About This Project

My research team and I will evaluate a new type of fishing gear that is designed to help reduce the unintended capture of sharks during commercial and recreational fishing. This unintended capture is called "bycatch". With millions of sharks dying each year due to the stress of capture, bycatch has contributed to the world-wide decline in shark populations. The new gear is designed to break away when a shark takes the the bait but retain target species such as tuna and swordfish

Ask the Scientists

What is the context of this research?

The World Wildlife Fund estimates that millions of sharks die each year due to unintended capture during fishing (see www.worldwildlife.org). While the survival of these sharks is likely very high after capture during sport-fishing, shark survival after commercial capture is very low. In some cases, the post-capture survival is only a few percent. This low survival, combined with other factors, has resulted in shark populations declining world-wide. A world without sharks would be a far less interesting place and would lead to deleterious ecological changes that are difficult to predict. For example, one study found that shark declines have resulted in a situation referred to as a "trophic cascade", that began with declining shark numbers and resulted in a collapse in the scallop fishery.

What is the significance of this project?

The successful development of the fishing gear described herein will return many millions of sharks to the oceans unharmed and will help reverse the world-wide downward trend in shark populations. The new fishing gear has loops of line that break when the shark takes the baited hook. The blade-like teeth of the shark readily cut through the line whereas target species (tuna and swordfish) have very small teeth that are not designed for cutting. When the loops break, the shark is released and swims away. Preliminary testing of this new gear has been very promising with many sharks captured on control lines (no loops) and no sharks taken on the experimental lines (affectionately referred to as the "loopy leader").

What are the goals of the project?

The goal of the project is to develop and successfully test the new gear. Although some preliminary tests have been conducted, additional research is needed for final development. The manner in which the tests are conducted are very work intensive requiring long hours on-board a research vessel. Baited hooks, half with the experimental hooks and half without are set and the numbers of sharks captured on each are recorded. Please note that the lines are set for very short periods of time and any animals captured are immediately released. The study areas where we conduct tests include Gulf of Mexico waters offshore of Florida, Alabama and Mississippi.