Patterns of lake occupancy by fish indicate different adaptations to life in a harsh Arctic environment

Abstract

Summary For six fish species sampled from 86 lakes on the Arctic Coastal Plain, Alaska, we examined whether lake occupancy was related to variables representing lake size, colonisation potential and/or the presence of overwintering habitat. We found the relative importance of each factor for a given species could be related to its ecology and adult size. The three large‐bodied migratory species, least cisco (Coregonus sardinella), broad whitefish (Coregonus nasus) and arctic grayling (Thymallus arcticus), were influenced by factors associated with the likelihood of fish recolonising lakes, including whether the lakes had a stream connection. Of the large‐bodied species, least cisco had the highest likelihood of occupancy (0.52 ± 0.05) and models provided evidence that least cisco exhibit both migratory and resident forms. Models for small‐bodied fish differed among species, indicating different niches. Ninespine stickleback (Pungitius pungitius) were the most widespread and ubiquitous of the species captured (occupancy probability = 0.97 ± 0.01); they were captured in lakes that freeze to the bottom, suggesting that they disperse widely and rapidly after the spring freshet, including colonisation of sink habitats. Alaska blackfish (Dallia pectoralis) had a lower occupancy (occupancy probability = 0.76 ± 0.05) with a distribution that reflected tolerance to harsh conditions. Slimy sculpin (Cottus cognatus) had an occupancy probability of 0.23 ± 0.06, with a distribution indicating its marine origin. Based on these patterns, we propose an overall model of primary controls on the distribution of fish on the Arctic Coastal Plain of Alaska. Harsh conditions, including lake freezing, limit occupancy in winter through extinction events while lake occupancy in spring and summer is driven by directional migration (large‐bodied species) and undirected dispersal (small‐bodied species).

The complementary role of lentic and lotic habitats for Arctic grayling in a complex stream‐lake network in Arctic Alaska

“…spawning substrate and warm temperatures) and food. Regionally, our results are supported by Haynes et al (2014) and Morris (2003), who documented Arctic grayling, least cisco (Coregonus sardinella), broad whitefish (Coregonus nasus) and burbot (Lota lota) using off-channel ephemeral habitats and shallow lakes in the Arctic Coastal Plains. Ephemeral lakes may serve similar functions, since the period of drying (and perhaps freezing) and accumulation of organic materials can precondition these habitats for periods of peak productivity when inundated just like river floodplains (Junk, Bayley & Sparks 1989).…”

“…Recognising the role of stream-lake linkages can lead to better broad-scale understanding of abundance and distribution patterns of fish in both lakes and streams (Haynes, Rosenberger, Lindberg, Whitman, & Schmutz, 2014;Pépino et al, 2017). For example, considering the presence or absence of a stream connection helped predict the species composition and occupancy of fish in Arctic lakes (Haynes et al, 2014;Laske et al, 2016).…”

Seasonal cues of Arctic grayling movement in a small Arctic stream: the importance of surface water connectivity

“…We found that the strongest peak in within-stream movement was during the spring flooding period in both years, suggesting that this annual and relatively predictable event is a critical period for Arctic grayling dispersal and seasonal habitat access. Our observations support the conceptual model of the role of flood dispersal in Arctic lakes by Haynes et al (2014).…”

“…For example, low water conditions, freezing, and anthropogenic disturbance can limit movement between habitats and have pronounced ecological effects at individual, population, and metapopulation levels (Labbe and Fausch 2000;Fagan 2002). Alternatively, periodic flooding can connect formerly isolated habitats allowing for dispersal and gene flow among metapopulations (Schlosser and Angermeier 1995;Haynes et al 2014). Thus, mechanistic explanations of fish movement in rivers and streams should include environmental variation as it may mediate both habitat connectivity and relative differences in habitat quality through time.…”

Mitochondrial DNA phylogeography of least cisco Coregonus sardinella in Alaska

“…sardinella , with a mixture of migratory and resident individuals, especially on the Arctic coastal plain. A recent model of fish occupancy in lakes on the Arctic coastal plain provides further support of this variation in life histories, with resident fishes selecting deep‐water refugia in which to overwinter and migratory fishes selecting lakes closer to the coastline, where lakes act as migratory stepping stones to marine waters (Haynes et al , ). Although some variation is shared among the three regions identified, not enough variation is maintained among regions to consider Alaskan C .…”