Paul Kemp

Paul Kemp
University of Southampton

Doctor of Philosophy

About

138
Publications
27,496
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Introduction
Skills and Expertise

Publications

Publications (138)
Article
Full-text available
The decline in European eel ( Anguilla anguilla ) recruitment over the past half-century is partly due to river infrastructure that delays or blocks upstream migration to rearing habitat. Stimuli, such as electricity, can be used to modify the behaviour of downstream moving fish and guide them to preferred routes of passage at river infrastructure;...
Article
Full-text available
Water-Energy-Food (WEF) Nexus interactions vary from seemingly negative and intractable wicked problems to opportunities for enhanced sustainability. The aim of this paper is to review the current state of understanding on WEF resource interactions and to provide a roadmap to enhance integrated resource management. A qualitative perspective based o...
Preprint
We estimate over 200,000 km or 10% of previously free-flowing river habitat length has been lost due to impoundments, an amount equivalent to the entire length of rivers in Italy. This loss strongly depends on the biogeographical location and a type of impounding barrier. European rivers are disconnected by more than one million man-made barriers t...
Article
b>Highlights • Horizontally and vertically oriented bar racks were evaluated for fish screening • Downstream movements of groups of chub and barbel were recorded and analysed • Sweeping flows across the rack face to the bypass were not established • Consequently, total guidance was low for both species under all treatments • The bar racks used w...
Article
Acoustic bubble curtains have been marketed as relatively low cost and easily maintained behavioural deterrents for fisheries management. Their energy efficiency can be improved by reducing air flow and exploiting bubble resonance. In a series of three flume experiments, we: (1) investigated the reactions of carp to a low air flow bubble curtain, (...
Article
Like many other species of diadromous fish, the European eel (Anguilla anguilla) is threatened by entrainment at hydropower intakes and resultant injury and mortality during passage through turbines. Historically, physical screens have been installed to prevent European eel access to intakes but these are not wholly effective and can incur high cos...
Article
Anthropogenic infrastructure in rivers (e.g. culverts, dams and weirs) can block the movements of fish and negatively impact their communities. Recent research has shown that fish passage at such barriers can be improved through the use of cylindrical bristle cluster (CBC) arrays. The relationship between the hydrodynamic environment created by dif...
Article
Collective behaviour, such as shoaling in fish, benefits individuals through a variety of activities such as social information exchange and anti-predator defence. Human driven disturbance (e.g. anthropogenic noise) is known to affect the behaviour and physiology of individual animals, but the disruption of social aggregations of fish remains poorl...
Article
Full-text available
Globally, freshwaters are the most degraded and threatened of all ecosystems. In northern temperate regions, beaver reintroductions are increasingly used as a low-cost and self-sustaining means to restore river corridors. River modifications by beavers can increase availability of suitable habitat for fish, including salmonids. This study investiga...
Article
Full-text available
Recruitment of temperate eel species Anguilla anguilla, A. rostrata & A. japonica has declined over the last few decades due to human activities, such as overfishing and construction of migratory barriers (e.g. dams, weirs and sluices) and hazardous energy infrastructure (e.g. turbines, intakes and outfalls). Numerical models, substantiated with da...
Article
River managers are consistently challenged to address two key threats to freshwater biodiversity. The first is the effects of habitat fragmentation by instream structures such as dams and weirs that disrupt life history migrations and impact species distributions. The second is the impact of non-native species on native species and ecological proce...
Article
Artificial light at night (ALAN) is considered one of the most pervasive forms of environmental pollution. It is an emerging threat to freshwater biodiversity and can influence ecologically important behaviours of fish. The European eel (Anguilla anguilla) is a critically endangered catadromous species that migrates downstream to the ocean to spawn...
Article
Full-text available
Rivers support some of Earth’s richest biodiversity1 and provide essential ecosystem services to society2, but they are often fragmented by barriers to free flow3. In Europe, attempts to quantify river connectivity have been hampered by the absence of a harmonized barrier database. Here we show that there are at least 1.2 million instream barriers...
