Skip to main content
SpringerLink
Log in

Contrast in the importance of arrow squid as prey of male New Zealand sea lions and New Zealand fur seals at The Snares, subantarctic New Zealand

  • Original Paper
  • Published:
Marine Biology Aims and scope Submit manuscript

Abstract

New Zealand sea lions (Phocarctos hookeri) are threatened by incidental bycatch in the trawl fishery for southern arrow squid (Nototodarus sloanii). An overlap between the fishery and foraging sea lions has previously been interpreted as one piece of evidence supporting resource competition for squid. However, there is currently no consensus about the importance of squid in the diet of New Zealand sea lions. Therefore, we investigated this importance independently of spatial and temporal differences in squid availability through a simultaneous study with sympatric New Zealand fur seals (Arctocephalus forsteri), a species known to target arrow squid. Diet sampling at The Snares (48°01′S 166°32′E), subantarctic New Zealand, in February 2012 coincided with peak annual catch in the nearby squid fishery. Diets were deduced by analyses of diagnostic prey remains from scats (faeces) and casts (regurgitations). The contribution of each prey species to the diet was quantified using the per cent index of relative importance (% IRI) that combined frequency of occurrence, mass and number of prey items. Arrow squid was a minor component in sea lion scats (2 % IRI), and none was found in their casts. In contrast, arrow squid was the major component in fur seal scats and casts (93 and 99 % IRI, respectively). This study found that New Zealand sea lions ate minimal squid at a time when squid was clearly available as evidenced by the diet of New Zealand fur seals; hence, there was no indication of resource competition between sea lions and the squid fishery.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2

Similar content being viewed by others

References

  • Allum LL, Maddigan FW (2012) Unusual stability of diet of the New Zealand fur seal (Arctocephalus forsteri) at Banks Peninsula, New Zealand. N Z J Mar Freshw Res 46:91–97. doi:10.1080/00288330.2011.604336

    Article  Google Scholar 

  • Augé AA, Chilvers BL, Moore AB, Davis LS (2011) Foraging behaviour indicates marginal marine habitat for New Zealand sea lions: remnant versus recolonising populations. Mar Ecol Prog Ser 432:247–256. doi:10.3354/meps09176

    Article  Google Scholar 

  • Augé AA, Lalas C, Davis LS, Chilvers BL (2012) Autumn diet of recolonizing female New Zealand sea lions based at Otago Peninsula, South Island, New Zealand. N Z J Mar Freshw Res 46:97–110. doi:10.1080/00288330.2011.606326

    Article  Google Scholar 

  • Boren LJ, Muller CG, Gemmell NJ (2006) Colony growth and pup condition of the New Zealand fur seal (Arctocephalus forsteri) on the Kaikoura coastline compared with other east coast colonies. Wildl Res 33:497–505. doi:10.1071/WR05092

    Article  Google Scholar 

  • Bradshaw CJA, Barker RJ, Harcourt RG, Davis LS (2003) Estimating survival and capture probability of fur seal pups using multistate mark-recapture models. J Mammal 84:65–80. doi:10.1644/1545-1542(2003)084<0065:ESACPO>2.0.CO;2

    Article  Google Scholar 

  • Bray RJ, Curtis JT (1957) An ordination of the upland forest communities of Southern Wisconsin. Ecol Mono 27:325–349. doi:10.2307/1942268

    Article  Google Scholar 

  • Browne P, Laake JL, DeLong RL (2002) Improving pinniped diet analyses through identification of multiple skeletal structures in faecal samples. Fish Bull 100:423–433

    Google Scholar 

  • Cannon DY (1987) Marine fish osteology: a manual for archaeologists. Archaeology Press Simon Fraser University, Burnaby

    Google Scholar 

  • Carey PW (1998) New Zealand fur seals (Arctocephalus forsteri) at the Snares Islands: a stabilised population? N Z J Mar Freshw Res 32:113–118. doi:10.1080/00288330.1998.9516810

    Article  Google Scholar 

  • Childerhouse S, Gales N (1998) Historical and modern distribution and abundance of the New Zealand sea lion, Phocarctos hookeri. N Z J Zool 25:1–16. doi:10.1080/03014223.1998.9518131

