For the past few decades the welfare of fish in their natural habitat has become a serious issue. For this reason, fish must be able to pass pumping station pumps (“pumps” in short), relatively unharmed. On June 12th and 13th 2012 Bedford Pumps model SAF.90.05.12 was tested for its ability to let fish pass the motor without being injured. Bedford Pumps pump has been specially developed to be fish survivable. The test known as “the fish survivability test”, was performed in a dry dock in the Netherlands. For the tests, three representative fish groups in two different size classes were forced to flow through the pump. The groups are:
- Percidae (perch-like species, mainly perch and ruff),
- Cyprinidae (carp-like species, mainly roach and bream) and
- Anguillidae (European eel).
The score is based on the amount of fish that pass the pump and survive without lethal injuries. The final rating of the pump is related to the score of other pumps of the same type. In total 823 fish were exposed to the pump by force (water elevating height of 2.9 m) during three different rotation speeds: 373 fish in scenario 1 (330 rpm, 1.3 m3/s); 363 fish in scenario 2 (425 rpm, 1.8 m3/s) and 87 fish in scenario 3 (518 rpm, 2.3 m3/s). In scenario 3 only eel were exposed.
1. Except for a few large cyprinids (bream), all fish survived the test at 330 rpm and no lethal injuries were observed. Therefore Bedford Pumps SAF pump can be rated as “Excellent” for its fish survivability for this rotation speed and discharge.
2. All small percids and 99% and 98% of small cyprinids and small eel survived the test at 425 rpm (all delayed mortalities). Of the big percids 94% survived, 96% of the big cyprinids, and 98 % of the big eel (2% was considered lost for a spinal injury) survived the test. Bedford Pumps SAF pump can be rated as “Good” for this rotation
speed and discharge.
3. In the test at 518 rpm 92 % of both small and big eel survived (8% was considered dead after 48 hours due to internal injuries). The end score fish survivability for Bedford Pumps model SAF.90.05.12 is a weighed average of the first two tests (330 and 425 rpm, water elevating height: 2.9 m) and is rated “Excellent”.