Prevalence of interactions between Hawaiian monk seals (Nemonachus schauinslandi) and nearshore fisheries in the main Hawaiian IslandsK. S. Gobush A B D , T. A. Wurth C , J. R. Henderson B , B. L. Becker B and C. L. Littnan B
A Present address: 505 Fifth Avenue South Suite 900, Seattle, WA 98104, USA.
B Pacific Island Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 1845 Wasp Boulevard, Building 176, Honolulu, HI 96818, USA.
C Joint Institute for Marine and Atmospheric Research, 1000 Pope Road, Honolulu, HI 96822, USA.
D Corresponding author. Email: email@example.com
Pacific Conservation Biology 23(1) 25-31 https://doi.org/10.1071/PC15029
Submitted: 20 September 2015 Accepted: 17 July 2016 Published: 6 September 2016
We determine the prevalence and characteristics of interactions between the Hawaiian monk seal (Nemonachus schauinslandi) and nearshore fisheries in the main Hawaiian Islands and examine impacts to the subpopulation. We documented 139 monk seal–fisheries interactions between 1976 and 2014: 132 hookings typically involving large circle hooks accompanied by slide-bait rigging, and 7 gill-net entanglements. We individually identified 297 monk seals between 1988 and 2014 and recorded that 83 (28%) of these had at least one documented hooking or entanglement. Most individuals were aged two years or younger and a quarter of them were hooked or entangled multiple times. Documented fisheries interactions typically occurred at a monk seal’s natal island and most frequently on Kauai and Oahu. Fisheries interaction was directly implicated in 11 monk seal deaths and was slightly higher in frequency than other known mortality factors. The proportion of monk seals alive one year after a documented fisheries interaction varied by age class and ranged between 76% and 84%. Survival one year later for monk seals with a documented fisheries interaction versus matched controls (all age classes combined) was not significantly different. Nonetheless, fully understanding the scale and impacts of fisheries interactions, as well as mitigating these impacts, is important if the monk seal population of the main Hawaiian Islands is to maintain a positive growth trajectory.
Additional keywords: endangered species, entanglement, hooking, pinniped.
ReferencesBaker, J. D., and Johanos, T. C. (2002). Effects of research handling on the endangered Hawaiian monk seal. Marine Mammal Science 18, 500–512.
| Effects of research handling on the endangered Hawaiian monk seal.CrossRef |
Baker, J. D., and Johanos, T. C. (2004). Abundance of the Hawaiian monk seals in the main Hawaiian Islands. Biological Conservation 116, 103–110.
| Abundance of the Hawaiian monk seals in the main Hawaiian Islands.CrossRef |
Baker, J. D., Harting, A. L., Wurth, T. A., and Johanos, T. C. (2011). Dramatic shifts in Hawaiian monk seal distribution and abundance are predicted to result from divergent regional trends. Marine Mammal Science 27, 78–93.
| Dramatic shifts in Hawaiian monk seal distribution and abundance are predicted to result from divergent regional trends.CrossRef |
Bohlander, J., Wurth, T., and Littnan, C. L. (2016). Report on Hawaiian monk seal survey on Niihau Island, September 2015. Internal Report, US Department of Commerce, NOAA. NOAA-NMFS-PIFSC-IR-16-006, Honolulu.
Cahoon, M. (2011). The foraging ecology of monk seals in the main Hawaiian Islands. M.Sc. thesis, University of Hawaii, Honolulu.
Carretta, J. V., Olsen, E., Weller, D. W., Lang, A. R., Forney, K. A., Muto, M. M., Orr, A. J., Huber, H., Lowry, M. S., Barlow, J., Lynch, D., Carswell, L., Brownnell, R. L., and Mattila D. K. (2014). US Pacific marine mammal stock assessments: 2013. Technical Memorandum, US Department of Commerce, NOAA. NOAA-TM-NMFS-SWFSC-532, Honolulu.