Article
Full-text available
Solar power is a renewable energy source with great potential to help meet increasing global energy demands and reduce our reliance on fossil fuels. However, research is scarce on how solar facilities affect wildlife. With input from professionals in ecology, conservation, and energy, we conducted a research-prioritization process and identified ke...
Article
Full-text available
Systematic experiments on European eel (Anguilla anguilla) in their juvenile, early life stage (glass eel), were conducted to provide new insights on the fish swimming performance and propose a framework of analysis to design swimming-performance experiments for bottom-dwelling fish. In particular, we coupled experimental and computational fluid dy...
Article
Full-text available
1. Understanding how collective behaviour of animals is influenced by anthropogenic activity is important for their conservation in an increasingly urbanised world. River infrastructure, e.g. for transport and electricity generation, and associated construction and operation, produce sound that can disrupt ecological processes. 2. Adopting a reduc...
Article
Full-text available
‘Trap and transport’ (T&T) is employed to facilitate the seaward migration of European eel (Anguilla anguilla) past obstacles such as hydropower facilities. Hence, previous studies assessing its efficacy have focussed on disrupted fluvial systems. The transferability of findings from lotic to lentic systems is uncertain because many of the environm...
Article
One of the most detrimental factors in the drastic decline of the critically endangered European eel (Anguilla anguilla) was the inadvertent introduction of the invasive nematode Anguillicoides crassus. Infection primarily impacts the swimbladder, a gas-filled organ that enables the eel to control its depth in the water. A reduction in swimbladder...
Article
Full-text available
Brexit creates a systemic shock that provides a unique opportunity for the UK to implement a new sustainable Fisheries Policy to better manage the multiple stocks on which future fishers will depend on leaving the European Union. At the same time, the global slowdown of commercial fishing as a result of COVID-19 has reduced pressure on some threate...
Article
Spatial patterns in moving fish shoals originate from social interactions and are driven by factors that benefit individuals, such as predator avoidance or reduced energy expenditure. How shoaling is influenced by the presence and absence of a flow field is only partially understood. Adopting a reductionist approach, time spent shoaling, shoal stru...
Conference Paper
In assessing the impact of sound on aquatic life, or its potential to guide fauna away from hazards, there is reliance on decades of human audiology, for example by adapting tests such as behavioral audiograms and Auditory Evoked Potentials. However, now that human audiology has translated over decades from research laboratories to the high-street...
Article
Behavioral guidance systems are commonly used in freshwater fish conservation. The biological relevance of sound to fish and recorded responses to human-generated noise supports the viability of the use of acoustics as an effective stimulus in such technologies. Relatively little information exists on the long-term responses and recovery of fish to...
Article
To support eco-friendly hydropower planning in developing regions, we propose a spatial optimization model for locating dams to balance tradeoffs between hydropower generation and migratory fish species richness. Our model incorporates two special features. First, it is tailored to the dispersal of tropical migratory fishes, which require long, uni...
Article
Globally, gauging weirs are commonly installed in rivers to monitor flows. They have widespread negative impacts on the upstream movement of fish due to the barriers created by the unfavourable hydraulic conditions on the downstream face. There is a need to develop simple low-cost solutions to enhance multi-species fish passage, while not impacting...
Article
Massive exploitation of freshwater systems for hydropower generation in developing countries is challenging sustainability due to cumulative environmental impacts in regions with high endemism. Habitat fragmentation is recognized as a major impact on river ecosystems. The nature and magnitude of connectivity loss depend on characteristics of the hy...
Conference Paper
Full-text available
KEY POINTS  Artificial Vegetation Patches (VP) can be used for the design of fish passes.  The drag coefficient of VP depends on the patch solidity (SVF).  The drag coefficient vs SVF is explained by bleeding effects.  RANS-based CFD allows for a satisfactory prediction of VP drag.
