Live rock
Live rock is a term from aquaristics that is used primarily in saltwater aquariums that are operated according to the Berlin system . Live rock consists of coral skeletons, mussel shells and other calcareous material that is colonized by organisms. It is usually taken from the reef rubble zone in tropical seas.
The transport to the points of sale is usually carried out by plane and has to be carried out quickly so that as few organisms as possible die on and in the stones. It must therefore always be kept wet or at least moist during transport.
Use and effects
High-quality live rock can be recognized on the one hand by its porous nature, on the other hand it is characterized by the growth of calcareous red algae and other types of other algae and flower animals. Due to the holey structure with a high surface and the chemical composition, live rock contributes significantly to good water values.
According to the Berlin system, 5 to 15 percent of the aquarium volume is usually covered with live rock (i.e. around 5 to 15 kg of live rock in an aquarium with a 100 liter capacity). It takes on the role of a biological filter here. The bacteria living in live rock are able to break down ammonium , nitrite and nitrate . This filter function of the live rock plays a decisive role, especially in the running-in phase of an aquarium, as the ammonium and nitrite values are particularly high in this phase. The bacteria, which the stone serves as a habitat, ensure a successful run-in phase and good water values by breaking down these harmful substances. In addition, the rock brings life to the still inanimate soil, as microorganisms move from the rock to the sand.
In addition, plants and invertebrates get into the aquarium through live rock. These include cases in which corals grew out of the stones that are under species protection and, under normal circumstances, may no longer be imported. Live rock is therefore also referred to as a lucky bag for reef aquariums.
Small crustaceans, such as amphipods , which breed in the aquarium, also serve as a nutritional basis for fish, which are otherwise more difficult to feed, and as a welcome food supplement for all other aquarium occupants.
In addition, live rock looks more natural than dead corals or raw limestone, which is partly due to the greater variety of surface vegetation.
Among the creatures brought in are often also uninvited guests, such as B. mantis shrimps , coral-eating snails and crabs , glass roses and bristle worms , which survive the long transport in the numerous cavities still filled with water.
criticism
In Europe, live rock is often offered as a by-product of construction work near coral reefs - such sales statements are hardly verifiable. The amount of rock that is produced internationally in truly environmentally friendly construction measures is only a very small part of the amount declared in this way in German trade alone. In addition to the species protection aspect of hidden, actually illegal imports of protected species, environmental protection ( overexploitation of coral reefs) and consumer protection with misleading sales statements play a role in the criticism of the growing turnover in live rock.
literature
- Fosså, SA & Nilsen, AJ (1992): Coral Reef Aquarium, Volume 1 . Birgit Schmettkamp Verlag, Bornheim.