    Article  Google Scholar 

  • Childerhouse S, Dix B, Gales N (2001) Diet of New Zealand sea lions (Phocarctos hookeri) at the Auckland Islands. Wildl Res 28:291–298. doi:10.1071/WR00063

    Article  Google Scholar 

  • Chilvers BL (2008) New Zealand sea lion Phocarctos hookeri and squid trawl fisheries: bycatch problems and management options. Endanger Species Res 5:193–204. doi:10.3354/esr00086

    Article  Google Scholar 

  • Chilvers BL (2009) Foraging locations of female New Zealand sea lions (Phocarctos hookeri) from a declining colony. NZ J Ecol 33:106–113. ISSN 0110-6465

    Google Scholar 

  • Chilvers BL (2012a) Population viability analysis of New Zealand sea lions, Auckland Islands, New Zealand’s sub-Antarctics: assessing relative impacts and uncertainty. Polar Biol 35:1607–1615. doi:10.1007/s00300-011-1143-6

    Article  Google Scholar 

  • Chilvers BL (2012b) Using life-history traits of New Zealand sea lions, Auckland Islands to clarify potential causes of decline. J Zool (Lond) 287:240–249. doi:10.1111/j.1469-7998.2012.00910.x

    Article  Google Scholar 

  • Chilvers BL, Wilkinson IS, Childerhouse S (2007) New Zealand sea lion, Phocarctos hookeri, pup production—1995 to 2006. N Z J Mar Freshw Res 41:205–213. doi:10.1080/00288330709509909

    Article  Google Scholar 

  • Chilvers BL, Amey JM, Huckstadt LA, Costa DP (2011) Investigating foraging utilization distribution of female New Zealand sea lions. Polar Biol 34:565–574. doi:10.1007/s00300-010-0915-8

    Article  Google Scholar 

  • Clarke MR (1986) A handbook for the identification of cephalopod beaks. Clarendon Press, Oxford

    Google Scholar 

  • Cortés E (1997) A critical review of methods of studying fish feeding based on analysis of stomach contents: application to elasmobranch fishes. Can J Fish Aquat Sci 54:726–738. doi:10.1139/f96-316

    Article  Google Scholar 

  • Crawley MC, Cameron DB (1972) New Zealand sea lions, Phocarctos hookeri, on the Snares Islands. N Z J Mar Freshw Res 6:127–132. doi:10.1080/00288330.1977.9515412

    Article  Google Scholar 

  • Crocker DE, Gales NJ, Costa DP (2001) Swimming speed and foraging strategies of New Zealand sea lions (Phocarctos hookeri). J Zool (Lond) 254:267–277. doi:10.1017/S0952836901000784

    Google Scholar 

  • Dellinger T, Trillmich F (1999) Fish prey of the sympatric Galápagos fur seals and sea lions: seasonal variation and niche separation. Can J Zool 77:1204–1216. doi:10.1139/z99-095

    Article  Google Scholar 

  • Dunn MR (2009) Feeding habits of the ommastrephid Nototodarus sloanii on the Chatham Rise, New Zealand. N Z J Mar Freshw Res 43:1103–1113. doi:10.1080/00288330.2009.9626533

    Article  Google Scholar 

  • Fea NI, Harcourt R, Lalas C (1999) Seasonal variation in the diet of New Zealand fur seals (Arctocephalus forsteri) at Otago Peninsula, New Zealand. Wildl Res 26:147–160. doi:10.1071/WR98024

    Article  Google Scholar 

  • Furlani D, Gales R, Pemberton D (2007) Otoliths of common Australian temperate fish: a photographic guide. CSIRO Publishing, Collingwood. doi:10.1080/10236240902916722

    Google Scholar 

  • Gales NJ (1995) New Zealand (Hooker’s) sea lion recovery plan. Threatened Species Recovery Plan Series 17. Department of Conservation, Wellington, New Zealand

  • Gales NJ, Cheal AJ (1992) Estimating diet composition of the Australian sea lion (Neophoca cinerea) from scat analysis: an unreliable technique. Wildl Res 19:447–456. doi:10.1071/WR9920447

