Evaluation of Turtle Excluder Device in the Scallop Trawl Fishery

1. Daniel Lawson and Joe DeAlteris – University of Rhode Island, Dept. of Fisheries Jeff Gearhart and Henry Milliken– National Marine Fisheries Service Several commercial fishery gears in the U.S. have been observed by the National Marine Fisheries Service to interact with sea turtles. They include trawl nets, longlines, dredges and pound nets, among others. One particular fishery that has recently been documented to interact with sea turtles is the scallop trawl fishery off the mid-Atlantic coast. In October 2004, the NEFSC reported 3 loggerhead sea turtles (Caretta caretta) taken in scallop trawl gear. The scallop dredge fishery, which accounts for about 95% of the total scallop fishery in the Northeast region, has also been observed to take loggerhead and Kemp’s ridley (Lepidochelys kempi) sea turtles in this area. At this point, the exact extent of the impact of the scallop trawl fishery on sea turtle populations is unknown, but the NMFS has decided to take a proactive step to address this issue in a cooperative research effort with scallop trawl fishermen before serious regulatory action is required. Evaluation of Turtle Excluder Device in the Scallop Trawl Fishery During the summer of 2006 research into the effect of a Turtle Excluder Device (TED) on the catch of Atlantic sea scallops in commercial trawl nets was conducted by the University of Rhode Island in cooperation with NMFS and the commercial fishing industry. The FV Captain Dell, owned and operated by Eddie Newman was contracted to perform comparative tows and maintain the fishing gear. URI staff collected and analyzed the data. The Captain Dell, operated from Chincoteague, VA, tows two nets simultaneously, facilitating paired comparisons, with one experimental net having a TED installed and the other identical net used as a control. To minimize any side bias, the TED was switched from side to side on a daily basis. The TEDs used in this experiment were based TEDs used successfully in the whelk fishery, and were constructed by the NMFS lab in Pascagoula MS. The TED was evaluated using two of the different types of nets commonly used by general category scallop fisherman, also known as day scalloping. Beginning on July 9, a typical flounder net with a 4:1 taper and 55’ sweep was used for experimental tows. Due to the loss of one of the nets early on the third day, the vessel was forced to switch to a different set of flounder nets with a 66’ sweep. From July 14 through August 1, a total of 35 successful comparative tows over ten days at sea were completed. On August 4, experimental testing began with two brand new 7:1 taper 50’ sweep scallop nets purchased by NMFS. Through August 27, 14 days and 46 successful tows had been completed with these nets, and evaluation was ended. ff The results are given above and beside. There was a significant difference in scallop catch loss for all tows in with both types of net. For small tows, neither net showed a significant change. The larger tows are where the difference in catch shows up. One idea is that the increased weight in the codend changes the geometry of the TED and the TED opening. Use of underwater video had meager success, but did confirm scallop loss out of the TED opening. Height frequency plots are nearly identical for all tows for each net and do not reveal any shift size by using the TED. # The University of Rhode Island is currently pursuing research involving marine mammal behavior and trawl nets using underwater video cameras, and is interested in collaborating on any projects involving protected species and fishing gear. Please contact Dan Lawson ddandlaw@aol.com or Joe DeAlteris jdealteris@uri.edu for more information