Striped Marlin (Kajikia Audax)

I & I NSW Wild Fisheries research Program Striped Marlin (Kajikia audax)

Exploitation Status UNDEFINED

Status is yet to be determined but will be consistent with the assessment of the south-west Pacific stock by the Scientific Committee of the Central and Western Pacific Fisheries Commission.

Scientific name Standard name comment

Kajikia audax striped marlin Previously known as Tetrapturus audax.

Kajikia audax Image © I & I NSW

Background lengths greater than 250cm (lower jaw-to-fork Striped marlin (Kajikia audax) is a highly length) and can attain a maximum weight of migratory pelagic species distributed about 240 kg. Females mature between 1.5 and throughout warm-temperate to tropical 2.5 years of age whilst males mature between waters of the Indian and Pacific Oceans.T he 1 and 2 years of age. Striped marlin are stock structure of striped marlin is uncertain multiple batch spawners with females shedding although there are thought to be separate eggs every 1-2 days over 4-41 events per stocks in the south-west, north-west, east and spawning season. An average sized female of south-central regions of the Pacific Ocean, as about 100 kg is able to produce up to about indicated by genetic research, tagging studies 120 million eggs annually. and the locations of identified spawning Striped marlin spend most of their time in grounds. The south-west Pacific Ocean (SWPO) surface waters above the thermocline, making stock of striped marlin spawn predominately them vulnerable to surface fisheries.T hey are during November and December each year caught mostly by commercial longline and in waters warmer than 24°C between 15-30°S recreational fisheries throughout their range. from the east coast of Australia to Fiji and as far Commercial longline catches from the south- east as French Polynesia. Mature striped marlin west Pacific Ocean have varied between 2000 move south during summer months to feed and 4000 t since the 1960s, with large catches in cooler temperate waters off the NSW coast prior to that time peaking at about and northern New Zealand. Striped marlin are 12 000 t. Annual catches of the Commonwealth- opportunistic carnivores that predominately managed Eastern Tuna and Billfish Fishery consume small pelagic finfish and squid. (ETBF) were 359 t in 2007, 425 t in 2008 and Striped marlin grow rapidly during their first 361 t in 2009. two years of life, with about 70-75% of their Striped marlin is a popular gamefish and is maximum body length reached during this caught commonly during NSW recreational time. Male and female striped marlin grow at gamefish competitions. Harvest of striped similar rates although females tend to grow marlin by NSW recreational fisheries is slightly larger than males. Striped marlin can estimated to be less than 10% of the ETBF reach ages of at least 10 years and grow to catch. Additionally, more than 1000 striped

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marlin are tagged and released annually by Catch recreational fisheries on the east coast of Australia, with the majority of these from NSW Recreational Catch of Striped Marlin offshore waters. Over 80% of striped marlin The annual recreational harvest of striped caught by competition-based recreational marlin in NSW is likely to lie between 5 and 45 t. fisheries in NSW are tagged and released. This estimate is based upon the results of onsite Post-release mortality of recreationally-tagged surveys undertaken by I & I NSW. billfish range from 0-35% as estimated from tagging studies with post-release survival found to be higher when circle hooks were used. Competition-based recreational fisheries have altered their fishing rules to reflect this Growth Curve of Striped Marlin research with a mandatory rule in place within

gamefishing clubs that enforces the use of 250 circle hooks when using natural baits to target marlin. 200 There has been some conflict over access to the striped marlin resource between the domestic 150 longline and recreational fisheries, particularly on the south coast of NSW. These conflicts FL (cm) have been partially alleviated by a reduction 100 in longline fishing effort and reduced fishing by longliners at times and in areas where 50 there are high concentrations of gamefish vessels, particularly during recreational fishing 0 tournaments. 0 2 4 6 8 Age (Years)

