2023
Georgakakos, PB; Dralle, DN; Power, ME
Spring temperature predicts upstream migration timing of invasive Sacramento pikeminnow within its introduced range Journal Article
In: Environ Biol Fish, vol. 106, pp. 2069–2082, 2023.
Abstract | Links | BibTeX | Tags: ERCZO, migration, Sacramento pikeminnow
@article{Georgakakos2023,
title = {Spring temperature predicts upstream migration timing of invasive Sacramento pikeminnow within its introduced range},
author = {PB Georgakakos and DN Dralle and ME Power},
doi = {https://doi.org/10.1007/s10641-023-01486-y},
year = {2023},
date = {2023-11-23},
urldate = {2023-11-23},
journal = {Environ Biol Fish},
volume = {106},
pages = {2069–2082},
abstract = {Rapid climate change and invasive species introductions threaten ecological communities across the globe. Freshwaters are particularly vulnerable and impacted, especially when these stresses coincide. We document the migration of an invasive piscine predator, the Sacramento pikeminnow (Ptychocheilus grandis), within its introduced range, the South Fork Eel River, California, USA. Snorkel surveys and temperature monitoring in 2015–2019 showed that pikeminnow migrate upstream during spring and early summer, with earlier migration in warmer years. We developed a statistical temperature model to forecast the timing and extent of upstream migration by pikeminnow under varying combinations of discharge and air temperature. Modeled river temperature increased with air temperature and downstream and decreased with discharge. In years with low discharge and high air temperature, we predict pikeminnow will move upstream earlier, increasing spatial and temporal overlap in their summer range with native fishes. Managing conditions that reduce pikeminnow co-occurrence with native fishes (i.e., decreasing river temperature) could increase amount and duration of predator-free habitat for native fishes. We predict invasive pikeminnow will have larger impacts on invaded riverine communities with global warming and increasing drought severity. Knowledge of life history and phenology, for pikeminnow and other organisms, can guide effective management as conditions change and help to limit adverse impacts of introduced organisms on native species.},
keywords = {ERCZO, migration, Sacramento pikeminnow},
pubstate = {published},
tppubtype = {article}
}
Rapid climate change and invasive species introductions threaten ecological communities across the globe. Freshwaters are particularly vulnerable and impacted, especially when these stresses coincide. We document the migration of an invasive piscine predator, the Sacramento pikeminnow (Ptychocheilus grandis), within its introduced range, the South Fork Eel River, California, USA. Snorkel surveys and temperature monitoring in 2015–2019 showed that pikeminnow migrate upstream during spring and early summer, with earlier migration in warmer years. We developed a statistical temperature model to forecast the timing and extent of upstream migration by pikeminnow under varying combinations of discharge and air temperature. Modeled river temperature increased with air temperature and downstream and decreased with discharge. In years with low discharge and high air temperature, we predict pikeminnow will move upstream earlier, increasing spatial and temporal overlap in their summer range with native fishes. Managing conditions that reduce pikeminnow co-occurrence with native fishes (i.e., decreasing river temperature) could increase amount and duration of predator-free habitat for native fishes. We predict invasive pikeminnow will have larger impacts on invaded riverine communities with global warming and increasing drought severity. Knowledge of life history and phenology, for pikeminnow and other organisms, can guide effective management as conditions change and help to limit adverse impacts of introduced organisms on native species.
2021
Georgakakos, Philip B.
2021.
Abstract | Links | BibTeX | Tags: aquatic ecosystems, ERCZO, O. mykiss, pacific lamprey, Rana boylii, river communities, Sacramento pikeminnow, steelhead trout
@phdthesis{Georgakakos2021,
title = {Impacts of Native and Introduced Species on Native Vertebrates in a Salmon-Bearing River Under Contrasting Thermal and Hydrologic Regimes},
author = {Philip B. Georgakakos},
url = {https://media.proquest.com/media/hms/PFT/2/1qTlI?_s=%2Bx7JvOkubzD%2B%2Bv%2B6Qi79aySM%2FUc%3D},
year = {2021},
date = {2021-03-01},
abstract = {As organisms undergo life history transitions, track resources, avoid stress, and evade death, they distribute themselves across landscapes. Organismal co-occurrence sets the stage for biotic interactions, which can feedback to control the distribution and abundance of interacting species in ecological communities. Classically, competition and bottom-up forces have been thought to be the most important drivers of community structure, however, examples of predation, parasitism, mutualism, and facilitation highlight the ubiquity and importance of these other interactions. In freshwaters, anthropogenic impacts, especially species introductions and climate warming, have resulted in novel species assemblages, with altered webs of interactions compared to historic conditions. Human management often seeks to provide conditions that favor native species and inhibit non-natives. Success requires an understanding species interactions and their roles in community dynamics. In my first chapter, I describe the distributional dynamics of the assemblage of aquatic fishes, reptiles and amphibians in the South Fork Eel River. In Chapter 2, I describe the seasonal migration of an introduced predatory fish, Sacramento Pikeminnow (Ptychocheilus grandis), and how climate warming and water withdrawals could increase their negative impact on rearing native salmonids and other fauna.In Chapter 3, my colleagues and I explore the positive interactions between Pacific Lamprey(Entosphenus tridentatus), juvenile Steelhead trout (Oncorhynchus mykiss), and Foothill Yellow-legged Frogs(Rana boylii). These case studies emphasize the need to consider ecological interactions, and in general, community ecology thinking, as we try to restore and manage ecosystems},
keywords = {aquatic ecosystems, ERCZO, O. mykiss, pacific lamprey, Rana boylii, river communities, Sacramento pikeminnow, steelhead trout},
pubstate = {published},
tppubtype = {phdthesis}
}
As organisms undergo life history transitions, track resources, avoid stress, and evade death, they distribute themselves across landscapes. Organismal co-occurrence sets the stage for biotic interactions, which can feedback to control the distribution and abundance of interacting species in ecological communities. Classically, competition and bottom-up forces have been thought to be the most important drivers of community structure, however, examples of predation, parasitism, mutualism, and facilitation highlight the ubiquity and importance of these other interactions. In freshwaters, anthropogenic impacts, especially species introductions and climate warming, have resulted in novel species assemblages, with altered webs of interactions compared to historic conditions. Human management often seeks to provide conditions that favor native species and inhibit non-natives. Success requires an understanding species interactions and their roles in community dynamics. In my first chapter, I describe the distributional dynamics of the assemblage of aquatic fishes, reptiles and amphibians in the South Fork Eel River. In Chapter 2, I describe the seasonal migration of an introduced predatory fish, Sacramento Pikeminnow (Ptychocheilus grandis), and how climate warming and water withdrawals could increase their negative impact on rearing native salmonids and other fauna.In Chapter 3, my colleagues and I explore the positive interactions between Pacific Lamprey(Entosphenus tridentatus), juvenile Steelhead trout (Oncorhynchus mykiss), and Foothill Yellow-legged Frogs(Rana boylii). These case studies emphasize the need to consider ecological interactions, and in general, community ecology thinking, as we try to restore and manage ecosystems