Specifically these are my recent projects and current areas of interest:   

Invasion Ecology:  1. I am a co-author, with Dr.’s. Julie Lockwood (Rutgers) & Martha Hoopes (Mt. Holyoke) of the first textbook on invasion ecology (Blackwell Press 2006).  This undergraduate text examines all aspects of biological invasions in the language of an invasion process with multiple steps: transport, release, establishment, spread and integration.  The book was first available in 2006 2. Landscape Level Patterns of Invasion - Peter Moyle(UCD), Theo Light (Shippensburg Univ.), and Josh Viers (UCD) and I have examined how both environmental and natural history parameters influence patterns of fish invasion across the state of California.  This work may expand to include the Iberian Peninsula and New Zealand. 3. The process of biotic homogenization- Biotic homogenization is a process of contracting the species pool of a region through the dual processes of invasion and extinction, which over time creates a more homogeneous fauna.  Julie Lockwood (Rutgers), Theo Light (Shippensburg Univ) and myself have examined patterns of biotic homogenization among fishes.  4. Individual Species - for example the Sacramento Perch ( Archoplites interruptus) is California's only native Centrarchid.  This fish is basically extinct throughout its native range (the Central Valley of CA).  Part of its decline can be explained by negative interactions with introduced centrarchids (bluegill, green sunfish, largemouth bass etc).

 

Effect of Flow Alteration Its well known that the annual pattern in stream discharge often drives the dynamics of lotic systems.  Alterations to these patterns through water diversions, impoundment and discharge regulation have a profound impact on the associated aquatic communities.  Through extensive field and laboratory studies my lab has been examining the ecological impact of these types of changes for fish and macroinvertebrate assemblages:

Ecological Importance of Seasonal Tributaries California's  Mediterranean climate produces tremendous variation in stream-flow patterns.  One pattern  that has received little research attention is that of seasonally inundated tributaries, or streams that flow for only portions of the calendar year.  These tributaries are proving to be extremely important in the life history of many of our  native non-game fishes as well as the for the macroinvertebrate assemblages.

 

Larval ecology of native fishes [pictured here:prickly sculpin (Cottus asper) post-larval stage].  1. Phenology of Native Fish Larvae - Larval fish are cool and very little studied in streams, mostly because they are a pain in the rear-end to identify.  One thing my lab is studying is the distribution and abundance of fish larvae in Northern CA small streams and large rivers (Feather). 2.  Methodological Aspects of Larval fish capture - My graduate students and I are doing some work looking at visual color preference in fish larvae.

   

Ecological Effects of Invasive Species on Hawaiian Streams  In collaboration with Dan Pickard (CDFG) (pictured here) and Anne Brasher (USGS), my lab is examining the impact that multiple aquatic invaders (fish, invertebrates, amphibians and reptiles) has on the food web structure of Hawaiian streams. This picture is from a recent field class at CSU Chico where we spent 10 days sampling the aquatic fauna of streams on Kauai.

General ecology and conservation of native species: A Tule perch (Hysterocarpus traskii ) giving birth to live young.  The tule perch is the only freshwater species of the family Embiotocidae (surf perch), and  it is only found in the Central Valley of California.  Young males will be reproductively active within approximately 24 hours of being born. Surprisingly very little is known about many of California's native non-game species of fish. There are many opportunities for general ecological and natural history investigations into these species. [picture was provided by S. A. Matern]

      

Stream and lake ecology of the bioregion: There are many facinating streams and rivers in Northern California, including Eagle Lake (pictured here on a  cold limnology field trip), a Lake Lahontan relictual lake in the Great Basin.  Eagle Lake is the second largest natural lake entirely within California and the only natural lake in California that retains an entirely native fish fauna. (any guess why?  see below)

Eagle Lake Ecology: CSU Chico and UC Davis co-manage a field station on the eastern shore of Eagle Lake (Lassen County).  The station has laboratory space, two classrooms, cabins, dormatories, a dining hall, wireless internet access and a library.  Located in the northeastern corner of California Eagle Lake is relatively undisturbed and undeveloped.  The high pH of the lake (near 9) permit only five species of native fish in the lake (no exotics), including the trophy sized Eagle Lake trout.  The lake is highly productive and contains many invertebrates and attracts numerous fish-eating birds.  This view is taken from the deck behind one of the classrooms.  In conjunction with the Limnology Lab at University of Nevada Reno, we are conducting a long term study of the food web of the lake using stable isotopes