The Zebra Mussel
Zebra mussels, Dreissena polymorpha, are aggressive, small-sized mollusk, native to fresh waters in Eurasia that are up to an inch in length. Their name comes from the dark, zigzagged stripes on each shell.
Zebra mussels most likely arrived in the Great Lakes in the 1980s through ballast water that was discharged by great ships from Europe. They have spread quickly all through the Great Lakes region and into the great rivers of the eastern Mississippi drainage. They have likewise been found in Texas, Colorado, Utah, Nevada, and California. An additional Zebra Mussel species, Quagga mussels, was discovered in North America.
Effects From Zebra Mussel
Zebra Mussels play an essential role in the economy as well as the oceanic ecosystem. Firstly, Zebra Mussels filter water by consuming small plants and animals in large portions, consequently altering food webs. The result is an ecological imbalance of the water body over time.
Adverse effects of Zebra Mussels include their rapid reproduction. In large number, Zebra Mussels clog up water and drain pipes causing problems for industries and municipal water supplies. The Zebra Mussel population continues to grow, and this causes countries massive losses in trying to control them.
Why Did The Zebra Mussel Come From?
The zebra mussel, Dreissena polymorpha, is believed to have arrived in North America as a freshwater ballast stowaway in ships coming from Europe around 1986.
Ballast water is water carried in ships’ ballast tanks to increase steadiness and stability. Ballast water is needed when cargo is packed or unpacked as well as when the vessel requires extra balance during lousy weather.
When ships take on ballast water, the aquatic life in the ocean is also picked up. Discharging this ballast water releases these organisms into new areas.
Problems associated with Ballast water Ballast water has been a significant method of species introduction all across the world. Studies show that around 2700 species are transported in ships around the world per day. Therefore, it causes natural ecosystem disruptions, diseases and troubles in the economy among other problems.
Zebra Mussels have continuously continued to spread and disperse over the years, since their estimated year of introduction, 1996.
Zebra Mussel control
The European community has not been able to develop any non-toxic measures to curb the infestation of these organisms. Although Zebra Mussels have been around for over two hundred years, every discovered method of eliminating them proofs to be harmful to aquatic life.
Zebra Mussels are such a hindrance that in several parts of Europe vast populations of diving ducks have changed their patterns of migration to feed on masses of Zebra Mussels. High Mussel reproduction rates however replenished the population each year.
The species most likely to prey on Zebra Mussels are not very abundant. Studies, however, show increasing numbers of migrating ducks around Pt.Pelee in western Lake Erie which have been observed to feed on Zebra Mussels.
An overall approach of regulating the population of Zebra Mussel populations is by disturbing their reproductive process. This may be done by disrupting the harmonization of spawning by males hence females may reduce the number of fertilized eggs.