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The history of FADS in Hawaii

By Staff | Nov 26, 2010

Since Kamehameha’s days, fishermen throughout Polynesia knew that fish aggregate around debris.

In 1977, the National Marine Fisheries Service (NMFS), using funds from the defunct Pacific Fisheries Development Foundation, anchored experimental rafts off Oahu, Lanai and Kona.

With these first buoys, aku boats found a bonanza with catches of five to 15 tons, while sportfishers caught between 300 to 700 pounds of skipjack tuna a trip.

In 1980, the Department of Land and Natural Resources’ (DLNR) Division of Aquatics (DAR) built on the experimental success and established the Fish Aggregation Device (FAD) program.

They used money from the Federal Aid to Sport Fish Restoration Program, also known as Dingell-Johnson. Public meetings helped place 26 FADs around the islands. They were located 2.4 to 25 miles offshore in depths of 80 to 1,510 fathoms.

A big change to the FAD program came in 1996, when the state attempted to cut the hugely popular program. When the Hawaii Institute of Marine Biology (HIMB) at the University of Hawaii at Manoa took over, the program changed dramatically.

FAD Specialist Warren Cortez is head of the program, located at Sand Island, Oahu.

FADs were introduced in Hawaii in an attempt to increase sport fishing opportunities, and revitalize the fishing industry by taking advantage of the “aggregating” behavior of pelagic fishes around floating objects.

Since their introduction, FAD buoy and mooring system designs have undergone considerable technological changes.

The Hawaii FAD System evolved from the use of foam-filled tire buoys, using one type of synthetic line, to the present sphere buoy design with two types of line. The design changes were developed to create a buoy and mooring line system that would remain on station for a long time and enhance sport fishing opportunities.

Today, Hawaii’s 77 FADs make up a system, including 55 surface and 22 mid-water buoys. There are 18 surface FADs on the Big Island, 14 in Maui County, 14 on Oahu and nine on Kauai.

The FADs have proven to be very popular among Hawaii’s fishermen. Catch statistics show that the FADs have contributed to increased catches, and historical data on FAD survival in the field shows that design improvements have produced longer lasting FADs. Future developments in FAD systems point to a combination of surface and mid-water FADs around the main Hawaiian Islands.

Setting out buoys in 9,000 feet of water is a complicated task worthy of engineering skills. At first, steel cables tied to train wheels anchored FADs. An early program problem was electrolysis caused by the galvanized chain reacting to the steel wheels. Danforth anchors were tried, but finally to stop electrolysis, the anchors became cast concrete.

Rope had to be tested out. The tremendous pressure of nearly 2.5 miles of length shredded rope. Tensile strength was not an exact science, because manufacturers tested rope in the air, not in salt water. It took years to discover that the first two-thirds of line needed to float to prevent bottom hand-ups, while the top third required sinking to stop entanglements.

Rope is the most critical of all the buoy elements. All ropes are site-specific and manufactured and shipped from the Mainland. Ropes range in lengths from Lahaina’s LA-Buoy at 865 feet to the F-Buoy off Kailua-Kona that uses 13,709 feet. To put it in perspective, remember that the height of Mauna Kea is 13,796 feet.

Ropes come in two parts. The top part of the rope, which is roughly one-third of the total length, is a sinking type of a polyethylene mixture. The bottom two-thirds is a floating type of a polypropylene mixture. The total length of the rope is roughly 30 percent longer than the depth. In theory, the mooring line should look like a sideways “S.”

The relatively simple element of FAD deployment is the concrete anchor. The 26.5-inch by 26.5-inch by 24-inch concrete anchors weigh 1,700 pounds, and three are used for each FAD system. A trio of anchors is used because concrete weighs 40 percent less in saltwater.

Total supply cost of a FAD is around $6,000. The FAD program has been able to continue to provide responsive deployment and maintenance for the 77 FADs in Hawaiian waters. Considering the rising cost, the program has managed to perform well and stay on budget.

The Western Pacific Regional Fishery Management Council (WESTPAC) will be adding at least two new buoys off the north side of Maui. The West Side fishermen need to put in our request for a few more.

I have been talking to a few of the captains about where they would like to see another buoy located. The top three spots will be sent to WESTPAC in a request for us.

There is money available for construction and deployment, but it needs to be done now, not later. Please e-mail me at tatemaui@aol.com with any location suggestions you might have.