The data set contains swordfish (Xiphias gladius) bycatches from artisanal bluefin tuna fishing traps located at four sites in Italy. Data records include the locations and dates for the catches and the catch in numbers and/or weight on given days during 1896-2010.The data have been recovered to increase understanding of the long-term dynamics of the population and its fisheries, including effects of exploitation and climate variability and change, and to provide baseline knowledge against which future variations can be compared. There are presently few other similarly long data sets for this species in this region. The data have been recovered from historical records, reports and archives associated with the traps.

Corresponding authors: Teresa Romeo (teresa.romeo@szn.it) and Brian R. MacKenzie (brm@aqua.dtu.dk)The project was supported by the participating institutes. An initial travel grant (Short Term Scientific Mission) was provided to BRM from the EU COST Action IS1403 (Oceans Past Platform: OPP) to visit colleagues (TR, PB, PC, FA) at Milazzo, Italy to discuss and plan project objectives and data recovery.The trap locations Favignana and Formica are close (ca. 10 km) to each other. The data for these two sites were only available as a combined sum for the 1970s and for a few single daily observations in other years. In years when only combined catch data from both traps were available, the event code is listed as "FavignanaFormica" and spatial coordinates are a simple average of latitudes and longitudes for the two individual sites. Similarly, the minimum and maximum depth of the rooms of the trap are averages of the minima and maxima.