<p> Ocean acidification can reduce survival and growth of marine larvae. However, if populations have the genetic capacity to adapt and increase their tolerance to low pH levels, then such genetic changes may offset the harmful effects of ocean acidification. I used methods in quantitative genetics to measure the genetic variance and project the potential rate of evolution for low pH tolerance in a nearshore forage-fish: the California grunion (<i> Leuresthes tenuis</i>). I raised grunion larvae across an experimental pH gradient and measured their mortality and growth rates over a 14-day interval during the early larval stage. My results indicated that low pH levels significantly decreased the survival rates of grunion larvae overall. Surprisingly, low pH levels did not significantly affect larval growth rates. However, families varied widely with respect to pH tolerance, and many families had similar mortality and growth rates in high and low pH treatments. Quantitative genetic analyses indicated that low pH tolerance had a substantial genetic basis and is highly heritable within grunion populations. These results suggest that populations of California grunion, and possibly other nearshore fishes, may adapt relatively quickly to long-term changes in ocean pH.</p><p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10600671 |
| Date | 30 September 2017 |
| Creators | Tasoff, Alexander J. |
| Publisher | California State University, Long Beach |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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