The Urban River Syndrome

[Full title: The Urban River Syndrome: Achieving Sustainability Against a Backdrop of Accelerating Change]

International Journal of Environmental Research and Public Health Review The Urban River Syndrome: Achieving Sustainability Against a Backdrop of Accelerating Change Martin Richardson * and Mikhail Soloviev * Citation: Richardson, M.; Soloviev, M. The Urban River Syndrome: Achieving Sustainability Against a Backdrop of Accelerating Change Int J. Environ. Res. Public Health 2021 , 18 , 6406. https://doi.org/10.3390/ ijerph 18126406 Academic Editors: William A. Toscano and Jan Hofman Received: 28 March 2021 Accepted: 10 June 2021 Published: 13 June 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations Copyright: © 2021 by the authors Licensee MDPI, Basel, Switzerland This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/) Department of Biological Sciences, Royal Holloway University of London, Egham TW 20 0 EX, UK * Correspondence: Martin.Richardson.2014@live.rhul.ac.uk (M.R.); Mikhail.Soloviev@rhul.ac.uk (M.S.) Abstract: Human activities have been affecting rivers and other natural systems for millennia Anthropogenic changes to rivers over the last few centuries led to the accelerating state of decline of coastal and estuarine regions globally. Urban rivers are parts of larger catchment ecosystems, which in turn form parts of wider nested, interconnected systems. Accurate modelling of urban rivers may not be possible because of the complex multisystem interactions operating concurrently and over different spatial and temporal scales. This paper overviews urban river syndrome, the accelerating deterioration of urban river ecology, and outlines growing conservation challenges of river restoration projects. This paper also reviews the river Thames, which is a typical urban river that suffers from growing anthropogenic effects and thus represents all urban rivers of similar type A particular emphasis is made on ecosystem adaptation, widespread extinctions and the proliferation of non-native species in the urban Thames. This research emphasizes the need for a holistic systems approach to urban river restoration Keywords: urban river syndrome; urban stream syndrome; pollution; sustainability; ecosystem; adaptation; anthropogenic changes; the Thames; restoration 1. Introduction Anthropogenic changes to rivers have been apparent for at least two centuries [ 1 ], and despite sporadic improvements [ 2 ], coastal and estuarine regions are in an accelerating state of decline. Work is needed to catch up with a historical deficit in terms of accumulated pollution, waste and other damage. There is a long history associated with the study of rivers (Table 1 ). For example, stream invertebrates have been used as indicators of water quality since the 19 th century, e.g., the Macroinvertebrate Community Index in New Zealand. Theories to predict ecological patterns associated with features of river morphology have been widely employed for many years [ 3 , 4 ]. However, some such theories assume pristine baseline conditions, which are no longer appropriate. Nonetheless, due to their historical value, these theories are continually updated and are in use at the current time Table 1. Notable ecological theories Ecological Theories Year Introduced Recently Reviewed The River Continuum Concept (RCC) 1980 [ 4 ] Hierarchical Patch Dynamics (HPD) 1940 s [ 5 ] Functional Process Zones (FPZ) 1980 [ 6 ] Urban rivers are one component of catchment systems. Though not usually studied together [ 7 ], system changes are connected and coactive. They operate at different levels (Figure 1 ) and at different rates, which means they can give rise to unexpected outcomes in the form of ‘surprises’ [ 8 ] or ‘shocks’ and even ecosystem collapse, which are recognised features of dynamical systems behaviour in general. Close observation, monitoring and Int. J. Environ. Res. Public Health 2021 , 18 , 6406. https://doi.org/10.3390/ijerph 18126406 https://www.mdpi.com/journal/ijerph

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 2 of 16 assessment, is thus increasingly important. Whilst generally problematic, some changes may be beneficial, at least temporarily for certain species, e.g., invasive species, which may thrive as environmental parameters (e.g., temperature) transition through their preferred range or niche and a population irruption occurs. Other changes interact antagonistically to reduce their individual effect, but this is happening against a backdrop of overall decline. River catchments are affected by connections to the wider Earth system and beyond along a gradient of risk in geologic time pertaining to landslides, earthquakes, and other hazards. Individual stressors vary in temporal and spatial extent, they drive ecosystem response and inform adaptation as well as the potential longevity of restoration work. Their persistence and the rate at which they are changing, both when speeding up and also when slowing down, are often overlooked. Just like rivers, which over millennia sculpt intricate paths across a landscape, ecosystems will change, adapt and re-assemble. Such processes may take far longer than several decades and therefore could not be observed in their entirety over the course of a human lifetime, a phenomenon known as ‘shifting baseline syndrome’ (Papworth, 2009). In this respect, it is worth considering the changes wrought through the building of dams, for example, over the previous few centuries Int. J. Environ. Res. Public Health 2021 , 18 , x 2 of 16 in the form of ‘surprises’ [8] or ‘shocks’ and even ecosystem collapse, which are recognised features of dynamical systems behaviour in general. Close observation, monitoring and assessment, is thus increasingly important. Whilst generally problematic, some changes may be beneficial, at least temporarily for certain species, e.g., invasive species, which may thrive as environmental parameters (e.g., temperature) transition through their preferred range or niche and a population irruption occurs. Other changes interact antagonistically to reduce their individual effect, but this is happening against a backdrop of overall decline. River catchments are affected by connections to the wider Earth system and beyond along a gradient of risk in geologic time pertaining to landslides, earthquakes, and other hazards. Individual stressors vary in temporal and spatial extent, they drive ecosystem response and inform adaptation as well as the potential longevity of restoration work. Their persistence and the rate at which they are changing, both when speeding up and also when slowing down, are often overlooked. Just like rivers, which over millennia sculpt intricate paths across a landscape, ecosystems will change, adapt and re-assemble. Such processes may take far longer than several decades and therefore could not be observed in their entirety over the course of a human lifetime, a phenomenon known as ‘shifting baseline syndrome’ (Papworth, 2009). In this respect, it is worth considering the changes wrought through the building of dams, for example, over the previous few centuries. Figure 1. Interactions between nested, interconnected systems operating over different spatial and temporal scales. The solar system affects tides, causes mutations in DNA through cosmic radiation, mass extinctions and changes in geomorphology through meteor impacts, and solar energy powers much of life on earth. The Earth system returns heat to space in maintaining equilibrium and affects the biosphere in multiple ways, including climate change. Feedbacks from the biosphere influence the Earth system and return anthropogenic pollution. Figure 1. Interactions between nested, interconnected systems operating over different spatial and temporal scales. The solar system affects tides, causes mutations in DNA through cosmic radiation, mass extinctions and changes in geomorphology through meteor impacts, and solar energy powers much of life on earth. The Earth system returns heat to space in maintaining equilibrium and affects the biosphere in multiple ways, including climate change. Feedbacks from the biosphere influence the Earth system and return anthropogenic pollution Accurate modelling of a complex system such as a river catchment may not be possible Many components of such a system may be unknown, poorly understood or inaccessible to observation, e.g., be underwater or below ground. Knock-on effects generated by such components, the so-called co-benefits and trade-offs, may be either positive or negative.

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 3 of 16 This chain of events continues ad infinitum , meaning that a degree of abstraction is required However, these difficulties, though seldom recognised, have always applied to the limits of knowledge of ecosystems. This has made correlating multiple, individual studies particularly difficult since the relative importance of the effects is unclear. It is not always possible to make a connection between studies, especially when different sets of environmental variables are used. An isomorphic issue has recently been addressed by the Coupled Model Intercomparison Project (CMIP 6) through adoption of a standardised set of experiments and other forms of rationalisation [ 9 ]. However, at the present time, it is inevitable that different ecosystem studies, especially at the detailed level, will produce different results Accelerating rates of change of key stressors [ 10 ] threaten to render much of what has been learnt about ecosystems obsolete. Further, change is far outpacing the ability of many species to disperse or adapt, making it probable we are entering an as yet unrecognised chaotic epoch as ecosystems destabilise further, leading to the sixth major extinction [ 11 ]. Pollution is a fundamental problem. Urban rivers will continue to decline until comprehensive solutions are developed and implemented. Urban run-off [ 12 – 14 ] has sublethal effects but can kill fish at all life stages: eggs, larvae, juveniles and adult [ 15 ]. Degraded urban waterways have higher levels of parasitism in all taxa [ 16 ], many of them invasive, e.g., Anguillicoloides crassus in eels. Chemicals are released into groundwater and surface waters through multiple routes. Animal treatments for livestock, which may promote parasitism through development of resistance, and fertilizers used in agriculture are washed into rivers with soil as run-off from fields [ 17 ]. Many can also be deposited directly by the wind (atmospheric deposition). Some chemicals, including nicotinoid pesticides, are water-soluble, and that makes them even more mobile [ 17 ]. Manure from grazing animals in fields may aggravate organic pollution in the uplands and lowlands. Slurry from cattle and solid waste from pigs, chickens and other animals contain antibiotics and antimicrobialresistant bacteria (ARB) and are often stored close to bodies of water. Warming waters with reduced oxygen content and enriched with nutrients make surface water eutrophic and anoxic, which aggravates these issues, especially in the lower reaches of rivers and estuaries. In most major rivers, a nutrient-rich, toxic plume extends into the ocean, where it can stimulate harmful algal blooms, further aided by increasing temperatures. Associated anoxic conditions, ‘dead zones’, in combination with generally reduced oxygen affect significant areas of the oceans, although recent studies indicate that they may not become widely distributed throughout oceans globally [ 18 , 19 ]. Habitat stewardship and species husbandry have been conducted by indigenous peoples for millennia [ 20 – 22 ]. To achieve a sustainable future, these will need to be incorporated as a central tenet of the Anthropocene together with a radical change in environmental hygiene in general. To be socially and culturally relevant and therefore to progress, restoration must include local and regional stakeholders and any work prioritized and justified through valuation within a global framework (Figure 2 ). River restoration projects are typically conducted over a relatively short period of time (one or two years) and often with little follow-up monitoring. Even well-funded, long-term restoration projects may be overshadowed and overcome by climate change and other stressors that were not foreseen or properly considered beforehand, as was the case with salmon habitat restoration in the United States [ 23 ]. Such changes and stressors might override ecosystem restoration and therefore must be assessed and anticipated. Therefore, a wide variety of related factors should be considered, for example, through modelling, to formulate a hypothesis and a model (albeit imperfect) as to how these might interact with each other, influence system function and affect the outcomes. Even small changes may render restoration work obsolete, and there is increasing potential for highly destructive ‘extreme events’, e.g., major flooding, to cause extensive damage in a typical, heavily engineered urban river catchment Accumulation of pollution, species loss, the potential for disease transmission and flooding are of particular concern. Further work is necessary to address these compounding problems, to improve overall resilience and reduce the possibility of further shocks. Achieving sustainability while starting from a condition of accumulated deficit against a backdrop

