Category: Publications

Recurring bleaching events disrupt the spatial properties of coral reef benthic communities across scales

Ford HV, Gove JM, Healey JR, Davies AJ, Graham NAJ, Williams GJ

Marine heatwaves are causing recurring coral bleaching events on tropical reefs that are driving ecosystem change. Yet, little is known about how bleaching and subsequent coral mortality impacts the spatial properties of tropical seascapes, such as patterns of organism spatial clustering and heterogeneity across scales. Changes in these spatial properties can offer insight into ecosystem recovery potential following disturbance. Here we repeatedly quantified coral reef benthic spatial properties around the circumference of an uninhabited tropical island in the central Pacific over a 9-year period that included a minor and subsequent severe marine heatwave. Benthic communities showed increased biotic homogenisation following both minor and mass bleaching, becoming more taxonomically similar with less diverse intra-island community composition. Hard coral cover, which was highly spatially clustered around the island prior to bleaching, became less spatially clustered following minor bleaching and was indiscernible from a random distribution across all scales (100–2000 m) following mass bleaching. Interestingly, the reduced degree of hard coral cover spatial clustering was already evident by the onset of mass bleaching and before any dramatic wholesale loss in island-mean coral cover occurred. Reductions in hard coral spatial clustering may therefore offer an early indication of the ecosystem becoming degraded prior to mass coral mortality. In contrast, the spatial clustering of competitive fleshy macroalgae remained unchanged through both bleaching events, while crustose coralline algae and fleshy turf algae became more spatially clustered at larger scales (200–700 m) following mass bleaching. Overall, benthic community spatial patterning became less predictable following bleaching and was no longer reflective of gradients in long-term environmental drivers that typically structure these remote reefs. Our findings provide novel insights into how climate-driven marine heatwaves can impact the spatial properties of coral reef communities over multiple scales.

[sendpaper paperurl=”2023_Ford.pdf”]

Full Citation

Ford HV, Gove JM, Healey JR, Davies AJ, Graham NAJ, Williams GJ (2023) Recurring bleaching events disrupt the spatial properties of coral reef benthic communities across scales. Remote Sensing in Ecology and Conservation 

Manuscript DOI

https://doi.org/10.1002/rse2.355

Beyond the tip of the seamount: Distinct megabenthic communities found beyond the charismatic summit sponge ground on an arctic seamount (Schulz Bank, Arctic Mid-Ocean Ridge)

H.K. Meyer, A.J.Davies, E.M.Roberts, J.R. Xavier, P.A. Ribeiro, H.Glenner, S.-R. Birkely, H.T.Rapp

Abstract

Our understanding of the benthic communities on arctic seamounts and descriptions of such communities in habitat classification systems are limited. In recent years, Schulz Bank (73°52′N 7°30′E), a seamount on the Arctic Mid-Ocean Ridge (AMOR), has become well studied but the work has primarily focused on an arctic sponge ground at the summit. This has compounded a general assumption that the most biologically interesting community is on the summit alone. With the potential threat of deep-sea mining on nearby sites on AMOR, it is crucial to form a baseline understanding of the benthic megafaunal communities not only on the summit, but on the slopes and base of the seamount as well. Using video footage collected by a remotely operated vehicle in 2017 and 2018 to survey the seamount from 2700 to 580 m depth, several distinct megafauna communities on Schulz Bank were identified. Specifically, five biotopes, two of which were dominated by large structure-forming sponges, appeared to follow a depth gradient and change with the type of substrata present. The sponge-dominated communities on the summit and lower slope had the highest average community densities and number of morphotaxa per image compared to the upper slope and seamount base communities. Most notably, sponge-dominated bedrock walls on the lower slopes challenge the assumption that the summit is the most dense and diverse community on Schulz Bank. The results from this study lay the foundation for future research and conservation efforts of arctic sponge grounds by looking beyond the seamount summit to bring a full view of enigmatic sponge dominated ecosystems.

