Category: Marine ecology

Applying landscape metrics to species distribution model predictions to characterize internal range structure and associated changes

Curd A, Chevalier M, Vasquez M, Boyé A, Firth LB, Marzloff MP, Bricheno LM, Burrows MT, Bush LE, Cordier C, Davies AJ, Green JAM, Hawkins SJ, Lima FP, Meneghesso C, Mieszkowska N, Seabra R, Dubois SF

Abstract

Distributional shifts in species ranges provide critical evidence of ecological responses to climate change. Assessments of climate-driven changes typically focus on broad-scale range shifts (e.g. poleward or upward), with ecological consequences at regional and local scales commonly overlooked. While these changes are informative for species presenting continuous geographic ranges, many species have discontinuous distributions—both natural (e.g. mountain or coastal species) or human-induced (e.g. species inhabiting fragmented landscapes)—where within-range changes can be significant. Here, we use an ecosystem engineer species (Sabellaria alveolata) with a naturally fragmented distribution as a case study to assess climate-driven changes in within-range occupancy across its entire global distribution. To this end, we applied landscape ecology metrics to outputs from species distribution modelling (SDM) in a novel unified framework. SDM predicted a 27.5% overall increase in the area of potentially suitable habitat under RCP 4.5 by 2050, which taken in isolation would have led to the classification of the species as a climate change winner. SDM further revealed that the latitudinal range is predicted to shrink because of decreased habitat suitability in the equatorward part of the range, not compensated by a poleward expansion. The use of landscape ecology metrics provided additional insights by identifying regions that are predicted to become increasingly fragmented in the future, potentially increasing extirpation risk by jeopardising metapopulation dynamics. This increased range fragmentation could have dramatic consequences for ecosystem structure and functioning. Importantly, the proposed framework—which brings together SDM and landscape metrics—can be widely used to study currently overlooked climate-driven changes in species internal range structure, without requiring detailed empirical knowledge of the modelled species. This approach represents an important advancement beyond predictive envelope approaches and could reveal itself as paramount for managers whose spatial scale of action usually ranges from local to regional.

[sendpaper paperurl=”2022_Curd.pdf”]

Full Citation

Curd A, Chevalier M, Vasquez M, Boyé A, Firth LB, Marzloff MP, Bricheno LM, Burrows MT, Bush LE, Cordier C, Davies AJ, Green JAM, Hawkins SJ, Lima FP, Meneghesso C, Mieszkowska N, Seabra R, Dubois SF (2022) Applying landscape metrics to species distribution model predictions to characterize internal range structure and associated changes. Global Change Biology 

Manuscript DOI

https://doi.org/10.1111/gcb.16496

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/