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 4 of 16 of accelerating change will require continuous environmental stewardship. It will mean making hard-earned incremental improvements [ 24 ] within a coordinated, over-arching catchment plan, which can be adapted in response to system behaviour. Just as ‘continuous change’ [ 25 ] became the mantra of business in the 1990 s, ‘continuous adaptation’ might be a suitable motto for environmental work in the Anthropocene Int. J. Environ. Res. Public Health 2021 , 18 , x 4 of 16 obsolete, and there is increasing potential for highly destructive ‘extreme events’, e.g., major flooding, to cause extensive damage in a typical, heavily engineered urban river catchment. Accumulation of pollution, species loss, the potential for disease transmission and flooding are of particular concern. Further work is necessary to address these compounding problems, to improve overall resilience and reduce the possibility of further shocks. Achieving sustainability while starting from a condition of accumulated deficit against a backdrop of accelerating change will require continuous environmental stewardship. It will mean making hard-earned incremental improvements [24] within a coordinated, over-arching catchment plan, which can be adapted in response to system behaviour. Just as ‘continuous change’ [25] became the mantra of business in the 1990 s, ‘continuous adaptation’ might be a suitable motto for environmental work in the Anthropocene. Figure 2. Hierarchical framework for coordinated river restoration work at global to local scale. NBSAP refers to the National Biodiversity Strategies and Action Plans described in Article 6 of the United Nations Convention on Biological Diversity (CBD). 2. The Urban River Syndrome—Ecosystems Previously Transformed Surface water impairment, especially eutrophication and water quality, has been studied since the late 1960 s. Overall degradation has been understood to be progressing for at least 60 years, but assessment and improvements have not kept up. The gradual, generally monotonic decline produced by the urban river (stream) syndrome (URS) [26,27] can be used to describe newer or previously unknown types of river ecosystems degradation, such as that resulting from additional waste materials such as plastics [28] and chemicals, including pharmaceuticals [29,30] and narcotics [31,32], in the sediment, soil and water. Changes in temperature regimes and patterns of rainfall, and ecosystem modifications, e.g., fisheries augmentation and species range shifts, are also not included. However, not all such effects are negative. For example, increased UV light can promote destruction of xenobiotics and pathogens. The positive effect of turbidity on photolysis (by means of increasing diffusion of light through water) contributes to purification in wetlands, which was recognised long ago. Wildlife switching to human food items alters food webs and can promote unnatural growth, but may also alter behaviour and promote disease in animals [33,34]. Figure 2. Hierarchical framework for coordinated river restoration work at global to local scale NBSAP refers to the National Biodiversity Strategies and Action Plans described in Article 6 of the United Nations Convention on Biological Diversity (CBD) 2. The Urban River Syndrome—Ecosystems Previously Transformed Surface water impairment, especially eutrophication and water quality, has been studied since the late 1960 s. Overall degradation has been understood to be progressing for at least 60 years, but assessment and improvements have not kept up. The gradual, generally monotonic decline produced by the urban river (stream) syndrome (URS) [ 26 , 27 ] can be used to describe newer or previously unknown types of river ecosystems degradation, such as that resulting from additional waste materials such as plastics [ 28 ] and chemicals, including pharmaceuticals [ 29 , 30 ] and narcotics [ 31 , 32 ], in the sediment, soil and water Changes in temperature regimes and patterns of rainfall, and ecosystem modifications, e.g., fisheries augmentation and species range shifts, are also not included. However, not all such effects are negative. For example, increased UV light can promote destruction of xenobiotics and pathogens. The positive effect of turbidity on photolysis (by means of increasing diffusion of light through water) contributes to purification in wetlands, which was recognised long ago. Wildlife switching to human food items alters food webs and can promote unnatural growth, but may also alter behaviour and promote disease in animals [ 33 , 34 ]. Large urban rivers are now characterised by shipping and container ports, power stations, increased boat traffic, accelerating rates of non-native species settlement and light and noise pollution. Inadequate sewage treatment and increased fine sediment and effluent presage health concerns with regard to the possibility of zoonoses and outbreaks of novel disease. The growing size of cities with associated increases in storm run-off from roads and combined sewer systems, reduced oxygen content, erosion of topsoil from agricultural

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 5 of 16 areas [ 35 ] and the effects of nutrient, pesticide and salt pollution are all established concurrent synergistic features. Rubbish and toxin accumulation in sediment with anoxic plumes and harmful algal blooms in the estuary are fundamental for a description of an urban river such as the Thames (Table 2 ). Table 2. Additional and increasing symptoms of an updated urban river syndrome 1 Aquatic & Riparian Biota Recent Reports Species range shifts New [ 36 ] Accelerating non-native species establishment New [ 37 ] Riparian vegetation degradation and die-back, tree disease, invasive plants, clearance by humans New [ 38 – 40 ] Increased prevalence of pathogens, including viruses, bacteria, and parasites New [ 41 ] Reductions in biodiversity because of fish stocking and farming New [ 42 , 43 ] Behavioural changes due to domesticated transplants and xenobiotics New [ 44 ] Ecosystem processes Migration between landfills and waste sites by gulls with increasing predation in rivers and estuaries New [ 45 , 46 ] Cancers in aquatic animals: birds, fish, bivalves and mammals New [ 47 ] Toxin bioaccumulation in prey species with trophic amplification (e.g., perand polyfluoroalkyl substances, PFASs) New [ 48 – 51 ] Changes in diet New [ 52 , 53 ] Interference with sound, light and chemical signalling regimes New [ 54 – 57 ] Atmosphere, soils, water, and sediment chemistry Global warming (e.g., warmer water) with marine heat waves in the estuary and ocean Increasing [ 58 ] Anthroposphere New [ 59 ] NO 2 , CH 4 and CO 2 emissions from water bodies, landfills and sewage treatment plants (STPs) New [ 60 ] Rubbish, including microand nanoplastics. Accumulation in animals, soils and the substrate with transport to the ocean New [ 61 , 62 ] Hydrology Increasing extreme flooding and drought events Increasing [ 63 ] Channel morphology Soil erosion with silt banks forming in the lower reaches Increasing [ 64 ] 1 Previously, the urban river syndrome has emphasised changes to river morphology and water chemistry but riparian habitat, soils or related fauna and flora were not included. In order to make the concept more general, these are added here together with disease. Further work is needed to incorporate extreme events such as flooding and landslides and combinations of different ecosystem processes to facilitate comprehensive assessment of condition While range shifts are now understood to be occurring in many species [ 65 ], more nuanced ecological impacts from increasing light and sound pollution have far-reaching effects on both terrestrial and aquatic animals. In extreme instances, pile-driving used for installation of river revetments or other construction can cause physical harm and complex behavioural changes such as avoidance and reduced vocalization [ 54 , 66 , 67 ]. Urban birds now sing differently, employing complex strategies to compensate for increased ambient levels of noise [ 68 ], but it is reasonable to believe that there are wider effects on the ecosystem generally. Fish such as cod, Gadus morhua , use sound for communication in agonistic displays and during courtship [ 66 , 69 , 70 ]. Changes to river structure from dams and modified flow as well as boat and shipping traffic affect the ‘soundscape’ [ 71 ], the ambient underwater sound profile, changing behaviour in fish. Some species have adapted to this and increase predation success by taking advantage of confusion in prey [ 72 ]. Similarly, light pollution affects bats and insects, with mayflies being attracted to lamps, for example [ 73 ]. Many species of insects (e.g., fireflies) and fish have evolved complex signalling through bioluminescence. Night-time light pollution can affect diel vertical migration of plankton in the water column and other aquatic species, including many salmonids that synchronise spawning in accordance with lunar cycles [ 74 ], which are also vulnerable to disruption In cities, rivers have been historically used to transport waste. Wastewater (before treatment) consists mainly of water with a small amount of solid material, most of which is organic and includes food waste, faecal matter, urine and soaps. Two metrics are frequently associated with wastewater treatment. One is chemical oxygen demand (COD), which is a theoretical measure of the oxygen requirement for breaking down organic matter, even though materials such as fats are not completely broken down. Bacterial oxygen