[sendpaper paperurl=”2022_Meyer.pdf”]

Full Citation

Meyer HK, Davies AJ, Roberts EM, Xavier JR, Ribeiro PA, Glenner H, Birkely S_R, Rapp HT (2022) Beyond the tip of the seamount: Distinct megabenthic communities found beyond the charismatic summit sponge ground on an arctic seamount (Schulz Bank, Arctic Mid-Ocean Ridge). Deep-sea Research Vol 1

Manuscript DOI

https://doi.org/10.1016/j.dsr.2022.103920

Specific niche requirements underpin multidecadal range edge stability, but may introduce barriers for climate change adaptation

Firth LB, Harris D, Blaze JA, Marzloff MP, Boyé A, Miller PI, Curd A, Vasquez M, Nunn JD, O’Connor NE, Power AM, Mieszkowska N, O’Riordan RM, Burrows MT, Bricheno LM, Knights AM, Nunes FLD, Bordeyne F, Bush LE, Byers JE, David C, Davies AJ, Dubois SF, Edwards H, Foggo A, Grant L, Green JAM, Gribben PE, Lima FP, McGrath D, Noël LMLJ, Seabra R, Simkanin C, Hawkins SJ (2021) Specific niche requirements underpin multidecadal range edge stability, but may introduce barriers for climate change adaptation. Diversity and Distributions 27(4): 668-683.

Aim

To investigate some of the environmental variables underpinning the past and present distribution of an ecosystem engineer near its poleward range edge.

Location

>500 locations spanning >7,400 km around Ireland.

Methods

We collated past and present distribution records on a known climate change indicator, the reef‐forming worm Sabellaria alveolata (Linnaeus, 1767) in a biogeographic boundary region over 182 years (1836–2018). This included repeat sampling of 60 locations in the cooler 1950s and again in the warmer 2000s and 2010s. Using species distribution modelling, we identified some of the environmental drivers that likely underpin S. alveolata distribution towards the leading edge of its biogeographical range in Ireland.

Results

Through plotting 981 records of presence and absence, we revealed a discontinuous distribution with discretely bounded sub‐populations, and edges that coincide with the locations of tidal fronts. Repeat surveys of 60 locations across three time periods showed evidence of population increases, declines, local extirpation and recolonization events within the range, but no evidence of extensions beyond the previously identified distribution limits, despite decades of warming. At a regional scale, populations were relatively stable through time, but local populations in the cold Irish Sea appear highly dynamic and vulnerable to local extirpation risk. Contemporary distribution data (2013–2018) computed with modelled environmental data identified specific niche requirements which can explain the many distribution gaps, namely wave height, tidal amplitude, stratification index, then substrate type.

Main conclusions

In the face of climate warming, such specific niche requirements can create environmental barriers that may prevent species from extending beyond their leading edges. These boundaries may limit a species’ capacity to redistribute in response to global environmental change.
[sendpaper paperurl=”2021_Firth.pdf”]

Full Citation

Firth LB, Harris D, Blaze JA, Marzloff MP, Boyé A, Miller PI, Curd A, Vasquez M, Nunn JD, O’Connor NE, Power AM, Mieszkowska N, O’Riordan RM, Burrows MT, Bricheno LM, Knights AM, Nunes FLD, Bordeyne F, Bush LE, Byers JE, David C, Davies AJ, Dubois SF, Edwards H, Foggo A, Grant L, Green JAM, Gribben PE, Lima FP, McGrath D, Noël LMLJ, Seabra R, Simkanin C, Hawkins SJ (2021) Specific niche requirements underpin multidecadal range edge stability, but may introduce barriers for climate change adaptation. Diversity and Distributions 27(4): 668-683.

