LTER network Toolik Field Station MBLhome page

Sun and Moon

Toolik Weather Graphs

Arctic LTER Weather Stations

Toolik Webcam

Animated Gif of yesterday's Webcam

Arctic LTER Inhouse login

Timeline of Streams Experiments

This file describes the experimental manipulations in each stream reach for each year.


  • 1983, Kuparuk River: Phosphoric acid added at 0.0 km (approximately 1.7 km upstream of Dalton Highway crossing), increasing soluble reactive phosphorus (SRP) by 0.32 uM.
  • 1984, Kuparuk River: Phosphoric acid added at 0.0 km, increasing SRP by 0.32 uM.
  • 1985, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM.
  • 1986, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM. Phosphoric acid and ammonium sulfate added at 1.11 km, increasing SRP by 0.32 uM and N by 7.1 uM. Adult Arctic grayling densities fixed at ~100 fish/km in unfertilized and P+N-enriched 1-km reaches of the river.
  • 1987, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM.
  • 1988, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM. Adult Arctic grayling densities fixed at ~50 fish/km in unfertilized and P-enriched 1-km reaches of the river.
  • 1989, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM. Ammonium sulfate added at 1.11 km, increasing N by 7.1 uM. Adult Arctic grayling densities fixed at ~15 fish/km in an unfertilized 1-km reach and ~120 fish/km in a P+N-enriched 1-km reach.
  • 1990, Kuparuk River: Phosphoric acid added at 0.59 km, increasing P by 0.32 uM. Adult Arctic grayling confined by weirs to unfertilized and P-enriched 1-km reaches of the river.
  • 1991, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM. Stable nitrogen isotope (15-N) added at -1.5 km to trace nitrogen pathways in the Kuparuk. Adult Arctic grayling confined by weirs to unfertilized and P-enriched 1-km reaches of the river.
  • 1992, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM. Adult Arctic grayling confined by weirs to unfertilized and P-enriched 1-km reaches of the river.
  • 1993, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM. Adult Arctic grayling confined by weirs to unfertilized and P-enriched 1-km reaches of the river.
  • 1994, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM. Weir placed at 2 km to restrict Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 1995, Kuparuk River: Phosphoric acid added at 0.59 km, increasing SRP by 0.32 uM. Weir placed at -0.4 km to restrict Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 1996, Kuparuk River: Phosphoric acid added at 1.4 km, increasing SRP by 0.32 uM. The dripper was moved in order to examine the response of mosses to absence of fertilizer, from 0.59 to 1.39km. Weir placed at -0.4 km to restrict Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 1997, Kuparuk River: Phosphoric acid added at 1.4 km, increasing SRP by 0.32 uM. Second year of recovery for the 0.59 to 1.39km reach. Weir placed at -0.4 km to restrict Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 1998, Kuparuk River: Phosphoric acid added at 1.4 km, increasing SRP by 0.32 uM. Third year of recovery for the 0.59 to 1.39km reach. Weir placed at -0.4 km to restrict adult Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 1999, Kuparuk River: Phosphoric acid added at 1.4 km, increasing SRP by 0.32 uM. Forth year of recovery for the 0.59 to 1.39km reach. Weir placed at -0.4 km to restrict adult Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 2000, Kuparuk River: Phosphoric acid added at 1.4 km, increasing SRP by 0.32 uM. Fifth year of recovery for the 0.59 to 1.39km reach. Weir placed at -0.4 km to restrict adult Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 2001, Kuparuk River: Phosphoric acid added at 1.4 km, increasing SRP by 0.32 uM. Sixth year of recovery for the 0.59 to 1.39km reach. Weir placed at -0.4 km to restrict adult Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 2002, Kuparuk River: Phosphoric acid added at 1.4 km, increasing SRP by 0.32 uM. Seventh year of recovery for the 0.59 to 1.39km reach. Weir placed at -0.4 km to restrict adult Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 2003, Kuparuk River: Phosphoric acid added at 1.4 km, increasing SRP by 0.32 uM. Eighth year of recovery for the 0.59 to 1.39km reach. Weir placed at -0.4 km to restrict adult Arctic grayling movements between unfertilized and P-enriched reaches of the river.
  • 1989, Oksrukuyik Creek: Pre-fertilization year. Sampling done to study baseline conditions in the creek.
  • 1990, Oksrukuyik Creek: Pre-fertilization year. Sampling done to study baseline conditions in the creek. Adult Arctic grayling confined by weirs to a 1.1-km reach and a 0.4-km reach of the creek.
  • 1991, Oksrukuyik Creek: Phosphoric acid added at 0.0 km (approximately 2.6 km upstream of the Dalton Highway crossing), increasing SRP by 0.32 uM. Adult Arctic grayling confined by weirs to an unfertilized 1.1-km reach and a 1.8-km P-enriched reach of the creek.
  • 1992, Oksrukuyik Creek: Phosphoric acid added at 0.0 km, increasing SRP by 0.32 uM. Adult Arctic grayling confined by weirs to an unfertilized 1.1-km reach and a 1.8-km P-enriched reach of the creek.
  • 1993, Oksrukuyik Creek: Phosphoric acid and ammonium sulfate added at 0.0 km, increasing SRP by 0.32 uM and N by 7.1 uM. Adult Arctic grayling confined by weirs to an unfertilized 1.1-km reach and a 1.8-km P+N-enriched reach of the creek.
  • 1994, Oksrukuyik Creek: Phosphoric acid and ammonium sulfate added at 0.0 km, increasing SRP by 0.32 uM and N by 7.1 uM. Adult Arctic grayling confined by weirs to an unfertilized 1.1-km reach and a 1.8-km P+N-enriched reach of the creek.
  • 1995, Oksrukuyik Creek: Phosphoric acid and ammonium sulfate added at 0.0 km, increasing SRP by 0.32 uM and N by 7.1 uM. Adult Arctic grayling confined by weirs to an unfertilized 1.1-km reach and a 1.8-km P+N-enriched reach of the creek.
  • 1996, Oksrukuyik Creek: Phosphoric acid and ammonium sulfate added at 0.0 km, increasing SRP by 0.32 uM and N by 7.1 uM. Adult Arctic grayling confined by weirs to an unfertilized 1.1-km reach and a 1.8-km P+N-enriched reach of the creek.
  • 1997, Oksrukuyik Creek: Recovery year one. Phosphoric acid and ammonium sulfate were not added this season. Adult Arctic grayling confined by weirs to an unfertilized 1.1-km reach and a 1.8-km formerly P+N-enriched reach of the creek.
  • 1998, Oksrukuyik Creek: Recovery year two. Adult Arctic grayling confined by weirs to an unfertilized 1.1-km reach and a 1.8-km formerly P+N-enriched reach of the creek.
  • 1999, Oksrukuyik Creek: Recovery year three. Maintenance level monitoring of former reference reach.
  • 2000, Oksrukuyik Creek: Recovery year four. Maintenance level monitoring of former reference reach.
  • 2001, Oksrukuyik Creek: Recovery year five. Maintenance level monitoring of former reference reach.
  • 2002, Oksrukuyik Creek: Recovery year six. Maintenance level monitoring of former reference reach.
  • 2003, Oksrukuyik Creek: Recovery year seven. Maintenance level monitoring of former reference reach.