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 6 of 16 demand (BOD) uses bacterial digestion to assess potential environmental impact, but the test would need to continue for an infinitely long time to be accurate. Therefore, BOD generally underestimates the oxygen requirement for material to reach a stable state of degradation. Sewage treatment plants (STPs) use a lot of electricity to circulate and oxygenate ponds and enable aerobic bacteria to break down waste, producing greenhouse gas (GHG) emissions. Reducing oxygen levels saves energy but can increase production of NO 2 —a more powerful, shorter-lived GHG than CO 2 , which is otherwise produced Storm water flows are increasing because of climate change [ 75 ], and many STPs are not designed to accommodate the increase in run-off, and despite the water being improved after treatment, there are still many contaminants that are not removed in the current processes used It is widely recognised that there are thousands of man-made chemicals circulating in the environment—a major feature of the Anthropocene [ 76 , 77 ]. The biological effects of most are understudied since the majority of research into toxicity is focused on a relatively small number of familiar compounds [ 78 , 79 ]. Sometimes these are used as models from which wider inferences and conclusions are made without investigating analogous yet non-identical compounds, and combinations are rarely considered despite synergistic effects being well known for many. Endocrine disruptors such as heavy metals and synthetic oestrogens cause intersex in aquatic animals [ 80 ]. Pharmaceuticals, including antibiotics from farm use or waste water, alter microbial communities [ 81 , 82 ], play a role in the development of antibiotic resistant-strains of bacteria such as Staphlococcus aureus (MRSA) and are capable of affecting human health and presenting a wider escalating problem [ 83 , 84 ]. Phosphorous and heavy metals such as cadmium and mercury accumulate in river banks and benthic sediment [ 85 ] and can be remobilized through erosion, dredging, boat traffic, riverside works or increased river flows. These subsequently accumulate in fish, birds, pinnipeds and cetaceans and magnify as they progress up the food chain [ 86 ], which results in contaminant loads that affect reproduction and behaviour. However, loss of fertility is a concern even at lower trophic levels [ 87 ]. Chemical pollution may impact the role of semiochemicals, affecting interactions between species and conspecifics, particularly those occurring over longer distances, such as herbivory defence in plants and prey availability in animals [ 57 ]. Olfactory reception plays an important role in navigation in fish and birds [ 88 ], and pheromones are important during reproduction in fish, both internally in terms of reproductive function and also externally to aid synchrony [ 89 ]. There are other types of ecologically important chemical signals used by plants and animals, for example, attractants, repellents and kairomones. Some of these are beneficial to the host and detrimental to other species, and vice versa, indicating a complex sensory landscape. However, individual compounds have been found to affect behaviour through chemical pathways. Rats, for example, undergo profound behavioural changes when exposed to certain chemicals, even at low concentrations [ 56 ]. Low-level exposure to copper in juvenile salmon renders them more vulnerable to predators [ 90 ]. Psychoactive drugs are specifically designed to work at low concentrations and these are now ubiquitous in urban rivers, affecting behaviour [ 91 ]. A sometimes overlooked aspect of change is the increase of cancers in animals [ 34 , 92 ] Heavy metals and other xenobiotics, including those released by plastics following ingestion, can induce cancer. There are multiple other ways humans increase the prevalence of cancer in animals (Figure 3 ). Wild trout, once shy, have changed their behaviour and take bread from humans, which promotes growth and accumulation of fat. This leads in turn to accumulation of lipophilic xenobiotics. Even pollution-tolerant species like catfish can develop tumours [ 47 ], though little is known about the effects of neoplasia on mortality generally. Another feature of urban rivers is intersex in fish, gastropods and molluscs, which frequently occurs because of parasites [ 93 ] or endocrine disruptors such as synthetic hormones in wastewater effluent or industrial activities [ 94 ]. Feminisation of male roach, Rutilus rutilus , occurs widely in English rivers [ 95 ]. Many aquatic species change sex as

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 7 of 16 a feature of their lifecycle and are sensitive to changes in environmental hormone levels, which can result in populations becoming less viable [ 96 ]. Int. J. Environ. Res. Public Health 2021 , 18 , x 7 of 16 A sometimes overlooked aspect of change is the increase of cancers in animals [34,92]. Heavy metals and other xenobiotics, including those released by plastics following ingestion, can induce cancer. There are multiple other ways humans increase the prevalence of cancer in animals (Figure 3). Wild trout, once shy, have changed their behaviour and take bread from humans, which promotes growth and accumulation of fat. This leads in turn to accumulation of lipophilic xenobiotics. Even pollution-tolerant species like catfish can develop tumours [47], though little is known about the effects of neoplasia on mortality generally. Another feature of urban rivers is intersex in fish, gastropods and molluscs, which frequently occurs because of parasites [93] or endocrine disruptors such as synthetic hormones in wastewater effluent or industrial activities [94]. Feminisation of male roach, Rutilus rutilus , occurs widely in English rivers [95]. Many aquatic species change sex as a feature of their lifecycle and are sensitive to changes in environmental hormone levels, which can result in populations becoming less viable [96]. Figure 3. Pathways from effects caused by human activity that may promote disease in wild animals [33]. Physical changes to urban rivers and streams over the past several decades show shrinking dendritic topology and increasing patchiness due to modification and climate change, with reductions expected to increase further [97]. Despite clean-up of industrial point source pollution, there has been a transformation in appearance of freshwater bodies over a period of several decades, with reduction in shoreline and benthic macrophytes due to reduction of the euphotic zone and silt smothering of the substrate. Chalk streams in the UK have a perpetual layer of brown algae covering the substrate. Similarly, there have been changes in species composition with increasing homogeneity, transformation of microbial communities and declines in native fish, insect and bird populations [98–100]. Cold water species and river flies have seen major declines [101,102]. In the UK, the fall in river fly numbers has been detailed in the 2015 Riverfly Census compiled by Salmon and Trout Conservation UK [101]. Phenotypic and eco-evolutionary change in native fish and plants is widespread [103], the phenomenon exacerbated in urban rivers, with humans becoming one of the primary drivers of evolution [104]. River flies that spend most or part of their lifecycle in aquatic environments and other invertebrates are undergoing large reductions, in part because of agricultural insecticide pollution [105]. Herbicide use, e.g., glyphosate, has transformed grassland and riparian habitat especially in urban settings. Figure 3. Pathways from effects caused by human activity that may promote disease in wild animals [ 33 ]. Physical changes to urban rivers and streams over the past several decades show shrinking dendritic topology and increasing patchiness due to modification and climate change, with reductions expected to increase further [ 97 ]. Despite clean-up of industrial point source pollution, there has been a transformation in appearance of freshwater bodies over a period of several decades, with reduction in shoreline and benthic macrophytes due to reduction of the euphotic zone and silt smothering of the substrate. Chalk streams in the UK have a perpetual layer of brown algae covering the substrate. Similarly, there have been changes in species composition with increasing homogeneity, transformation of microbial communities and declines in native fish, insect and bird populations [ 98 – 100 ]. Cold water species and river flies have seen major declines [ 101 , 102 ]. In the UK, the fall in river fly numbers has been detailed in the 2015 Riverfly Census compiled by Salmon and Trout Conservation UK [ 101 ]. Phenotypic and eco-evolutionary change in native fish and plants is widespread [ 103 ], the phenomenon exacerbated in urban rivers, with humans becoming one of the primary drivers of evolution [ 104 ]. River flies that spend most or part of their lifecycle in aquatic environments and other invertebrates are undergoing large reductions, in part because of agricultural insecticide pollution [ 105 ]. Herbicide use, e.g., glyphosate, has transformed grassland and riparian habitat especially in urban settings Weed treatments can drastically alter a river’s insect populations through complicated mechanisms, which may be difficult to foresee. Genetically modified crops, as used in some countries, might have similarly unpredictable outcomes for insects, a key component of the riverine food web. For example, the expansion of transgenic corn in Iowa in the United States resulted in dramatic decline of the Monarch butterfly, Danaus plexippus , through deposition of toxic pollen on leaves of the Milkweed plant, Asclepias syriaca , on which the larvae feed [ 106 ]. That and other similar multifaceted interactions, many of which may yet be unknown, will most probably be occurring on a larger scale in and around rivers, thus altering communities of fish, insects, birds and mammals. Many commonly used agricultural chemicals are water-soluble, thereby having direct impacts on aquatic plants and animals through run-off and atmospheric deposition when blown as dust from fields into waterways.

