Humber Estuary Research Articles

Coastal Lagoonal Evolution within the Early Holocene Humber Estuary, eastern England

ABSTRACTRapid sea‐level rise during the Early Holocene around the North Sea coastal lowlands provided conditions under which estuarine and coastal features, with no modern equivalents, could be created. Investigation of nearshore sediments within the Outer Humber Estuary, UK, has identified a tidal lagoonal system, created between c. 9000 and 7800 cal a bp. These sequences show the initial flooding of a carr woodland, prior to the establishment of more saline conditions as the tidal lagoonal system developed. Inter‐core comparisons, based on diatom and pollen analyses, suggest variations in the structure of a tidal lagoon setting, which probably lasted for only a brief period before being submerged by rising sea levels. The absence of an erosive contact in several of the sequences studied has permitted the creation of the oldest sea‐level index points for the Outer Humber Estuary, providing validation for the current glacial isostatic adjustment models for the region.

Using acoustic tracking of an anadromous lamprey in a heavily fragmented river to assess current and historic passage opportunities and prioritise remediation

AbstractAnthropogenic structures extensively fragment riverine systems, reducing longitudinal connectivity, inhibiting migration and leading to severe declines in many fish populations, especially for diadromous species. This study investigated the upstream spawning migration of anadromous river lamprey (Lampetra fluviatilis) in a heavily fragmented tributary of the Humber Estuary, the location of one of the largest UK river lamprey populations. Overall, this study quantified river lamprey migration, spawning habitat distribution and historic river levels to develop a novel empirical index to understand the impact of man‐made barriers and prioritise their remediation. Passage at all weirs only occurred during episodic high river levels, often after prolonged delays with no lamprey passing below average levels for the time of year or utilising the fish pass at the first weir (T1) at the tidal limit. Barrier passage opportunities at the first four weirs were only possible for 30.3%, 38.7%, 52.1% and 6.7% of the migration period, but were lower and severely limited in 15 of the last 21 years. In addition, more lamprey (60%, n = 18) were last detected in reaches with no spawning habitat than in spawning habitat (40%, n = 12). Given the impassibility of, and lack of retreat from, T1 to other Humber tributaries, the River Trent is currently considered an ecological trap for a large proportion of lamprey that enter from the Humber Estuary. This passage should be urgently remediated, per the prioritisation index presented here, to aid river lamprey conservation, especially given their status as a designated feature of the Humber SAC.

Loss of shallow water physiotope areas in tidal estuaries of the North Sea since the nineteenth century

PurposeThe main aim of this study was to quantify changes in shallow water physiotopes in the North Sea estuaries of Elbe, Humber, Scheldt, and Weser and to collect information on engineering activities which influenced the estuarine hydrology and potentially the spatial range of physiotopes, both between the nineteenth century and present day. A second aim was to provide a database on the recent physiotope distribution for the assessment of future interventions on these estuaries.MethodicallyPhysiotopes were defined by water depth and salinity. The area of the sub-, supra-, and intertidal physiotopes was calculated from digitised maps from different times since the nineteenth century. The spatial changes were opposed to the dates of implementation of the hydraulic engineering activities.ResultsFrom the nineteenth century onwards, the shallow water physiotopes of Elbe, Sea Scheldt, and Weser decreased spatially between 4 and 30%, whereas for the Humber estuary the areas have remained stable. The loss of areas was particularly located in the inner estuaries and concerned mostly freshwater physiotopes. The oligohaline and mesohaline zones exhibited less of a reduction in size, although, in the same order of magnitude, while the area of polyhaline physiotopes remained nearly unchanged.ConclusionThe loss of physiotopes which occurred mainly in the freshwater and oligohaline zones is important because physiotopes host different salinity-dependent biological communities. This loss of physiotopes could be observed after the implementation of hydraulic engineering projects, which could have led to higher current velocities, further upstream tidal penetration and very likely a corresponding shift of the salt-/freshwater interface upstream. All these effects altered the physiotope areas of the estuaries, except of the Humber estuary. The Humber had been modified to its today’s shape essentially before the nineteenth century. Nevertheless, the data describing the recent size of physiotopes provide a reference base for the assessment of future interventions in the estuaries of Elbe, Humber, Sea Scheldt, and Weser.

