Angelo Coast Range Reserve

01 Jul, 05 AM - 30 Jun, 05 AM

At present, freshwater mssels populations are declining rapidly in many regions of the United States, yet the currentl status of California's freshwter mussel populations is poorly documented, and controls on their distribution ad abundance are poorly understood. To assess and interpret changes in these mussel populations it is necessary to establish a benchmark for future studies by documenting current populations. Further,it is necessary to understand how physical variability of the river bed habitat affects variability of mussel populations in California streams. In addition to substantial pupulation declines, several factors make freshwater mussels a prticularly interesting subject ofr research, and such studies may yield unique insight int the health of California's aquatic ecosystms. Through their dependence on suitable riverine habitat, mussel poulations are potentially sensitive to environmental changes throughout a watershed. They also depend on fish hosts(including salmonids)for one stge in their reproductive cycle. Mussel individuals are also long-lived, with lifespans of up to one century. The age distribution of active mussel populations therefore may reveal information about the timing and causes of population change. The proposed research focuses strictly on two streams in the norther Coast Ranges, (S. Fork Eel and Navarro rivers) which currently have host fish and where our preliminary investigations have found mussel beds. Here we wish to establish field sites, along six reaches, for which we will ducument and characterize current mussel populations in terms of density and spatial distribution, and statistical distribution of individuals' species, size and age. The interrelations of these variables will be quantified. Further, for one of the streams(S. Fork Eel) we propse to place this informationin its proper geomorphologic context by also measuring and mapping rive channel physical properties which may be important habitt-limiting variables (including substrate type, turbidity and near-bed velocity gradients). Statistical analysis will be used to demonstrate co-variation of population traits and physical haitat (or lack thereof), and process-bsed hypotheses for such links will be offered.

Visit #5179 @Angelo Coast Range Reserve

Approved

Under Project # 4112 | Research

Freshwater mussels in California's North Coastal Streams: Crrent Status and geomorphologic controls

professional - Nature Conservancy

Reservation Members(s)

Jeanette Howard Jul 1, 2003 - Jun 30, 2004 (366 days)
Group of 2 Volunteer Jul 1, 2003 - Jun 30, 2004 (366 days)

Reserve Resources(s) | Create Invoice

HQ House 3 Jul 1, 2003 - Jun 30, 2004