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 8 of 16 Trees are an important component of riparian habitat. Their root systems can increase bank stability, and the shade they provide helps maintain lower water temperatures, which can be beneficial to many aquatic species as climate warms. While improvements are being made to riparian vegetation and margins between roads and the river in some locations, the overall condition is impaired through climate change (drought and flooding), die-back, temperature changes and non-native diseases such as root and collar rot in alder, Alnus glutinosa , caused by Phytophthora alni . Several other non-native pathogens are affecting riparian vegetation (Table 3 ), and more may arrive in the UK in future, such as Ceratocystis platani fungus, affecting plane trees. While this pathogen has not been reported in the UK, the fungus affects trees along river corridors in other European countries, where it is particularly problematic due to water-borne transmission [ 107 ]. The insect vector for this pathogen, a beetle, Platypus cylindrus , acts as a pioneer, facilitating further attacks by other species. It was once rare in the UK but is now common, paving the way for rapid spread upon arrival [ 108 ]. Additional stressors on riparian habitat include excess nutrients and pollution in the soil and water, which can impair growth by interfering with the mycorrhizal fungi, replacing fungi that provide nutrients in return for carbon with parasitic species Table 3. Emerging tree diseases, some of which are affecting riparian vegetation in the UK Condition Causative Agent Root and collar rot in alder Phytophthora alni (Phytopthora) Canker stain of plane trees Ceratocystis platani (fungus) Acute oak decline Multiple environmental causes (e.g., pollution and climate change) Horse chestnut leaf miner Cameraria ohridella (moth) Chalara die-back of Ash Hymenoscyphus fraxineus (fungus) Massaria disease Splanchnonema platani (fungus) Oak processionary moth Thaumetopoea processionea (moth) 3. Ecosystem Adaptation and Non-Native Species in the Urban Thames The Thames is a typical urban river that suffers from growing anthropogenic effects, as is the case with all rivers of similar type. It is a highly modified, fragmented river (Figure 4 ) with a long history of exploitation of fisheries, disposal of wastes and transport. It provides some of the largest green space in London, helps to mediate the heat island effect in the city and offers extensive opportunities for recreation. The urban Thames suffered a major decline in the first half of the 19 th century due to rapid increases in population in London as well as other towns along the river, resulting in increased discharges to the Thames and tributaries. As a result, oxygen content of the water became severely reduced. The opening of the London sewer system in 1870 improved the situation temporarily, but the acute oxygen depletion problem returned during the first half of the 20 th century as the system became overwhelmed. Stretches of the tidal Thames again turned anoxic with widespread hypoxia and anoxic sediment, resulting in a gross depletion of aquatic life. Additional improvements to the sewer network in the second half of the 20 th century, termed ‘sanitisation’, resulted in amelioration of these harsh environmental conditions with a concomitant re-use of the river by endemic UK North Sea coastal species. Recent remedial action around point source pollution has generally improved some aspects of water quality, although pollution events still occur regularly; continuing diffuse pollution is another growing problem. Migratory native species that use the entire catchment, such as salmon, have not re-colonised the river in significant numbers and populations have fluctuated, with many opportunistic, non-native species becoming permanently established and new species immigrating at an accelerating pace. Attempts to restore Atlantic salmon, Salmo salar , through stock augmentation and improved river connectivity have not met with success, and although salmon do occur in the Thames, they originate from other rivers [ 109 ]. Overall, the tidal community is now adapted to polluted, low-oxygen conditions with high turbidity and silt smothering the benthos.

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 9 of 16 Int. J. Environ. Res. Public Health 2021 , 18 , x 9 of 16 the acute oxygen depletion problem returned during the first half of the 20 th century as the system became overwhelmed. Stretches of the tidal Thames again turned anoxic with widespread hypoxia and anoxic sediment, resulting in a gross depletion of aquatic life. Additional improvements to the sewer network in the second half of the 20 th century, termed ‘sanitisation’, resulted in amelioration of these harsh environmental conditions with a concomitant re-use of the river by endemic UK North Sea coastal species. Recent remedial action around point source pollution has generally improved some aspects of water quality, although pollution events still occur regularly; continuing diffuse pollution is another growing problem. Migratory native species that use the entire catchment, such as salmon, have not re-colonised the river in significant numbers and populations have fluctuated, with many opportunistic, non-native species becoming permanently established and new species immigrating at an accelerating pace. Attempts to restore Atlantic salmon, Salmo salar , through stock augmentation and improved river connectivity have not met with success, and although salmon do occur in the Thames, they originate from other rivers [109]. Overall, the tidal community is now adapted to polluted, low-oxygen conditions with high turbidity and silt smothering the benthos. Figure 4. The Thames catchment. Image created in ESRI ArcGIS using data from the UK Ordnance Survey and European Environment Agency. The overall decline in condition and associated biodiversity loss in the Thames, particularly in terms of reduced abundance, have gone largely unreported until recently. However, it is to be expected that biodiversity loss is generally manifested as a decline in abundance with highly reduced populations rather than complete extirpation. Stock augmentation and hybridisation cause reduction in genetic biodiversity [110], so the overall decline is chronic rather than acute. Although serious pollution events and mass die-offs Figure 4. The Thames catchment. Image created in ESRI ArcGIS using data from the UK Ordnance Survey and European Environment Agency The overall decline in condition and associated biodiversity loss in the Thames, particularly in terms of reduced abundance, have gone largely unreported until recently. However, it is to be expected that biodiversity loss is generally manifested as a decline in abundance with highly reduced populations rather than complete extirpation. Stock augmentation and hybridisation cause reduction in genetic biodiversity [ 110 ], so the overall decline is chronic rather than acute. Although serious pollution events and mass die-offs do occur on occasion, these do not usually affect the entire river, and many species use different areas of habitat at different times of year and varying stages of their lifecycle. Extinction is no doubt a continuing process for many native species and this will persist until overall conditions start to improve, or until they are able to translocate to a more suitable habitat. Therefore, complete, local (e.g., within the tidal Thames) extirpation is a long-term process A typical feature of urban rivers is an increasing number of non-native species [ 111 ]. Much like other similar river systems globally, the Thames catchment is home to a large and increasing number of non-native species [ 37 ]. Some are presently—or have previously been—invasive. They include ornamental garden plants like rhododendron, which grows wild in many areas of the UK, fish such as goldfish, Carassius auratus auratus , which can grow large and create hybrids, and birds, including the ring-necked parakeet, Psittacula krameria , now common in the London area. Invasive species in the Thames estuary include the American slipper limpet, Crepidula fornicata , a filter feeder. This species comprises the largest biomass in the estuary. Densities of several thousand per square metre could be reached [ 112 ] under optimal conditions, and they are subject to mass die-off during cold weather as the Thames is towards the northerly limit of their range [ 113 ]. As a

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 10 of 16 result, empty shells build drifts on beaches along the Kent coast and around the estuary, an indication that occurs in other invasive bivalves such as the Asiatic clam and zebra mussel in the Great Lakes in the United States. However, densities of C. fornicata in the UK remain low compared to those in warmer waters and may therefore be expected to increase. For comparison, the species is a problem in France, where populations are large and dense enough to reduce available habitat for flatfishes [ 114 ]. Dredging is performed to reduce density, but this may aggravate the problem through provision of additional habitat. The shells are used to supplement building materials [ 115 ]. It is not possible to conclude that native bivalve populations have been only negatively affected and driven out by the slipper limpet as most were in decline in many areas due to other problems, including invasive drill predation on oyster spat and Tributyltin (TBT) contamination from antifouling paint applied to boats and other structures. Studies indicate that native oysters occupy different areas of the benthos [ 116 ]. However, as filter feeders, the slipper limpet can cause a reduction in food availability. In relation to other species, C. fornicata can reduce star fish predation on the blue mussel, Mytilus edulis [ 117 ]. Epifaunal slipper limpets can promote increased byssal production in blue mussels, thereby redirecting resources away from growth and reproduction. They accumulate in reproductive stacks on top of the mussels, increasing stress on the byssal fibres anchoring them to the substrate, which can also trigger their detachment during storms An example of problems associated with non-native species can be illustrated with the American oyster, Crassostrea virginica . In the 1950 s, this species aided the importation of an associated assemblage through ‘hitch-hiking’, where other species travelled attached to or inside the oysters. These included the oyster drill, Urosalpinx cinereal , and various pathogens that have led to outbreaks of disease and decline of European oysters, Ostrea edulis . Populations of the oyster drill reached densities of 15,000–20,000 per hectare in areas of Thames estuary and were believed to account for spat mortalities of up to 75%, with each drill capable of consuming 40 oysters per year. However, U. cinereal numbers declined along with oyster populations. They were further severely affected through imposex, the development of male gonads in females, caused by Tributyltin (TBT), leading to their rapid decline in the mid-twentieth century [ 118 ]. As with many banned chemicals, TBT persists in sediment and continues to be an important pollutant affecting aquatic species and human health [ 119 ]. Fossorial species are a concern as they can cause damage to exposed banks. Several species of crayfish now occur in the UK, including the native white-clawed variety and Turkish narrow-clawed crayfish. The brown rat, Rattus norvegicus , originally an invasive species from Asia, has been present in the UK since before 1800. It is very numerous in the Thames and in terms of damage is certainly one of the most destructive. Additional burrowing animals include the black rat, Rattus rattus , American mink, Neovison vison, and to a lesser extent, the Chinese mitten crab, Eriocheir sinensis . Invasions by Eriocheir sinensis , the Chinese mitten crab, occurred in northern Europe in the early 1900 s and in California in the United States in the 1990 s. The species has established viable populations in several countries, including the UK, where it has not been designated as invasive. Species invasions are frequently a symptom of wider environmental problems that initiate changes before settlement occurs and reduce resilience in the face of propagule pressure The concept of non-native invasive species (NNIS) against a static, native flora and fauna needs to be re-evaluated in the face of climate change and accumulated degradation of waterbodies, as in its current form NNIS embodies many contradictions, which could impede efforts to maintain habitat and ecosystem resilience. For example, species range shifts are proceeding at an accelerating pace, i.e., native species are moving and there is increasing interest in translocations for conservation purposes, termed ‘assisted migration’ Additionally, the endemic flora and fauna of rivers worldwide now include a variety of NNIS that have become endemic over decades or centuries. A comprehensive ecosystem restoration framework over the entire warming event (perhaps several centuries) and its aftermath together with consideration of positive contributions from non-native species,

