Patterns of Temporal and Spatial Variability of Sponge Assemblages

The primary goals of this thesis were to understand the spatial and temporal pattern of sponge assemblage variation over a variety of scales and investigate suitable monitoring methods for sponge assemblages. Sponges are an ecologically significant group in benthic marine communities, which are often ignored in current monitoring schemes. In chapter two the sponge biodiversity of New Zealand waters to 200m was examined using Taxonomic Distinctness measures initially to test if genera data could be used as a proxy for species level data in New Zealand waters. It was found that over 50% of the variation in genera biodiversity could be explained by location and depth around New Zealand. The study helped pinpoint where there were gaps in the New Zealand dataset, in particular for the West Coast of the South Island and also areas such as the Wellington South Coast, which had higher than expected values for Average and Variation Taxonomic distinctness measures, which as important areas where sponges should be monitored to make sure the high levels of biodiversity are protected. Taxonomic distinctness measures are useful for initially assessing how the biodiversity is distributed, especially when using a data set with uneven sampling effort, as it is robust to spatial and temporal bias in the majority of cases. However, there was an outlier to the genera data correlating well with the variation in species data in the case of a site dominated by Haliclona sp (Lyttelton Harbour). In chapters three and four the spatial and temporal variability of sponge assemblages of the Wellington South Coast were explored creating both a species list for the area and an understanding of how the sponge assemblage varies over time and space. There were significant differences in the sponges assemblages in similar habitat types over a scale of a few hundred metres. In addition, although all the sponge assemblages changed seasonally, the changes at each sampling site responded in a slightly different way most likely due to spatiotemporal variation in environmental conditions. A similar seasonal pattern was also observed in chapter five for sponge assemblages at Skomer Marine Reserve and this pattern was also clear when using morphological monitoring methods. This means that once a site has been mapped for biodiversity it is possible for some habitats to use morphological monitoring to identify if the sponge assemblage is changing significantly saving time and money. The results from Indonesia (chapter six) showed that although the sponge assemblages were changing significantly in the actual species present and their abundances, the proportion of diversity within each spatial level (quadrat, site and region) remained consistent when sampled at the same time each year throughout the five year study. In species rich assemblages there are a variety of life strategies that can respond differently to shifts in environmental conditions and contribute to ecological functioning in various ways. Various monitoring methods have been tested using sponge assemblages over various spatial and temporal scales in this thesis. Spatial, temporal and the interaction of spatial and temporal factors were all important for identifying significant assemblage differences at all of the sites. Further studies integrating the interaction of spatial and temporal factors into understanding monitoring data sets are vital to understand the patterns of assemblage variability and therefore incorporate into habitat management plans

Hexactinellida (Porifera) from the Drake Passage (Southern Ocean) with a description of three new species

Goodwin, Claire E., Berman, Jade, Janussen, Dorte, Göcke, Christian, Hendry, Katharine R. (2016): Hexactinellida (Porifera) from the Drake Passage (Southern Ocean) with a description of three new species. Zootaxa 4126 (2): 207-220, DOI: http://doi.org/10.11646/zootaxa.4126.2.

Carnivorous sponges (<i>Porifera, Demospongiae, Poecilosclerida, Cladorhizidae</i>) from the Drake Passage (Southern Ocean) with a description of eight new species and a review of the family <i>Cladorhizidae </i>in the Southern Ocean

This study reviews the taxonomy and biogeography of carnivorous sponges (family Cladorhizidae) in the Southern Ocean. Specimens were collected from seamounts in the Drake Passage by dredging and trawling and biogeographical information from other sources was compiled and reviewed. Eight new species of carnivorous sponges are described: Abyssocladia leverhulmei, sp. nov., Asbestopluma (Asbestopluma) sarsensis, sp. nov., A. (A.) gemmae, sp. nov., A. (A.) rhaphidiophorus, sp. nov., Asbestopluma (Helophloeina) keraia, sp. nov., Chondrocladia (Chondrocladia) saffronae, sp. nov., Cladorhiza scanlonae, sp. nov. and Lycopodina drakensis, sp. nov. Specimens of three previously described species, L. callithrix, L. calyx and A. (A.) bitrichela, were also found. These new records increase the number of known carnivorous sponge species in the Southern Ocean by more than a third. We demonstrate that the Cladorhizidae is the second most species-rich family of Demospongiae in the Southern Ocean and many of its species are highly endemic, with 70% found only in this region. Southern Ocean species represent close to 20% of all known carnivorous sponges. This study highlights the importance of seamount and bathyal benthic habitats for supporting the rich and endemic carnivorous sponge fauna of the Southern Ocean.</jats:p