    Article  Google Scholar 

  • Gibson DJM (1995) The New Zealand squid fishery 1979–93. N Z Fish Tech Rep 42:1–43. ISSN 0113-2180

  • Goldsworthy SD, Bulman C, Xi H, Larcombe J, Littman C (2003) Trophic interactions between marine mammals and Australian fisheries: an ecosystem approach. In: Gales N, Hindell M, Kirkwood R (eds) Marine mammals: fisheries, tourism and management issues. CSIRO Publishing, Collingwood, pp 62–99. doi:10.1071/9780643090712_04

    Google Scholar 

  • Green K, Kerry KR, Disney T, Clarke MR (1998) Dietary studies of light-mantled sooty albatrosses Phoebetria palpebrata from Macquarie and Heard Islands. Mar Ornithol 26:19–26. ISSN 1018-3337

    Google Scholar 

  • Harcourt R (2005) New Zealand fur seal. In: King KM (ed) The handbook of New Zealand mammals, 2nd edn. Oxford University Press, Melbourne, pp 225–235

    Google Scholar 

  • Harcourt RG, Bradshaw CJA, Davis LS (2001) Summer foraging behaviour of a generalist predator, the female New Zealand fur seal (Arctocephalus forsteri). Wildl Res 28:599–606. doi:10.1071/WR01045

    Article  Google Scholar 

  • Harcourt RG, Bradshaw CJA, Dickson K, Davis LS (2002) Foraging ecology of a generalist predator, the female New Zealand fur seal. Mar Ecol Prog Ser 227:11–24. doi:10.3354/meps227011

    Article  Google Scholar 

  • Hecht T (1987) A guide to the otoliths of southern ocean fishes. S Afr J Antarct Res 17:1–87

    Google Scholar 

  • Holborow J (1999) The diet of New Zealand fur seals (Arctocephalus forsteri) in southern New Zealand. Dissertation, University of Otago

  • IUCN (2012) IUCN red list of threatened species. http://www.iucnredlist.org Downloaded on 17 October 2012

  • Jackson GD, McKinnon JF (1996) Beak length analysis of arrow squid Nototodarus sloanii (Cephalopoda: Ommastrephidae) in southern New Zealand waters. Polar Biol 16:227–230. doi:10.1007/BF02329211

    Article  Google Scholar 

  • Jackson GD, Shaw AGP, Lalas C (2000) Distribution and biomass of two squid species off southern New Zealand: Nototodarus sloanii and Moroteuthis ingens. Polar Biol 23:699–705. doi:10.1007/s003000000141

    Article  Google Scholar 

  • Joy R, Tollit DJ, Laake JL, Trites AW (2006) Using simulations to evaluate reconstructions of sea lion diet from scat. In: Trites AW, Atkinson SK, DeMaster DP, Fritz LW, Gelatt TS, Rea LD, Wynne KM (eds) Sea lions of the world. Alaska Sea Grant College Program University of Alaska, Fairbanks, pp 205–221

    Chapter  Google Scholar 

  • Klages NTW (1996) Cephalopods as prey. II seals. Philos Trans R Soc Lond (Biol) 351:1045–1052. doi:10.1098/rstb.1996.0092

    Article  Google Scholar 

  • Lalas C (1997) Prey of Hooker’s sea lions Phocarctos hookeri based at Otago Peninsula New Zealand. In: Hindell M, Kemper C (eds) Marine mammal research in the Southern hemisphere vol 1: status, ecology and medicine. Surrey Beatty and Sons, Chipping Norton, pp 130–136

    Google Scholar 

  • Lalas C (2009) Estimates of size for the large octopus Macroctopus maorum from measures of beaks in prey remains. N Z J Mar Freshw Res 43:635–642. doi:10.1080/00288330909510029

    Article  Google Scholar 

  • Lalas C, Bradshaw CJA (2001) Folklore and chimerical numbers: review of a millennium of interaction between fur seals and humans in the New Zealand region. N Z J Mar Freshw Res 35:477–497. doi:10.1080/00288330.2001.9517017

