Shark kryptonite
Sharks have superpowers, one of which is the ability to detect electrical currents. Eric and his team have developed a special magnetic fish hook that they hope will repel sharks and prevent them from becoming by-catch.
Eric Stroud
Working as an organic chemist in a field dominated by marine biologists and fishery scientists has been an interesting journey for the past 12 years!
My interest in sharks began as a simple suggestion during the ‘summer of the shark’ in 2001. Bad weather kept my wife and me in our stateroom during a cruise and the satellite TV news was airing an unending blitz of shark attack stories. ‘Why don’t you work on a shark repellent?’ asked my wife. This was the spark that led me to years of chemical research, field work alongside renowned scientists, travelling the world and...
SMART circle hooks for shark by-catch reduction
This project seeks to reduce accidental shark catch in a swordfish fishery by using an experimental fishing hook that is capable of repelling sharks, but not fish.
Unwanted catch, or by-catch, of sharks is a major problem in any longline fishery that uses hooks and is not targeting sharks. A fishing hook is not selective enough to catch a tuna or a swordfish in favour of a shark, therefore a need exists to repel sharks but not valuable fish.
The SMART Hook™ (Selective Magnetic and Repellent Treated) is the first hook technology available that selectively reduces shark catch without affecting target fish catch. Previous experiments with the SMART Hook™ using captive sharks demonstrated a 60% to 94% reduction in shark catch.
Experiments with captive adult bonnethead sharks at Key West (Florida) demonstrated about three times more unsuccessful feeding attempts on SMART Hooks™ compared to control hooks. Captive adult bonnethead shark experiments conducted at Aquaranch in Long Key, Florida, demonstrated approximately 16 times more unsuccessful feeding attempts on SMART Hooks™ compared to control hooks. Captive sub-adult lemon shark experiments conducted at Aquaranch in Long Key, Florida, demonstrated approximately 2.5 times more unsuccessful feeding attempts on SMART Hooks™ compared to control hooks. A preliminary collaborative study in the Gulf of Maine during June 2011 showed an increase in ground fish catch with a corresponding decrease in spiny dogfish catch.
Our SOSF project will deploy hundreds of plain circle hooks and SMART Hooks™ in a real commercial longline swordfishery. We will evaluate its performance based on shark catch and swordfish catch.
Fishermen using the SMART Hook™ are able to catch more fish and less sharks, and obtain less damage to their gear in exchange for a slightly more expensive hook. Increasing their target fish catch by even a few additional fish on hooks that would otherwise be occupied by sharks, offsets the additional expenses of purchasing SMART Hooks™. The SMART Hook™ could potentially provide fishery agencies throughout the world with a tool to assist shark conservation efforts while promoting sustainable fishing practices.