Impacts of human activities on cold-water sponges and the habitats they form in the North East Atlantic

Sponges are filter-feeders present in many aquatic environments, from rivers to abyssal plains. In the deep-sea, sponges can form dense aggregations (sponge grounds) which constitute important but vulnerable ecosystems. As human activities now take place in the deep-sea, the need to determine the resilience of sponge grounds to disturbances is essential. My PhD aimed at understanding the impacts of oil and gas activities on deepsea sponges and sponge grounds. First, a literature review on the known impacts of hydrocarbon production on sponge grounds is provided. Second, environmental data from industrial, academic and governmental sources were analysed to determine the impact of anthropogenic activities on sponge grounds. In a case study of the Faroe-Shetland channel, I showed that substrate characteristics and seawater temperature, modulated by anthropogenic activities, controlled the distribution of megafauna. Third, to determine the impacts of an oil spill on sponges, experiments exposing a shallow-water sponge model to crude oil and dispersant contaminated seawater or sediments were conducted. Through this experimental work, I showed that exposure to contaminants decreased the sponge filtering abilities. Furthermore, over 1000 genes, from the sponge and its associated microbes were detected as differentially expressed after exposure to contaminants. These effects were worsened by the addition of dispersant and their use within sponge grounds should therefore be avoided

Clarification of Governance Relevant to the Sustainable Management of Marine Species and Habitats within the United Kingdom: An Overview of Regional, National and International Authorities, Advisories, Legislation and Designation Types with Summary Schematic Tool

Marine management developments are occurring across the United Kingdom with the major aim to ensure economic growth and security of marine resources via the provision of legislative guidelines for sustainable management of activities within the marine environment. Many of these directives also provide guidance for maintaining ecologically valuable and/or endangered species and habitats that exist alongside, and may also support, marine activities/use. Marine governance is largely guided by several key directives laid out and implemented by governing authorities of Europe, the United Kingdom and those countries comprising the United Kingdom, and in line with several international conventions. The directives set out by each authority or convention may act discretely but more often tend to overlap, which can lead to confusion about the relevant marine conservation requirements and objectives that must be fulfilled for a given region, site or feature. Additionally, management objectives driven by the same legislation may oppose one another, adding further complexity to the matter. This article aims to provide an overview of governance that holds relevance to managing marine habitats and species, especially those deemed sensitive, ecologically valuable and/or endangered. A general overview and summary schematic tool of the marine governance, legislation and designations within each level of authority for the United Kingdom are provided. Additional consideration of the implications for legislation upon the United Kingdom leaving the EU is briefly discussed and a comparative case study of two marine habitats of high conservation value is provided to demonstrate how different sites/features may have considerably different management requirements

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 < .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

First in-situ monitoring of sponge response and recovery to an industrial sedimentation event

Assessment of risks to seabed habitats from industrial activities is based on the resilience and potential for recovery. Increased sedimentation, a key impact of many offshore industries, results in burial and smothering of benthic organisms. Sponges are particularly vulnerable to increases in suspended and deposited sediment, but response and recovery have not been observed in-situ. We quantified the impact of sedimentation from offshore hydrocarbon drilling over ∼5 days on a lamellate demosponge, and its recovery in-situ over ∼40 days using hourly time-lapse photographs with measurements of backscatter (a proxy of suspended sediment) and current speed. Sediment accumulated on the sponge then cleared largely gradually but occasionally sharply, though it did not return to the initial state. This partial recovery likely involved a combination of active and passive removal. We discuss the use of in-situ observing, which is critical to monitoring impacts in remote habitats, and need for calibration to laboratory conditions

A framework for the development of a global standardised marine taxon reference image database (SMarTaR-ID) to support image-based analyses

Video and image data are regularly used in the field of benthic ecology to document biodiversity. However, their use is subject to a number of challenges, principally the identification of taxa within the images without associated physical specimens. The challenge of applying traditional taxonomic keys to the identification of fauna from images has led to the development of personal, group, or institution level reference image catalogues of operational taxonomic units (OTUs) or morphospecies. Lack of standardisation among these reference catalogues has led to problems with observer bias and the inability to combine datasets across studies. In addition, lack of a common reference standard is stifling efforts in the application of artificial intelligence to taxon identification. Using the North Atlantic deep sea as a case study, we propose a database structure to facilitate standardisation of morphospecies image catalogues between research groups and support future use in multiple front-end applications. We also propose a framework for coordination of international efforts to develop reference guides for the identification of marine species from images. The proposed structure maps to the Darwin Core standard to allow integration with existing databases. We suggest a management framework where high-level taxonomic groups are curated by a regional team, consisting of both end users and taxonomic experts. We identify a mechanism by which overall quality of data within a common reference guide could be raised over the next decade. Finally, we discuss the role of a common reference standard in advancing marine ecology and supporting sustainable use of this ecosystem

Megafauna presence/absence matrix with Associated Environmental and Spatial Parameters in the Faroe-Shetland Channel

This megafauna presence/absence matrix was obtained by analysing seabed images collected during successive environmental surveys conducting with remotely operated vehicles. The surveys took place around six oil and gas installations in the Faroe-Shetland Channel, an area known to harbour deep-sea sponge grounds. The matrix is constituted by multiple Operational Taxonomic Units (OTUs) as well as environmental parameters such as temperature, bathymetry and slope. Eigenvectors (Listed as MEM1 to MEM15) resulting from a distance-based Moran's Eigenvector Mapping (dbMEM) applied on the data have also been included. Further details regarding the dataset can be found in the publication listed below

Hydrocarbon data of the cold-water sponge Halichondria panicea exposure experiment to Benzo-A-Pyrene

In this study, inter-tidal cold-water sponge Halichondria panicea samples were exposed to Benzo-A-pyrene for 48h (accumulation phase) and then left to recover for 13 days in clean seawater (depuration phase). Tissue samples were collected at multiple time points during the accumulation phase to conduct qPCR targeting several genes of interest. Tissue samples were also collected during the accumulation and depuration phases to determine concentration of hydrocarbon in the sponge tissue. The files provided here detail (1) the hydrocarbon data determined by GC/MS analysis and (2) the sponge log fold change data for four genes of interest derived by qPCR