Purity Pred PTN-SW Shallow-Water Plankton Net

Overview

The Purity Pred PTN-SW Shallow-Water Plankton Net is a field-deployable, manually operated plankton sampling instrument engineered for standardized vertical and stratified collection of zooplankton, ichthyoplankton (fish eggs and larval fish), and larger phytoplankton in freshwater and marine environments up to 30 meters depth. Designed in accordance with internationally recognized plankton sampling protocols—including those referenced in ISO 20665:2018 (Water quality — Guidance on sampling of plankton) and ASTM D5116–22 (Standard Guide for Laboratory Design for Environmental Chamber Testing)—the PTN-SW series employs a conical net geometry optimized for hydrodynamic efficiency and minimal flow distortion during descent and ascent. Its robust 316 stainless steel structural components resist corrosion in brackish and saline conditions, while the precisely calibrated mesh aperture ensures taxon-selective retention without excessive clogging or mechanical damage to fragile specimens.

Key Features

• Three interchangeable configurations (PTN-SW1, PTN-SW2, PTN-SW3) tailored to distinct plankton size classes—macrozooplankton/ichthyoplankton (0.505 mm), mesozooplankton/dinoflagellates (0.160 mm), and net phytoplankton/microalgae (0.077 mm)
• Full-body construction using 10 mm diameter 316 stainless steel hoops and rigid conical framing for dimensional stability under tension and current-induced drag
• Seamless, low-tension nylon monofilament mesh with certified pore uniformity (±2% tolerance per ISO 472:2013) and traceable calibration documentation
• Detachable 316 stainless steel collecting tube with threaded cap and silicone O-ring seal, enabling sterile sample transfer and immediate fixation in situ
• Integrated suspension eyelet compatible with standard marine-grade winch systems and manual hand-haul deployment
• Optional sinkers (5 kg and 10 kg variants) with hydrodynamically shaped profiles to minimize lateral drift and ensure near-vertical descent trajectories

Sample Compatibility & Compliance

The PTN-SW series supports compliant sampling across regulatory and research frameworks requiring traceable, reproducible biological capture. It is routinely deployed in studies aligned with EPA Method 240.1 (Phytoplankton Enumeration), ICES Cooperative Research Report No. 329 (Zooplankton Sampling Guidelines), and EU Water Framework Directive (WFD) monitoring programs. The 0.077 mm mesh (PTN-SW3) captures diatoms, dinoflagellates, and colonial cyanobacteria; the 0.160 mm variant (PTN-SW2) retains copepod nauplii, rotifers, and noctiluca; while the 0.505 mm configuration (PTN-SW1) recovers cladocerans, adult copepods, fish eggs, and early-stage larvae. All materials meet USP Class VI biocompatibility requirements for environmental sample integrity, and the 316 stainless steel components conform to ASTM A240/A240M for corrosion resistance in chloride-rich media.

Software & Data Management

As a non-electronic, mechanically operated sampling tool, the PTN-SW requires no embedded firmware or proprietary software. However, it integrates seamlessly into digital field data workflows via companion metadata templates compliant with Darwin Core (DwC) and OBIS-ENV-DATA standards. Users may log deployment parameters—including depth strata, GPS coordinates, water temperature, salinity, time stamps, and mesh specification—using mobile applications such as QField or Ocean Data Logger (ODL), ensuring FAIR (Findable, Accessible, Interoperable, Reusable) data practices. Audit trails for sinker mass verification, mesh certification batch numbers, and pre/post-deployment visual inspections can be archived within LIMS platforms supporting ISO/IEC 17025:2017 documentation requirements.

Applications

• Long-term ecological monitoring of reservoirs, lakes, estuaries, and coastal bays under national and regional WFD or Clean Water Act mandates
• Baseline biodiversity assessment for Environmental Impact Assessments (EIAs) prior to hydroelectric, aquaculture, or offshore infrastructure development
• Ichthyoplankton surveys supporting fisheries stock assessments and larval dispersal modeling
• Algal bloom surveillance programs targeting harmful algal species (HABs) including Alexandrium, Pseudo-nitzschia, and Cylindrospermopsis
• Method validation studies comparing net-based capture efficiency against in situ imaging systems (e.g., ZooScan, UVP5) and molecular metabarcoding pipelines

FAQ

What is the maximum recommended towing speed for the PTN-SW series?

For optimal retention efficiency and minimal net deformation, a vertical descent/ascent rate of 0.3–0.5 m/s is recommended. Horizontal towing is not advised due to uncontrolled mouth opening dynamics.
Can the PTN-SW be used in turbid or high-sediment environments?

Yes—its open-cone design and stainless steel frame resist abrasion from suspended solids. Mesh clogging is mitigated by periodic rinsing with filtered seawater between depths.
Is mesh certification documentation provided with each unit?

Each PTN-SW net is supplied with a traceable calibration certificate specifying nominal aperture, measured pore distribution (via image analysis per ISO 472), and batch-specific material test reports for 316 stainless steel components.
How should the collecting tube be prepared for preservation of live samples?

Pre-chill the tube and add buffered glutaraldehyde (1–2% final concentration) or Lugol’s iodine solution (1% final) immediately upon retrieval to fix morphology and inhibit bacterial degradation.
Are replacement mesh kits available for field repair?

Yes—Purity offers OEM-certified mesh replacement kits (including hoop alignment jigs and crimping tools) with full technical support for on-site maintenance under GLP-compliant conditions.