Purpose and Applicability

The purpose of this report is to provide guidance for the construction and use of an automatous bait delivery platform that can be deployed in lakes and large rivers. The platform has been designed for independent use or in combination with different fish collection techniques. Although bait platforms can be modified for specific requirements and local conditions, this report documents guidelines for a field-tested system. Design modifications were made over 2 years of field testing to help construct a safe, reliable platform that can contain enough bait for a month-long deployment and can withstand high water conditions with minimal need for daily monitoring. During the 2 years of deployment on the Sandusky River, Ohio (not shown), platforms withstood river conditions ranging from 0.99 to 390.77 cubic meters per second of streamflow and 2.44 meters of fluctuation in river height.

Design

The base of the floating platform was constructed from two dock floats measuring 91.44 x 182.88 x 30.48 centimeters (cm) and a 2.54- x 3.81-cm steel rectangle tube with a wall thickness of 3.18 millimeters (fig. 1). Galvanized steel or powder-coated steel is recommended to reduce corrosion for a platform that will be used for long periods or over multiple seasons. Other materials may be used for framing, but consideration must be taken to maintain structural integrity and buoyancy. The final platform measured 182.88 x 182.88 cm and was rated to support as much as 952.5 kilograms (+0/−5 percent tested buoyancy rating by the manufacturer). For safety and integrity of the platform, floats were filled with expanded polystyrene (more commonly known as EPS) foam to ensure the platform would not sink if a float was punctured. Metal plates welded to the top of the frame were used to secure a feeder to the platform with two stainless-steel bolts (fig. 2). Feeder attachment plates were positioned to center the weight of the feeder on the platform. Once the feeder is full, the center of mass is high. If theft of the feeder is a concern, attachment plates can be welded close to the deck’s surface, and stainless-steel nylon insert lock nuts can be used on the underside of the plate.

Two support brackets (8.89 x 8.89 cm) with a wall thickness of 4.76 millimeters were welded to opposite corners of the platform to allow for anchor pole attachment (fig. 3). Because of a high center of mass, a single support pole and (or) anchors for securing bait platforms should be avoided. As designed, if two support poles are used to anchor it, the platform can safely support a full feeder and two personnel for filling and maintenance (fig. 4). Multiple anchor points also help ensure the feeder is deploying bait in the desired direction. It is recommended that hardware, fasteners, and pipe designed for floating docks not be used because this equipment cannot withstand the added stress bait platforms endure being left independent of other structures (for example, docks and shoreline), effects from debris, and fluctuating river conditions. Anchor poles need to be sturdy enough to withstand bending and tall enough to accommodate high water. Schedule 40 carbon structural American Society for Testing and Materials A500 grade B pipe (6.033-cm outside diameter x 0.391-cm width) was used in locations with potential for high river velocities. Metal or plastic pipe augers were attached to each pipe for easy installation and removal (fig. 5). It is important that pipes do not bend, have plenty of extra room to move within the support brackets, and are installed in a vertical position at the proper distance for the platform to adjust to fluctuating river conditions and to simplify platform removal (fig. 6).

Different types of feeders can be attached to this platform if the frame and attachment plates are in accommodating positions. Directional feeders built for aquaculture ponds ensure bait is being deployed in the desired direction, but a nondirectional wildlife feeder can also be used. An aluminum plate (45.72 x 50.80 cm) was attached below the feeder opening to keep bait off the platform and in the water (fig. 7). Depending on pellet size and density of bait, the hopper capacity of the feeder used to deliver bait to grass carp in the Sandusky River, Ohio, from 2020 to 2022 was 193 kilograms. Manufacturer recommendations specify a bait pellet size less than or equal to 0.76 cm. Feeders are operated with a 12-volt sealed lead acid battery charged with a solar panel. A programmable control panel allows for as many as nine feeding events daily, each as many as 60 seconds long.

Safety Considerations

Visibility to watercraft operators is vital for the safe use and automatous operation of the bait delivery platform. Platforms must be visible during the day and night in clear and inclement weather. Depending on where a platform will be placed, it is important to contact local law enforcement, the U.S. Coast Guard, and the U.S. Army Corps of Engineers about required local visibility safety requirements. Safety design features described in this document were required for installation in the Sandusky River, Ohio, but may not encompass all requirements elsewhere. In addition to physical design features, placement of platforms within the river channel or lake can affect how safe the platform will be. It is recommended that a platform not be placed in conspicuous locations, such as a tight river bend or behind an island or high vegetation. If a platform will be installed close to the shoreline, it is important to understand that they can easily blend in with trees and vegetation behind the platform during daylight hours.

A solar powered marine light (white) must be attached to the top of each platform and be visible on all sides for as much as 1 mile at night. Reflective tape should be used on all sides of the platform and feeder. Using reflective tape and solar lights on the platform and feeder separately should be considered if the platform may be left out without the feeder for any time or theft is a concern. We also used orange safety flags and high-visibility tape to increase daytime visibility. Anchor pipes that are long enough to accommodate river flood stage and allow the platform to float off its support brackets under extreme conditions should be installed to protect the platform from being destroyed and to prevent debris in the river during high water conditions. As an additional layer of safety, a back-up anchor should be used to hold the platform in place if it comes off the anchor pipes in high water.

A job hazard analysis should be completed for each installation site to identify possible safety concerns. Hardhat usage is recommended when installing anchor pipes. Operational and safety procedures for working in the field should be followed by all personnel (Yobbi and others, 1996).

Deployment

If the installation location and environmental conditions allow, the feeder should be attached to the platform onshore for the simplest and safest method for deployment. Once attached, the feeder and platform can be towed to the location with a parallel alongside tow attachment towing approach. If feeders and platforms must be transported to the deployment location in a boat, the platform should be secured in place with anchor poles before the feeder is attached. The feeder should not be filled until the platform is secured in place with anchor poles. A dock post auger wrench can simplify anchor pole installation and removal and should be attached to the pole before inserting it through the support brackets to improve maneuverability and handling while the support pole is vertical. Once the pole is vertical, the auger wrench cannot be attached to the pole because of its height.

Equipment List

Between 2019 and 2021, the total cost for one platform ranged from $2,250 to $2,925. The equipment needed is as follows: