversity and biogeography of cold-water coral reefs (CWCRs). CWCRs are often hotspots of biodiversity and ecosystem services and are in the frontline of exposure to multiple human pressures and climate change. Almost nothing is known about how large-scale atmospheric variability affects the structure of CWCRs’ communities over ecological timescales, and this hinders their efficient conservation. This knowledge gap is especially evident for species-rich macrofauna, a key component for ecosystem functioning. Location: The Mingulay Reef Complex, a protected biogenic ecosystem in the northeast Atlantic (120–190 m). Methods: A unique time series (2003–2011) at 79 stations was used to make the first assessment of interannual changes in CWCRs’ macrofaunal biodiversity, biogeography and functional traits. We quantified the impacts of interannual changes in North Atlantic Oscillation Index (NAOI)—the major mode of atmospheric variability in the North Atlantic, bottom temperature and salinity alongside static variables of seafloor terrain and hydrography. Results: Environmental gradients explained a significant amount of community composition (urn:x-wiley:13669516:media:ddi13363:ddi13363-math-0001 = 26.7%, p &lt; .01) with interannual changes in bottom temperature, salinity and NAOI explaining nearly twice as much variability than changes in terrain or hydrography. We observed significant differences in community composition, diversity and functional traits but not in species richness across interannual variability in bottom temperature. In warmer years, the biogeographic composition shifted more towards a temperate and subtropical affinity. Main Conclusions: Our findings highlight the necessity for thorough investigations of faunal communities in CWCRs as they may be sensitive to interannual changes in regional oceanography. Considering the scientific consensus on the substantial warming of North Atlantic by 2100, we recommend the establishment of programmes for the monitoring of CWCRs. This will support an advanced understanding of CWCRs’ environmental status over time and will serve their conservation for the future

North Atlantic ecosystem sensitivity to Holocene shifts in Meridional Overturning Circulation

Rapid changes in North Atlantic climate over the last millennia were driven by coupled sea surface/atmospheric processes and rates of deep-water formation. Holocene climate changes, however, remain poorly documented due to a lack of high-resolution paleoclimate records, and their impacts on marine ecosystems remain unknown. We present a 4500 years absolute-dated sea surface radiocarbon record from northeast Atlantic cold-water corals. In contrast to the current view that surface ocean changes occurred on millennial-scale cycles, our record shows more abrupt changes in surface circulation. Changes were centered at 3.4, 2.7, 1.7 and 1.2 ky BP, and associated with atmospheric re-organization. Solar irradiance may have influenced these anomalies, but changes in North Atlantic deep-water convection are likely to have amplified these signals. Critically, we provide the first evidence that these perturbations in Atlantic Meridional Overturning Circulation led to the decline of cold-water coral ecosystems from 1.2 to ~ 0.1 ky BP

Sensitivity of marine protected area network connectivity to atmospheric variability

International efforts are underway to establish well-connected systems of marine protected areas (MPAs) covering at least 10% of the ocean by 2020. But the nature and dynamics of ocean ecosystem connectivity are poorly understood, with unresolved effects of climate variability. We used 40-year runs of a particle tracking model to examine the sensitivity of an MPA network for habitat-forming cold-water corals in the northeast Atlantic to changes in larval dispersal driven by atmospheric cycles and larval behaviour. Trajectories of Lophelia pertusa larvae were strongly correlated to the North Atlantic Oscillation (NAO), the dominant pattern of interannual atmospheric circulation variability over the northeast Atlantic. Variability in trajectories significantly altered network connectivity and source–sink dynamics, with positive phase NAO conditions producing a well-connected but asymmetrical network connected from west to east. Negative phase NAO produced reduced connectivity, but notably some larvae tracked westward-flowing currents towards coral populations on the mid-Atlantic ridge. Graph theoretical metrics demonstrate critical roles played by seamounts and offshore banks in larval supply and maintaining connectivity across the network. Larval longevity and behaviour mediated dispersal and connectivity, with shorter lived and passive larvae associated with reduced connectivity. We conclude that the existing MPA network is vulnerable to atmospheric-driven changes in ocean circulation

Coral cities of the deep. Species–habitat associations on the Mingulay Reef Complex

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