Invasive Species

The Lionfish which was previously unknown to America is now found  from Rhode Island to Belize.
PHOTO BY CLAUDIA NEUNER

An invasive species is one that exist in a habitat in which it does not belong. When a foreign species arrive at a new location, it can either find its new habitat unsuitable and die off or thrive and take over the habitat. The later occurs due to the lack of its predators to control its population.

Killer Algae (Caulerpa taxifolia):

PHOTO BY ANTOIE N' YEURT

The hybrid form of Caulerpa taxifolia came about due to the aquarium business. They wanted to find and bred a type of seaweed that can be used in commercially saltwater aquarium and have a attractive colour and form, making a nice backdrop for exotic fishes. However, after being exposed to chemicals and ultraviolet light for a long period of time, Caulerpa taxifolia became mutated. The species than leaked out into the environment when samples of it was transferred around. 

The hybrid seaweed is very strong and can survive in nutrients depleted areas, polluted water and in a wide range of temperature. As a result of being leaked into the environment, the species can cover the entire seabed. It produces toxins that is harmful to certain fishes and invertebrates and their eggs. Furthermore, there is hardly any marine organism that feed on it. The plant grows unrestrained and many marine organism leaves the area.  

 Zebra Mussel (Dreissena polymorpha):

PHOTO BY USFWS

The Zebra mussels were accidentally introduced by cargo ships in the North American Great Lakes from the Black Sea. Many marine species are stowed away in ship ballast and get released at the ships' destination. In the case of the Zebra mussels, it multiplied rapidly and staved out the Great Lake's native mussels species and got in the way of man made structures (e.g factory pipes and ships rudders). It has further spread to Canada and Mexico and a lot of money is spent annually to remove the species. 

References:

Cotton, K.I. 2005. Introduced Species Summary Project: Killer Algae . [ONLINE] Available at:http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Caulerpa_taxifolia.htm. [Accessed 27 October 14]

Ocean portal. 2014. 5 Invasive Species You Should Know. [ONLINE] Available at:http://ocean.si.edu/ocean-news/5-invasive-species-you-should-know. [Accessed 27 October 14].

National geographic. 2014. Marine Invasive Species. [ONLINE] Available at:http://ocean.nationalgeographic.com/ocean/critical-issues-marine-invasive-species/. [Accessed 27 October 14].