Procedures and protocol for biota sampling to determine contaminant body burdens in fish, invertebrates, and vegetation will be standardized to complement recent or current studies conducted by USFWS and CDFG.

Fish: Fish monitoring is essential for the program because of their importance in wildlife food chains and because they would indicate any potential health risk to humans. Mosquitofish (Gambusia affinis) will be selected for monitoring, as it represents the most prevalent fish inhabiting both the SLD and sloughs. Mosquitofish may not be sufficiently abundant for sampling at the San Joaquin River stations, in which case another small species such as fathead minnows (Pimephales promelas), red shiners (Cyprinella lutrensis), or inland silversides (Menidia beryllina) will be selected for sampling. All of these species are important as forage for piscivorous fish and birds inhabiting the areas adjacent to both Mud and Salt Sloughs. Changes in fish species could be made in the monitoring program if it is ascertained that other species are found more consistently at certain sites. Selection of fish species to be sent for trace element analysis will be dependent on numbers and species collected at each sampling location during each sampling quarter. Fish specimens will be collected at all biological monitoring sites by dipnetting, seining or electrofishing.

Fish samples analyzed will include three replicates of adult fish, composited by species, at each sampling site. Each replicate sample will include composited whole-body tissue samples from 5 specimens to obtain a representative sample of a minimum of 2 grams (preferably 5 grams or more) of tissue.

Gamefish: Gamefish species are expected to vary among project stations and time periods, but the most common species of larger fish will be selected for analysis (at each collection location and time). Species likely to be collected include channel catfish (Ictalurus punctatus), white catfish (Ameiurus catus), bluegill (Lepomis macrochirus), green sunfish (Lepomis cyanellus), Sacramento blackfish (Orthodon microlepidotus), and common carp (Cyprinus carpio). Selection of fish species to be sent for trace element analysis will be dependent on numbers and species collected at each sampling location during each sampling quarter. Gamefish will be collected at all biological monitoring sites where they are available (other than in the SLD) by dipnetting, seining or electrofishing. Gamefish samples analyzed will include three replicates, composited by species, at each sampling site. Each replicate sample will include composited fillets from five fish per replicate (unless it is not practical to collect that many per station where larger fish are scarce) to obtain a representative sample of at least 2 grams (preferably 5 grams or more) of tissue. Since boron is of less concern from a public health standpoint, analyses after the first year may be limited to selenium.

Invertebrates: Crayfish (Procambarus sp.), which represent an omnivorous epibenthic foraging species, will be collected at all biological monitoring stations where they are available (other than in the SLD) by dipnetting, seining or electrofishing. Crayfish samples analyzed will include three replicates, composited by species, at each location. Each replicate sample will include composited whole-body tissue samples from enough specimens to obtain a representative sample of a minimum of 2 grams (preferably 5 grams or more) of tissue.

Aquatic insects such as water boatman (Corixidae), dragonflies (Odonata), damselflies (Odonata), and back swimmers (Notonectidae), which represent important food items for breeding waterfowl, will be collected from all biological monitoring sites (A through I); insects will be collected opportunistically utilizing dip nets, kick nets, and seines. Aquatic insect sample analysis will include three replicates, composited by species, at each location. Each replicate sample will include composited whole-body tissue samples from 5 specimens to obtain a representative sample of a minimum of 2 grams (preferably 5 grams or more) of tissue. The collection of a sufficient number of target insects to provide adequate sample sizes for chemical analysis on three replicate samples will be attempted but may prove to be impractical depending on relative abundance of target species.

If sample sizes are not adequate for analysis of both selenium and boron, then selenium will receive higher priority for analysis.

Vegetation: Instream and/or stream side vegetation such as widgeon grass (Ruppia maritima), sego pondweed (Potamogeton pectinatus), smartweed (Polygonum sp.), swamp timothy (Heleochloa schoenoides), and bulrush (Scirpus sp.) will be collected once per year in the fall from all biological monitoring sites (A through I). The most appropriate vegetative species will be selected at each site on the basis of its potential for consumption by birds, its abundance, and its expected long term occurrence there. Since interpretation of monitoring data will depend more on temporal trends than spatial differences among sites, it is not necessary to monitor the same plant species at all locations. The same species should be sampled consistently at each individual site once a species has been selected for that site. Vegetation samples analyzed will include three replicates, composited by species, at each location.

Each replicate sample will include composited plant material samples from enough specimens to obtain a representative sample of a minimum of 2 grams (preferably 5 grams or more) of plant tissue.