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 11 of 16 such as their functional role, as well as side-effects of control methods (some of which are currently performed for purely cosmetic reasons) would improve resource allocation and planning. In the Thames, for example, non-native species, including the Chinese mitten crab and several species of fish and plants, such as Japanese knotweed and Himalayan balsam, will not easily be extirpated and are likely to remain as long as climate remains suitable, so more nuanced control methods are required 4. Conclusions This paper overviews anthropogenic changes to rivers in the urban environment, the so-called urban river syndrome, and discusses urban rivers’ deteriorating ecology and conservation challenges of river rejuvenation. Sustainable use of natural resources by humans will require transformation of many processes in order that they return a positive contribution to the environment. It will require movement towards a more sustainable, circular economy, one that recycles natural resources, otherwise conditions will worsen through continued accumulation of wastes Systems theory is frequently mentioned in relation to rivers, but particular aspects of systems integration are not widely appreciated, in particular, how general systems theory might elucidate phenomena such as phase change or abrupt, nonlinear decline. We believe, for example, that non-native species irruptions may be described in these terms as transient phenomena rather than permanent issues Restoration projects addressing urban rivers and wider ecosystems will need to consider a broad range of scientific, social and economic factors at a wide range of spatial and temporal scales to maximise potential benefits. Non-native species, some of which are thriving in the face of environmental change, will need to be assessed for their potential contribution to ecosystem stability, particularly in the face of potential collapse. Restoration work will need to make a positive contribution towards sustainability, satisfy stakeholder wishes and achieve benefits for an appropriate period of time in relation to cost The current definition of the urban river syndrome is expanded to include other features of rivers, such as riparian habitat degradation, as an initial step in transforming the concept (as well as river restoration in general) to comply with the requirements of achieving sustainability. A small demonstration project has been conducted in the river Thames in the application of the revised definition. The work has been carried out as a transdisciplinary experiment with assistance from multiple commercial, academic and non-profit partners and charities with involvement of the local community. An assessment of riparian soil contamination, river bank stability and erosion was made with wider consideration of climate change, sea-level rise, pollution and other features highlighted in the revised URS In progressing towards a more holistic and therefore general definition, we hope eventually to incorporate or connect it with other elements of socio-ecological-technical systems (SETs) so that restoration work may be comprehensively assessed: it should be socially warranted (achieving outcomes desired by the community and stakeholders), conform with and value historical and cultural aspects, be economically justifiable, and the life-expectancy of the work must be explored. In this manner restoration will be guided by the multifarious interests of stakeholders and prioritised against hazards, existential risk, costs and benefits within a rational and forward-looking context Funding: This research received no external funding Institutional Review Board Statement: Not applicable Informed Consent Statement: Not applicable Conflicts of Interest: The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 12 of 16 References 1 Downs, P.W.; Pi é gay, H. Catchment-scale cumulative impact of human activities on river channels in the late Anthropocene: Implications, limitations, prospect Geomorphology 2019 , 338 , 88–104. [ CrossRef ] 2 Wood, L.B.; Ager, D.V The Restoration of the Tidal Thames ; Hilger: Bristol, UK, 1982 3 Hughes, A The Riverine Ecosystem Synthesis: Towards Conceptual Cohesiveness in River Science ; Academic Press: London, UK, 2012 4 Doretto, A.; Piano, E.; Larson, C.E. The river continuum concept: Lessons from the past and perspectives for the future Can. J Fish. Aquat. Sci 2020 , 77 , 1856–1864. [ CrossRef ] 5 Li, C.; Li, J.; Wu, J. Quantifying the speed, growth modes, and landscape pattern changes of urbanization: A hierarchical patch dynamics approach Landsc. Ecol 2013 , 28 , 1875–1888. [ CrossRef ] 6 Thorp, J.H.; Thoms, M.C.; Delong, M.D. The riverine ecosystem synthesis: Biocomplexity in river networks across space and time River Res. Appl 2006 , 22 , 123–147. [ CrossRef ] 7 Liu, J.; Mooney, H.; Hull, V.; Davis, S.J.; Gaskell, J.; Hertel, T.; Lubchenco, J.; Seto, K.C.; Gleick, P.; Kremen, C.; et al. Systems integration for global sustainability Science 2015 , 347 , 1258832. [ CrossRef ] 8 Di Baldassarre, G.; Brandimarte, L.; Beven, K. The seventh facet of uncertainty: Wrong assumptions, unknowns and surprises in the dynamics of human–water systems Hydrol. Sci. J 2016 , 61 , 1748–1758. [ CrossRef ] 9 Eyring, V.; Bony, S.; Meehl, G.A.; Senior, C.A.; Stevens, B.; Stouffer, R.J.; Taylor, K.E. Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP 6) experimental design and organization Geosci. Model Dev 2016 , 9 , 1937–1958. [ CrossRef ] 10 Bates, N.R.; Johnson, R.J. Acceleration of ocean warming, salinification, deoxygenation and acidification in the surface subtropical North Atlantic Ocean Commun. Earth Environ 2020 , 1 , 1–12. [ CrossRef ] 11 Ceballos, G.; Ehrlich, P.R.; Barnosky, A.D.; Garc í a, A.; Pringle, R.M.; Palmer, T.M. Accelerated modern human-induced species losses: Entering the sixth mass extinction Sci. Adv 2015 , 1 , e 1400253. [ CrossRef ] 12 Greater London Authority. Road Runoff Water Quality Study. 2019. Available online: https://www.london.gov.uk/sites/ default/files/road_runoff_water_quality_study_exec_summary_dec_19.pdf (accessed on 11 June 2021) 13 Masoner, J.R.; Kolpin, D.W.; Cozzarelli, I.M.; Barber, L.B.; Burden, D.S.; Foreman, W.T.; Forshay, K.J.; Furlong, E.T.; Groves, J.F.; Hladik, M.L.; et al. Urban Stormwater: An Overlooked Pathway of Extensive Mixed Contaminants to Surface and Groundwaters in the United States Environ. Sci. Technol 2019 , 53 , 10070–10081. [ CrossRef ] 14 Kuhlemann, L.M.; Tetzlaff, D.; Soulsby, C. Urban water systems under climate stress: An isotopic perspective from Berlin, Germany Hydrol. Process 2020 , 34 , 3758–3776. [ CrossRef ] 15 Spromberg, J.A.; Baldwin, D.H.; Damm, S.E.; Mcintyre, J.K.; Huff, M.; Sloan, C.A.; Anulacion, B.F.; Davis, J.W.; Scholz, N.L. EDITOR’S CHOICE: Coho salmon spawner mortality in western US urban watersheds: Bioinfiltration prevents lethal storm water impacts J. Appl. Ecol 2016 , 53 , 398–407. [ CrossRef ] [ PubMed ] 16 Vidal-Mart í nez, V.M.; Pech, D.; Sures, B.; Purucker, S.T.; Poulin, R. Can parasites really reveal environmental impact? Trends Parasitol 2010 , 26 , 44–51. [ CrossRef ] 17 Boardman, J. Extreme rainfall and its impact on cultivated landscapes with particular reference to Britain Earth Surf. Process Landf 2015 , 40 , 2121–2130. [ CrossRef ] 18 Diaz, R.J.; Rosenberg, R. Spreading Dead Zones and Consequences for Marine Ecosystems Science 2008 , 321 , 926–929. [ CrossRef ] 19 Breitburg, D.; Levin, L.A.; Oschlies, A.; Gr é goire, M.; Chavez, F.P.; Conley, D.J.; Garçon, V.; Gilbert, D.; Guti é rrez, D.; Isensee, K.; et al. Declining oxygen in the global ocean and coastal waters Science 2018 , 359 , eaam 7240. [ CrossRef ] 20 Bruce Johnsen, D. Salmon, science, and reciprocity on the Northwest Coast Ecol. Soc 2009 , 14 , 43. [ CrossRef ] 21 Rivera-N ú ñez, T.; Fargher, L. The concept of “palimpsest” in a reconceptualization of bidiversity conservation Environ. Conserv 2020 , 48 , 1–4. [ CrossRef ] 22 Thompson, V.D.; Rick, T.; Garland, C.J.; Thomas, D.H.; Smith, K.Y.; Bergh, S.; Sanger, M.; Tucker, B.; Lulewicz, I.; Semon, A.M.; et al. Ecosystem stability and Native American oyster harvesting along the Atlantic coast of the United States Sci. Adv 2020 , 6 , eaba 9652. [ CrossRef ] 23 Lichatowich, J Salmon, People, and Place: A Biologist’s Search for Salmon Recovery ; Oregon State University: Corvallis, ON, USA, 2013; ISBN 9780870717253 24 Bennett, E.M.; Biggs, R.; Peterson, G.D.; Gordon, L.J. Patchwork Earth: Navigating pathways to just, thriving, and sustainable futures One Earth 2021 , 4 , 172–176. [ CrossRef ] 25 Stebbings, H.; Braganza, A. Exploring Continuous Organizational Transformation: Morphing through Network Interdependence J. Chang. Manag 2009 , 9 , 27–48. [ CrossRef ] 26 Walsh, C.J.; Roy, A.H.; Feminella, J.W.; Cottingham, P.D.; Groffman, P.M.; Morgan, R.P. The urban stream syndrome: Current knowledge and the search for a cure J. N. Am. Benthol. Soc 2005 , 24 , 706–723. [ CrossRef ] 27 Booth, D.B.; Roy, A.H.; Smith, B.; Capps, K.A. Global perspectives on the urban stream syndrome Freshw. Sci 2016 , 35 , 412–420 [ CrossRef ] 28 Emmerik, T.; Schwarz, A. Plastic debris in rivers WIREs Water 2020 , 7 , e 1398. [ CrossRef ] 29 Daughton, C.G.; Ternes, T.A. Pharmaceuticals and Personal Care Products in the Environment: Agents of Subtle Change? Environ Toxicol 2009 , 28 , 2663–2670. [ CrossRef ] [ PubMed ] 30 Richmond, E.K.; Rosi, E.J.; Walters, D.M.; Fick, J.; Hamilton, S.K.; Brodin, T.; Sundelin, A.; Grace, M.R. A diverse suite of pharmaceuticals contaminates stream and riparian food webs Nat. Commun 2018 , 9 , 4491. [ CrossRef ]