 

  • 1994, New Reach Stream (Blueberry Creek): Stable nitrogen isotope (15-N) added 0.3 km below the outlet of Lake I-8 to trace nitrogen pathways in a lake outlet stream.
  • 1995, New Reach Stream (Imnavait Creek): Stable nitrogen isotope (15-N) added roughly 150m upstream of the haul road to trace nitrogen pathways in a beaded stream.
  • 1996, New Reach Stream (Lower Kuparuk River): Stable nitrogen isotope (15-N) added roughly 7 km upstream of the spine road (approximately 15 km from the Kuparuk mouth) to trace nitrogen pathways in a large river.
  • 1997, New Reach Stream (E-1 Outlet Creek): Stable nitrogen isotope (15-N) added approximately 260m upstream of Toolik Lake to trace nitrogen pathways in a small outlet stream.
  • 1998, New Reach Streams: No intensive stable nitrogen isotope (15-N) addition experiment was performed this year. Instead, brief 15N additions were conducted on two glacial streams within a 50-miles of Toolik Lake (Trevor Branch and Gates Stream).
  • 1999, New Reach Streams (Hershey Creek): Stable nitrogen isotope (15-N) added approximately 2 km upstream of where it enters the Kuparuk River.
  • 2000, New Reach Streams (Toolik River): Stable nitrogen isotope (15-N) added approximately 1.1 km downstream of where the stream intersects the Haul Rd.
  • 2001
  • 2002, Stable nitrogen isotope (15-N) added simultaneously to Ivishak Mountain Stream and Ivishak Spring Stream. Hershey Creek: Ammonium chloride and Sodium phosphate were added approximately 620m downstream of the upper road crossing.
  • 2003
Please contact arc_im@mbl.edu with questions, comments, or for technical assistance regarding this web site.