Bycatch of rockfish in spot prawn traps and estimated magnitude of trap loss in Washington waters of the Salish Sea

Derelict fishing gear is a known stressor to rockfish populations in the Washington waters of the Salish Sea, including two species currently federally protected under the Endangered Species Act. In Washington and British Columbia, rockfish bycatch in actively fished (non-derelict) prawn traps has been documented in spot prawn test fisheries conducted by state and provincial government, and both live and dead rockfish have been found in derelict prawn traps encountered during derelict fishing gear removal operations in Washington. This study calculates rockfish bycatch rates in actively fishing prawn traps and provides preliminary trap loss rates for both commercial and recreational fisheries. Rockfish bycatch rates were determined through analysis of Washington Department of Fish and Wildlife (WDFW) Spot Prawn Test Fishery Data collected from 2004 to 2013. Data from WDFW creel surveys were used to update preliminary prawn trap loss rates. Interviews with WDFW marine enforcement officers were conducted to estimate the number of lost traps that are recovered before becoming derelict. The overall rockfish catch rates in Washington waters of the Salish Sea were 0.023 rockfish per trap drop, with considerable spatial and temporal variability. The lowest catch rates were consistently seen in Marine Area 7 (San Juan Islands and North Puget Sound); while the highest catch rates were seen in Marine Area 11 (south-central Puget Sound). The trap loss rate estimated for the recreational fishery is 2.33% of all traps fished. We estimate that over the years 2012 and 2013 an average of 653 recreational prawn traps became derelict each year. The accumulation of derelict prawn traps has a mostly unknown effect on benthic habitats of Puget Sound, which warrants additional research. While rockfish bycatch and prawn trap loss rates reported here are low, our findings support evaluating methods to reduce rockfish encounters with prawn traps.

Comparison of two types of pheromone traps for the capture of the red palm weevil (Rhynchophorus ferrugineus)

This work presents the results of the comparison of two pheromone traps for the capture of the red palm weevil. Trap A was a yellow funnel trap with green top, while trap B was a yellow pitfall trap, both equipped with pheromone. The experiment took place at Sissi and Milatos villages of Lasithi prefecture, mid-North coastline of Crete, from March 2009 to February 2010. The total number of traps deployed at each sampling varied between 24 and 36 due to various disturbances (trap loss, dirt in traps etc.). In each location, always both trap types were present. A total of 3139 adults of red palm weevil were captured during the trials. Temporal variability shows similar pattern for both trap types, as well as for both sexes. Type A traps captured 1376 insects with a ratio of 1♂ to 3.40♀, while type “B” captured 1763 insects with a ratio of 1♂ to 3.15♀. ANOVA revealed significant differences between the two traps in the number of catches (Trap A: 38.22 insects per fortnight /trap, Traps B: 48.97 insects per fortnight /trap). Comparing females and males of both trap types as separate groups, the statistical significance is more profound. At Sissi on average 1.61 males and 5.32 females were captured per fortnight/trap, with an average male to female ratio of 1:3.30, being 1♂: 3.85♀ for type A traps and 1♂: 2.94♀ for type B traps. At Milatos 1.33 males and 4.04 females per trap were recorded and the male to female ratio was 1:3.04, this ratio being 1♂:2.36♀ and 1♂:3.86♀ for type A and B traps respectively. Impressively high captures (more than 150 up to almost 250 in traps of B type and from almost 150 up to more than 350 in traps of A type) were observed from September 2009 to January 2010 with a peak of 356 and 240 on January the 15th for both A and B type traps.