Are Bull Kelp Gametophytes Differentially Adapted to Increased Temperature in the Salish Sea
Mentor 1
Filipe Alberto
Start Date
28-4-2023 12:00 AM
Description
Rising ocean temperatures due to climate change and marine heatwaves have drastically affected bull kelp, Nereocystis luetkeana, along the Pacific Coast and in the Puget Sound. In the Salish Sea, there is a marked transition region in genetic diversity between the richer outer coast and Strait of Juan de Fuca and the impoverished inner Sounds. The overarching goal of this experiment is to understand if inner sound regions are locally adapted to their warmer summer environment. Finding if localized adaptation is a significant factor in this system is fundamental before considering a genetic enrichment conservation strategy. The goal of this study is to compare the fertility and survival of gametophytes from the two regions after being exposed to heatwave conditions. Eight pools of gametophytes separated by sex and genetic diversity level were created and exposed to three different cycles of simulated heatwaves, which had maximum temperatures of 19, 21, and 23°C, respectively. After exposure to the heatwave, we returned the gametophytes into vegetative conditions to recover before crossing. The vegetative conditions promote growth of the gametophyte but inhibit them from becoming reproductive before crossing occurs. Before crossing, we fragmented the gametophyte tissue and put it back into vegetative conditions to recover from mechanical stress. However, the crosses could not be completed because the tissue died. We believe that it was stress from fragmentation, not the heatwave, which caused these gametophytes to die. We have been able to grow the groups in vegetative conditions for seven months and both groups have produced consistent biomass which we will use to run this experiment again. Finally, our aim is to extract RNA from this experiment to compare gene expression across regions and temperature treatments.
Are Bull Kelp Gametophytes Differentially Adapted to Increased Temperature in the Salish Sea
Rising ocean temperatures due to climate change and marine heatwaves have drastically affected bull kelp, Nereocystis luetkeana, along the Pacific Coast and in the Puget Sound. In the Salish Sea, there is a marked transition region in genetic diversity between the richer outer coast and Strait of Juan de Fuca and the impoverished inner Sounds. The overarching goal of this experiment is to understand if inner sound regions are locally adapted to their warmer summer environment. Finding if localized adaptation is a significant factor in this system is fundamental before considering a genetic enrichment conservation strategy. The goal of this study is to compare the fertility and survival of gametophytes from the two regions after being exposed to heatwave conditions. Eight pools of gametophytes separated by sex and genetic diversity level were created and exposed to three different cycles of simulated heatwaves, which had maximum temperatures of 19, 21, and 23°C, respectively. After exposure to the heatwave, we returned the gametophytes into vegetative conditions to recover before crossing. The vegetative conditions promote growth of the gametophyte but inhibit them from becoming reproductive before crossing occurs. Before crossing, we fragmented the gametophyte tissue and put it back into vegetative conditions to recover from mechanical stress. However, the crosses could not be completed because the tissue died. We believe that it was stress from fragmentation, not the heatwave, which caused these gametophytes to die. We have been able to grow the groups in vegetative conditions for seven months and both groups have produced consistent biomass which we will use to run this experiment again. Finally, our aim is to extract RNA from this experiment to compare gene expression across regions and temperature treatments.