System responses to Holocene relative sea-level rise and sediment supply in a macrotidal estuary

Estuaries are at the interface of marine and terrestrial systems and as such, are subject to environmental change arising from multiple driving mechanisms, with the interplay between the dominant controls varying spatially and temporally. Relative sea-level (RSL) change and sediment supply can play a significant role in driving environmental change. This study examines the relative influence of these drivers during the Holocene. Biostratigraphic records and RSL data are presented from two locations in the inner portion and upper reaches of the macrotidal Humber Estuary, eastern England. The results provide a new terrestrial limiting point and six sea-level index points, two of which at c. 1500 cal years BP provide the youngest sea-level index points for the inner estuary. An early-mid Holocene tidal lagoon system, that lacks modern equivalent, is recorded at one site. The results indicate a shift in the dominance of RSL rise driving the early Holocene creation of wetlands, to sediment supply dominating changes in the mid-late Holocene against the backdrop of a reduced rate of RSL rise, with a submergence of wetlands evident after c. 4000 cal years BP. The persistence of fen carr evident between c. 6800 and 5500 cal years BP suggests stability and resilience of the peatland system to continuing RSL rise. As rates of contemporary RSL rise increase, combined with climate and human impacts on the landscape, the drivers of change in these type of estuary systems will shift, with the records providing analogues of potential system responses that can help inform coastal management strategies.

Individual, sexual and temporal variation in the winter home range sizes of GPS-tagged Eurasian Curlews Numenius arquata

ABSTRACT Capsule: Eurasian Curlews Numenius arquata were faithful to foraging and roosting areas on their coastal wintering grounds, including a habitat creation site. Home range sizes were greater at night than during the day, and showed high inter-individual variability which was not related to sex. Aims: To examine factors affecting variation in the winter home range size of the largest European wader species: the near-threatened Eurasian Curlew Numenius arquata. Methods: We examined individual, sexual and temporal (day/night, seasonal and annual) variation in the size of the home ranges of 18 GPS tagged Curlews captured at two sites on the Humber Estuary, UK. Results: Home ranges were small (mean ± SD = 555.5 ± 557.9 ha) and varied slightly in size through the non-breeding season (September–March). We found some annual differences in home range size, and there was some evidence that home range size was greater at night compared to daytime. There was strong inter-individual variation in home range size, which was not related to the species’ sexual size dimorphism and thus potential differences in resource use. Conclusions: Our results highlight that wintering Curlews on the Humber Estuary maintain small home ranges which vary strongly between individuals. Knowledge of the home range size of wintering waders is vital to inform management responses to the potential impacts of environmental changes such as sea-level rise and improving the efficacy of compensatory habitats.

Feeder 9 Gas Pipeline Replacement Tunnel – Achieving a world record for pipe insertion of a new gas pipeline within a tunnel beneath the river Humber (UK)

AbstractSince December 2020, at a pressure of 70 bar, up to 25 % of Britain's gas requirements was flowing through the new Feeder 9 gas pipeline, which installed in a 4.9 km long tunnel 30 m below the River Humber. With the insertion of the new pipeline, the Humber Pipeline Joint Venture (HPT JV), consisting of the companies Porr, Skanska and A. Hak, achieved a major milestone when it was officially recognised as a Guinness World Record for the longest hydraulically‐inserted pipe at 4,963.7 m long. Replacing the existing pipeline was an absolute necessity due to the shifting river bed which, over the years, had exposed sections of the pipeline threatening the supply to the customers in the UK. The solution adopted by the client, National Grid to provide a long‐term permanent solution, was for the construction of a segmental lined tunnel with an inner diameter of 3.65 m accommodating the new 1050 mm diameter welded steel gas pipe. The tunnel was excavated with a 4.4 m diameter mix shield type TBM. The small diameter together with the length, without intermediate access including a tidal range in the Humber estuary of up to 6.4 m and an overburden on the tunnel of 10 m below the river bed resulted in a number of challenges. The installation of the concrete‐coated steel pipeline was particularly high risk. The individual strings ranging from 595 to 620 m in length and weighing about 850 t, were pushed consecutively into the water‐filled tunnel employing two hydraulic thrusters in just 18 days.