Article
Traditional physical screens designed to prevent fish entering dangerous areas (e.g. turbine intakes) can have negative impacts due to impingement or mechanical abrasion at high velocities. Behavioural deterrents may provide an alternative approach to screening. This study investigated the potential for a continuous broadband sound to modify the be...
Article
No PDF available ABSTRACT Acoustic-bubble barriers show potential as a management tool for fish passage. Although greater efforts are now being made to better understand the fundamentals that underpin reactions of fish to such barriers, the phenomenon of bubble coalescence has not yet been considered. When introducing air underwater smaller bubbles...
Preprint
Artificial barriers are one of the main threats to river ecosystems, resulting in habitat fragmentation and loss of connectivity. Yet, the abundance and distribution of most artificial barriers, excluding high-head dams, is poorly documented. We provide a comprehensive assessment of the distribution and typology of artificial barriers in Great Brit...
Article
Artificial barriers are one of the main threats to river ecosystems, resulting in habitat fragmentation and loss of connectivity. Yet, the abundance and distribution of most artificial barriers, excluding high-head dams, is poorly documented. We provide a comprehensive assessment of the distribution and typology of artificial barriers in Great Brit...
Article
European eel, Anguilla anguilla (L.), is vulnerable to entrainment at a variety of man‐made intakes, including those that lead to hydropower turbines or other abstraction points. Two experiments were conducted to investigate the potential for acoustic stimuli to improve the efficiency of a vertical bar screen to guide downstream moving eel. Three u...
Conference Paper
Acoustic behavioral deterrent systems are deployed to control range expansion of invasive species, and protect migratory fish from hazardous anthropogenic physical barriers. Installation sites (e.g. dams and weirs) are generally dominated by high-level background acoustic noise, a commonly neglected consideration when testing the effectiveness of a...
Article
1. Groundwater-fed rivers, such as the chalk streams of southern England, exhibit high levels of stability (e.g. flow and temperature) and physical homogeneity (e.g. depth and substrate grain size). However, growth of instream macrophytes is highly variable depending on season, providing an important but ever changing source of cover for stream dwe...
Article
Full-text available
Oxygen supply to the salmonid egg surface can be limited by external factors such as sedimentation and groundwater upwelling, while the egg membrane itself can impede diffusion from the egg surface to the embryo. Therefore, the structure of egg membranes could affect the rate at which embryos obtain oxygen from their surroundings. Published field d...
Article
Culverts used to convey river water under roads and embankments are one of the most common small-scale barriers to longitudinal fish movements worldwide. Using an open channel flume, this study assessed the ability of upstream migrating adult river lamprey (Lampetra fluviatilis) to ascend a pipe culvert when unmodified (control [C]) and retrofitted...
Article
Passage performance of upstream-migrating lamprey (Lampetra fluviatilis) was compared between sections of a Crump flow-gauging weir with and without studded tiles, and at a bottom-baffle fishway, on the River Derwent, England. The effects of microhydropower operation on attraction to multiple routes were also studied. Studded tiles were fixed horiz...
Article
According to Signal Detection Theory, the ability to detect a stimulus (discriminability, d′) is inversely related to the magnitude of internal and external noise. In this study, downstream moving brown trout Salmo trutta were used to investigate whether external hydrodynamic noise (in this case turbulence) could mask a signal that induced an unwan...
Article
Physical screens are commonly installed to prevent downstream moving fish from entering dangerous areas (e.g. intakes to hydropower turbines, irrigation canals, and fish farms), and divert them to preferred alternative routes (e.g. bypass systems). In northern temperate regions, assessments of the functioning of screens have largely focused on diad...
Article
Full-text available
There has been an increase in the abundance of small hydropower (< 10 MW) installations. These tend to be ‘run-of-river’, thereby reducing or averting the need for impoundment and water storage, and so are considered to have lower environmental impact. The Archimedes screw turbine (AST) has been described as ‘fish friendly’ based on magnitude of ob...
