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Ecosystem engineers enhance the multifunctionality of an urban novel ecosystem: Population persistence and ecosystem resilience since the 1980s
No full textIn degraded urban habitats, nature-based solutions aim to enhance ecosystem functioning and service provision. Bivalves are increasingly reintroduced to urban environments to enhance water quality through biofiltration, yet their long-term sustainability remains uncertain. Following the restoration of the disused South Docks in Liverpool in the 1980s, natural colonization of mussels rapidly improved dock-basin water quality and supported diverse taxa, including other filter feeders. While the initial colonization phase has been well documented, there has been limited published research since the mid-1990s, despite ongoing routine water quality monitoring. Here, we assessed the long-term persistence of mussel populations, their associated biodiversity, and physico-chemical parameters of the water in Queens and Albert Docks by comparing historical (1980s to 1990s) and contemporary data from follow-up surveys (2012,2022). Following an initial period of poor water quality (high contamination and turbidity, low oxygen), the natural colonization of mussels from Albert Dock in 1988 extended throughout the South Docks. By the mid-1990s, the environment of the South Docks and its mussel populations had stabilized. The dock walls were dominated by mussels which provided important complex secondary substrate for invertebrates and macroalgae. Surveys conducted in 2012 and 2022 confirmed the continued dominance of mussels and estimates of mussel biofiltration rates confirm that mussels are continuing to contribute to maintaining water quality. A decline in salinity was observed in both docks in 2022, with evidence of recovery. While these ecosystems appear relatively stable, careful management of the hydrological regime is crucial to ensuring the persistence of mussels and resilient ecosystem service provision through biofiltratio
The genome sequence of a segmented worm, Terebella lapidaria Linnaeus, 1767
No full textWe present a genome assembly from an individual Terebella lapidaria(segmented worm; Annelida; Polychaeta; Terebellida; Terebellidae).The genome sequence spans 765.20 megabases. Most of the assembly is scaffolded into 16 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 15.97 kilobases in length
Partitioning of metals in the tissues and cytosolic fraction of Cerastoderma edule
No full textThe concentrations of Cd, Cu and Zn have been determined in the tissues and the cytosolic fraction of the common cockle, Cerastoderma edule, collected from sediments in the Tamar, Plym and Avon estuaries (South West, England). Metal concentrations in the tissues of C. edule from the Avon were lower than those from the Tamar and Plym, except for Cu in the digestive gland. Significant statistical relationships were only obtained between the total sedimentary metal concentrations and Cd in the body of C. edule and Cu in the digestive gland. The cytosolic fraction was extracted from each of the tissues and separated for protein analysis thereby allowing determination of the metal contents in high molecular weight (HMW) compounds, metallothionein-like proteins (MTLP) and very low molecular weight (VLMW) compounds. The digestive glands of C. edule from the Avon had relatively low concentrations of MTLP, whereas MTLP concentrations in the digestive gland of cockles from the Tamar and Plym were higher. The cytosolic fraction of C. edule had relatively low total Cd and Cu concentrations associated with MTLP, whereas Zn was preferentially associated with the HMW and the VLMW components. The results are relevant to metal distributions in C. edule and the role of cytosols in the management of metals by C. edule and other invertebrate
A sentinel watching over inter-tidal seagrass phenology across Western Europe and North Africa
No full textSeagrasses are marine flowering plants that form extensive meadows from the inter-tidal zone up to ~50 m depth. As biological and ecological Essential Biodiversity Variables, seagrass cover and composition provide a wide range of ecosystem services. Inter-tidal seagrass meadows provide services to many ecosystems, so monitoring their occurrence, extent, condition and diversity can be used to indicate the biodiversity and health of local ecosystems. Current global estimates of seagrass extent and recent reviews either do not mention inter-tidal seagrasses and their seasonal variation, or combine them with sub-tidal seagrasses. Here, using high-spatial and high-temporal resolution satellite data (Sentinel-2), we demonstrate a method for consistently mapping inter-tidal seagrass meadows and their phenology at a continental scale. We were able to highlight varying seasonal patterns that are observable across a 23° latitudinal range. Timings of peaks in seagrass extent varied by up to 5 months, rather than the previously assumed marginal to non-existent variation in peak timing. These results will aid management by providing high-resolution spatio-temporal monitoring data to better inform seagrass conservation and restoration. They also highlight the high level of seasonal variability in inter-tidal seagrass, meaning combination with sub-tidal seagrass for global assessments will likely produce misleading or incorrect estimate
Influence of in situ temperature and maternal provisioning on the medusa-to-polyp transition in a year-round population of the scyphozoan Aurelia aurita