Numerical Modelling of Oil Spill Transport in Tide-Dominated Estuaries: A Case Study of Humber Estuary, UK

Oil spills in estuaries are less studied and less understood than their oceanic counterparts. To address this gap, we present a detailed analysis of estuarine oil spill transport. We develop and analyse a range of simulations for the Humber Estuary, using a coupled hydrodynamic and oil spill model. The models were driven by river discharge at the river boundaries and tidal height data at the offshore boundary. Satisfactory model performance was obtained for both model calibration and validation. Some novel findings were made: (a) there is a statistically significant (p < 0.05) difference in the influence of hydrodynamic conditions (tidal range, stage and river discharge) on oil slick transport; and (b) because of seasonal variation in river discharge, winter slicks released at high water did not exhibit any upstream displacement over repeated tidal cycles, while summer slicks travelled upstream into the estuary over repeated tidal cycles. The implications of these findings for operational oil spill response are: (i) the need to take cognisance of time of oil release within a tidal cycle; and (ii) the need to understand how the interaction of river discharge and tidal range influences oil slick dynamics, as this will aid responders in assessing the likely oil trajectories.

Long-Term Changes in the Abundance of Benthic Foraging Birds in a Restored Wetland

Estuaries have historically been subject to considerable habitat loss, and continue to be subjected to such in areas where the natural landward migration of intertidal habitats is constrained by hard coastal defences. Thus, in estuaries where direct (e.g., port development) or indirect (e.g., sea level rise) processes are predicted to threaten intertidal habitats and associated waterbird species, there is a regulatory requirement to produce compensatory intertidal habitats. Managed realignment (MR) is a shoreline management practise that is undertaken to build sustainable coastal defences and create intertidal habitats in estuaries. This nature-based solution brings multiple benefits in the form of carbon storage, increased resilience to flooding, and, potentially, the formation of new habitats, which is the topic of this study. A 75-ha site at the Paull Holme Strays (Humber Estuary, United Kingdom) was monitored over a 10-year period following MR to examine the change in the abundance of waterbirds in the chosen site in response to the physical processes occurring there. Using digital terrain models (DTMs) collected via light detection and ranging (LiDAR), we examined how four compensatory target species responded to changes in elevation after the creation of the site. It was shown that the very rapid accretion of estuarine sediment occurred in the first decade of the new re-created intertidal, which, over time, led to changes in the numbers of benthic foraging birds supported. Furthermore, elevation change was also driven by this sediment accretion, the rate of which depended on the initial bed elevation of the sectors within the site. Ten years after the recreation of the habitat, the spatial heterogeneity in the bed elevation remained high; however, the sectors with the lowest elevations accreted the most over the 10-year period. The foraging number of the four waterbird species that colonised the MR site significantly declined above a certain elevation, with this effect being most pronounced for the Eurasian curlew (Numenius arquata). The number of common shelducks (Tadorna tadorna), dunlins (Calidris alpina), and common redshanks (Tringa totanus) declined significantly after initial peaks 5–7 years after the creation of the site, reflecting the ongoing elevation changes. Thus, this study highlighted the need for long-term studies to understand how species respond to large-scale habitat construction. It can also aid in predicting the suitability of an MR site for waterbirds in the medium and long term.

Forecasting System for Predicting the Dynamics of Oil Spill in a Tide-Dominated Estuary

ABSTRACT Crude oil is predicted to become one of the most detrimental sources of anthropogenic pollution to estuaries. A comprehensive survey of oil spill literature reveals that oil spill transport in estuaries presents a gap in academic knowledge and literature. To address this gap, we present the first detailed analysis of estuarine oil spill dynamics. We develop and analyse a range of simulations for the Humber Estuary, using TELEMAC3D; a coupled hydrodynamic and oil spill models. The river boundary of the Humber Estuary is forced by discharge data, while the offshore boundary is driven by tidal height data, including estuarine water temperature and salinity. The calibrated model shows good agreement with measured data during the validation process. Results show that: (a) the time of oil release within a tidal cycle significantly influences oil slick transport; and (b) the tidal range significantly influences oil slick impacted area and overall distance travelled, as oil slick released under spring tide is approximately double the oil slick size under neap tides and travels on average 71% farther. This study emphasises the need to: a) understand how the interaction of river discharge and tidal range influences oil slick transport; and (b) be aware of the time of release within a tidal cycle, to efficiently deal with oil spills. Findings should be useful for future operational oil spill response and could be equally applicable to other tide-dominated estuaries.