Manuscript DOI

https://onlinelibrary.wiley.com/doi/10.1111/ddi.13224

Replicating natural topography on marine artificial structures – A novel approach to eco-engineering

Evans AJ, Lawrence PJ, Natanzi AS, Moore PJ, Davies AJ, Crowe TP, McNally C, Thompson B, Dozier AE, Brooks PR

Ocean sprawl is a growing threat to marine and coastal ecosystems globally, with wide-ranging consequences for natural habitats and species. Artificial structures built in the marine environment often support less diverse communities than natural rocky marine habitats because of low topographic complexity. Some structures can be eco-engineered to increase their complexity and promote biodiversity. Tried-and-tested eco-engineering approaches include building-in habitat designs to mimic features of natural reef topography that are important for biodiversity. Most designs mimic discrete microhabitat features like crevices or holes and are geometrically-simplified. Here we propose that directly replicating the full fingerprint of natural reef topography in habitat designs makes a novel addition to the growing toolkit of eco-engineering options. We developed a five-step process for designing natural topography-based eco-engineering interventions for marine artificial structures. Given that topography is highly spatially variable in rocky reef habitats, our targeted approach seeks to identify and replicate the ‘best’ types of reef topography to satisfy specific eco-engineering objectives. We demonstrate and evaluate the process by designing three natural topography-based habitat units for intertidal structures, each targeting one of three hypothetical eco-engineering objectives. The process described can be adapted and applied according to user-specific priorities. Expanding the toolkit for eco-engineering marine structures is crucial to enable ecologically-informed designs that maximise biodiversity benefits from burgeoning ocean sprawl.
[sendpaper paperurl=”2021_Evans.pdf”]

Full Citation

Evans AJ, Lawrence PJ, Natanzi AS, Moore PJ, Davies AJ, Crowe TP, McNally C, Thompson B, Dozier AE, Brooks PR (2021). Replicating natural topography on marine artificial structures – A novel approach to eco-engineering. Ecological Engineering 160, 106144

Manuscript DOI

https://doi.org/10.1016/j.ecoleng.2020.106144

Musical Chairs on Temperate Reefs: Species Turnover and Replacement Within Functional Groups Explain Regional Diversity Variation in Assemblages Associated With Honeycomb Worms

Alexandre Muller, Camille Poitrimol, Flávia L. D. Nunes, Aurélien Boyé, Amelia Curd, Nicolas Desroy, Louise B. Firth, Laura Bush, Andrew J. Davies, Fernando P. Lima, Martin P. Marzloff, Claudia Meneghesso, Rui Seabra and Stanislas F. Dubois1

Abstract

Reef-building species are recognized as having an important ecological role and as generally enhancing the diversity of benthic organisms in marine habitats. However, although these ecosystem engineers have a facilitating role for some species, they may exclude or compete with others. The honeycomb worm Sabellaria alveolata (Linnaeus, 1767) is an important foundation species, commonly found from northwest Ireland to northern Mauritania, whose reef structures increase the physical complexity of the marine benthos, supporting high levels of biodiversity. Local patterns and regional differences in taxonomic and functional diversity were examined in honeycomb worm reefs from 10 sites along the northeastern Atlantic to explore variation in diversity across biogeographic regions and the potential effects of environmental drivers. While taxonomic composition varied across the study sites, levels of diversity remained relatively constant along the European coast. Assemblages showed high levels of species turnover compared to differences in richness, which varied primarily in response to sea surface temperatures and sediment content, the latter suggesting that local characteristics of the reef had a greater effect on community composition than the density of the engineering species. In contrast, the functional composition of assemblages was similar regardless of taxonomic composition or biogeography, with five functional groups being observed in all sites and only small differences in abundance in these groups being detected. Functional groups represented primarily filter-feeders and deposit-feeders, with the notable absence of herbivores, indicating that the reefs may act as biological filters for some species from the local pool of organisms. Redundancy was observed within functional groups that may indicate that honeycomb worm reefs can offer similar niche properties to its associated assemblages across varying environmental conditions. These results highlight the advantages of comparing taxonomic and functional metrics, which allow identification of a number of ecological processes that structure marine communities.

