Lecture 6 Knowledge needs for RiverSea System management

Lecture 6 Knowledge needs for River-Sea System management – Sediments & Management 1

Sediments & Management • Movement from catchment-to-coast and how that is altered • Significantly affected by catchment, river and coastal management Requires understanding of sediment dynamics in a source to sink system to manage sustainably across River-Sea continua 2

Sediments & Management background Salient facts: Ø Sediment is a resource utilised for fertile farmland as a source of construction material Ø Hydromorphological characteristics of the river influence sediment regimes and are crucial for the diversity of habitats and biota Effects: Ø Erosion and sedimentation processes interact with human interventions in the sediment regime, like deepening of navigation channels, dredging for maintenance, damming for energy generation or drinking water reservoirs Challenges include: Ø Understanding how large scale sediment regimes of a River-Sea System affects general ecological conditions and lead to risks across multiple objectives 3

Sediments & Management – knowledge gaps 4

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Research Priorities for Sediments & Management 8

Healthy ecosystems • Threatened by changes in habitats, water quality, river regimes • Need to maintain biodiversity that maintains ecosystem structure Requires understanding of biodiversity and connectivity across RSSs and how it affects future provision of ecosystem services 9

Healthy ecosystems- background Salient facts: Ø Pressures of river regulation, channelization, deepening and widening, as well as diking and bank stabilization, lead to habitat changes and losses Ø Nutrient loading and chemical pollution due to agriculture, urbanisation and industry further challenge ecosystem structure and functioning Effects: Ø Decline of biodiversity, which is most pronounced in freshwaters Ø Land use changes affect ecosystem services, through fundamental shifts in the structure and functioning of freshwater, transitional water and coastal ecosystems Challenges include: Ø Understanding how changes in ecosystem structure and functioning relate to ecosystem services and ecosystem health 10

Healthy ecosystems – knowledge gaps 11

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Research Priorities for Healthy ecosystems: Biodiversity 14

Research Priorities for Healthy ecosystems: Ecosystem services 15