Research on the biology and culture of shellfish
News about ongoing investigations
Shellfish filter the water column to get food. Several factors in the water, such as temperature, salinity, suspended solids and food availability, affect the uptake of particles from the water and thus the growth and condition of shellfish. These factors can vary greatly in an estuary or bay. Measurements in breeding plots in the Wadden Sea show significant differences in growth rates in mussels. To read more about this see: https://schelpdieren.com/2023/10/30/ruimtelijke-karakterisering-van-specifieke-voedselparameters-in-de-waddenzee/
Zhao, Z., Capelle, JJ, de Smit, JC, Gerkema, T, van de Koppel, J, Yuan, L, Bouma, TJ, Stability of subtidal mussel beds under hydrodynamic stress: A novel approach for threshold quantification and risk assessment (in preparation for publication). Determining the critical threshold for runoff (CDT) for example by flow is very important in estimating risks to ecosystems. It helps identify vulnerable areas to make management decisions. On mussel plots, some individuals or groups may be…
Knowledge base
Currently, we usually measure the threshold at which mussels are released by hydrodynamic forces in the laboratory, for example, with stream channels. But we do not yet have a practical tool that mussel farmers can use on site to measure mussel bed stability. Our goal was to develop such a tool. The ideal design would be a small framework that mussel farmers could use from their vessels. This framework has a mechanism to move mussels…
Mussel beds respond to storms in two ways: how well they can weather the storm and how quickly they recover after the storm is over. If clams return to normal quickly after a storm, they can limit the damage from the storm. But if the effects of the storm last long, it becomes more difficult for mussels to recover. Over the past 12 years, the Royal Netherlands Meteorological Institute (KNMI) has recorded 32 severe storms…
Mussels that clump together in groups are initially well protected from being washed away by currents caused by waves. However, when they are washed away, it happens in those groups, which can lead to significant loss of mussel beds or breeding plots. The release of mussels from the bottom by runoff is determined by a threshold value. When this threshold is exceeded, many mussels may be released at the same time. The occurrence of mussel…
Before the mussel larvae settle anywhere, they are carried along by the current, which is also partly determined by the prevailing wind direction. Successful establishment of mussel larvae requires a short period of calm conditions with little or no current and the absence of wave action. Breeding fall is a very crucial phase in, where the suitability of the substrate plays a major role. There are large differences between years in terms of breeding success.…
MZIs were developed for mussel seed capture. Mussel larvae scattered by the water attach themselves to the ropes or nets and grow into mussel seed. Besides mussels, there are many other hard-substrate organisms that spread through the water as larvae or spores and attach to the substrate of MZIs. Density Seed collection efficiency can be expressed as harvest per (square) meter of substrate or harvest per hectare. Over the past decade, the harvest per (square)…
Pocket pipes Fouling on the MZIs is also a common problem, resulting in less capture. One example is pocket pipes. In Canada, bagpipes are causing great damage to mussel-hanging culture. Bagpipes on MZIs can compete with mussels for space and for food. Like clams, pocket squirts are efficient filterers. Buttonpipes can filter particles as small as 1 to 2 µm from the water with their gill gut. This makes them competitors to the mussels on…