Global overview of the major constituent-based billfish tagging programs and their results since 1954

Abstract

Release and recovery files from the world's five major constituent-based billfish (Istiophoridae) tagging programs were assembled into a single composite database. Data sources included the National Marine Fisheries Service's (NMFS) Cooperative Tagging Center (MIA) in the Atlantic Ocean, the NMFS's Cooperative Billfish Tagging Program (LJA) in the Pacific and Indian Oceans, the Australian Cooperative Tagging Program in the Pacific and Indian Oceans, the New Zealand Cooperative Game Fish Tagging Program in the Pacific Ocean, and The Billfish Foundation's (TBF) tagging program in the Atlantic, Pacific and Indian Oceans. Results for the main target species, including black marlin (Makaira indica), blue marlin (Makaira nigricans), white marlin (Tetrapturus albidus), striped marlin (Tetrapturus audax) and sailfish (Istiophorus platypterus) were compared and contrasted based on species, ocean body and tagging program. A total of over 317 000 billfish have been tagged and released, and 4122 have been recovered since 1954. Tag recovery percentages were generally higher for a recently developed doublebarb nylon anchor tag compared with the typically used stainless steel dart tag. Greatest distances moved were largest for blue marlin and black marlin, followed by striped marlin, white marlin and sailfish. The TBF program had the highest tag recovery percentages for white marlin (2.4%) and blue marlin (1.7%), whereas the MIA program had the highest percentage recovery for sailfish (1.8%). The LJA program had the highest recovery percentages for black marlin (1.9%) and striped marlin (1.4%). The annual number of releases and recoveries for each target species tended to increase over the time series, particularly during the last decade. Cyclic annual movement patterns and/or seasonal site fidelity were evident for black marlin and white marlin. The data suggest that tag recovery percentages can be affected by tag type, reporting rate, localized fishing activities, outreach activities, and a variety of logistical issues indirectly related to size of ocean body. The efficiencies of the tagging programs are compared and recommendations are made to improve the programs. The composite tagging database provides the opportunity for a more comprehensive evaluation of the data and tagging programs than has previously been possible by examining the individual programs in isolation. The main advantage of constituent-based tagging programs is that large numbers of billfish can be tagged at a minimum cost. The main drawbacks are a lack of control over the tagging event and return of recovery data. Constituent-based tagging programs provide essential data on billfish movement and biology, and should be expanded and improved to meet the increasing need for this information.

Scientists and recreational fishers: Communication manners and its efficiency

“…the quantity and quality of data collected through tagging programs may be compromised. Despite the widespread use of tagging programs in fisheries science (Ortiz et al, 2003), there is little information available about how to properly inform anglers about tagging programs and encourage their participation at the level required to obtain useful data. To ensure the recovery of tagged fish recaptured by anglers in the RRP, a series of communication activities were carried out to inform the angler community and solicit their assistance with data collection through tag returns (Table 1).…”

Assessing billfish stocks: A review of current methods and some future directions

“…Ehrhardt and Deleveaux, 2006), movement and estimates of total mortality (e.g. Ortiz et al, 2003). Unfortunately, recapture rates for tagging studies are often very low, making the data useful qualitatively, e.g.…”

“…For example, assessments for striped marlin in the North Pacific are based on the assumption of three stocks (southwest Pacific, western and central North Pacific, and eastern Pacific) derived from the results of genetics studies (e.g. Graves and McDowell, 1994;McDowell and Graves, 2008;Purcell and Edmunds, 2011), the presence of spatially-distinct spawning grounds (Bromhead et al, 2004), and the results of tagging studies (Ortiz et al, 2003), although unsurprisingly perhaps, the results from the various data sources are not in total agreement (Lee et al, 2012a).…”

Regional variation in the otolith chemistry of blue marlin (Makaira nigricans) and white marlin (Tetrapturus albidus) from the western North Atlantic Ocean

“…Several studies have documented that blue marlin and white marlin are capable of long-distance migrations (e.g., >1000 km, Ortiz et al, 2003;Orbesen et al, 2008), consisting of both transAtlantic and trans-equatorial movements Snodgrass et al, 2010). Due to the highly migratory nature of these species, mixing of individuals from different regions of the Atlantic is expected to be high.…”