    Article  Google Scholar 

  • Lalas C, Ratz H, McEwan K, McConkey SD (2007) Predation by New Zealand sea lions (Phocarctos hookeri) as a threat to the viability of yellow-eyed penguins (Megadyptes antipodes) at Otago Peninsula, New Zealand. Biol Conserv 35:235–246. doi:10.1016/j.biocon.2006.10.024

    Google Scholar 

  • Langley AD (2001) Summary of catch and effort data from the SQU 1 J, SQU 1T, and SQU 6T fisheries for 1989–90 to 1999–2000. N Z Fish Assess Rep 51:1–45. ISSN 1175-1584

    Google Scholar 

  • Last PR, Stevens JD (2009) Sharks and rays of Australia, 2nd edn. CSIRO Publishing, Collingwood

    Google Scholar 

  • Leach F (1997) A guide to the identification of fish remains from New Zealand archaeological sites. N Z J Archaeol Special Publication. ISBN-10:0473045877

  • Leach BF, Davidson JM, Horwood LM (1997a) The estimation of live fish size from archaeological cranial bones of the New Zealand blue cod Parapercis colias. Int J Osteoarchaeol 7:481–496. doi:10.1002/(SICI)1099-1212(199709/10)7:5<481:AID-OA393>3.0.CO;2-T

    Article  Google Scholar 

  • Leach F, Davidson J, Samson J, Burnside G (1997b) The estimation of live fish size from archaeological cranial bones of the New Zealand red cod Pseudophycis bachus. Tuhinga 12:17–38

    Google Scholar 

  • Leach F, Davidson J, Robertshawe M, Leach P (2001) The estimation of live fish size from archaeological cranial bones of the New Zealand Labridae. Archaeofauna 6:41–58

    Google Scholar 

  • Leung ES, Chilvers BL, Nakagawa S, Moore AB, Robertson BC (2012) Sexual segregation in juvenile New Zealand sea lion foraging ranges: implications for intraspecific competition, population dynamics and conservation. PLoS ONE 7:1–9. doi:10.1371/journal.pone.0045389

    Google Scholar 

  • Main WL (1974) Distribution and ecology of Nectocarcinus antarcticus and N. bennetti (Brachyura: Portunidae) in the New Zealand region. N Z J Mar Freshw Res 8:15–38. doi:10.1080/00288330.1974.9515489

    Article  Google Scholar 

  • Mangel M (2010) Scientific inference and experiment in ecosystem based fishery management, with application to Steller sea lions in the Bering Sea and Western Gulf of Alaska. Mar Policy 34:836–843

    Article  Google Scholar 

  • Marchant S, Higgins PJ (1990) Handbook of Australian, New Zealand & Antarctic birds, vol 1. Oxford University Press, Melbourne

    Google Scholar 

  • McConkey S, McConnell H, Lalas C, Heinrich S, Ludmerer A, McNally N, Parker E, Borofsky C, Schimanski K, McIntosh G (2002a) A northward spread in the breeding distribution of the New Zealand sea lion Phocarctos hookeri. Aust Mammal 24:97–106. doi:10.1071/AM02097

    Article  Google Scholar 

  • McConkey S, Heinrich S, Lalas C, McConnell H, McNally N (2002b) Pattern of immigration of New Zealand sea lions Phocarctos hookeri to Otago, New Zealand: implications for the management of the species. Aust Mammal 24:107–116. doi:10.1071/AM02107

    Article  Google Scholar 

  • McKenzie J, Page B, Goldsworthy SD, Hindell MA (2007) Growth strategies of New Zealand fur seals in southern Australia. J Zool 272:377–389. doi:10.1111/j.1469-7998.2006.00278.x

    Article  Google Scholar 

  • McNally (2001) New Zealand sea lion abundance, demographics and movements in southern New Zealand. Dissertation, University of Otago

  • Meynier L, Morel PCH, Chilvers BL, Mackenzie DDS, MacGibbon A, Duignan PJ (2008) Temporal and sex differences in the blubber fatty acid profiles of the New Zealand sea lion Phocarctos hookeri. Mar Ecol Prog Ser 366:271–279. doi:10.3354/meps07617