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 13 of 16 31 Yadav, M.K.; Short, M.D.; Aryal, R.; Gerber, C.; van den Akker, B.; Saint, C.P. Occurrence of illicit drugs in water and wastewater and their removal during wastewater treatment Water Res 2017 , 124 , 713–727. [ CrossRef ] [ PubMed ] 32 L ó pez-Garc í a, E.; Mastroianni, N.; Pons à -Borau, N.; Barcel ó , D.; Postigo, C.; L ó pez de Alda, M. Drugs of abuse and their metabolites in river sediments: Analysis, occurrence in four Spanish river basins and environmental risk assessment J. Hazard Mater 2021 , 401 , 123312. [ CrossRef ] [ PubMed ] 33 Giraudeau, M.; Sepp, T.; Ujvari, B.; Ewald, P.W.; Thomas, F. Human activities might influence oncogenic processes in wild animal populations Nat. Ecol. Evol 2018 , 2 , 1065–1070. [ CrossRef ] [ PubMed ] 34 Baines, C.; Lerebours, A.; Thomas, F.; Fort, J.; Kreitsberg, R.; Gentes, S.; Meitern, R.; Saks, L.; Ujvari, B.; Giraudeau, M.; et al. Linking pollution and cancer in aquatic environments: A review Environ. Int 2021 , 149 , 106391. [ CrossRef ] [ PubMed ] 35 Thaler, E.A.; Larsen, I.J.; Yu, Q. The Extent of Soil Loss across the US Corn Belt Proc. Natl. Acad. Sci 2021 , 118 , e 1922375118 [ CrossRef ] [ PubMed ] 36 Comte, L.; Grenouillet, G. Do stream fish track climate change? Assessing distribution shifts in recent decades Ecography 2013 , 36 , 1236–1246. [ CrossRef ] 37 Jackson, M.C.; Grey, J. Accelerating rates of freshwater invasions in the catchment of the River Thames Biol. Invasions 2013 , 15 , 945–951. [ CrossRef ] 38 Palmer, S.C.J.; Hunter, P.D.; Lankester, T.; Hubbard, S.; Spyrakos, E.; Tyler, A.N.; Pr é sing, M.; Horv á th, H.; Lamb, A.; Balzter, H.; et al. Validation of Envisat MERIS algorithms for chlorophyll retrieval in a large, turbid and optically-complex shallow lake Remote Sens. Environ 2015 , 157 , 158–169. [ CrossRef ] 39 Fei, S.; Morin, R.S.; Oswalt, C.M.; Liebhold, A.M. Biomass losses resulting from insect and disease invasions in US forests Proc Natl. Acad. Sci. USA 2019 , 116 , 1–6. [ CrossRef ] [ PubMed ] 40 Bass, D.; Stentiford, G.D.; Wang, H.-C.C.; Koskella, B.; Tyler, C.R. The Pathobiome in Animal and Plant Diseases Trends Ecol. Evol 2019 , 34 , 996–1008. [ CrossRef ] 41 Stentiford, G.D.; Becnel, J.J.; Weiss, L.M.; Keeling, P.J.; Didier, E.S.; Williams, B.A.P.P.; Bjornson, S.; Kent, M.L.; Freeman, M.A.; Brown, M.J.F.F.; et al. Microsporidia—Emergent Pathogens in the Global Food Chain Trends Parasitol 2016 , 32 , 336–348 [ CrossRef ] 42 Johnson, B.M.; Kemp, B.M.; Thorgaard, G.H. Increased mitochondrial DNA diversity in ancient Columbia River basin Chinook salmon Oncorhynchus tshawytscha PLoS ONE 2018 , 13 , e 0190059. [ CrossRef ] 43 Sommerwerk, N.; Wolter, C.; Freyhof, J.; Tockner, K. Components and drivers of change in European freshwater fish faunas J Biogeogr 2017 , 44 , 1781–1790. [ CrossRef ] 44 Wang, W.; Xu, N.; Zhang, L.; Andersen, K.H.; Klaminder, J. Anthropogenic forcing of fish boldness and its impacts on ecosystem structure Glob. Chang. Biol 2021 , 27 , 1239–1249. [ CrossRef ] 45 Osterback, A.M.K.; Frechette, D.M.; Shelton, A.O.; Hayes, S.A.; Bond, M.H.; Shaffer, S.A.; Moore, J.W. High predation on small populations: Avian predation on imperiled salmonids Ecosphere 2013 , 4 , 1–21. [ CrossRef ] 46 Ahlstrom, C.A.; van Toor, M.L.; Woksepp, H.; Chandler, J.C.; Reed, J.A.; Reeves, A.B.; Waldenström, J.; Franklin, A.B.; Douglas, D.C.; Bonnedahl, J.; et al. Evidence for continental-scale dispersal of antimicrobial resistant bacteria by landfill-foraging gulls Sci Total Environ 2021 , 764 , 144551. [ CrossRef ] 47 Black, J.J.; Baumann, P.C. Carcinogens and cancers in freshwater fishes Environ. Health Perspect 1991 , 90 , 27–33. [ CrossRef ] 48 Zhang, X.; Xu, Q.; Man, S.; Zeng, X.; Yu, Y.; Pang, Y.; Sheng, G.; Fu, J. Tissue concentrations, bioaccumulation, and biomagnification of synthetic musks in freshwater fish from Taihu Lake, China Environ. Sci. Pollut. Res 2013 , 20 , 311–322. [ CrossRef ] 49 Zhou, H.Y.; Wong, M.H. Mercury accumulation in freshwater fish with emphasis on the dietary influence Water Res 2000 , 34 , 4234–4242. [ CrossRef ] 50 Sham, R.C.; Tao, L.S.R.; Mak, Y.K.Y.; Yau, J.K.C.; Wai, T.C.; Ho, K.K.Y.; Zhou, G.-J.; Li, Y.; Wang, X.; Leung, K.M.Y. Occurrence and trophic magnification profile of triphenyltin compounds in marine mammals and their corresponding food webs Environ. Int 2020 , 137 , 105567. [ CrossRef ] [ PubMed ] 51 Zhou, Y.; Chen, Q.; Du, X.; Yin, G.; Qiu, Y.; Ye, L.; Zhu, Z.; Zhao, J. Occurrence and trophic magnification of polybrominated diphenyl ethers (PBDEs) and their methoxylated derivatives in freshwater fish from Dianshan Lake, Shanghai, China Environ Pollut 2016 , 219 , 932–938. [ CrossRef ] [ PubMed ] 52 Kliemann, B.C.K.; Delariva, R.L.; de Arruda Amorim, J.P.; da Silva Ribeiro, C.; da Silva, B.; Silveira, R.V.; Ramos, I.P. Dietary changes and histophysiological responses of a wild fish (Geophagus cf. proximus) under the influence of tilapia cage farm Fish Res 2018 , 204 , 337–347. [ CrossRef ] 53 Nardoto, G.B.; Murrieta, R.S.S.; Prates, L.E.G.; Adams, C.; Garavello, M.E.P.E.; Schor, T.; De Moraes, A.; Rinaldi, F.D.; Gragnani, J.G.; Moura, E.A.F.; et al. Frozen chicken for wild fish: Nutritional transition in the Brazilian Amazon region determined by carbon and nitrogen stable isotope ratios in fingernails Am. J. Hum. Biol 2011 , 23 , 642–650. [ CrossRef ] 54 Popper, A.N.; Hawkins, A.D.; Thomsen, F. Taking the Animals’ Perspective Regarding Anthropogenic Underwater Sound Trends Ecol. Evol 2020 , 35 , 787–794. [ CrossRef ] [ PubMed ] 55 Longcore, T.; Rich, C. Ecological Light Pollution—Review Ecol. Soc. Am 2004 , 2 , 191–198. [ CrossRef ] 56 Jackson, M.D.; Keyzers, R.A.; Linklater, W.L. Single compounds elicit complex behavioural responses in wild, free-ranging rats OPEN Sci. Rep 2018 , 8 , 12588. [ CrossRef ] [ PubMed ]

