File Geodatabase Feature Class
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Pacific Lamprey, anadromous, distribution, range, habitat, California, Mexico
This dataset depicts the estimated historical range and current distribution of Pacific Lamprey (Entosphenus tridentatus) in California and Mexico. It is to be used to identify areas were Pacific Lampreys should be considered in riverine management. Unfortunately, the historical record of lampreys is sparse. Early ichthyological surveys and historical accounts often did not mention lampreys, even in drainages where they were most likely present, and specimens were rarely preserved. In order to assess the potential historical range of Pacific Lamprey prior to anthropogenic alterations of the hydroscape, we utilized multiple sources of information, including: historical museum records, early scientific papers, ethnographic accounts, known elevational limits for Pacific Lamprey, elevational limits for closely related species of lamprey (Entosphenus spp.) in California, geomorphic features (e.g. waterfalls and cascades, and gradient), and suitability of habitat, as well as our own more current surveys (contact authors for details). This analysis focused on anadromous streams throughout California and Mexico, including extension of the Klamath and Smith Rivers, into southern Oregon and the Rio Santo Domingo in Baja California, Mexico. Stream lines were derived from the NHDPlusV2 medium resolution stream network. We have generally limited the analysis to larger streams (4th order and greater as defined in NHDPlusV2). The exception is for 3rd order direct coastal drainages known to have been historically or currently occupied (Reid and Goodman 2016). These drainages are included to better describe the coastal distribution, which would not be captured at the 4th order. Further hydrography was developed for the Rio Santo Domingo based on satellite imagery. However, please note Pacific Lamprey are known to occupy suitable smaller tributaries below the resolution considered in this analysis. The dataset was originally published in 2017 and is now updated as of 2021. The 2017 dataset is updated with higher resolution of distribution data in the Sacramento River drainage to include streams of 3rd order and greater below impassible dams. Streams south of Point Conception have also been modified from historical distribution in 2017 to current distribution in 2021. In this region, occupancy of streams is currently dynamic with lampreys naturally recolonizing habitats when barriers are removed and habitat conditions are suitable. Finally, we have updated the dataset to include the Rio Santo Domingo in Baja California, Mexico, the southernmost river where Pacific Lamprey have been observed.
Pacific Lamprey are culturally important to indigenous peoples throughout their range. They also play a vital role in the ecosystem, providing food for mammals, fishes and birds, as well as nutrient cycling, ecosystem engineering and serving as a prey buffer for other species. Recent observations of reduced abundance and contraction of the range of Pacific Lamprey have spurred conservation interest in the species, with increasing attention from tribes, agencies, and others. Conservation actions are often hindered by our limited understanding of historical range and current distribution. The goal of this GIS layer is to document the historic range and current distribution of the species (2021). We hope this product facilitates consideration of Pacific Lamprey in conservation actions that may improve conditions where they currently exist and facilitate re-expansion of the species into their historical habitats where feasible.
Historically, Pacific Lamprey were the most widely distributed freshwater species in western North America with a range spanning from Mexico north into Alaska. The range of Pacific Lamprey includes anadromous drainages throughout California. Current distribution is approximately half of historical range in the state, and barriers to migration represent a primary threat facing the species. We considered streams part of the current distribution if Pacific Lampreys have been documented within the last 20 years. The construction of impassible dams and other man-made structures has restricted the current distribution by blocking access to upstream habitats. This GIS layer is to be used to identify areas where Pacific Lampreys should be considered in riverine management.
Preferred citation: Reid, S.B. and D.H. Goodman. 2021. Pacific Lamprey range and distribution in California. U.S. Fish and Wildlife Service.
Support for this product was provided by Region 8 of the U.S. Fish and Wildlife Service and the California Fish Passage Forum National Fish Habitat Partnership.
Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.
Although these data and information have been processed successfully on a computer system at the U.S. Fish and Wildlife Service, no warranty expressed or implied is made regarding the accuracy or utility of the data and information on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data, and information, and aggregate use with other data and information. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data and information. The USFWS shall not be held liable for improper or incorrect use of the data and information described and/or contained herein.
Extent
| West | -125.162854 | East | -116.387356 |
| North | 43.354704 | South | 31.591276 |
| Maximum (zoomed in) | 1:5,000 |
| Minimum (zoomed out) | 1:150,000,000 |
Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.
Although these data and information have been processed successfully on a computer system at the U.S. Fish and Wildlife Service, no warranty expressed or implied is made regarding the accuracy or utility of the data and information on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data, and information, and aggregate use with other data and information. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data and information. The USFWS shall not be held liable for improper or incorrect use of the data and information described and/or contained herein.