Incidental mortality of seabird species continues in many commercial fisheries, including species impacted by the 2010 Deepwater Horizon oil spill. The Open Ocean Trustees Implementation Group is using settlement money to fund research to restore populations of birds impacted by this oil spill, including Great Shearwaters (Ardenna gravis) found in New England waters. Bycatch of Great Shearwaters occurs in gillnets targeting spiny dogfish (Squalus acanthias) in the waters off Cape Cod, MA. Vessels participating in this fishery travel to and from fishing grounds during time windows limited by the tides, so fishermen bait their gillnets to shorten the time they are on bottom and increase catch per unit effort (CPUE). The shearwater bycatch spikes when fishermen toss bait directly on their gillnets while they are being deployed and near the surface. Baiting in front of the nets during setting (forward baiting), over the net string after setting (after baiting), or up-tide at the end of a set (end baiting) could increase dogfish CPUE while minimizing or eliminating shearwater bycatch. This project was designed to evaluate these methods and promote alternative baiting methods to reduce seabird bycatch through collaborations between scientists, fishermen, and fishing advocacy groups.

We tested these methods during two field seasons through a collaboration between scientists and commercial fishermen. After baiting consistently resulted in a significant increase in dogfish CPUE relative to control nets with no bait, and no Great Shearwaters were caught during after-baiting trials. The next phase of the project will focus on working with early adopters to engage the broader Cape Cod fishing industry and promote adoption of this solution to reduce seabird bycatch.