The objectives of this study were to assess fish passages/fish ladders on five dams on the Caspian’s main tributary rivers and best practice experience worldwide with the introduction of fish ladders and the improvement in recruitment and to develop and implement pilot project to modify a fish passage facility to increase efficiency and effectiveness and return on investment.
Specific tasks involved :
- Finalisation of list of diadromous species in the Caspian affected by barriers, inventories of barriers in Caspian region and fish-passage structures in place
- Discussion of the benefits of modelling the effects of installing various types of fish passage devices in certain rivers. Present examples of such models and discuss their potential use in the Caspian.
- Providing quality assurance editing on data to the extent possible and prepare data sets using available data.
- Working with GIS expert to map this data for presentation and discussion at regional meeting.
- Preparation of synopsis of best practice and experience from around the world on how dammed rivers can be managed to mimic natural flows and thereby restore or maintain the health of spawning grounds downstream.
- Supporting the PMCU/FBE in organizing a group mission to visit 3-5 priority dams to assess fish passage facilities or lack thereof and potential for improvement.
- Preparation of initial draft of report detailing assessments of as well as recommendations for top 7-10 ranked barriers on how to improve fish passages on each, with particular focus on the dams visited.
- Proposals of specific fish passage designs appropriate for each context and cost estimates for each design and recommend specific measures of success of improving fish passage (counting at fish ladder; telemetry; mark recapture below and above the site (before and after).
- Summary of 2-3 case studies from around the world where the introduction or improvement in fish passage on a dam led to increased recruitment and/or increased catch levels and present this report to responsible institutions in each country and to the TCIS.
- Assistance in create a TC Network and present draft connectivity report and draft report on fish passage facilities through the network, discuss final data set and resulting maps.
- Finalization and presentation of the “Enhancing Connectivity” report, agree upon prioritization of fish passage sites within Caspian basin, and produce final draft of report for circulation, review and formal consideration