Aquatic Ecology: Cycle II Activities (2001-2011)

Trend Network for Streams: Biological Characteristics
The primary goal of the Trend Network is to systematically assess long-term trends in the quality of the Nation's streams and to relate observed trends to probable causes. The Trend Network for Streams focuses on the chemical and physical quality of stream ecosystems.

Location of Surface Water Trend Sites for Biological Characteristics

Location of Surface Water Trend Sites for Biological Characteristics

The Trend Network for Streams for the San Joaquin-Tulare Basins NAWQA is made up of 4 sites, 3 of which were previously sampled in Cycle I. The basic sampling strategy includes the collection of fish, benthic invertebrates, and algae, and the description of instream and riparian habitat. Multiple reach assessments will be conducted in 2002 at trend sites where such assessments were not made during Cycle I.

Status Assessment of Mercury
Mercury is one of the most widespread contaminants affecting our Nation's aquatic ecosystems. Fish consumption is the predominant route of exposure of methylmercury for humans and wildlife. Mercury sampling within the first cycle of the San Joaquin-Tulare Basins NAWQA was limited to analyses of total mercury typically in fish livers and in streambed sediment, which yielded limited predictability of mercury in the edible part of the fish. Results and background information from the National Pilot Study of Mercury can be found in Brumbaugh and others (2001).

The second cycle of the NAWQA includes a Mercury Assessment Study and a Mercury Topical Study. The San Joaquin-Tulare Basins NAWQA participated in the Mercury Assessment Study in the summer of 2002, which involved analysis of water, sediment and fish for methyl and total mercury at 8 sites in the SANJ study area. The Mercury Topical Study which will examine mercury cycling in detail at a small subset of mercury status sites is not a part of the SANJ study design. However, data from the status assessment will be used by this topical study and contribute to a better understanding of bioaccumulation of mercury to target gamefish species.

Location of Mercury Sites

Salt Slough at Highway 165 near Stevinson, CA (11261100)
Merced River at River Road Bridge near Newman, CA (11273500)
Merced River at McConnell State Park near Livingston, CA (372450120423300)
San Joaquin River at Patterson Bridge near Patterson, CA (11274570)
Tuolumne River at Hickman Bridge near Waterford, CA (11289800)
San Joaquin River near Vernalis, CA (11303500)
Stanislaus River at Riverbank, CA (374419120570701)
Cosumnes River at Michigan Bar, CA (11335000)