Growth curve for striped marlin using parameters from Additional Notes Kopf (2010). Lengths are presented as fork length (FL). • Commercial exploitation off eastern Australia since 2006 has ranged from 10-14% of the total commercial catch of striped marlin in the Western and Central Pacific Fisheries Further Reading Commission Statistical Area. Collette, B.B., J.R. McDowell and J.E. Graves (2006). Phylogeny of recent billfishes (Xiphioidei).Bulletin of • Commonwealth status of striped marlin is Marine Science 79 (3): 455-468. uncertain based on an assessment done in the SWPO in 2006 (Langley et al., 2006). Domeier, M.L., H. Dewar and N. Nasby-Lucas (2003). Once status from other jurisdictions is better Mortality rate of striped marlin (Tetrapturus audax) caught with recreational tackle. Marine and documented, then this should be adopted for Freshwater Research 54 (4): 435-445. NSW. Graves, J.E., B.E. Luckhurst and E.D. Prince (2002). An • Local catch and catch rate information evaluation of pop-up satellite tags for estimating available (Murphy et al., 2002; Lowry & postrelease survival of blue marlin (Makaira Murphy, 2003; Park, 2007) nigricans) from a recreational fishery.Fishery Bulletin 100 (1): 134-142. • A bag limit of 1 for each marlin species (striped, black and blue) applies to NSW Graves, J.E. and A.Z. Horodysky (2008). Does hook recreational fishers. Commercial fishers choice matter? Effects of three circle hook models operating under NSW jurisdiction are on postrelease survival of white marlin. North American Journal of Fisheries Management 28 (2): prohibited from landing any species of 471-480. marlin. Holland, K., R. Brill and R.K.C. Chang (1990). Horizontal and vertical movements of Pacific blue marlin captured and released using sportfishing gear. Fishery Bulletin 88 (2): 397-402.

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Horodysky, A.Z. and J.E. Graves (2005). Application of pop-up satellite archival tag technology to estimate postrelease survival of white marlin (Tetrapturus albidus) caught on circle and straight-shank (“J”) hooks in the western North Atlantic recreational fishery.Fishery Bulletin 103 (1): 84-96. Kopf, R.K. (2010). Age, growth, and reproductive dynamics of striped marlin, Kajikia audax in the southwest Pacific Ocean. Faculty of Science. Australia, Charles Sturt University PhD Thesis: 256 pp. Langley, A., B. Moloney, D. Bromhead, K. Yokawa and B. Wise (2006). Stock Assessment of Striped Marlin (Tetrapturus audax) in the Southwest Pacific Ocean. Working Paper Sa Wp-6. 2nd Meeting of the Scientific Committee of the Western and Central Pacific Fisheries Commission, Manila, Philippines. Lowry, M. and J. Murphy (2003). Monitoring the recreational gamefish fishery off south-eastern Australia. Marine and Freshwater Research 54 (4): 425-434. Murphy, J.J., M.B. Lowry, G.W. Henry and D. Chapman (2002). The GamefishT ournament Monitoring Program - 1993 to 2000. Fisheries Final Report Series 38. Cronulla, NSW Department of Primary Industries: 93 pp. Park, T. (2007). NSW GamefishT ournament Monitoring. Final Report to Fisheries Research and Development Corporation. NSW Fisheries Final Report Series No. 94. Cronulla, NSW Department of Primary Industries: 121pp. Pepperell, J.G. and T.L.O. Davis (1999). Post-release behaviour of black marlin, Makaira indica, caught off the Great Barrier Reef with sportfishing gear.Marine Biology 135 (2): 369-380. Wilson, D., R. Curtotti, G. Begg and K. Phillips, Eds. (2009). Fishery Status Reports 2008: status of fish stocks and fisheries managed by the Australian Government. Canberra, Bureau of Rural Sciences & Australian Bureau of Agricultural and Resource Economics.

Please visit the CSIRO website, http://www.marine.csiro.au/caab/ and search for the species code (CAAB) 37 444002, common name or scientific name to find further information.

© State of New South Wales through Industry and Investment NSW 2010. You may copy, distribute and otherwise freely deal with this publication for any purpose, provided that you attribute Industry and Investment NSW as the owner.

D disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing (April 2010). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of Industry and Investment NSW or the user’s independent adviser.

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