RESIL RISK Northern Ireland: public perceptions of climate risks and adaptation in Northern Ireland

RESIL RISK Northern Ireland follows up from RESIL RISK, a research project that explored UK wide public perceptions of climate change and support for resilience building strategies. As part of the original project, a first survey was conducted with 1,401 British respondents in 2019 and a second (unpublished) survey repeated the survey during the global Covid-19 pandemic in October 2020. Furthermore the project informed a report summarising implications for effective climate communications, published in 2019 . While the original RESIL RISK maps out public perceptions of climate risks and support for adaptation strategies across the British public and provides insights into how these public perceptions are formed, it does not offer the opportunity to understand the unique situation of devolved UK administrations. Each UK region faces unique challenges when building regional resilience to the impacts of climate change and understanding how these translate into potential differences in public risk perception is essential for building climate resilient communities and nations. Northern Ireland is a post-conflict society where the most socially vulnerable experience disproportionate flood risks, and on average are exposed to higher expected annual damage costs in flood prone areas than any of the other UK nations . This project provides up to date insights into public perceptions of climate risks and support for adaptation strategies in Northern Ireland at a time when the country has ambitious Climate Legislation awaiting Royal Assent. Key research results and associated recommendations from RESiL RISK Northern Ireland are summarised in this report to support Government, local government and civil society action at a key time influencing legislation in progress and shaping the next NI Climate Change Adaptation Programme

Extreme phenotypic plasticity in metabolic physiology of Antarctic demosponges

Seasonal measurements of the metabolic physiology of four Antarctic demosponges and their associated assemblages, maintained in a flow through aquarium facility, demonstrated one of the largest differences in seasonal strategies between species and their associated sponge communities. The sponge oxygen consumption measured here exhibited both the lowest and highest seasonal changes for any Antarctic species; metabolic rates varied from a 25% decrease to a 5.8 fold increase from winter to summer, a range which was greater than all 17 Antarctic marine species (encompassing eight phyla) previously investigated and amongst the highest recorded for any marine environment. The differences in nitrogen excretion, metabolic substrate utilization and tissue composition between species were, overall, greater than seasonal changes. The largest seasonal difference in tissue composition was an increase in CHN (Carbon, Hydrogen, and Nitrogen) content in Homaxinella balfourensis, a pioneer species in ice-scour regions, which changed growth form to a twig-like morph in winter. The considerable flexibility in seasonal and metabolic physiology across the Demospongiae likely enables these species to respond to rapid environmental change such as ice-scour, reductions in sea ice cover and ice-shelf collapse in the Polar Regions, shifting the paradigm that polar sponges always live “life in the slow lane.” Great phenotypic plasticity in physiology has been linked to differences in symbiotic community composition, and this is likely to be a key factor in the global success of sponges in all marine environments and their dominant role in many climax communities

Reduced Diversity and High Sponge Abundance on a Sedimented Indo-Pacific Reef System: Implications for Future Changes in Environmental Quality

Although coral reef health across the globe is declining as a result of anthropogenic impacts, relatively little is known of how environmental variability influences reef organisms other than corals and fish. Sponges are an important component of coral reef fauna that perform many important functional roles and changes in their abundance and diversity as a result of environmental change has the potential to affect overall reef ecosystem functioning. In this study, we examined patterns of sponge biodiversity and abundance across a range of environments to assess the potential key drivers of differences in benthic community structure. We found that sponge assemblages were significantly different across the study sites, but were dominated by one species Lamellodysidea herbacea (42% of all sponges patches recorded) and that the differential rate of sediment deposition was the most important variable driving differences in abundance patterns. Lamellodysidea herbacea abundance was positively associated with sedimentation rates, while total sponge abundance excluding Lamellodysidea herbacea was negatively associated with rates of sedimentation. Overall variation in sponge assemblage composition was correlated with a number of variables although each variable explained only a small amount of the overall variation. Although sponge abundance remained similar across environments, diversity was negatively affected by sedimentation, with the most sedimented sites being dominated by a single sponge species. Our study shows how some sponge species are able to tolerate high levels of sediment and that any transition of coral reefs to more sedimented states may result in a shift to a low diversity sponge dominated system, which is likely to have subsequent effects on ecosystem functioning. © 2014 Powell et al