No full textWe investigated how environmental conditions translate into reproductive success or failure in Aurelia aurita from the medusa to the polyp life stage. This study examined how: (i) settlement success and development of planula larvae and polyps vary across the year, (ii) the role of temperature in determining the successful settlement of larvae and growth of polyps, and (iii) the influence of maternal provisioning in the successful settlement of larvae and growth of polyps. Medusae were collected monthly from February to December 2019 from Horsea Lake, UK. Planula larvae were settled in conditions mimicking the in situ temperature and salinity of collection. For the individual treatments, planula collected in August settled most rapidly. Early development rates (8 tentacles) and were positively correlated with temperature, unlike later growth rates. Planula length, used as an indicator of maternal provisioning, varied significantly across the year. In July 2019, a high temperature anomaly coincided with an increased time spent by planula larvae in the water column. Increasing temperatures past thermal limits through the increasing occurrence of temperature anomalies is likely to be detrimental to larval settlement and indirectly to the replenishment of temperate polyp population
Microplastic shape influences fate in vegetated wetlands
Get PDFCoastal areas are prone to plastic accumulation due to their proximity to land based sources. Coastal vegetated
habitats (e.g., seagrasses, saltmarshes, mangroves) provide a myriad of ecosystem functions, such as erosion
protection, habitat refuge, and carbon storage. The biological and physical factors that underlie these functions
may provide an additional benefit: trapping of marine microplastics. While microplastics occurrence in coastal
vegetated sediments is well documented, there is conflicting evidence on whether the presence of vegetation
enhances microplastics trapping relative to bare sites and the factors that influence microplastic trapping remain
understudied. We investigated how vegetation structure and microplastic type influences trapping in a simulated
coastal wetland. Through a flume experiment, we measured the efficiency of microplastic trapping in the
presence of branched and grassy vegetation and tested an array of microplastics that differ in shape, size, and
polymer. We observed that the presence of vegetation did not affect the number of microplastics trapped but did
affect location of deposition. Microplastic shape, rather than polymer, was the dominant factor in determining
whether microplastics were retained in the sediment or adhered to the vegetation canopy. Across the canopy,
microfibre concentrations decreased from the leading edge to the interior which suggests that even on a small�scale, vegetation has a filtering effect. The outcome of this study enriches our understanding of coastal vegetation
as a microplastics sink and that differences among microplastics informs where they are most likely to accu�mulate within a biogenic canopy
Partitioning climate uncertainty in ecological projections: Pacific oysters in a hotter Europe
Get PDFProjections of the range expansions of marine species are critical if we are to anticipate and mitigate the impacts
of climate change on marine ecosystems. However, most projections do not assess the level of uncertainty of
future changes, which brings their usefulness for scenario planning and ecosystem management into question.
For the overall climate system, these uncertainties take three forms: scenario uncertainty, climate model un�certainty and internal climate variability. Critically, internal variability, a measure of how natural variability
affects future climate projections, has largely been ignored in ecological studies. Here we use an ensemble
modelling approach for the non-native Pacific oyster in Europe to understand the impact of these uncertainties.
Future Pacific oyster recruitment was projected using a model that relates recruitment to cumulative and
instantaneous heat exposure. Model projections were carried out for four climate change scenarios: SSP1 2.6,
SSP2 4.5, SSP3 7.0 and SSP5 8.5. In each scenario an ensemble of over twenty climate models was used. The
impact of internal variability in climate models was assessed by using five climate models which were available
with multiple pre-industrial starting points. We find that model uncertainty within SSP1 2.6 is higher than the
differences between SSP1 2.6 and SSP 4.5, but it is unclear if overall scenario uncertainty is greater than climate
model uncertainty due to its subjective nature. Comparisons of scenario projections indicate that future
recruitment areas of Pacific oysters under the SSP5 8.5 scenario could be more than twice as high as in the low
emissions SSP1 2.6 scenario. Importantly, the ensemble showed that near-term changes in Pacific oysters are
highly uncertain due to internal variability, which is of a similar magnitude to climate model uncertainty on a
20-year timescale. Our results show that it is critical to think about the future in terms of potential scenarios and
not individual projections
The ecological value of fully enforced, no-entry, marine protected areas: A case study of harvested limpets
No full text1. Harvesting of intertidal gastropods can lead to a direct reduction in the biomass of targeted species through a reduction in the numbers and size of individuals, in turn leading to extensive changes to the structure of intertidal communities.