[sendpaper paperurl=”2021_Muller.pdf”]

Full Citation

Muller A, Poitrimol C, Nunes FLD, Boyé A, Curd A, Desroy N, Firth LB, Bush L, Davies AJ, Lima FP, Marzloff MP, Meneghesso C, Seabra R, Dubois SF (2021) Musical Chairs on Temperate Reefs: Species Turnover and Replacement Within Functional Groups Explain Regional Diversity Variation in Assemblages Associated With Honeycomb Worms. Front Mar Sci 8

Manuscript DOI

https://dx.doi.org/10.3389/fmars.2021.654141

Machine learning highlights the importance of primary and secondary production in determining habitat for marine fish and macroinvertebrates

Kevin D. Friedland, Michelle Bachman, Andrew Davies, Romain Frelat, M. Conor McManus, Ryan Morse, Bradley A. Pickens, Szymon Smoliński, Kisei Tanaka

Abstract

1. Species distribution models for marine organisms are increasingly used for a range of applications, including spatial planning, conservation, and fisheries management. These models have been constructed using a variety of mathematical forms and drawing on both physical and biological independent variables; however, what might be called first‐generation models have mainly followed the form of linear models, or smoothing splines, informed by data collected in the context of fish surveys.
2. The performance of different classes of variables were tested in a series of species occurrence models built with machine learning methods, specifically evaluating the potential contribution of lower trophic level data. Random forest models were fitted based on the classification of the absence/presence for fish and macroinvertebrates surveyed on the US Northeast Continental Shelf.
3. The potential variables included physical, primary production, secondary production, and terrain variables. For accepted model fits, six variable importance measures were computed, which collectively showed that physical and secondary production variables make the greatest contribution across all models. In contrast, terrain variables made the least contribution to these models.
4. Multivariable analyses that account for all performance measures reinforce the role of water depth and temperature in defining species presence and absence; however, chlorophyll concentration and some specific zooplankton taxa, such as Metridia lucens and Paracalanus parvus, also make important contributions with strong seasonal variations.
5. Our results suggest that lower trophic level variables, if available, are valuable in the creation of species distribution models for marine organisms.

[sendpaper paperurl=”2021_Friedland.pdf”]

Full Citation

Friedland, KD, Bachman, M, Davies, A, Frelat, R, McManus, MC, Morse, R, Pickens, BA, Smoliński, S, Tanaka, K. (2021) Machine learning highlights the importance of primary and secondary production in determining habitat for marine fish and macroinvertebrates. Aquatic Conservation: Marine and Freshwaster Ecosystems, 1–17. https://doi.org/10.1002/aqc.3527

Manuscript DOI

https://doi.org/10.1002/aqc.3527

Long‐term Observations Reveal Environmental Conditions and Food Supply Mechanisms at an Arctic Deep‐Sea Sponge Ground

Ulrike Hanz, Emyr Martyn Roberts, Gerard Duineveld, Andrew Davies, Hans van Haren, Hans Tore Rapp, Gert‐Jan Reichart, Furu Mienis

Abstract

Deep‐sea sponge grounds are hotspots of benthic biomass and diversity. To date, very limited data exist on the range of environmental conditions in areas containing deep‐sea sponge grounds and which factors are driving their distribution and sustenance. We investigated oceanographic conditions at a deep‐sea sponge ground located on an Arctic Mid‐Ocean Ridge seamount. Hydrodynamic measurements were performed along Conductivity‐Temperature‐Depth transects, and a lander was deployed within the sponge ground that recorded near‐bottom physical properties as well as vertical fluxes of organic matter over an annual cycle. The data demonstrate that the sponge ground is found at water temperatures of −0.5°C to 1°C and is situated at the interface between two water masses at only 0.7° equatorward of the turning point latitude of semi‐diurnal lunar internal tides. Internal waves supported by vertical density stratification interact with the seamount topography and produce turbulent mixing as well as resuspension of organic matter with temporarily very high current speeds up to 0.72 m s⁻¹. The vertical movement of the water column delivers food and nutrients from water layers above and below toward the sponge ground. Highest organic carbon flux was observed during the summer phytoplankton bloom period, providing fresh organic matter from the surface. The flux of fresh organic matter is unlikely to sustain the carbon demand of this ecosystem. Therefore, the availability of bacteria, nutrients, and dissolved and particulate matter, delivered by tidally forced internal wave turbulence and transport by horizontal mean flows, likely plays an important role in meeting ecosystem‐level food requirements.

