Our design is based on eel behavior, and perfected in Sweden. The Elverator not only protects elver from predators, independent studies have confirmed this unique floating system safely collects up to 300% more elver, including larger elver, than other existing systems.   

Key Substrate
The Specs
Key Substrate


The Whooshh Innovations EF-16 Climbing Substrate is a durable and modular substrate that is designed to attract and pass a broad cross-section of eels, from elver to yearlings, with a wide range of sizes. 

Original tiles are used throughout the entire ramp except for the uppermost part of the ramp were the end tile is used together with a PVC half pipe (3-4´´ diameter) to create a curved descent to the collecting box (sold separately.) 

The EF-16™ tiles comes with a standard width of 200 mm, a common ramp width of 400 mm needs four EF-16™ tiles per meter of ramp. 

*Specialized tile sizes can be produced

Typical rivet placement, maximum rivet/screw head size: 6.5 mm, five rivets/screws per tile

​revolutionary elver upstream floating collector
 design components


Two pontoon floating structures allow versatility of placement in the waterway where elver congregate. 

The floating design enables standardization of attraction flow and climbing distance regardless of river fluctuations. Easily removed from waterway for winter storage, extending product life. 


Redirects river flow creating a central channel through the collector that facilitates elver ramp approach by creating slow-moving backwater over which supplemental directed attraction flow is provided. 


Multiple flow dispersal points (blue arrows to right) Total attraction flow of ~66 gal/min directed down into the central channel. Water flow positioned at the top of each climbing substrate ramps at 25 gal/min facilitating migration attraction of elver up the ramp. 


The collector is fully covered from pontoon to pontoon creating a large, 138 square foot shadowed area. Elver are attracted to the dark environment. Successful elver collection in both day and night time hours have been documented. The cover also minimizes predation. 


Positioned perpendicular to river flow, the elver do not need to overcome the river flow rate to begin climbing up the ramp. The ramp length is standardized to a short distance of ~3 feet, reducing climb time, stress and energy reserve use required to climb and pass over the ramp crest. Two ramps, one on each side of the collector, with a width of 10 feet, extends the opportunity for the elver to locate the ramp ~16 times, increasing use efficiency. 


EF:16 is a proprietary climbing substrate designed for increased ease for elver navigating a climb, providing features that facilitate rest during the climb and variation of flow stream. 


Elver pass over the ramp crest into an enclosed collection channel. The elver flow with the small stream through the channel and into the collection trap positioned underwater. The trap is perforated to allow continual fresh river water flow through the trap. The collection container is subsequently manually emptied and elver transported to release locations. 

The Specs

Dimensions of Assembled Collector

12 ft long, 10.5 ft wide, 5 ft high 

Dimensions of Dis-Assembled Collector - Transport Mode 

(divides into two sections of similar size) 

12 ft long, 5 ft wide, 5 ft tall

Covered Area Producing Shade

138 sq ft 

Two Identical Ramps

~300 angle, 10.5 ft wide, 3 ft long 

(composed of 32 EF:16 plates per ramp) 

Portion of Ramp Below Water Level 

~1/3 m or 1 ft 

Typical Elver Climb Time from Out of Water to Ramp Crest

<30 seconds

Water Flow

Water Pump

~124 gal/min (7.8 liters/sec) 

Flow rate across each EF-16 plate 

1.1-1.6 gal/min (0.07-0.1l/s)

Power Requirements

Water Pump

Single phase, 110V, 13A, ~28 lb