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 14 of 16 57 McFrederick, Q.S.; Fuentes, J.D.; Roulston, T.; Kathilankal, J.C.; Lerdau, M. Effects of air pollution on biogenic volatiles and ecological interactions Oecologia 2009 , 160 , 411–420. [ CrossRef ] 58 Jacox, M.G.; Alexander, M.A.; Bograd, S.J.; Scott, J.D. Thermal displacement by marine heatwaves Nature 2020 , 584 , 82–86 [ CrossRef ] 59 Ellis, E.C. Ecology in an anthropogenic biosphere Ecol. Monogr 2015 , 85 , 287–331. [ CrossRef ] 60 Selvam, B.P.; Natchimuthu, S.; Arunachalam, L.; Bastviken, D. Methane and carbon dioxide emissions from inland waters in India—Implications for large scale greenhouse gas balances Glob. Chang. Biol 2014 , 20 , 3397–3407. [ CrossRef ] [ PubMed ] 61 Morritt, D.; Stefanoudis, P.V.; Pearce, D.; Crimmen, O.A.; Clark, P.F. Plastic in the Thames: A river runs through it Mar. Pollut Bull 2014 , 78 , 196–200. [ CrossRef ] [ PubMed ] 62 Michels, J.; Stippkugel, A.; Lenz, M.; Wirtz, K.; Engel, A. Rapid aggregation of biofilm-covered microplastics with marine biogenic particles Proc. R. Soc. B Biol. Sci 2018 , 285 , 20181203. [ CrossRef ] 63 Payne, A.E.; Demory, M.-E.; Leung, L.R.; Ramos, A.M.; Shields, C.A.; Rutz, J.J.; Siler, N.; Villarini, G.; Hall, A.; Ralph, F.M. Responses and impacts of atmospheric rivers to climate change Nat. Rev. Earth Environ 2020 , 1 , 143–157. [ CrossRef ] 64 Environment Agency The State of the Environment: Soil. Available online: https://assets.publishing.service.gov.uk/government/ uploads/system/uploads/attachment_data/file/805926/State_of_the_environment_soil_report.pdf (accessed on 28 March 2021) 65 Osland, M.J.; Stevens, P.W.; Lamont, M.M.; Brusca, R.C.; Hart, K.M.; Waddle, J.H.; Langtimm, C.A.; Williams, C.M.; Keim, B.D.; Terando, A.J.; et al. Tropicalization of temperate ecosystems in North America: The northward range expansion of tropical organisms in response to warming winter temperatures Glob. Chang. Biol 2021 , 27 , 3009–3034. [ CrossRef ] 66 Hawkins, A.; Popper, A. Assessing the impacts of underwater sounds on fishes and other forms of marine life Acoust Today 2014 , 10 , 30–41 67 Wiernicki, C.J.; Liang, D.; Bailey, H.; Secor, D.H. The Effect of Swim Bladder Presence and Morphology on Sound Frequency Detection for Fishes Rev. Fish. Sci. Aquac 2020 , 28 , 459–477. [ CrossRef ] 68 Slabbekoorn, H.; den Boer-Visser, A. Cities Change the Songs of Birds Curr. Biol 2006 , 16 , 2326–2331. [ CrossRef ] [ PubMed ] 69 Kunc, H.P.; Schmidt, R. The effects of anthropogenic noise on animals: A meta-analysis Biol. Lett 2019 , 15 , 20190649. [ CrossRef ] 70 Van der Sleen, P.; Lugo-Carvajal, A.; Zuanon, J.; Holmgren, M. Cats singing in the dark? Spawning aggregations of soundproducing fish in Amazonian floodplain forests Environ. Biol. Fishes 2020 , 103 , 1265–1267. [ CrossRef ] 71 Lee, J.J. The sound in the silence: Discovering a fish’s soundscape Science 2012 , 337 , 1290–1291. [ CrossRef ] 72 Roca, I.T.; Magnan, P.; Proulx, R. Use of acoustic refuges by freshwater fish: Theoretical framework and empirical data in a three-species trophic system Freshw. Biol 2018 , 65 , 45–54. [ CrossRef ] 73 Gaston, K.J.; Bennie, J.; Davies, T.W.; Hopkins, J. The ecological impacts of nighttime light pollution: A mechanistic appraisal Biol. Rev 2013 , 88 , 912–927. [ CrossRef ] 74 Taylor, M.H. Lunar Synchronization of Fish Reproduction Trans. Am. Fish. Soc 2011 , 113 , 484–493. [ CrossRef ] 75 Ekness, P.; Randhir, T.O. Effect of climate and land cover changes on watershed runoff: A multivariate assessment for storm water management J. Geophys. Res. Biogeosciences 2015 . [ CrossRef ] 76 Ekins, P.; Global, C.; Outlook, E.; Gupta, J.; Global, C.; Outlook, E.; UN Environment; United Nations Environment Programme (UNEP) Global Environment Outlook—GEO-6: Healthy Planet, Healthy People ; UNEP: Nairobi, Kenya, 2019 77 UNEP Global Chemicals Outlook II: From Legacies to Innovative Solutions ; UNEP: Nairobi, Kenya, 2019 78 Daughton, C.G. The Matthew Effect and widely prescribed pharmaceuticals lacking environmental monitoring: Case study of an exposure-assessment vulnerability Sci. Total Environ 2014 , 466–467 , 315–325. [ CrossRef ] 79 Anna, S.; Sofia, B.; Christina, R.; Magnus, B. The dilemma in prioritizing chemicals for environmental analysis: Known versus unknown hazards Environ. Sci. Process. Impacts 2016 , 18 , 1042–1049. [ CrossRef ] 80 Scott, P.D.; Bartkow, M.; Blockwell, S.J.; Coleman, H.M.; Khan, S.J.; Lim, R.; McDonald, J.A.; Nice, H.; Nugegoda, D.; Pettigrove, V.; et al. An assessment of endocrine activity in Australian rivers using chemical and in vitro analyses Environ. Sci. Pollut. Res 2014 , 21 , 1295112967. [ CrossRef ] [ PubMed ] 81 Pochodylo, A.L.; Helbling, D.E. Emerging investigators series: Prioritization of suspect hits in a sensitive suspect screening workflow for comprehensive micropollutant characterization in environmental samples Environ. Sci. Water Res. Technol 2016 , 3 , 54–65. [ CrossRef ] 82 Zhu, Y.G.; Penuelas, J. Changes in the environmental microbiome in the Anthropocene Glob. Chang. Biol 2020 , 26 , 3175–3177 [ CrossRef ] 83 Garcia-Armisen, T.; Vercammen, K.; Passerat, J.; Triest, D.; Servais, P.; Cornelis, P. Antimicrobial resistance of heterotrophic bacteria in sewage-contaminated rivers Water Res 2011 , 45 , 788–796. [ CrossRef ] 84 Hu, X.Y.; Logue, M.; Robinson, N. Antimicrobial resistance is a global problem—A UK perspective Eur. J. Integr. Med 2020 , 36 , 101136. [ CrossRef ] 85 Vane, C.H.; Beriro, D.J.; Turner, G.H. Rise and fall of mercury (Hg) pollution in sediment cores of the Thames Estuary, London, UK Earth Environ. Sci. Trans. R. Soc. Edinb 2015 , 105 , 285–296. [ CrossRef ] 86 Johnstone, K.M.; Rainbow, P.S.; Clark, P.F.; Smith, B.D.; Morritt, D. Trace metal bioavailabilities in the Thames estuary: Continuing decline in the 21 st century J. Mar. Biol. Assoc. UK 2016 , 96 , 205–216. [ CrossRef ] 87 Botelho, M.T.; Fuller, N.; Vannuci-Silva, M.; Yang, G.; Richardson, K.; Ford, A.T. Unusual male size vs sperm count relationships in a coastal marine amphipod indicate reproductive impairment by unknown toxicants Aquat. Toxicol 2021 , 233 , 105793. [ CrossRef ]