Influence of projected climatic conditions and varying lateral points of release on oil slick transport in a tide-dominated estuary

Oil spills in estuarine systems can strongly endanger habitats and water quality. However, the impacts of projected climatic conditions on oil spill transport in estuarine environments have received little attention. To address these key gaps, we analyse here a range of simulations for the Humber Estuary, UK, using coupled hydrodynamic and oil spill model. These simulations indicate that, for this well-mixed macro-tidal estuary: (a) the influence of projected sea level rise and river discharge on oil slick impacted area, slick length and overall distance travelled is relatively minor (<10%); (b) magnitude of currents determines differences in dynamics between oil slicks released along the estuary length; and (c) differences in lateral current speed and direction are key determinants of the differences in the dynamics of oil slicks released along the estuary width. The implications of these findings for operational oil spill response in estuaries similar to the Humber Estuary are: (i) the need to be aware of dominant current direction in different segments of the estuary; and (ii) the need take cognisance of the interaction between oil slicks and estuary bank and how it influences overall distance travelled by oil slicks.

Iron Age and Roman Settlement at Brough South, East Riding of Yorkshire

Excavations to the southeast of Brough on a site close to the Humber estuary identified three phases of an Iron Age roundhouse, where a community raised sheep and pigs, grew cereals, spun wool and made their own pots. This was followed by early Roman-British boundary and trackway ditches, albeit with likely Iron Age origins. Activity apparently ceased in the second century AD and this might reflect wetter conditions over time with settlement moving further north while previously occupied land was given over to agriculture. Rare earlier prehistoric and Anglo-Saxon finds attest to the longevity of this landscape’s use probably due to the richness of the hinterland between salt marsh and estuary to the south, and drier conditions to the north.

Spatial variability of macrofaunal traits across the Greater North Sea

Large-scale spatial variability of macrofaunal traits has rarely been studied. This paucity of information hinders progress to derive indicators of seabed integrity under current policy drivers. Based on data from 327 stations across the Greater North Sea, a sub-region of the EU Marine Strategy Framework Directive (MSFD), we describe variability in the numerical dominance of ten important macrofaunal traits and their relationships with the physical environment.For six traits (longevity, larval development position, egg development position, sediment position and bioturbation method), macrofaunal assemblages were dominated by one or two trait categories; these traits showed more pronounced spatial patterns than traits with a wider (and more even) trait category expression. Similar spatial distributions of some dominant categories were observed. For example, egg-brooding, surface-dwelling and suspension feeding traits were dominant in the central English Channel and off the Humber Estuary. Traits generally showed weak spatial relationships with environmental variables, although sediment position and feeding type were related to variations in bed shear stress and gravel content. We discuss the implications of these findings in relation to monitoring seabed integrity under the MSFD.

The Crosby Warren Field, Block DL001, UK Onshore

Abstract The Crosby Warren Field is located onshore the UK, south of the Humber Estuary. It was discovered by RTZ Oil &amp; Gas with the CW-1 (L46/12-3) well in 1986. The oil reservoir is Carboniferous, Namurian, Beacon Hill Flags sandstone, with gas found in Namurian sandstones of the Rough Rock, and the discovery well originally flowed waxy 40° API oil at rates of 45 bopd, which increased to nearly 700 bopd following fracture stimulation. The Beacon Hill Flags are a 10 m-thick group of laminated sandstones within a substantial gross thickness of sandstones, silts, muds and occasional thin claystones. The expected ultimate recovery for the field will be about 0.9 MMbbl of oil and 0.7 bcf of gas. Almost all of the oil and gas have already been recovered, and end of life for the field is expected to be in 2022.

