Since 2009, the FISHSCAPE Project (Grant #1719267, 1417754, and 0902153), based at Toolik Field Station, has monitored physical, chemical, and biological parameters within three watersheds: The Kuparuk (including Toolik Lake and Toolik outlet stream); The Sagavanirktok (primarily Oksrukuyik Creek, but also including sections of the Ailish and Atigun Rivers and the Galbraith Lakes); and The Itkillik (primarily the I-Minus outlet stream, a tributary that that feeds into the Itkilik River). The goals are to understand and predict the adaptability and persistence of a key Arctic species, the Arctic grayling (Thymallus arcticus), to changing climate and hydrology. Research questions include: (1) Does landscape structure determine movement within and among watersheds; (2) do populations adapt to stream characteristics at local and regional scales; and (3) will the relative adaptability of populations determine their persistence under future climate change.
To test ideas about local adaptation, we conducted an aquatic common garden experiment at Toolik Field Station, to investigate the genetic component of phenotypic variation among Arctic grayling populations on Alaska's North Slope. This file contains the growth data.
Data set ID:
EML revision ID:
A complete list of all protocols can be found here:
Summary of FISHSCAPE Site Locations:
See sheet titles: FISHSCAPE sites 2009 - 2017
Summary of Methods:
Spawning capable adults were capture from three genetically distinct populations, Oks3, Kup, and OksZev. Average summer water temperature for these populations differed: 1) Oks3 was cold (~8°C); 2) Kup was warm (~12°C), and 3) OksZev was hot (~16°C). We fertilized eggs in the field using a sib-ship design (2 females per one male) to create families that varied in relatedness from full-sib, to half-sib, to unrelated (Families: Kup = 16, Oks3 = 6, and OksZev = 0) and raised larval fish under controlled laboratory conditions using three large water bath tanks (cold = 8°C, warm = 12°C, and hot = 16°C). We monitored survival (number alive each day), growth (total length every 5 days), and respiration (VO2 = (mg O2/min) / fish mass (g)).
Spawning capable adult Arctic grayling were captured in early June 2017 and held until spawning ready. Following LTER protocols (see above) we measured, weighed, tagged and strip-spawned females and males in order to create unique families for use in common garden experiments. We used a sib-ship experimental design, dry fertilizing the eggs of two females with milt from one male, thereby creating families that varied in relatedness from full-sib, to half-sib, to non-sib (i.e. Haugen and Vollestad 2000, Jensen et al. 2008). Fertilized eggs were disinfected using betadine solution, water hardened, then transported to Toolik Field Station for sorting into experimental treatments. We place 300 eggs from each family in individual rearing chambers within each the three treatment tanks: cold (8°C), warm (12°C), and hot (16°C), so all families were equally represented across all treatments.
Measuring survival and growth:
We examined all rearing chambers daily, removed eggs that showed signs of mortality, and counted survivors. We collected 5 to 10 individuals from each rearing chamber every five days and fixed (10% buffered formalin) and preserved (70% ethanol) the individuals for growth measurements (length) and morphometric analyses. Due to high mortality in some of the treatment tanks, particularly the hot (16°C) treatment tank, and in order to retain enough individuals to test traits at the end of the experiment, we occasionally measured live individuals by placing them in a shallow, water filled dish, digitally imaging them, and placing them back in the rearing chamber from which they came. All length were determined from photographs processed in ImageJ.
Respiration was measured at the end of the experiment using Brett-type recirculating respirometers. Each respirometer consisted of a chamber to hold the fish, a pump to circulate water within the respirometer, and a temperature compensated optical dissolved oxygen (ODO) probe . We ran the respirometers under the same experimental temperature used for the common garden treatments (8, 12, and 16°C). Fish from each treatment were acclimated to the respiration temperature for at least 12 hours prior to being tested in the respirometers. We measured background respiration for at least 10 minutes prior to introducing fish to the chamber. The first 10 minutes of each fish run were excluded to allowed fish to acclimate to the chambers
Haugen, TO and Vollestad LA. 2000. Population differences in early life-history traits in grayling. Journal of Evolutionary Biology. 13:897-905.
Jensen LF, Hansen MM, Pertoldi C, Holdensgaard G, Dons Mensberg K, and Loeschcke V. 2008. Loval adaptation in brown trout early life-history traits: implications for climate change adaptability. Proceedings of the royal society B - Biological Sciences. 275:2859–2868.
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Version 2: removed acronyms in title and absract