    Article  Google Scholar 

  • Meynier L, Mackenzie DDS, Duignan PJ, Chilvers BL, Morel PCH (2009) Variability in the diet of New Zealand sea lion (Phocarctos hookeri) at the Auckland Islands, New Zealand. Mar Mamm Sci 25:302–326. doi:10.1111/j.1748-7692.2008.00252.x

    Article  Google Scholar 

  • Meynier L, Morel PCH, Chilvers BL, MacKenzie DDS, Duignan PJ (2010) Quantitative fatty acid signature analysis on New Zealand sea lions: model sensitivity and diet estimates. J Mamm 91:1484–1495. doi:10.1644/09-MAMM-A-299.1

    Google Scholar 

  • Ministry for Primary Industries (2012) Arrow squid. In: Report from the fisheries assessment plenary, May 2012: stock assessments and yield estimates. Compiled by the Fisheries Science Group, Ministry for Primary Industries, Wellington, pp 55–62

  • O’Shea S (1999) The marine fauna of New Zealand: Octopoda (Mollusca: Cephalopoda). NIWA Biodivers Memoir 112:1–280

    Google Scholar 

  • Paulin C, Stewart A, Roberts C, McMillan P (2001) New Zealand fish: a complete guide. Te Papa Press, Wellington

    Google Scholar 

  • Pinkas LM, Oliphant S, Iverson ILK (1971) Food habits of albacore, bluefin tuna and bonito in Californian waters. Calif Fish Game 152:1–105. http://escholarship.org/uc/item/7t5868rd

  • Rapson AM (1969) Report on seals. In: Sorenson JH (ed) New Zealand fur seals with special reference to the 1946 open season. New Zealand Marine Department Fisheries Technical Report No. 42, pp 30–40

  • Robertson B, Chilvers BL (2011) The population decline of the New Zealand sea lion Phocarctos hookeri: a review of possible causes. Mamm Rev 41:253–275. doi:10.1111/j.1365-2907.2011.00186.x

    Article  Google Scholar 

  • Schwarzhans W (1984) Fish otoliths from the New Zealand Tertiary. N Z Geol Surv Rep 113:1–269. ISSN: 0548-9784

  • Smale MJ, Watson G, Hecht T (1995) Otolith atlas of southern African fishes. Ichthyol Monogr 1:1–253

    Google Scholar 

  • Smith MH, Baird SJ (2009) Model-based estimation of New Zealand fur seal (Arctocephalus forsteri) incidental captures and strike rates for trawl fishing in New Zealand waters for the years 1994–95 to 2005–06. New Zealand Aquatic Environment and Biodiversity Report 40

  • Smith PJ, Mattlin RH, Roeleveld MA, Okutanp T (1987) Arrow squids of the genus Nototodarus in New Zealand waters: systematics, biology and fisheries. N Z J Mar Freshw Res 21:315–326. doi:10.1080/00288330.1987.9516227

    Article  Google Scholar 

  • Sokal RR, Rohlf FJ (1995) Biometry: the principles and practice of statistics in biological research, 3rd edn. W.H. Freeman and Co., New York

    Google Scholar 

  • Street RJ (1964) Feeding habits of the New Zealand fur seal (Arctocephalus forsteri). New Zealand Marine Department Fisheries Technical Report No. 9

  • Tate ML (1981) The autumn-winter diet of the New Zealand fur seal Arctocephalus forsteri (Lesson) with special reference to its cephalopod prey. Dissertation, University of Otago

  • Thompson FN, Abraham ER (2010a) Estimation of fur seal (Arctocephalus forsteri) bycatch in New Zealand trawl fisheries, 2002–03 to 2008–09. New Zealand Aquatic Environment and Biodiversity Report 61

  • Thompson FN, Abraham ER (2010b) Estimation of the capture of New Zealand sea lions (Phocarctos hookeri) bycatch in New Zealand trawl fisheries, from 1995–96 to 2008–09. New Zealand Aquatic Environment and Biodiversity Report 66

  • Tollit DJ, Stewart MJ, Thompson PM, Pierce GJ, Santos MB, Hughes S (1997) Species and size differences in the digestion of otoliths and beaks: implications for estimates of pinniped diet composition. Can J Fish Aquat Sci 54:105–119. doi:10.1139/f96-264