Poetry, Painting and Change on the Edge of England

AbstractIn this article we discuss our creative research on and with a contested coastal community on one of the UK's last existing plotlands, the humberston Fitties. Plotlands can be briefly defined as places where individuals have historically self‐built holiday houses. This 56‐acre strip of land with 319 chalets is on the Humber estuary and lies close to Cleethorpes, a seaside resort, and Grimsby, a seaport now facing post‐industrial decline. Our cross‐disciplinary collaborative practice between poetry and visual art explores open, environmentally aware engagements and methodologies with landscape and rural place. We investigate the relation of social, environmental and energy politics, looking out to land and sea and back to the community. Our results include original art and poetry presented innovatively together in exhibitions and books, in addition to local people's responses to our methodologies and the work itself.

Field investigation of bedform morphodynamics under combined flow

Fieldwork was conducted at the Red Cliff sandbar located in the upper Humber Estuary in order to investigate bedform dynamics under different hydrodynamic conditions related to combinations in tidal and wave-generated currents. A fixed mooring was deployed to obtain current flow and wave properties across the sand bar site at both spring and neap tidal flows and during conditions of high wind generated waves. A terrestrial laser scanner was used to scan the sandbar during low water across the various forcing conditions, acquiring detailed information of ripple geometries. Under spring tide and calm wave conditions, two-dimensional asymmetrical ripples with straight crest lines were generated on the sandbar. Surveys were also conducted during strong winds. Prior to high-wind-waves, two-dimensional symmetrical and washed-out ripples were observed, during spring and neap tidal conditions respectively. The lengths of these ripples were almost the same as those generated under current only conditions, but their heights were relatively smaller. After the strong wind periods, 2D current-induced ripples were replaced by flatbed conditions and 2D symmetrical wash-out ripples, which indicates wave-induced bed shear stress is enhanced by the presence of a tidal current. Most pertinently our study reveals discrepancies between field observations and existing predictions of bed configurations that are largely based on laboratory investigations. This is likely due to a larger grain size distribution in field conditions and due to turbulence dampening by high concentrations of suspended clay particles. The study thus highlights a need to extend a range of field investigations that explore the current deficiencies in our abilities to predict bedforms and bedform dynamics in estuarine systems.

Spatial and temporal occurrence of pharmaceuticals in UK estuaries

There is a lack of data on the occurrence of pharmaceuticals in estuaries worldwide, with little understanding of their temporal and spatial variations globally. Ibuprofen, paracetamol, diclofenac, trimethoprim and citalopram were measured in twelve estuaries in the UK. Initially, these compounds were monitored in the Humber Estuary, where samples were taken every two months over a twelve month period in order to assess their spatial and temporal variations. Ibuprofen was found at some of the highest concentrations ever measured in an estuary globally (18–6297 ng l−1), with paracetamol also measured at relatively high concentrations (4–917 ng l−1) in comparison to the other compounds. In terms of spatial distribution, a pattern was observed where the highest concentrations were found at a site at which wastewater is discharged, whilst compound concentrations were often lower upstream and downstream of this site. The downstream profile of pharmaceuticals differed temporally with concentrations highest downstream when input from wastewater effluent was highest. Eleven further estuaries were sampled around the UK in order to put the occurrence of pharmaceuticals in the Humber Estuary into a wider context. Pharmaceutical concentrations in the other estuaries sampled were <210 ng l−1 but, again, ibuprofen and paracetamol were found at concentrations higher than other compounds, whereas diclofenac and citalopram were absent in many estuaries. The Humber, which is the receiving environment for the sewage effluent of approximately 20% (13.6 million people) of the population of England, was observed to have the highest overall concentration of pharmaceuticals in contrast to the other estuaries sampled, thereby representing a worst case scenario for pharmaceutical pollution.

Climate, Power, and Possible Futures, from the Banks of the Humber Estuary

Nayan Kulkarni’s Blade, Lucy and Jorge Orta’s Raft of the Medusa, and Nikolaj Bendix Skyum Larsen’s Quicksand were exhibited in Hull during its year as the 2017 UK City of Culture. These artworks provide the impetus for an article that moves between the local, national, and global, in order to connect visual culture, climate politics, and questions of citizenship and borders in a warming world. In the first section, I discuss how Blade—a wind turbine rotor blade repurposed as a public art installation—provides the opportunity to examine the role of large-scale renewable energy transition in addressing the deep regional economic inequalities in the UK. In the second section, I consider how artworks displayed as part of the ‘Somewhere Becoming Sea’ exhibition linked Hull’s recent history to a global context of displacement and precarity, in the wake of the ongoing ‘refugee crisis’ within Europe and at its borders. In the final section, I seek to bring together a number of threads from the preceding discussion, in order to outline some alternative political horizons. I turn initially to Sean McAllister’s documentary A Northern Soul (2018) and its powerful examination of how personal debt, the toxic fuel of neoliberalism, forecloses the future. In opposition to a future of deepening inequality and climate breakdown, I trace a renewed politics of public ownership and expanded social welfare in the UK, and its place in a prospective global renewable energy transition. This is a hopeful vision, given the current political climate, I argue, but it is also an eminently feasible one.

