Currently browsing category


Current or completed Marsh & Associates projects

Imperial Ponds Final Report 2012

Imperial Ponds is a 19 hectare pond complex designed to provide habitat for two endangered native fish, bonytail (Gila elegans) and razorback …

Loach Minnow in Upper Blue River

Blue River is tributary to San Francisco River in the greater Gila River basin. Its headwaters are in the physiographic setting of …

Lake Havasu Bonytail: Annual Report 2014

Bonytail (Gila elegans) is federally listed as endangered and considered functionally extirpated from its historical range, and its presence in the Colorado …

Eagle Creek 2014

We sample Eagle Creek annually to collect long-term fish monitoring data. We have routinely collected 6 native fish species in the upper …

June Sucker Stocking Evaluation

June sucker Chasmistes liorus is an endangered species endemic to Utah Lake, Utah. The lake historically supported 13 native fish species, but …

Minckley Library is Online

The late W.L. Minckley, Professor of Life Sciences, Arizona State University, Tempe, amassed an extensive reprint library during his four-decade-long professional career, …

Imperial Ponds Native Fish Monitoring

Status: Ongoing

A series of ponds were constructed adjacent to the river on the U.S. Fish and Wildlife Service Imperial National Wildlife Refuge (INWR). These ponds were built to provide off-channel habitat free of nonnative fishes for the survival and reproduction of bonytail and razorback sucker. Marsh & Associates was contracted to conduct a three-year project to determine the suitability of these ponds for native fishes

Survival of Razorback Sucker Stocked into the lower Colorado River

Status:  Completed

Razorback sucker have been stocked into the lower Colorado River for nearly 30 years, but stocking was accelerated in recent years to meet requirements of a U.S. Fish and Wildlife Service Biological Opinion of lower river operations (USFWS 1997).  The purpose of this project was to assess survival of stocked fish by performing an intensive, opportunistic survey that targeted razorback sucker in approximately 282 km of river from Parker Dam downstream to Yuma.