    Article  Google Scholar 

  • Tollit D, Heaslip S, Deagle B, Iverson S, Joy R, Rosen D, Trites A (2006) Estimating diet composition in sea lions: which technique to use? In: Trites AW, Atkinson SK, DeMaster DP, Fritz LW, Gelatt TS, Rea LD, Wynne KM (eds) Sea lions of the world. Alaska Sea Grant College Program, University of Alaska Fairbanks, Fairbanks, pp 293–307

  • Uozumi Y, Ohara H (1993) Age and growth of Nototodarus sloanii (Cephalopoda: Oegopsida) based on daily increment counts in statoliths. Nippon Suisan Gakk 59:1469–1477

    Article  Google Scholar 

  • Waite JN, Burkanov VN, Andrews RD (2012a) Prey competition between sympatric Steller sea lions (Eumetopias jubatus) and northern fur seals (Callorhinus ursinus) on Lovushki Island, Russia. Can J Zool 90:110–127. doi:10.1139/z11-117

    Article  Google Scholar 

  • Waite JN, Trumble SJ, Burkanov VN, Andrews RD (2012b) Resource partitioning by sympatric Steller sea lions and northern fur seals as revealed by biochemical analyses and satellite telemetry. J Exp Mar Biol Ecol 416–417:41–54

    Article  Google Scholar 

  • Waluda CM, Trathan PN, Rodhouse PG (2004) Synchronicity in southern hemisphere squid stocks and the influence of the Southern Oscillation Index and Trans Polar Index. Fish Oceanogr 13:255–266. doi:10.1111/j.1365-2419.2004.00288.x

    Article  Google Scholar 

  • Wilkinson I, Burgess J, Cawthorn M (2003) New Zealand sea lions and squid: managing fisheries impacts on a threatened marine mammal. In: Gales N, Hindell M, Kirkwood R (eds) Marine mammals: fisheries, tourism and management issues. CSIRO Publishing, Collingwood, pp 192–207. doi:10.1071/9780643090712_10

    Google Scholar 

  • Williams R, McEldowney A (1990) A guide to the fish otoliths from waters off the Australian Antarctic Territory, Heard and Macquarie Islands. ANARE Res Notes 75:1–173

    Google Scholar 

  • Wolf N, Mangel M (2008) Multiple hypothesis testing and the declining-population paradigm in Steller sea lions. Ecol Appl 18:1932–1955

    Article  Google Scholar 

  • Xavier JC, Cherel Y (2009) Cephalopod beak guide for the Southern Ocean. British Antarctic Survey, Cambridge

    Google Scholar 

Download references

Acknowledgments

This project was funded by CL. Thanks to the crew of RV Polaris II, Bill Dickson, Phil Heseltine and Mike Kestila for logistical assistance and expedition leader Steve Wing, University of Otago. Department of Conservation staff in Invercargill were very helpful in providing permits and access to The Snares, especially Pete McClelland and Doug Veint. CL thanks Sanford Ltd for permission to collect fish otoliths and cephalopod beaks aboard trawlers. Thanks to Louise Chilvers, Department of Conservation, Wellington, for providing the age of the tagged sea lion and Hamish Bowman for bathymetric data used in Fig. 1. Estimated catch and length frequency data for southern arrow squid were provided by the Ministry for Primary Industries via Deepwater Group Ltd (with thanks to Richard Wells). Thanks to Will Rayment, Helen McConnell and three anonymous reviewers for making valuable comments and improvements to this manuscript.

Author information

Authors and Affiliations

  1. Department of Marine Science, University of Otago, PO Box 56, Dunedin, New Zealand

    Chris Lalas & Trudi Webster

Authors
  1. Chris Lalas
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Trudi Webster
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Trudi Webster.

Additional information

Communicated by U. Siebert.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lalas, C., Webster, T. Contrast in the importance of arrow squid as prey of male New Zealand sea lions and New Zealand fur seals at The Snares, subantarctic New Zealand. Mar Biol 161, 631–643 (2014). https://doi.org/10.1007/s00227-013-2366-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00227-013-2366-6

Keywords

Search

Navigation