Type
Text
Type
Thesis
Advisor
Baumann, Hannes | Chapman, Demian | Gobler, Christopher.
Date
2013-12-01
Keywords
Biology
Department
Department of Marine and Atmospheric Science.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76196
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Marine organisms are under pressure to adapt to anthropogenic changes that are rapidly altering ocean water chemistry. Since the Industrial Revolution, human activities have caused an increase in atmospheric CO2 which is partly absorbed by the world's oceans, thereby reducing ocean pH, aragonite and calcite saturation states in a process known as ocean acidification (OA). Concern over these changes has caused a surge in scientific interest to better understand and predict how OA affects marine organisms from single celled algae to marine calcifying invertebrates and vertebrates such as fish. Since most studies thus far have focused on short-term responses of marine organisms exposed to future CO2 levels, the long-time, i.e. | evolutionary potential for adaptation to high CO2 environments remains poorly understood. This thesis investigated the potential for evolutionary responses in the Atlantic Silverside, Menidia menidia, an abundant and ecologically important coastal forage fish with a large spatial distribution from Florida, USA to Nova Scotia, CA. Laboratory experiments have demonstrated that when reared under conditions of elevated CO2 (~2,300 µatm) larval M. menidia show increased, but not complete mortality when compared to control larvae reared at ambient CO2 (~600 µatm). This suggests that larvae from some parental lines may be resistant to these conditions. If this tolerance to high CO2 is genetically determined, at least in part, fish may adapt to OA through natural selection in the long-term. Using quantitative genetic methods (the `animal model'), I simultaneously estimated the heritability and maternal effects of larval resistance to elevated CO2. Mean days survived post-hatch (MDS) (`the trait value') was quantified on a daily basis for 1,000 fertilized eggs reared from crossing 71 parents (42 males, 29 females) caught from an undisturbed estuary on the north shore of Long Island (Poquott, 40º 57.78'N, 73º 8.22'W) at the beginning of the spawning season. This approach quantitatively assessed the species potential of responding to the selection introduced by a high CO2 environment. Heritability and maternal effects of post-hatch survival at high CO2 for 772 larvae were estimated to be 0.11±0.07 and 0.03±0.03, respectively. Therefore the potential for an evolutionary response to ocean acidification in M.menidia appears to be low, perhaps because this species already utilizes alternative adaptive mechanisms to cope with rapid environmental change in the short-term. The ability to assess the microsatellite genotypes of all individuals within the ten replicates (n =100) used in this experiment revealed that survival increased with increasing heterozygosity, allelic richness and number of parents, perhaps suggesting that larval survival is dependent on sufficient genetic variability among populations. | Marine organisms are under pressure to adapt to anthropogenic changes that are rapidly altering ocean water chemistry. Since the Industrial Revolution, human activities have caused an increase in atmospheric CO2 which is partly absorbed by the world's oceans, thereby reducing ocean pH, aragonite and calcite saturation states in a process known as ocean acidification (OA). Concern over these changes has caused a surge in scientific interest to better understand and predict how OA affects marine organisms from single celled algae to marine calcifying invertebrates and vertebrates such as fish. Since most studies thus far have focused on short-term responses of marine organisms exposed to future CO2 levels, the long-time, i.e. | evolutionary potential for adaptation to high CO2 environments remains poorly understood. This thesis investigated the potential for evolutionary responses in the Atlantic Silverside, Menidia menidia, an abundant and ecologically important coastal forage fish with a large spatial distribution from Florida, USA to Nova Scotia, CA. Laboratory experiments have demonstrated that when reared under conditions of elevated CO2 (~2,300 µatm) larval M. menidia show increased, but not complete mortality when compared to control larvae reared at ambient CO2 (~600 µatm). This suggests that larvae from some parental lines may be resistant to these conditions. If this tolerance to high CO2 is genetically determined, at least in part, fish may adapt to OA through natural selection in the long-term. Using quantitative genetic methods (the `animal model'), I simultaneously estimated the heritability and maternal effects of larval resistance to elevated CO2. Mean days survived post-hatch (MDS) (`the trait value') was quantified on a daily basis for 1,000 fertilized eggs reared from crossing 71 parents (42 males, 29 females) caught from an undisturbed estuary on the north shore of Long Island (Poquott, 40º 57.78'N, 73º 8.22'W) at the beginning of the spawning season. This approach quantitatively assessed the species potential of responding to the selection introduced by a high CO2 environment. Heritability and maternal effects of post-hatch survival at high CO2 for 772 larvae were estimated to be 0.11±0.07 and 0.03±0.03, respectively. Therefore the potential for an evolutionary response to ocean acidification in M.menidia appears to be low, perhaps because this species already utilizes alternative adaptive mechanisms to cope with rapid environmental change in the short-term. The ability to assess the microsatellite genotypes of all individuals within the ten replicates (n =100) used in this experiment revealed that survival increased with increasing heterozygosity, allelic richness and number of parents, perhaps suggesting that larval survival is dependent on sufficient genetic variability among populations. ,50 pages
Recommended Citation
Malvezzi, Alex James, "Using quantitative genetics methods to estimate heritability of larval CO2-resistance in a coastal marine fish" (2013). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2133.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2133