First report of Freshwater Mold Saprolegnia on Aanaakłiq, Broad Whitefish (Coregonus nasus), in the Colville River near Nuiqsut, Alaska

Subsistence Fishing in Nuiqsut

Fishing photos

Saprolegnia Life History Summary • Saprolegnia is a freshwater mold that is responsible for

the fungal infection saprolegniosis, or Cotton Wool Disease.

• It is found in freshwater worldwide.

• Typically, this disease is an opportunistic pathogen, infecting already injured or stressed fish.

• It is able to reproduce sexually or asexually.

• Well known to infect salmonid species in Alaska

Saprolegnia Affected Area 2013–present

• Fish represent a significant contribution to the nutritional and cultural resources of the Inupiat people of the North Slope of Alaska (Braund 2010; Bacon et al. 2011).

• Subsistence fishing for Aanaakłiq takes place every month of the year, but the highest catches occur when these fish migrate upstream to spawning locations during June–October (Moulton and Pausanna 2007).

• For the village of Nuiqsut, Alaska (Figure 1), fish represent nearly one-third of the annual subsistence diet of local residents (Braund 2013).

• Aanaakłiq (Broad Whitefish, Coregonus nasus) is valued for its flavor, size, and abundance in the Colville River.

Saprolegnia Outbreak

• In October 2013, Nuiqsut fishermen began to see “sick fish” in their nets.

• These Aanaakłiq had severe cottony, white lesions covering their entire body.

• Fishermen contacted the North Slope Borough-Department of Wildlife Management (NSB-DWM) for assistance in understanding the reasons for the appearance of sick Aanaakłiq.

• NSB-DWM worked with the Alaska Department of Fish & Game-Fish Pathology Lab (ADF&G-FPL) to determine that the infection was caused by the genus Saprolegnia.

Institutions

Todd Sformo1,2, Billy Adams1, John Seigle3, Jayde Ferguson4, Raphaela Stimmelmayr1,2, Joseph H. Welch3, Leah V. Ellis3, Jason C. Leppi5,6, John C. George1

Figure 2. Life cycle of the water mold, Saprolegnia [photo courtesy of Pinterest].

Literature Cited

October 2013: • First appearance of sick Aanaakłiq in subsistence fishing nets. • ABR fishery harvest monitors (work supported by ConocoPhillips Alaska, Inc.

[CPAI]) observed dozens of sick fish in gill nets. • Samples were collected by NSB-DWM and shipped to ADF&G-FPL for analysis. Fall/Winter 2013: • ADF&G-FPL confirmed infection of Aanaakłiq by Saprolegnia. • NSB-DWM distributed Saprolegnia notice to stakeholders (Figure 3).

Fall 2014: • More Saprolegnia infected fish were caught in subsistence gill nets. • Three Aanaakłiq were sent to NSB-DWM for analysis. • ABR fishery harvest monitors observed ~10 more sick fish. Fall 2015: • ABR fish monitors observed 2 infected Aanaakłiq during fall under-ice fishery

monitoring. Summer 2016: • Graduate student from University of Alaska Fairbanks (UAF)/The Wildlife

Society(TWS ) observed infected Aanaakłiq migrating upstream on Colville River to spawning/overwintering grounds.

Fall 2016: • Several (~20–30) infected Aanaakłiq observed by fishers and by NSB-DWM and

ABR fishery monitors on the Colville River during under-ice fishery. Fall 2016: • Confirmation of a second infected subsistence species during fall under-ice

fishery. Two Pikuktuuq (Humpback Whitefish, Coregonus pidschain) were caught in gill net downstream of Nuiqsut.

Outbreak Timeline

Next Steps

The importance of subsistence fish for nutrition and cultural continuity can not be overstated for the residents of Nuiqsut. The community of Nuiqsut, the NSB-DWM, and other stakeholders (including industry) are interested in determining the driver(s) of saprolegniosis. To that end, the NSB-DWM has created an in-house working group of biologists, subsistence resource specialists, and veterinarians to study the issue.

Long-term Goal: Address concerns of local residents regarding Saprolegniosis and the potential threat that this disease may pose to future food security.