Cohen, J. (1992). A power primer: quantitative methods in psychology. Psychological Bulletin 112, 155–159.
| A power primer: quantitative methods in psychology.CrossRef | 1:STN:280:DC%2BD1MvlsV2mug%3D%3D&md5=f2d020a16f7dc82295b481ff8d05478dCAS | 19565683PubMed |
International Union for the Conservation of Nature (IUCN) (2015). ‘IUCN RedList of Threatened Species (Version 2015.1).’ Available at: http://www.iucnredlist.org [accessed 15 July 2015].
Johanos, T. C., Becker, B. L., and Ragen, T. J. (1994). Annual reproductive cycle of the female Hawaiian monk seal (Monachus schauinslandi). Marine Mammal Science 10, 13–30.
| Annual reproductive cycle of the female Hawaiian monk seal (Monachus schauinslandi).CrossRef |
Johanos, T. C., Harting, A. L., Wurth, T. A., and Baker, J. D. (2014). Range-wide movement patterns of Hawaiian monk seals. Marine Mammal Science 30, 1165–1174.
| Range-wide movement patterns of Hawaiian monk seals.CrossRef |
Juvik, S. P., and Juvik J. O. (1998). ‘Atlas of Hawaii.’ (University of Hawaii Press: Honolulu, HI.)
Lewison, R. L., Crowder, L. B., Wallace, B. P., Moore, J. E., Cox, T., Zydelis, R., McDonald, S., DiMatteo, A., Dunn, D. C., Kot, C. Y., Bjorkland, R., Kelez, S., Soykan, C., Stewart, K. R., Sims, M., Boustany, A., Read, A. J., Helping, P., Nichols, W. J., and Safina, C. (2014). Global patterns of marine mammal, seabird, and sea turtle bycatch reveal taxa-specific and cumulative megafauna hotspots. Proceedings of the National Academy of Sciences of the United States of America 111, 5271–5276.
| Global patterns of marine mammal, seabird, and sea turtle bycatch reveal taxa-specific and cumulative megafauna hotspots.CrossRef | 1:CAS:528:DC%2BC2cXksVSmsL4%3D&md5=01e6507bc98ee3bfc36ba8b2845f70e1CAS | 24639512PubMed |
NMFS (National Marine Fisheries Service) (2012). Hawaiian monk seal population summaries for the main and Northwestern Hawaiian Islands 2011. NOAA Internal Report IR-12-003, 30 pp.
Meyer, C. G. (2003). An empirical evaluation of the design and function of a small marine reserve (Waikiki Marine Life Conservation District). Ph.D. thesis, University of Hawaii, Honolulu.
Read, A. J. (2008). The looming crisis: interactions between marine mammals and fisheries. Journal of Mammalogy 89, 541–548.
| The looming crisis: interactions between marine mammals and fisheries.CrossRef |
Read, A. J., Drinker, P., and Northridge, S. (2006). Bycatch of marine mammals in U.S. and global fisheries. Conservation Biology 20, 163–169.
| Bycatch of marine mammals in U.S. and global fisheries.CrossRef | 16909669PubMed |
Reeves, R. R., McClellan, K., and Werner, T. B. (2013). Marine mammal bycatch in gillnet and other entangling net fisheries, 1990 to 2011. Endangered Species Research 20, 71–97.
| Marine mammal bycatch in gillnet and other entangling net fisheries, 1990 to 2011.CrossRef |
Shester, G. G., and Micheli, F. (2011). Conservation challenges for small-scale fisheries: bycatch and habitat impacts of traps and gillnets. Biological Conservation 144, 1673–1681.
| Conservation challenges for small-scale fisheries: bycatch and habitat impacts of traps and gillnets.CrossRef |
Smith, M. K. (1993). An ecological perspective on inshore fisheries in the main Hawaiian Islands. Marine Fisheries Review 55, 34–49.
U.S. Census Bureau (2010). United States Census 2010. Available at: http://www.census.gov/prod/2010pubs.pdf [accessed 15 January 2015].