Biological Processes Monitoring Accurate predictions of climate change effects on fish cannot be made without sufficient information about the underlying biological processes that drive aquatic ecosystem functions. Monitoring changes in physical parameters will be most useful if conducted in conjunction with field-based observations and focused studies to clarify the mechanisms by which environmental variables influence populations. Baseline information on presence, abundance, life history traits, and genetic diversity of fish populations in representative watersheds must be collected and analyzed over time. While studies of arctic fish populations have been conducted in the past, a more complete body of knowledge is required before the true effects of climate change on habitat use and population success can be assessed. Future work with invertebrate productivity and shifts in the aquatic invertebrate community, measuring fish productivity, age and length at maturity, timing and extent of seasonal migrations and population status, as well as primary productivity within drainage systems would allow for evaluating the effects of habitat change on biological processes. Information on spatial variation (population-level adaptive variation) would be useful in assessing adaptive potential and whether or not some populations may be more successful in responding to change. For example, fish may be able to distribute more widely and exploit more available habitat during longer summer migratory periods, but this will go unnoticed if appropriate reference baseline information is unavailable. Increased competitive interactions with species expanding their range northward may occur, if species share habitat and have similar life history, foraging and spawning behavior, although the timeline and degree of competition is highly uncertain. Understanding the response to climate-associated habitat change may be difficult if baseline distribution, habitat use, feeding strategies, or life history traits are not sufficiently documented before these changes occur. Group members acknowledged that interspecific interactions are important, but recognized that understanding these as a function of climate change adds a level of complexity requiring understanding of physical process change, as well as biotic responses, which may be highly individualistic.
Biological Processes Monitoring Accurate predictions of climate change effects on fish cannot be made without sufficient information about the underlying biological processes that drive aquatic ecosystem functions. Monitoring changes in physical parameters will be most useful if conducted in conjunction with field-based observations and focused studies to clarify the mechanisms by which environmental variables influence populations. Baseline information on presence, abundance, life history traits, and genetic diversity of fish populations in representative watersheds must be collected and analyzed over time. While studies of arctic fish populations have been conducted in the past, a more complete body of knowledge is required before the true effects of climate change on habitat use and population success can be assessed. Future work with invertebrate productivity and shifts in the aquatic invertebrate community, measuring fish productivity, age and length at maturity, timing and extent of seasonal migrations and population status, as well as primary productivity within drainage systems would allow for evaluating the effects of habitat change on biological processes. Information on spatial variation (population-level adaptive variation) would be useful in assessing adaptive potential and whether or not some populations may be more successful in responding to change. For example, fish may be able to distribute more widely and exploit more available habitat during longer summer migratory periods, but this will go unnoticed if appropriate reference baseline information is unavailable. Increased competitive interactions with species expanding their range northward may occur, if species share habitat and have similar life history, foraging and spawning behavior, although the timeline and degree of competition is highly uncertain. Understanding the response to climate-associated habitat change may be difficult if baseline distribution, habitat use, feeding strategies, or life history traits are not sufficiently documented before these changes occur. Group members acknowledged that interspecific interactions are important, but recognized that understanding these as a function of climate change adds a level of complexity requiring understanding of physical process change, as well as biotic responses, which may be highly individualistic.
Species%20and%20Habitats%20Work%20Group%20Report_July_2012_Review.docx