AIM 3 - Aquatic Sampling Equipment

Topic Three ~ Sampling Equipment

Plankton Net

-          Towed vertically for qualitative sampling

-          60 – 110 μm mesh size

-          Volume filtered,

d = net opening diameter (m)

L = net length (m)

1m³ = 1000 liters

MTD Net

-          Towed horizontally for quantitative sampling

-          Has net holder stabilizing net + messenger ties net prevent plankton drift out

-          Mesh size replaceable

Bongo Net

-          Towed horizontally with winch & cable system

-          Mesh size 500 / 330 μm

-          Depressor weight stabilizes

-          Volume measured by flow meter

Nano plankton Net

-          Collected manually by hand

-          Near shore area (collect from surface)

-          Suitable for qualitative sampling

Flow meter

-          In all nets but nanoplankton net

-          Tied at opening, slight lower from centre

-         

n: number of rotation

d: opening diameter (m)

-          Plankton concentration or density = no/liter

Clynometer

-          Measure degree of steepness of wire tied to plankton net

-          Estimate exact depth/position

-         

L = length of submerged wire

Smith McIntyre Grab

-          Collect sediment from bottom of water body (ocean, lake, river)

-          Tied to cable control by winch

-          No messenger, shock releases lock holding arms of Van Veen grab

Ekman Grab

-          Collect sediment from bottom of water body (lake, estuaries, river)

-          Soft, fine, divided littoral; free of vegetation, intermixtures of sand, stone, coarse debris

-          Messenger present

Van Veen Grab

-          Lightweight grab

-          Soft / sandy bottoms

-          Self-releasing pinch-pin on two closing arms, tension releases upon impact

-          Scoop close when rope lifted

Box Corer

-          Large sediment quantity (coarse sea bottom / fine clay, mud, peat)

-          < 4 kg weight drove further into sediment

Niskin Water Sampler

-          Collect various depth water

-          Open, messenger released, closes

Hydrolab

-          Record hydrological data (temperature, pH, salinity, conductivity, dissolved O₂, depth, turbidity)

-          Data stored in pc for analysis

Dissolved O₂ Meter

-          Record dissolved O₂ & temperature of water

-          Portable device, suitable for shallow water (1-2m)

Valeport

-          Record current velocity (ms^-1), direction, temperature, time, salinity

-          Measure strong currents at open sea

GPS

-          Determine location (longitude, latitude) of sampling station

-          Data received from satellites (4 needed for accuracy)

-          To navigate (sampling site identification)

Fluorometer

-          Measure fluorosence

-          Intensity & wavelength of emission spectrum

Measure presence & amount specific molecules in media