Diversity patterns of benthic bacterial communities along the salinity continuum of the Humber estuary (UK)

Intertidal mudflats are fluctuating environments that support highly diverse microbial communities. The highly variable physico-chemical conditions complicate the understanding of the environmental controls on diversity patterns in estuarine systems. We investigated the bacterial diversity in the surface and subsurface sediments along the salinity gradient of the Humber estuary (UK) using amplicon sequencing of the 16S rRNA gene and correlated its variations with environmental variables. The sediment depths sampled were selected based on the local resuspension patterns. In general, bacterial communities showed similar composition at the different sites and depths, with Proteobacteria being the most abundant phylum. The richness of operational taxonomic units (OTUs) was uniform along the salinity gradient. However, Hill numbers, as bacterial diversity measures, showed that the common and dominant OTUs exhibited a decreasing trend from the inner towards the outer estuary sites. Additionally, surface and subsurface bacterial communities were separated by non-metric multi-dimensional scaling (NMDS) analysis only in the mid- and outer estuary samples, where redox transitions with depth were more abrupt. Salinity, porewater ammonium concentration and acid-extractable Fe(II) in solids were the subset of environmental factors that best correlated with community dissimilarities. Analysis of regional diversity indicated that the dataset may include 2 potentially distinct communities: (1) a near-surface community that is the product of regular mixing and transport and is subjected to a wide range of salinity conditions, and (2) a bacterial community indigenous to the more reducing subsurface sediments of the mudflats of the mid- and outer estuary.

Reoxidation of estuarine sediments during simulated resuspension events: Effects on nutrient and trace metal mobilisation

Estuarine environments are considered to be nutrient buffer systems as they regulate the delivery of nutrients from rivers to the ocean. In the Humber Estuary (UK) seawater and freshwater mixing during tidal cycles leads to the mobilisation of oxic surface sediments (0–1 cm). However, less frequent seasonal events can also mobilise anoxic subsurface (5–10 cm) sediments, which may have further implications for the estuarine geochemistry. A series of batch experiments were carried out on surface and subsurface sediments taken from along the salinity gradient of the Humber Estuary. The aim was to investigate the geochemical processes driving major element (N, Fe, S, and Mn) redox cycling and trace metal behaviour during simulated resuspension events. The magnitude of major nutrient and metal release was significantly greater during the resuspension of outer estuarine sediments rather than from inner estuarine sediments. When comparing resuspension of surface versus subsurface sediment, only the outer estuary experiments showed significant differences in major nutrient behaviour with sediment depth. In general, any ammonium, manganese and trace metals (Cu and Zn) released during the resuspension experiments were rapidly removed from solution as new sorption sites (i.e. Fe/Mn oxyhydroxides) formed. Therefore Humber estuary sediments showed a scavenging capacity for these dissolved species and hence may act as an ultimate sink for these elements. Due to the larger aerial extent of the outer estuary intertidal mudflats in comparison with the inner estuary area, the mobilisation of the outer estuary sediments (more reducing and richer in sulphides and iron) may have a greater impact on the transport and cycling of nutrients and trace metals. Climate change-associated sea level rise combined with an increasing frequency of major storm events in temperate zones, which are more likely to mobilise deeper sediment regions, will impact the nutrient and metal inputs to the coastal waters, and therefore enhance the likelihood of eutrophication in this environment.

Peter Pritchard: general practitioner with “legendary” improvisation skills

Peter Pritchard, who died just a few months short of his centenary, had an extraordinary ability to improvise pragmatic solutions to practical problems, whether physical or organisational. This made him...