2. In the Azores, two patellid species co-occur, and both are exploited for human consumption. However, one of these species, Patella aspera (Röding, 1798), is larger and has a greater economic value and is thus favoured in comparison to the smaller Patella candei (d'Orbigny, 1840).
3. This study investigates the effects of human exploitation on the interaction between these two species by comparing their densities and sizes within two areas of a marine protected area (MPA): a no-entry area where human access is strictly prohibited and an adjacent area where human access is allowed and collection still occurs despite it being prohibited.
4. Patella aspera attained similar densities in the two areas, but individuals were much larger within the no-entry MPA. In contrast, P. candei were more abundant in the adjacent area but were of a similar size as in the no-entry MPA. Limpet biomass was much greater within the no-entry MPA. The abundance (% cover) of upright macroalgae and barnacles as well as bare rock were also significantly reduced within the no-entry MPA, where grazer-resistant algal crusts cover was significantly greater.
5. This study highlights the influence of human activities and how these may affect the complex dynamics of biotic interactions with wider community-level cascading effects
Atmospheric oxygen as a tracer for fossil fuel carbon dioxide: a sensitivity study in the UK
Get PDFWe investigate the use of atmospheric oxygen (O2) and carbon dioxide (CO2) measurements for the estimation of the fossil fuel component of atmospheric CO2 in the UK. Atmospheric potential oxygen (APO) – a tracer that combines O2 and CO2, minimizing the influence of terrestrial biosphere fluxes – is simulated at three sites in the UK, two of which make APO measurements. We present a set of model experiments that
estimate the sensitivity of APO simulations to key inputs: fluxes from the ocean, fossil fuel flux magnitude and
distribution, the APO baseline, and the exchange ratio of O2 to CO2 fluxes from fossil fuel combustion and the terrestrial biosphere. To estimate the influence of uncertainties in ocean fluxes, we compare three ocean
O2 flux estimates from the NEMO–ERSEM, the ECCO–Darwin ocean model, and the Jena CarboScope (JC) APO inversion. The sensitivity of APO to fossil fuel emission magnitudes and to terrestrial biosphere and fossil fuel exchange ratios is investigated through Monte Carlo sampling within literature uncertainty ranges and by
comparing different inventory estimates. We focus our model–data analysis on the year 2015 as ocean fluxes
are not available for later years. As APO measurements are only available for one UK site at this time, our
analysis focuses on the Weybourne station. Model–data comparisons for two additional UK sites (Heathfield and
Ridge Hill) in 2021, using ocean flux climatologies, are presented in the Supplement. Of the factors that could
potentially compromise simulated APO-derived fossil fuel CO2 (ffCO2) estimates, we find that the ocean O2
flux estimate has the largest overall influence at the three sites in the UK. At times, this influence is comparable
in magnitude to the contribution of simulated fossil fuel CO2 to simulated APO. We find that simulations using
different ocean fluxes differ from each other substantially. No single model estimate, or a model estimate that
assumed zero ocean flux, provided a significantly closer fit than any other. Furthermore, the uncertainty in the
ocean contribution to APO could lead to uncertainty in defining an appropriate regional background from the data. Our findings suggest that the contribution of non-terrestrial sources needs to be better accounted for in
model simulations of APO in the UK to reduce the potential influence on inferred fossil fuel CO2 using APO
Physiological and morphological plasticity in response to nitrogen availability of a yeast widely distributed in the open ocean
No full textYeasts are prevalent in the open ocean, yet we have limited understanding of their ecophysiological adaptations, including their response to nitrogen availability, which can have a major role in determining the ecological potential of other planktonic microbes. In this study, we characterised the nitrogen uptake capabilities and growth responses of marine-occurring yeasts. Yeast isolates from the North Atlantic Ocean were screened for growth on diverse nitrogen substrates, and across a concentration gradient of three environmentally relevant nitrogen substrates: nitrate, ammonium, and urea. Three strains grew with enriched nitrate while two did not, demonstrating that nitrate utilisation is present but not universal in marine yeasts, consistent with existing knowledge of non-marine yeast strains. Naganishia diffluens MBA_F0213 modified the key functional trait of cell size in response to nitrogen concentration, suggesting yeast cell morphology changes along chemical gradients in the marine environment. Meta-analysis of the reference DNA barcode in public databases revealed that the genus Naganishia has a global ocean distribution, strengthening the environmental applicability of the culture-based observations. This study provides novel quantitative understanding of the ecophysiological and morphological responses of marine-derived yeasts to variable nitrogen availability in vitro, providing insight into the functional ecology of yeasts within pelagic open ocean environment