You are here:
Influence of predicted climage change elements on Z. japonica distribution in Washington State
Citation:
Shafer, D. AND J. E. KALDY, III. Influence of predicted climage change elements on Z. japonica distribution in Washington State. Presented at Workshop on Zostera japnica, Friday Harbor, WA, September 22 - 23, 2010.
Impact/Purpose:
Global climate change (GCC) is expected to have pronounced impacts on estuarine and marine habitats including sea level rise, increased storm intensity, increased air and water temperatures, changes in upwelling dynamics and ocean acidification.
Description:
Global climate change (GCC) is expected to have pronounced impacts on estuarine and marine habitats including sea level rise, increased storm intensity, increased air and water temperatures, changes in upwelling dynamics and ocean acidification. All of these elements are likely to impact the growth and potential distribution of the non-indigenous seagrass Zostera japonica both within the State of Washington and within the region. Understanding how Z. japonica will respond to GCC requires a thorough understanding of plant physiology and predictions of GCC effects. Furthermore, Washington State is proposing to list Z. japonica as a “noxious weed” which will allow the state to use herbicide controls for management. We present data from manipulative experiments designed to better understand how Z. japonica photosynthetic physiology responds to temperature, salinity and light. We found that Z. japonica is well adapted to moderate temperatures and salinity with maximum photosynthesis of salinity of 20. The Coos Bay population had greater Pmax and saturation irradiance (Ik) than the Padilla bay population (p < 0.001) and tolerates daily exposure to both freshwater and marine water, suggesting that this population tolerates fairly extreme environmental fluctuations. Extreme temperatures (35 °C) were generally lethal to Z. japonica populations from Padilla, Coos and Yaquina Bays. High salinity (35) had lower mortality than either salinity of 5 or 20 (p = 0.001). However, the Yaquina population had greater survival than either Padilla or Coos Bay populations (p < 0.001). Taken together, our data suggest that southern Z. japonica populations may possess greater ecological fitness and are likely to continue to expand their distribution into areas with favorable environmental characteristics. This work forms the basis of a discussion on how Z. japonica may respond to environmental changes associated with GCC.