Research on the biology and culture of shellfish
News about ongoing investigations
Zhao, Z., Capelle, JJ, de Smit, JC, Gerkema, T, van de Koppel, J, Yuan, L, Bouma, TJ, Boosting efficiency of mussel seed collection for ecological sustainability: identifying critical drivers and informing management (in preparation for publication). Mussel farming is closely linked to the availability of young mussels, or mussel seed. Originally, all mussel seed was collected from natural mussel seed banks and then transferred to specially designated areas to further grow into consumer mussels. From…
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…
Knowledge base
The quality of a plot is a sum of the local variation in food quantity (location relative to the sea holes and other plots), food quality, spatial variation in predators and/or competitors, current velocity, salinity, substrate (foundation), susceptibility to storms (depth) and ice cover. The quality of a mussel plot can be expressed in terms of production (mussel ton per ha.), average fish weight per plot, yield and suitable area. The yield of a mussel…
There are several interactions between mussel beds and the nutrient homeostasis in their environment. By placing plastic tunnels over mussel beds, much knowledge has been gained in the past about food intake and nutrient production in a mussel bed in the Dutch and German Wadden Sea, Eastern Scheldt and Marennes-Oléron Bay. For this purpose, water samples were taken at the inflow and outflow sides of the tunnels. By examining the difference in composition, it was…
Mussel growth, both in shell length and flesh weight, depends largely on the amount and quality of food ingested. In addition to food quality and quantity, water temperature, salinity, current velocity and wave action, mussel size and age, and competition between mussels and other (shell) animals or the presence of barnacles on the shell also play a role. The tidal range may also affect mussel growth. This is because the duration of dryness determines the…
Density-dependent processes play an important role in the self-organization of mussels and hence growth and survival rates. Mussels form spatial patterns through an interaction between competition for food and clumping together to reduce loss from predators or wave action. Because of this pattern formation, the food supply and competition pressure within a mussel bank but also within a clump of mussels is not the same everywhere. Thus, the location of a mussel within a natural…
In natural mussel beds, distinct spatial patterns can be observed from the air. Particularly in young mussel beds, bands with high mussel densities and uncovered bare sediment strips alternate. Biologists previously showed that these patterns are a form of mussels’ self-organization. In fact, the bands result from an interaction in which mussels like to clump together to form dense mates and competition among mussels for food. Mussels like to sit close together because it provides…
A mussel larva does not yet have the same digestive system as those that have already found a place on a hard substrate. Mussel larvae swim through the water where a kind of membrane with vibrating hairs called a velum traps food particles from the water. As the larva grows larger, the velum disappears and a foot develops. The larva can then no longer swim and sinks to the bottom. Using the foot, the whole…