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 15 of 16 88 Nevitt, G.A.; Bonadonna, F. Sensitivity to dimethyl sulphide suggests a mechanism for olfactory navigation by seabirds Biol. Lett 2005 , 1 , 303–305. [ CrossRef ] 89 Stacey, N. Hormones, pheromones and reproductive behavior Fish Physiol. Biochem 2003 , 28 , 229–235. [ CrossRef ] 90 McIntyre, J.K.; Baldwin, D.H.; Beauchamp, D.A.; Scholz, N.L. Low-level copper exposures increase visibility and vulnerability of juvenile coho salmon to cutthroat trout predators Ecol. Appl 2012 , 22 , 1460–1471. [ CrossRef ] [ PubMed ] 91 Polverino, G.; Martin, J.M.; Bertram, M.G.; Soman, V.R.; Tan, H.; Brand, J.A.; Mason, R.T.; Wong, B.B.M. Psychoactive pollution suppresses individual differences in fish behaviour Proc. R. Soc. B Biol. Sci 2021 , 288 , 20202294. [ CrossRef ] [ PubMed ] 92 Kurelec, B. The Genotoxic Disease Syndrome Mar. Environ. Res 1993 , 35 , 341–348. [ CrossRef ] 93 Tang, B.; Wang, Q.; Chen, L.; Yang, S. Features of an intersex Chinese mitten crab, (Eriocheir Japonica Sinensis)(Decapoda, Brachyura) Crustaceana 2005 , 78 , 371–377. [ CrossRef ] 94 Godfray, H.C.J.; Stephens, A.E.A.A.; Jepson, P.D.; Jobling, S.; Johnson, A.C.; Matthiessen, P.; Sumpter, J.P.; Tyler, C.R.; McLean, A.R. A restatement of the natural science evidence base on the effects of endocrine disrupting chemicals on wildlife Proc. R. Soc B Biol. Sci 2019 , 286 , 20182416. [ CrossRef ] 95 Tyler, C.R.; Jobling, S. Roach, sex, and gender-bending chemicals: The feminization of wild fish in English rivers Bioscience 2008 , 58 , 1051–1059. [ CrossRef ] 96 Jobling, S.; Coey, S.; Whitmore, J.G.; Kime, D.E.; Van Look, K.J.W.; McAllister, B.G.; Beresford, N.; Henshaw, A.C.; Brighty, G.; Tyler, C.R.; et al. Wild intersex roach (Rutilus rutilus) have reduced fertility Biol. Reprod 2002 , 67 , 515–524. [ CrossRef ] 97 Jaeger, K.L.; Olden, J.D.; Pelland, N.A. Climate change poised to threaten hydrologic connectivity and endemic fishes in dryland streams Proc. Natl. Acad. Sci. USA 2014 , 111 , 13894–13899. [ CrossRef ] 98 Nogales, B.; Lanfranconi, M.P.; Piña-Villalonga, J.M.; Bosch, R. Anthropogenic perturbations in marine microbial communities FEMS Microbiol. Rev 2010 , 35 , 275–298. [ CrossRef ] 99 Liu, L.; Yang, J.; Yu, X.; Chen, G.; Yu, Z. Patterns in the composition of microbial communities from a subtropical river: Effects of environmental, spatial and temporal factors PLoS ONE 2013 , 8 , 1–10. [ CrossRef ] 100. Olden, J.D.; Comte, L.; Giam, X. The homogocene: A research prospectus for the study of biotic homogenisation NeoBiota 2018 , 36 , 23–36. [ CrossRef ] 101. Measham, N. Riverfly Census 2015 Salmon Trout Conserv. UK 2015 . Available online: https://www.salmon-trout.org/wpcontent/uploads/2017/08/2015-Report_Riverfly-Census.pdf (accessed on 28 March 2021) 102. Barbarossa, V.; Bosmans, J.; Wanders, N.; King, H.; Bierkens, M.F.P.; Huijbregts, M.A.J.; Schipper, A.M. Threats of global warming to the world’s freshwater fishes Nat. Commun 2021 , 12 , 1–10. [ CrossRef ] [ PubMed ] 103. Alberti, M.; Correa, C.; Marzluff, J.M.; Hendry, A.P.; Palkovacs, E.P.; Gotanda, K.M.; Hunt, V.M.; Apgar, T.M.; Zhou, Y. Global urban signatures of phenotypic change in animal and plant populations Proc. Natl. Acad. Sci. USA 2017 , 114 , 8951–8956 [ CrossRef ] 104. Sih, A.; Ferrari, M.C.O.; Harris, D.J. Evolution and behavioural responses to human-induced rapid environmental change Evol Appl 2011 , 4 , 367–387. [ CrossRef ] 105. Casado, J.; Brigden, K.; Santillo, D.; Johnston, P. Screening of pesticides and veterinary drugs in small streams in the European Union by liquid chromatography high resolution mass spectrometry Sci. Total Environ 2019 , 670 , 1204–1225. [ CrossRef ] [ PubMed ] 106. Hansen Jesse, L.C.; Obrycki, J.J. Field deposition of Bt transgenic corn pollen: Lethal effects on the monarch butterfly Oecologia 2000 , 125 , 241–248. [ CrossRef ] [ PubMed ] 107. Jeger, M.; Bragard, C.; Chatzivassiliou, E.; Dehnen-Schmutz, K.; Gilioli, G.; Jaques Miret, J.A.; MacLeod, A.; Navajas Navarro, M.; Niere, B.; Parnell, S.; et al. Risk assessment and reduction options for Ceratocystis platani in the EU EFSA J 2016 , 14 , e 04640 [ CrossRef ] 108. Soulioti, N.; Tsopelas, P.; Woodward, S. Platypus cylindrus, a vector of Ceratocystis platani in Platanus orientalis stands in Greece For. Pathol 2015 , 45 , 367–372. [ CrossRef ] 109. Griffiths, A.M.; Ellis, J.S.; Clifton-Dey, D.; Machado-Schiaffino, G.; Bright, D.; Garcia-Vazquez, E.; Stevens, J.R. Restoration versus recolonisation: The origin of Atlantic salmon (Salmo salar L.) currently in the River Thames Biol. Conserv 2011 , 144 , 2733–2738 [ CrossRef ] 110. Des Roches, S.; Pendleton, L.H.; Shapiro, B.; Palkovacs, E.P. Conserving intraspecific variation for nature’s contributions to people Nat. Ecol. Evol 2021 , 5 , 574–582. [ CrossRef ] [ PubMed ] 111. Sinclair, J.S.; Brown, J.A.; Lockwood, J.L. Reciprocal human-natural system feedback loops within the invasion process NeoBiota 2020 , 508 , 489–508. [ CrossRef ] 112. Martin, S.; Thouzeau, G.; Richard, M.; Chauvaud, L.; Jean, F.; Clavier, J. Benthic community respiration in areas impacted by the invasive mollusk Crepidula fornicata Mar. Ecol. Prog. Ser 2007 , 347 , 51–60. [ CrossRef ] 113. Bohn, K.; Richardson, C.; Jenkins, S. The invasive gastropod Crepidula fornicata: Reproduction and recruitment in the intertidal at its northernmost range in Wales, UK, and implications for its secondary spread Mar. Biol 2012 , 159 , 2091–2103. [ CrossRef ] 114. Kostecki, C.; Rochette, S.; Girardin, R.; Blanchard, M.; Desroy, N.; Le Pape, O. Reduction of flatfish habitat as a consequence of the proliferation of an invasive mollusc Estuar. Coast. Shelf Sci 2011 , 92 , 154–160. [ CrossRef ]

Int. J. Environ. Res. Public Health 2021 , 18 , 6406 16 of 16 115. Bouasria, M.; Khadraoui, F.; Benzaama, M.H.; Touati, K.; Chateigner, D.; Gascoin, S.; Pralong, V.; Orberger, B.; Babouri, L.; El Mendili, Y. Partial substitution of cement by the association of Ferronickel slags and Crepidula fornicata shells J. Build. Eng 2021 , 33 , 101587. [ CrossRef ] 116. Cugier, P.; Struski, C.; Blanchard, M.; Mazuri é , J.; Pouvreau, S.; Olivier, F.; Trigui, J.R.; Thi é baut, E. Assessing the role of benthic filter feeders on phytoplankton production in a shellfish farming site: Mont Saint Michel Bay, France J. Mar. Syst 2010 , 82 , 21–34 [ CrossRef ] 117. Thieltges, D.W. Benefit from an invader: American slipper limpet Crepidula fornicatareduces star fish predation on basibiont European mussels Hydrobiologia 2005 , 541 , 241–244. [ CrossRef ] 118. Gibbs, P.E.; Spencer, B.E.; Pascoe, P.L. The American Oyster Drill, Urosalpinx Cinerea (Gastropoda): Evidence Of Decline in an Imposex-Affected Population (R. Blackwater, Essex) J. Mar. Biol. Assoc. UK 1991 , 71 , 827–838. [ CrossRef ] 119. Sousa, A.C.A.; Pastorinho, M.R.; Takahashi, S.; Tanabe, S. History on organotin compounds, from snails to humans Environ Chem. Lett 2014 , 12 , 117–137. [ CrossRef ]

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