Article
Using an open channel flume, this study quantified upstream passage of European eel (Anguilla anguilla) and river lamprey (Lampetra fluviatilis) at a model Crump weir provisioned with vertically or horizontally oriented studded tiles, under high and low velocity. Tiles stopped short of the weir crest, as often required at gauging weirs. For eel, wh...
Article
Understanding of the winter ecology of stream salmonids is biased by research conducted in northern temperate and boreal regions dominated by hard rock geology. Such systems are driven by highly dynamic surface-flow regimes and tend to be physically diverse, nutrient poor and influenced by ice. This study investigated how the behaviour of brown tro...
Article
The bighead carp (Hypophthalmichthys nobilis) is one of the most commercially important freshwater fish species in China, but their abundance has declined considerably in recent decades, partly due to river regulation. In other countries it is invasive, posing an ecological and economic threat. To improve fish pass effectiveness at impediments to m...
Article
Over recent years, there has been increasing challenge to the accepted wisdom that the environmental impacts of river engineering can be adequately mitigated through the installation of infrastructure, such as fish passes. This has led to a debate on the value of fish passage with some arguing that increased research and development will advance so...
Article
It is commonly assumed that stream-dwelling fish should select positions where they can reduce energetic costs relative to benefits gained and enhance fitness. However, the selection of appropriate hydrodynamic metrics that predict space use is the subject of recent debate and a cause of controversy. This is for three reasons: 1) flow characteristi...
Article
Freshwater ecosystems are declining faster than their terrestrial and marine counterparts because of physical pressures on habitats. European legislation requires member states to achieve ecological targets through the effective management of freshwater habitats. Maps of habitats across river networks would help diagnose environmental problems and...
Article
The conditions experienced by incubating Atlantic salmon (Salmo salar) eggs are strongly influenced by hyporheic exchange. In some rivers, periods of intense groundwater upwelling can reduce oxygen levels in the incubation zone to 0% saturation. The present study investigated the effect of oxygen sags on the posthatch fitness of Atlantic salmon. A...
Article
Tide gates, used to regulate tidal flow as part of land reclamation programmes, temporally block fish movement by closing during the flood tide. Their impact on the upstream movement of brown trout, Salmo trutta, and other fish species has received little consideration. The River Stiffkey, UK, discharges into the North Sea via three top-hung tide g...
Article
Full-text available
The presence of dams, stream-road crossings and other infrastructure often compromises the connectivity of rivers, leading to reduced fish abundance and diversity. The assessment and mitigation of river barriers is critical to the success of restoration efforts aimed at restoring river integrity. In this study, we present a combined modelling appro...
Article
Variation in global climate during the Quaternary has helped shape current species distributions. The stenohaline fish fauna of the British Isles is generally thought to have colonised eastern England via a landbridge following the last glacial maximum. This theory is investigated using the nationally extinct burbot, Lota lota, as a model species....
Conference Paper
Full-text available
The decline of freshwater fish biodiversity is proceeding at an alarming and persistent rate. Given that most fish must undertake some form of migration in order to complete their life-cycle, of particular concern is the proliferation of hydropower schemes that block migration routes, as well as a variety of other barriers such as weirs and culvert...
Conference Paper
Shipping creates large near-field background noises at levels similar to or higher than fish vocalizations and in the same critical bandwidths. This noise has the potential to "mask" biologically important signals and prevent fish from hearing them; any interference with the detection and recognition of sounds may impact fish survival. The Lombard...
Article
Globally, populations of diadromous anguilliform morphotype fish, such as eel and lamprey, have experienced substantial declines, partly as a result of habitat fragmentation caused by river infrastructure. In the UK, a new configuration of hydraulically unobtrusive bristle pass (side-mounted and vertically oriented) has been developed to help upstr...
Article
Shipping creates large near-field background noises at levels similar to or higher than fish vocalizations and in the same critical bandwidths. This noise has the potential to "mask" biologically important signals and prevent fish from hearing them; any interference with the detection and recognition of sounds may impact fish survival. The Lombard...
