Survival of White Marlin (Tetrapturus albidus) Released from Commercial Pelagic Longline Gear in the Western North Atlantic

To estimate postrelease survival of white marlin (Tetrapturus albidus) caught incidentally in regular commercial pelagic longline fishing operations targeting swordfish and tunas, short-duration popup satellite archival tags (PSATs) were deployed on captured animals for periods of 5-43 days. Twenty (71.4%) of 28 tags transmitted data at the preprogrammed time, including one tag that separated from the fish shortly after release and was omitted from subsequent analyses. Transmitted data from 17 of 19 tags were consistent with survival of those animals for the duration of the tag deployment. Postrelease survival estimates ranged from 63.0% (assuming all nontransmitting tags were evidence of mortality) to 89.5% (excluding nontransmitting tags from the analysis). These results indicate that white marlin can survive the trauma resulting from interaction with pelagic longline gear, and indicate that current domestic and international management measures requiring the release of live white marlin from this fishery will reduce fishing mortality on the Atlantic-wide stock

Specific identification of western Atlantic Ocean scombrids using mitochondrial DNA cytochrome C oxidase subunit I (COI) gene region sequences

Identification of scombrids (tunas, mackerels, bonitos, etc.) is difficult when morphological characters are ambiguous or missing, such as with early life history stages or tissues found in the stomachs of predators. The mitochondrial cytochrome c oxidase subunit I (COI) gene region was evaluated as a molecular marker for the specific identification of the 17 members of the family Scombridae common to the western Atlantic Ocean. A 950 base pair region in the COI gene was sequenced from up to 20 individuals of each species, and suites of nucleotide polymorphisms that unambiguously distinguish among these scombrid species were identified. A shorter 250 base pair fragment of COI proved to be sufficient for species identification and was better suited for analyzing degraded tissue samples. Scombrid larvae collected in the Florida Straits and scombrid remains in the stomachs of large pelagic predators were used to demonstrate the utility of both the long and short COI fragments

Habitat Preferences and Diving Behavior of White Marlin (Tetrapturus albidus) Released from the Recreational Rod-and-Reel and Commercial Pelagic Longline Fisheries in the Western North Atlantic Ocean: Implications for Habitat-Based Stock Assessment Models

To improve billfish assessments, researchers have applied habitat-based models that incorporate behavioral and oceanographic parameters to standardize historical catch-per-uniteffort time -series data, accounting for significant gear changes over time. However, there has been little behavioral data from Atlantic billfishes to support these models. We provide information on habitat preferences of white marlin released from recreational and commercial fisheries in the western North Atlantic. White marlin were tagged with pop-up satellite archival tags (PSATs) from recreational rod and reel (n=22) and commercial pelagic longline (n=2) fisheries between May-November 2002. Our data indicate that each surviving white marlin spent the majority of time at depths of 10m or less, with all fish displaying repetitive short duration diving behavior (less than 30 minutes) to depths of 60-100m. These dives were presumably related to foraging activities. Furthermore, the depths of many of the repetitive dives were within the range of deep-set pelagic longline gear. Longline sets targeting bigeye tuna may actually increase white marlin by-catch by placing baits at depths where this species may be highly motivated to feed. Until billfish feeding motivation is better understood, it may be premature to apply habitat-based stock assessment models to billfishes in the Atlantic Ocean

Best Practices for Commercial Vehicle Monitoring Facilities Design

The great technological advances that were made over the last decade in monitoring traffic and the increased emphasis on highway safety for truck traffic have prompted a need to determine more effective ways to monitor and inspect truck traffic. Commercial Vehicle Monitoring (CVM) facilities provide the highway community with the means of supervising truck traffic. However, in an era with limited funds and space for roadway expansion. some consideration must be given to the types of facilities needed and the most efficient way to spend the available funds. Hence, a research study was initiated to determine the successful practices for designing a new CVM facility or retrofitting or upgrading an existing facility; the findings are presented here. A questionnaire was distributed to all 50 states to identify the state of the nation with respect to the newly constructed and lately upgraded CVM facilities. This report focuses on the presentation of issues that need to be considered and addressed when designing or upgrading a CVM facility and provides a checklist of critical factors, considerations for facility components, and typical facility layouts

Genetic Analysis of Blue Marlin (Makaira nigricans) Stock Structure in the Atlantic Ocean

The genetic basis of stock structure of blue marlin (Makaira nigricans Lacepède 1802) in the Atlantic ocean was inferred from analyses of mitochondrial control region sequences. Blue marlin were collected in 1998 from 4 major geographic locations: western North Atlantic, Caribbean Sea, western South Atlantic and eastern Atlantic. Haplotype diversity (h) ranged from 0.99-1.0 and nucleotide sequence diversity (π) ranged from 0.11-0.13 within samples indicating that the control region harbors a significant amount of genetic variation. However, no significant differences were found in the spatial partitioning of genetic variation among the 4 collections; all pairwise ϕST values were negative and were therefore all taken as estimates around a true value of 0. As with previous studies of blue marlin, sequences were comprised of 2 distinct mitochondrial lineages separated by an average of 138 base pairs and ϕST between clades of 0.799 (P \u3c 0.0001). These 2 lineages were present in similar frequencies across sampling locations. Genetic data from this study support management of Atlantic blue marlin as a single, Atlantic-wide stock