[sendpaper paperurl=”2021_Hanz.pdf”]

Full Citation

Hanz, U., Roberts, E. M., Duineveld, G., Davies, A., Van Haren, H., Rapp, H. T., Reichart, G. J. and Mienis, F. 2021. Long–term observations reveal environmental conditions and food supply mechanisms at an Arctic deep‐sea sponge ground. — Journal of Geophysical Research: Oceans 126: e2020JC016776. 10.1029/2020jc016776

Manuscript DOI

https://doi.org/10.1029/2020JC016776

Climate change winner in the deep sea? Predicting the impacts of climate change on the distribution of the glass sponge Vazella pourtalesii

Beazley L, Kenchington E, Murillo FJ, Brickman D, Wang Z, Davies AJ, Roberts EM, Rapp HT

Shallow-water sponges are often cited as being ‘climate change winners’ due to their resiliency against climate change effects compared to other benthic taxa. However, little is known of the impacts of climate change on deep-water sponges. The deep-water glass sponge Vazella pourtalesii is distributed off eastern North America, forming dense sponge grounds with enhanced biodiversity on the Scotian Shelf off Nova Scotia, Canada. While the strong natural environmental variability that characterizes these sponge grounds suggests this species is resilient to a changing environment, its physiological limitations remain unknown, and the impact of more persistent anthropogenic climate change on its distribution has never been assessed. We used Random Forest and generalized additive models to project the distribution of V. pourtalesii in the northwest Atlantic using environmental conditions simulated under moderate and worst-case CO2 emission scenarios. Under future (2046-2065) climate change, the suitable habitat of V. pourtalesii will increase up to 4 times its present-day size and shift into deeper waters and higher latitudes, particularly in its northern range where ocean warming will serve to improve the habitat surrounding this originally sub-tropical species. However, not all areas projected as suitable habitat in the future will realistically be populated, and the reduced likelihood of occurrence in its core habitat on the Scotian Shelf suggests that the existing Vazella sponge grounds may be negatively impacted. An effective monitoring programme will require tracking changes in the density and distribution of V. pourtalesii at the margins between core habitat and where losses and gains were projected.
[sendpaper paperurl=”2021_Beazley.pdf”]

Full Citation

Beazley L, Kenchington E, Murillo FJ, Brickman D, Wang Z, Davies AJ, Roberts EM, Rapp HT (2021) Climate change winner in the deep sea? Predicting the impacts of climate change on the distribution of the glass sponge Vazella pourtalesii. Marine Ecology Progress Series 657: 1-23.

Manuscript DOI

https://www.int-res.com/abstracts/meps/v657/p1-23/

Editorial: Advances in 3D Habitat Mapping of Marine Ecosystem Ecology and Conservation

Renata Ferrari, Javier X. Leon, Andrew J. Davies, John H. R. Burns, Stuart A. Sandin, Will F. Figueira and Manuel Gonzalez-Rivero

Abstract

Advances in 3D technology have enabled low-cost and accurate measurements of habitat structure and organism size in both terrestrial and marine environments. However, there is still a need for guidance on how to apply novel 3D technologies for marine ecology and conservation. Multiple teams from around the world are leading the application of 3D photogrammetry in marine ecosystems. The widespread adoption of 3D methodologies produces a growing need for agreed standards to assess the quality of 3D data (e.g., error metrics). Similarly, standardized techniques where possible, will ensure collaboration and compatibility of 3D data across space and time.

This Research Topic is a first step toward the standardization of methods and communication of the state of the field to the wider audience in marine science and conservation using or considering the use of 3D technologies. The Topic provides relevant information that: (1) defines standard methods for the application of 3D technologies to marine ecosystem ecology and conservation, (2) advances fundamental marine ecological and conservation knowledge relevant to the habitat structure of marine ecosystems; and (3) highlights knowledge gaps and directions to move toward a high-resolution 3D map of the world’s oceans.