Article
During recent decades, new insights regarding the spawning migration of lampreys have been gained due to advances in technology and growing interest in this key life history phase. The development of miniaturized active and passive transmitters has led to detailed information on the timing and extent of lamprey migrations. These tools, together wit...
Article
River infrastructure such as weirs and hydropower stations commonly present migrating fish with multiple potential passage routes. Knowledge of the cues fish use to navigate such environments is required to protect migrants from hazardous areas and guide them towards safe passage; however, this is currently lacking for many species. Employing high-...
Chapter
Globally, rivers directly support a large proportion of the human population and provide ecosystem services essential for quality of life, including the provision of protein through maintenance of fisheries. Many systems have been extensively engineered to support agricultural production, urbanization and industrialization, activities that can nega...
Article
To facilitate the upstream passage of small fish, corrugated culverts are often preferred over smooth pipes, due to the lower edge and mean cross sectional water velocities created. This benefit could be lost if greater intensities of turbulence induced by wall roughness cause instability and increase the energetic expense of fish locomotion. Commo...
Article
Full-text available
Anthropogenic structures (e.g. weirs and dams) fragment river networks and restrict the movement of migratory fish. Poor understanding of behavioural response to hydrodynamic cues at structures currently limits the development of effective barrier mitigation measures. This study aimed to assess the effect of flow constriction and associated flow pa...
Article
This study demonstrated that juvenile (glass) eels used a specific substrate (eel tiles) to circumvent a model Crump weir under an experimental setting. Upstream passage efficiency was 0 and 67% for the unmodified (no studded eel tiles on the downstream face; control) and modified (with studded eel tiles on the downstream face; treatment) setups ,...
Article
The effect of Anguillicola crassus, Pseudodactylogyrus bini and Pseudodactylogyrus anguillae infection on the behaviour of downstream migrating adult European eels Anguilla anguilla as they encountered accelerating water velocity, common at engineered structures where flow is constricted (e.g. weirs and bypass systems), was evaluated in an experime...
Article
Tide gates form a temporal barrier to fish migration, closing during the flood tide and opening during the ebb, primarily for flood prevention and land reclamation. Their impact on downstream adult migration of the critically endangered European eel, Anguilla anguilla, is unknown. The River Stiffkey, UK, has three top-hung tide gates (one counterba...
Article
Installation of baffles intended to improve fish passage through culverts can reduce discharge capacity and trap debris, increasing flood risk. A sloping upstream face may reduce this risk, but new designs must be tested for fish passage efficiency. The European eel (Anguilla anguilla) is a critically endangered species, yet the suitability of even...
Article
As part of flood protection and land reclamation schemes, tide gates allow rivers to discharge to sea when open, and prevent salt water intrusion when closed. Their impact on diadromous fish migration between essential spawning and rearing habitats, and the effectiveness of mitigation measures, have received little consideration. The River Meon, UK...
Conference Paper
River fragmentation and associated flow alteration and habitat degradation are significant factors in the decline and extinction of freshwater biota. One group of imperilled fishes, pelagic-broadcast spawning cyprinids release semi-buoyant eggs that require sufficient velocities and river-fragment length during early development. However, it is unk...
Article
Full-text available
Physical modelling is a key tool for generating understanding of the complex interactions between aquatic organisms and hydraulics, which is important for management of aquatic environments under environmental change and our ability to exploit ecosystem services. Many aspects of this field remain poorly understood and the use of physical models wit...
Article
To mitigate negative impacts of delayed migration it is necessary to understand the causes of avoidance exhibited by animals at behavioural barriers. For downstream migrating juvenile salmon, avoidance of velocity gradients at anthropogenic structures may compromise fitness. Building on previous experimental investigations on salmonid response to v...
Article
Fluvial disconnectivity can have important impacts on fish populations, including hindering movement between habitats required for different ontogenic stages. Recruitment of the European eel (Anguilla anguilla) has reduced by over 90% since the early 1980's, in part due to the effect of riverine barriers on its catadromous migration. There is a leg...