HR: 11:30h
AN: NB22A-05 [Abstracts]
TI: Impact of Invasive Fish on Nitrogen Transport to Adjacent Stream Habitats
AU: * Tronstad, L
EM: tronstad@uwyo.edu
AF: University of Wyoming, Department of Zoology and Physiology, University of Wyoming, Laramie, WY
82071-3166 United States
AU: Hall, R
EM: bhall@uwyo.edu
AF: University of Wyoming, Department of Zoology and Physiology, University of Wyoming, Laramie, WY
82071-3166 United States
AU: Koel, T
EM: todd_koel@nps.gov
AF: Fisheries and Aquatic Sciences Section, Yellowstone Center for Resources, Yellowstone National Park,
Mammoth, WY 82190 United States
AB:
Consumers can alter in-situ ecosystem processes, but less is known about their impacts on adjacent habitats. Animals
may influence ecosystem dynamics in adjacent areas, especially if energy is exchanged between systems. Lake trout (Salvelinus namaycush) were introduced to Yellowstone Lake and are reducing the native Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri) through predation. Both trout live in Yellowstone Lake, but only cutthroat spawn in and
transport nutrients to streams. To estimate the indirect impact of lake trout on nutrient cycling in adjacent streams, we
estimated how much nitrogen cutthroat transport. Spawners supplied 100 mg NH4-N m-2d-1 prior to lake trout
when 50,000 cutthroat spawned, but only 1.8 mg NH4-N m-2d-1 to tributary streams in 2004 when 1,400 fish
spawned. In contrast, cutthroat excreted 5.9 mg NH4-N m-2d-1 in Yellowstone Lake prior to lake trout and only
1.9 mg NH4-N m-2d-1 currently. Given a 90 day spawning period, tributary streams are more impacted (8,838 mg
NH4-N m-2yr-1) than Yellowstone Lake (1,460 mg NH4-N m-2yr-1). Consumers can have large impacts not only in their primary habitat, but also in neighboring areas. Less transported nitrogen could reduce stream primary and
secondary production, and cutthroat recruitment through time.
DE: 9810 New fields (not classifiable under other headings)
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly