Acoustic receiver network for fish: An acoustic receiver network for fish is an ideal way to study and map the behavior and migration of both marine and freshwater fish. This acoustic receiver network is based on acoustic telemetry. With a surgical procedure, a transmitter is placed in the belly of the fish. In the Belgian part of the North Sea and the Western Scheldt, a permanent acoustic network has been installed.
Apstein net
The Apstein net is a ring net with a funnel shape and a small haze specially designed to fertilize plankton. The plankton is collected in a removable cylinder where the sides are covered with sieve mesh. The Apstein net is mainly used for freshwater studies.
Compared to the CalCoFi and WP2 plankton net, this is a remarkably small and light plankton net.
Batcoder
Batcorders are used to record the activity of bats. They do this by recording the ultrasonic sounds that bats emit to orient themselves and locate their prey (echolocation). Because these ultrasonic signals are characteristic of each bat species, these signals are used as a taxonomic marker. In this way, the batcorder is the way to study the ecology of bats.
Bongonet
A bongonet consists of two plankton nets mounted side by side. These plankton nets are ring nets with a small mesh size and a long funnel shape. Both nets are closed by a cylinder (cod-end) that collects the plankton. The bongonet is pulled horizontally by a research vessel in the water column. A bongonet allows the researcher to work with two different mesh sizes at the same time.
Beam trawl
A beam trawl consists of fishing net held open by a steel beam ("beam") with two steel plates ("shoes") at its ends. Behind the steel beam hangs a net that ends in a kind of bag in which the fish catch is collected. A beam trawl is towed across the seabed by a research vessel (or fishing boat) and is mainly used to catch shrimp, flatfish or fish that live near the seabed.
Plate net
A plate net consists of a large fishing net pulled along the seafloor or in the pelagic by a vessel. The mouth of the net is held open by two large boards (board net) located along both sides of the net. In the vertical direction, the net is held open by a row of floats.
The otter net is mainly used to catch roundfish living above the bottom such as whiting and cod. When the otter net is deployed for pelagic use, fish such as herring, sprat, horse mackerel, etc. are caught.
Hydrophone network for cetaceans using C-PODs
A C-POD is a hydrophone, a device that converts underwater sounds into electrical pulses. A C-POD is used to determine, within a radius of 200-400 m, the occurrence of toothed whales (Odontoceti).
Anno 2017, eight C-PODs are operational in the Belgian part of the North Sea. They form a hydrophone network that records the presence of porpoises and dolphins. This network has been active since 2014.
CalCoFi plankton net
A CalCoFi plankton net is a ring net with a small mesh size and it has a long funnel shape. The net is closed by a cylinder (cod-end) that collects the plankton. A CalCofi plankton net is towed horizontally by a research vessel and it is mainly used for research on the larger mesozooplankton.
The CalCoFi plankton net can sometimes be confused with the WP2 plankton net. There are three major differences between these two nets: (1) the diameter of the net opening is different; CalCoFi nets are larger than the WP2 nets. (2) the mesh size of the net is different; CalCoFi net has a mesh size of 1 mm while a WP2 net has a mesh size of 200 µm. (3) The CalCoFi net is pulled horizontally by a research vessel while the WP2 net is raised and lowered vertically in the water.
Flow cytometer
A flow cytometer is an instrument used for counting and studying microscopic particles (cells) occurring in a flowing fluid. Characteristics such as the relative size, internal structures and relative fluorescence intensity of the cell can be determined thanks to this instrument. In marine biology, this device is extremely useful: the natural fluorescence of algal cells is used to study the composition and distribution of phytoplankton.
FlowCAM
The FlowCAM is a device intended for the semi-automatic identification of particles, between 2µm and 2 mm. It visualizes - mainly - phytoplankton based on morphological properties and fluorescence, although the FlowCAM can also be used for the analysis of zooplankton. The FlowCAM has its permanent location in the Ostend Marine Station, the lab facilities of the VLIZ. But the device can also be deployed aboard the research vessel Simon Stevin.
Gilson dredge
The Gilson dredge consists of a kind of plow with a net behind it. This instrument is towed by a research vessel and is mainly used for sampling rough substrates, for example for sampling oysters and shells. The Gilson dredge also appears to be efficient for collecting archaeological artifacts. The treble is not suitable for sampling fish. The Gilson dredge provided by the VLIZ is a replica of the dredge designed by Professor Gustave Gilson (1859-1944).
Hamon grab
A Hamon grab is an instrument used for taking bottom samples. These bottom samples may contain coarse-grained or mixed sediment (including small boulders/stones). The bottom samples are usually used for particle size analysis or macrobenthos surveys. From a research vessel, a Hamon grab is brought to the seafloor where the sediment is "grabbed" and contained by a 90° rotational movement of a grab (bucket).
Hyperbenthic sled
A hyperbenthic sled is used to collect hyperbenthos (organisms living at some height above the sea floor). The sled is divided into two compartments, each equipped with a hyperbenthos net. This allows a distinction to be made between the hyperbenthos close to the seabed (<50 cm) and those just a little higher (between 50 and 100 cm above the bottom).
Measuring buoy
A measuring buoy is an anchoring floating object in which measuring instruments are placed. The VLIZ installed a measurement buoy at the level of the artificial reef in the C-Power wind farm, on the Belgian part of the North Sea. A CTD is mounted in the buoy for the continuous measurement of seawater temperature and salinity supplemented by sensors to determine turbidity, current, dissolved oxygen, acidity (pH) and seawater productivity. An acoustic telemetry-based receiver network to monitor the behavior and movement patterns of fish around the artificial reefs is also attached to the buoy. A C-POD, designed to detect the presence of toothed whales, was also attached to it. The presence of a permanent monitoring station at a fixed point adds value to marine research.
Microscopes
Microscopes are widely used optical instruments within marine sciences. They allow small organisms to be studied where it is difficult or impossible to do so with the naked eye. The VLIZ has two binocular microscopes (Leica DM500 and DM1000) and two stereo microscopes (Leica M80 and M205a).
Multi-corer
A multi-corer is an instrument to which a series of drill cores are attached. These drill cores can take undisturbed soil samples. The multi-corer is set up from a survey vessel with a metal cable. The use of this instrument is particularly useful for investigating variations in local fauna. Samples can also be taken from the sediment-seawater interface.
Spooling table
The spooling table is a commonly used instrument when collecting macrobenthos. This instrument is set up on the aft deck of a research vessel. The sediment sample to be examined is washed up on the washer table, using a jet of water, so that the sediment is washed away and infauna can be collected for examination.
Reineck box corer
A Reineck box corer (also called a "spade corer") is one of the most widely used and simplest instruments for taking sediment cores in the sea. This device is set up from a research vessel and brought to the seafloor using a metal cable. The Reineck box corer is suitable for any water depth and takes a virtually undisturbed bottom sample. From this, smaller subsamples can be taken that are used for biological studies, geochemical analyses, interstitial water studies or environmental impact evaluation.
Sediment profile imaging (SPI)
Sediment Profile Imaging (SPI) is a device that images the top layers of the seafloor through a vertical cross section. This technique allows researchers to take high-resolution images of the bottom-water interface from sediments in a much faster and more efficient manner than traditional sampling techniques (box cores, piston cores, etc.). The SPI can image 15 to 20 cm of the sediment surface. This image provides both quantitative and qualitative information about the biological (bioturbation, epifauna), chemical (redox depths) and physical (stratification, human/natural disturbance) character of the sediment. By taking a series of images over different time periods, one can obtain information about how organisms behave or how the structure of the sediment changes over time. The SPI can be used for both marine and freshwater systems as well as in estuaries up to a depth of 4000 m.
Large-bird sensor network
To promote the monitoring of habitat use and migration patterns of large birds, a high-tech transmitter network was set up as part of the Flemish contribution to the LifeWatch infrastructure. VLIZ is responsible for the installation, maintenance and data flows of the transmitter network. Herring gull, lesser black-backed gull and marsh harrier are monitored by this sensor network.
Such research on migration patterns and habitat use is usually based on observations of individuals with color-rings. However, these data are heavily influenced by the location of the observations (densely populated areas, areas where rings can be easily read, etc.) and thus a sensor network for large birds is an appropriate addition!
Underway data acquisition system aboard the RV Simon Stevin
An underway data acquisition system has been installed in the dry lab, aboard the research vessel Simon Stevin. The pumped seawater, flows through a system of sensors that measures various characteristics of the seawater such as temperature, salinity, turbidity, oxygen, nutrients, surface pCO2 and fluorescence. The respective sensors are: a thermosalinograph, oxygen sensor, optical nitrate sensor, surface pCO2 sensor, flow cytometer, fluorimeter and a fast repetition rate fluorimeter. The data obtained by this flow-through system serves to support the marine science research carried out on board and adds value to long-term marine sequences.
Van Veen grab
A Van Veen grab takes (disturbed) sediment samples, to a depth of 15 cm, from the seabed. When brought to the bottom, this grab can "bite" sediment using the grab halves. The Van Veen grab is primarily used to study macrofauna and is less suitable for sampling (1) coarse-grained substrate, (2) harder bottoms, and (3) in an environment where strong currents occur.
Vertical plankton net - WP2
A vertical plankton net - Working Party (WP)2 is a ring net with a small mesh size and it has a long funnel shape. The net is closed by a cylinder (cod-end) that collects the plankton. A vertical plankton net - WP2 is dropped vertically into the water from a research vessel. It is mainly used to investigate the vertical/diagonal stratification of plankton. Thus, among other things, the abundance and distribution of mesozooplankton can be determined.
The WP2 plankton net can sometimes be confused with the CalCoFi plankton net. There are three major differences between these two nets: (1) the diameter of the net opening is different; CalCoFi nets are larger than the WP2 nets. (2) The mesh size of the net is different; CalCoFi net has a mesh size of 1 mm while a WP2 net has a mesh size of 200 µm. (3) The CalCoFi net is pulled horizontally by a research vessel while the WP2 net is raised and lowered vertically in the water.
Video plankton recorder
A video planton recorder (VPR) is essentially an underwater microscope that takes images of the plankton (100 µm to a few cm). With this device, scientists can examine the distribution patterns of plankton and taxa with delicate shapes can be monitored (these delicate taxa are sometimes destroyed during sampling using plankton nets). In addition, the VPR can also be used in combination with CTD measurements to investigate the distribution of plankton in relation to varying environmental factors.
Zooscan
The zooSCAN is a device used to (1) take digital images of zooplankton samples, (2) process and analyze zooplankton samples in a rapid and semi-automated manner, and (3) collect data from rapidly degenerating gelatinous plankton. Because zooplankton are at the base of the food chain and the composition of zooplankton species is sometimes used to estimate water ecology, the zooSCAN offers a great advantage especially in analyzing large sample sets.