benthic sampling

Knowledge graph centered on benthic sampling with 73 nodes and 180 connections. Top connected: Rocky Mountain Biological Laboratory, Gothic, Beetles, Crested Butte, Pekania pennanti.

Method synopsis

Plastic pan traps with soapy water deployed along stream transects to capture terrestrial invertebrates falling into or near the river. Traps are pooled by transect and processed for taxonomic identification and biomass measurement.

Synthesized from method descriptions across 41 papers using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Nonconsumptive effects of Brook Trout predators reduce secondary production of mayfly prey (2020), Freshwater Science. The protocol was originally introduced by Sampling stream invertebrates using electroshocking techniques: implications for basic and applied research (2001), Canadian Journal of Fisheries and Aquatic Science. Implementations in other papers (listed below) may differ.

1. Quantitative sampling of mayfly larvae
   Collected 3 samples at each 150-m reach on each sampling date. Sample locations were determined by randomly choosing a meter mark within each of the upper, middle, and lower sections of the 150-m study reach. Used area-restricted electroshocking with a custom-built Hess-style sampler with mesh size of 250 μm and sample area of 0.104 m². Applied continuous pulsed DC waveform (60 pulses/s, pulse width = 6 ms) with voltage ranging from 300 to 600 V depending on stream water conductivity.
   Quantities: 3 samples per reach per date, 150 m reach length, 0.104 m² sample area, 250 μm mesh, 11 total sampling dates, 60 pulses/s, 6 ms pulse width, 300-600 VDuration: 90 s shocking time per sample, sampling every 8 to 14 days from June to SeptemberConditions: Stream conditions, voltage adjusted based on water conductivity
   Equipment: backpack electrofisher fitted with 15-cm anode, custom-built Hess-style sampler, 250 μm mesh collection net
2. Laboratory processing of mayfly samples
   Preserved each sample individually in 70% ethanol in the field. In laboratory, counted all Baetis B larvae and measured the total length of each individual to the nearest 0.1 mm. Scored sex of each individual ≥3.0 mm in length based on presence or absence of developing secondary eyes. Used sex-specific length–mass regressions for Baetis B mayflies to calculate biomass as ash-free dry mass (AFDM).
   Quantities: 0.1 mm measurement precision, 3.0 mm minimum size for sexing, 70% ethanol concentration

Typical Equipment

• plastic pan traps
• metal poles
• non-scented colorless soap
• 250-micron sieve
• sample bottles
• magnification glasses
• glass vials
• ethanol
• dry oven

Output Measurements

• terrestrial invertebrate abundance
• invertebrate dry mass
• order-level taxonomy

Papers Using This Protocol (41)

Species Studied With This Protocol

Places Where Used