The Research Topic focuses on the use of high-resolution 3D reconstructions of underwater ecosystems. It includes 13 articles, of which six are original research articles, one is a perspective, and six are methodological advances. Most of the original research articles also included a methodological validation or comparison. The geographic scope of this Research Topic ranges from the Caribbean to Greenland to the Pacific Islands and Australasia. Nine articles were conducted in coral reefs, three in temperate rocky reefs, and one on a deep-sea cliff, which highlights the versatility of 3D technologies. The diverse group of articles explored the relationship between habitat features, benthic and fish abundance, health, diversity, the potential of reef scape genomics, and the effectiveness of marine protection. A range of equipment from action cameras and DSLRs, to machine vision cameras, underwater robots, and echo-sounders were used to generate 3D reconstructions, emphasizing how a broad range of 3D technologies can benefit a wide variety of end users and applications. Similarly, the breath of the research published in this Research Topic captured 3D reconstructions of sub-millimeter resolutions, as well as 3D maps across large spatial extents.

[sendpaper paperurl=”2022_Ferrari_Frontiers.pdf”]

Full Citation

Ferrari R, Leon JX, Davies AJ, Burns JHR, Sandin SA, Figueira WF, Gonzalez-Rivero M (2022) Editorial: Advances in 3D Habitat Mapping of Marine Ecosystem Ecology and Conservation. Front Mar Sci 8

Manuscript DOI

https://www.frontiersin.org/articles/10.3389/fmars.2021.827430/full

Connectivity of sponge grounds in the deep sea: genetic diversity, gene flow and oceanographic pathways in the fan-shaped sponge Phakellia ventilabrum in the northeast Atlantic

Sergi Taboada, Connie Whiting, Shuangqiang Wang, Pilar Ríos, Andrew Davies, Furu Mienis, Ellen Kenchington, Paco Cárdenas, Alex Cranston, Vasiliki Koutsouveli, Javier Cristobo, Hans-Tore Rapp, Jim Drewery, Francisco Baldó, Christine Morrow, Bernard Picton, Joana Xavier, María Belén Arias, Ana Riesgo

Abstract

A complex interplay of biotic and abiotic factors underpins the distribution of species and operates across different levels of biological organization and life history stages. Understanding ecosystem engineer reproductive traits is critical for comprehending and managing the biodiversity-rich habitats they create. Little is known about how the reproduction of the reef-forming worm, Sabellaria alveolata, varies across environmental gradients. By integrating broad-scale environmental data with in-situ physiological data in the form of biochemical traits, we identified and ranked the drivers of intraspecific Little is known about dispersal in deep-sea sponges, yet understanding patterns of gene flow and connectivity is essential for their effective management. Given rising pressure from harmful anthropogenic activities, schemes that manage resource extraction whilst conserving species diversity are increasingly necessary. Here, we used ddRADseq derived SNPs to investigate the genetic diversity and connectivity for the deep-sea sponge Phakellia ventilabrum across the northeast Atlantic Ocean (from the Cantabrian Sea to Norway). The analysis of 166 individuals collected from 57 sampling stations were grouped into 17 different areas, including two MPAs, one SAC and other areas with different levels of protection. The 4,017 neutral SNPs we uncovered indicated high connectivity and panmixis amongst the majority of areas, spanning a ca. 2,500-kilometre range and depths of 99–900 m. This was likely due to the presence of strong ocean currents aiding larval transport, as supported by our migration analysis and also by 3D particle tracking modelling using information on the reproductive cycle of P. ventilabrum. We also observed significant genetic similarity between samples from the Cantabrian Sea and Roscoff (France) as compared to the remainder of the collection areas, likely arising from physical drivers such as prevailing current circulation patterns and topographic features, acting as barriers for gene flow. Despite this, our results suggest that all protected areas studied are well connected with each other. The relatively low genetic diversity observed in all areas, though, highlights the potential fragility of this species to changing climates, which might compromise resilience to future threats.

Manuscript DOI

Preprint