ZSL guidance for fish conservation in the tidal Thames

The Zoological Society London (ZSL) has published Conservation of Tidal Thames Fish Through the Planning Process, a guide to help improve fish conservation for planners, developers and stakeholders in  the tidal Thames,. The area encompasses all Local Authority areas adjoining the river Thames between Teddington Lock (where the Thames ceases to be tidal), and Gravesend.

ZSL presented to developers at a Thames Estuary Partnership event in May 2017: “The Evolution of the Estuary: an update on Key Projects”. ZSL presented four major projects at planning stage at Farrells’s offices in London at that time:

  •       The Castle Green regeneration project at Barking, a Chinese-backed scheme by an Australian listed investment company ASF Group, with a plan for a 90 hectare re-routing the A13 trunk road in a 1.3km. cut-and-cover tunnel, improving north-south access to Barking riverside;
  •        The Royal Albert Dock development by Chinese developer ABP as a new business district providing a trading base for Chinese commerce, with a vision of an end-to-end rail service between London and China.
  •       The London Paramount Entertainment Resort development at the Swanscombe peninsula, supported by the Kuwaiti Sovereign Wealth Fund, and connecting to the international rail service at Ebbsfleet.
  •        A new port at Tilbury being developed by Forth Ports with a plan to provide a centre for the distribution of construction materials by river and sea.

The ZSL guidance provides links to sources of information, regulations, strategies and local plans. One such source is the Tidal Thames Habitat Action Plan, developed by the Thames Estuary Partnership Biodiversity Action Group as input to the London Biodiversity Action Plan.

The Tidal Thames is of ecological importance as a route for migratory fish to move between freshwater and salt water and vice versa.

  • It is a rich foraging ground for fish, including certain species that live exclusively in the Thames;
  • It is a territory for fish to spawn and young fish to grow.

All development operations and decommissioning along the Thames could disturb fish in the Thames, including light and water pollution, sound/vibration, change of water temperature or sediment deposit or suspension and local changes to water flow.

The area between Teddington and Gravesend is:

  • A route for migratory fish to move between freshwater and salt water and vice versa. It is a rich foraging ground for fish.
  • A territory for fish to spawn and young fish to grow.
  • And it harbours 124 fish species caught in the tidal Thames since 1964, 15% of which are protected by regulations.

All development. operations and decommissioning along the Thames could upset fish life in the Thames. For example it could affect light and water pollution, sound/vibration, change of water temperature or sediment deposit or suspension and local changes to water flow.

The guidance’s main message is that the nature and the duration of the work required relies on the sensitivity of the design of the development, and scheduling of the process.

The report emphasised that the effect of the works on fish had to be considered in the planning and development process. The report commented that “permanent loss of inter-tidal and/or sub-tidal habitats should be avoided.”

The report said that specific steps were needed:

  • A baseline survey.
  • Scheduling works to avoid “ecological events” for fish (e.g. migration)
  • Create additional or replacement foreshore habitat, modify surfaces in contact with the river (walls, piers, piles).
  • Design sustainable drainage systems.
  • Reduce  environmental impact during works (control of sedimentation change, vibration, run-off).

Zoological Society of London (ZSL) 2017: guidance document – Conservation of Tidal Thames Fish through the Planning Process.

Available online:https://www.zsl.org/sites/default/files/media/2017-01/Tidal%20Thames%20Fish%20Guidance%20Document%202017.pdf