Primary research objectives: 1) Determine the timing, distribution, and frequency of Saprolegnia spp. Infections on subsistence fish. 2) Conduct necropsies to determine the health status of both normal and diseased fish. 3) Investigate possible factors (e.g., contaminants, habitat alteration, climate change) that may contribute to increased saprolegniosis in fish caught in the Colville River.

Acknowledgments

1North Slope Borough-Department of Wildlife Management; P.O. Box 69 Barrow, Alaska 99723 2Institue of Arctic Biology, University of Alaska Fairbanks ; 902 N. Koyukuk Dr., P.O. Box 57000 Fairbanks, AK 99775 3ABR, Inc.—Environmental Research and Services; P.O. Box 240268 Anchorage, Alaska 99524 4State of Alaska Fish Pathology Laboratory, Alaska Department of Fish and Game; 333 Raspberry Rd. Anchorage, Alaska 99518 6Alaska Cooperative Fish and Wildlife Research Unit, College of Fisheries and Ocean Sciences University of Alaska Fairbanks; 902 Koyukuk Ave., P.O. Box 757020 Fairbanks, AK 99775 7The Wilderness Society; 705 Christensen Dr., Anchorage, AK 99501

Todd.Sformo@north-slope.org Billy.Adams@north-slope.org jseigle@abrinc.com jayde.ferguson@alaska.gov Raphaela.Stimmelmayr@north-slope.org jwelech@abrinc.com lellis@abrinc.com jason_leppi@tws.org Craig.George@north-slope.org

Figure 1. The Colville River delta near Nuiqsut , Alaska with the area of Saprolegnia outbreak highlighted.

We wish to acknowledge the fishermen and concerned citizens of Nuiqsut, AK for raising awareness of this issue. We thank the Native Village of Nuiqsut, Kuukpikmiut Subsistence Oversight Panel (KSOP), and Kuukpik Corporation for providing information and feedback since the onset of the outbreak. We acknowledge Dr. Maureen K. Purcell and Dr. James Winton, of the Fish Health Section, United States Geological Survey- Western Fisheries Research Center, Dr. Theodore Meyers, Fisheries Scientist, (ADF&G), C. Bentz (ADF&G), and I. Dickson (ADF&G) for their technical support to date. Adrian Gall and Pam Odom of ABR provided editorial review. Finally, we would also like to thank Robyn McGhee and Lisa Pekich (CPAI) for their support during water testing and sample collection events that took place under their sponsorship during 2013 and 2016.

Figure 3. NSB-DWM notice of tests of Aanaakliq caught during the 2013 fall fishery on the Colville River.

Bacon, J. J., Hepa, T. R., Brower, H. K. B, Jr., Pederson, M., Olemaun, T.P., George, J.C., and Corrigan, B.G. 2011. Estimates of subsistence harvest for village on the North Slope of Alaska, 1994-2003. Unpubl. ms. Available at the North Slope Borough Department of Wildlife Management, Barrow, AK.

Braund, Stephen R. & Associates (SRB&A). 2010. Subsistence mapping of Nuiqsut, Kaktovik, and Barrow. Report by SRB&A, Anchorage, AK for the United States Department of the Interior, Minerals Management Service, Alaska OCS Region, Environmental Studies Program. MMS OCS Study Number 2009-003. Anchorage, AK.

Braund, Stephen R. & Associates (SRB&A). 2013. Greater Mooses Tooth 1 Development Supplemental Environmental Impact Statement: Subsistence, APPENDIX G: Overview of Nuiqsut subsistence uses. Report by SRB&A, Anchorage, AK for SLR International Corporation, Anchorage, AK. In Alpine Satellite Development Plan GMT1 Development Project Final Supplemental Environmental Impact Statement Volume 4: Appendices. Prepared by U.S. Department of the Interior Bureau of Land Management Anchorage, Alaska. October 2014.

Moulton, L., and Pausanna, J. 2007. Harvest rates for the 2006 Colville River Broad Whitefish and Burbot fisheries. Report prepared for ConocoPhillips Alaska, Inc., Anchorage, AK by MJM Research, Lopeze Island, WA..