Thus, the importance of the smaller streams within the headwaters of catchments and their role in the maintenance of microbial biodiversity within the river network is highlighted. [...] Given the ongoing declines in water and habitat quality across NI river networks (see Chapter 6), it is essential to reassess the significance of the combined total of the dendritic nature of the small stream network (SSN) to the biodiversity potential of each headwater branch. [...] 18 The UWWTD defines eutrophication as: “The enrichment of water by nutrients, especially compounds of nitrogen and/or phosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned.” The NiD defines eutrophication as: “The enrichment of water by nitro. [...] These patterns arise from the shape and size of the channel, the distribution of riffle and pool habitats, the abundance and diversity of gravel bars and the stability of the substrate, determined by the interactions between flow regime and local geology and topography (Frissell et al., 1986). [...] The WFD identifies the importance of longitudinal connectivity to the character of rivers, both for upstream and downstream movement of aquatic organisms and for sediment transport and re-naturalisation of constrained rivers.
Authors
- Pages
- 130
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- United Kingdom
Table of Contents
- Impact of Nutrient Enrichment and Hydromorphological Modification on Riverine Biodiversity in Northern Ireland 1
- Contents 3
- Abbreviations 5
- Executive summary 7
- Chapter 1 Introduction 9
- Chapter 2 Biodiversity patterns across the riverine landscape 12
- Chapter 3 The policy context for biodiversity protection 16
- Chapter 4 The major drivers of biodiversity 20
- I. Nutrient enrichment as a driver of biodiversity 20
- II. Hydromorphology as a driver of biodiversity 24
- I. Morphological condition 25
- II. River continuity 26
- III. Hydrological regime 27
- Chapter 5 Evolution of key pressures 30
- Nutrient enrichment 30
- I. Phosphorus enrichment 30
- I. Physical barriers 33
- II. Arterial drainage 36
- Chapter 6 Current trends in water quality monitoring 38
- Chapter 7 Evidence of key pressures 39
- Part I. Hydromorphology Pressures and impacts 40
- I. Key pressures impacting river morphology 41
- II. Key pressures impacting river continuity 47
- III. Key pressures impacting the hydrological regime 49
- Summary 52
- Part II. Nutrient enrichment Pressures and impacts 53
- I. Land use Forestry and agriculture 57
- II. Wastewater management Centralised treatment 62
- III. Wastewater management Decentralized treatment systems 65
- Summary 70
- Chapter 8 Evidence gaps for prioritisation 71
- Priority Area 1 Understanding the interconnected drivers of biodiversity 71
- Priority Area 2 Identifying cumulative and emerging threats to biodiversity 73
- Priority Area 3 Implementing e-flows as a strategy for biodiversity protection 77
- Priority Area 4 A national framework for assessing freshwater resources 78
- Priority Area 5 Transboundary cooperation key to protecting biodiversity 83
- Chapter 9 Recommendations 85
- I. Rethinking river biodiversity beyond traditional metrics 85
- II. River habitat and biodiversity the critical role of river sources 85
- III. Navigating change functional diversity and species rearrangements 86
- IV. Enhancing public engagement flagship habitats and species 87
- Chapter 10 Conclusion 88
- References 90
- Appendix 125
- Method Statement 125
- Development of search strings 125
- Partial search strings for drivers 126
- Inclusion of databases and other sources 128
- Screening criteria and inclusion criteria 129