Carnivorous sponges (Porifera : Demospongiae : Poecilosclerida : Cladorhizidae) from the Drake Passage (Southern Ocean) with a description of eight new species and a review of the family Cladorhizidae in the Southern Ocean

This study reviews the taxonomy and biogeography of carnivorous sponges (family Cladorhizidae) in the Southern Ocean. Specimens were collected from seamounts in the Drake Passage by dredging and trawling and biogeographical information from other sources was compiled and reviewed. Eight new species of carnivorous sponges are described: Abyssocladia leverhulmei, sp. nov., Asbestopluma (Asbestopluma) sarsensis, sp. nov., A. (A.) gemmae, sp. nov., A. (A.) rhaphidiophorus, sp. nov., Asbestopluma (Helophloeina) keraia, sp. nov., Chondrocladia (Chondrocladia) saffronae, sp. nov., Cladorhiza scanlonae, sp. nov. and Lycopodina drakensis, sp. nov. Specimens of three previously described species, L. callithrix, L. calyx and A. (A.) bitrichela, were also found. These new records increase the number of known carnivorous sponge species in the Southern Ocean by more than a third. We demonstrate that the Cladorhizidae is the second most species-rich family of Demospongiae in the Southern Ocean and many of its species are highly endemic, with 70% found only in this region. Southern Ocean species represent close to 20% of all known carnivorous sponges. This study highlights the importance of seamount and bathyal benthic habitats for supporting the rich and endemic carnivorous sponge fauna of the Southern Ocean

Demosponges from the sublittoral and shallow-circalittoral (<24m depth) Antarctic Peninsula with a description of four new species and notes on in situ identification characteristics

Goodwin, Claire E., Berman, Jade, Hendry, Katharine R. (2019): Demosponges from the sublittoral and shallow-circalittoral (<24m depth) Antarctic Peninsula with a description of four new species and notes on in situ identification characteristics. Zootaxa 4658 (3): 461-508, DOI: https://doi.org/10.11646/zootaxa.4658.3.

Decadal variability in sponge abundance and biodiversity on an Indo-Pacific coral reef

Natural communities can undergo large temporal changes in abundance and species composition that may be difficult to detect without long-term ecological monitoring. Characterizing temporal variability in coral reef fauna is critical for predicting how reef ecosystems will be impacted by environmental change. Sponges are an ecologically important component of coral reefs, yet descriptions of temporal dynamics of multi-species sponge assemblages are scarce. We studied temporal changes in abundance and biodiversity of an Indonesian coral reef sponge assemblage over 13 yr (2005−2017). Mean (±SE) sponge abundance (sponge patches m) initially increased from 124.06 ± 8.46 to 183.73 ± 12.12 in 2005−2007 (p < 0.001), declined to 66.53 ± 10.62 in 2007−2014 (p < 0.001), and increased to 105.87 ± 15.42 in 2014−2017 (p < 0.001). These patterns in sponge abundance did not depend on water temperature. Overall, we recorded 141 sponge taxa. However, species composition showed strong temporal patterns driven by a few abundant taxa (e.g. Protosuberites sp., Sycon sp., and Pericharax sp., respectively accounting on average for ~25, 20, and 5% of total sponge abundance). Species richness increased with sponge abundance (p < 0.001), whereas evenness decreased due to dominance of some taxa in years of high sponge abundance (p = 0.002). Our study highlights that the abundance and biodiversity of Indo-Pacific sponge assemblages undergo dramatic temporal changes driven by species-specific population variability. This variability has important implications for designing monitoring programs, for interpreting experimental studies, and for understanding long-term responses of coral reefs to perturbations