Sea Urchin.... Anthocidaris crassispina

Physical Effects...

When there are Massive populations of Sea Urchins found in certain areas of the ocean specifically near kelp forest they can destroy large areas of the forest. This creates large areas of barren land. Kelp is used not only for nutrition by many animals but also it is used for protection and shelter by animals from there predictors.

Chemical and Geological .

There have been studies out there which have shown how the ocean it self has effected the sea urchin. A study done on two different regions (Sargassum area and Corallina area). Showed that warmed climates allow sea urchins to populate at a much faster rate then those found in colder regions. The Warmer regions are also the regions which seem to collect sea urchins for food more than other areas.

Reference: Density, growth and reproduction of the sea urchin Anthocidaris crassispina (A. Agassiz) in two different adjacent habitats, the Sargassum area and Corallina area.

Authors:YATSUYA, K ousuke

NAKAHARA, H iroyuki

Source: Fisheries Science; Apr2004, Vol. 70 Issue 2, p233-240, 8p

Recent growth of the bird population within the rocky shore areas has had a large effect on the sea urchin population. sea urchins are one of the main food supply for birds which are found in the rocky shore areas. as everything in nature there needs to be a even balance and when there is an unbalance which is being created now a lot of tings are thrown off. So in some areas where there are too many sea urchins were see the complete destruction of kelp forest then in areas where either there is extreme gathering because of human collection or because of over populated bird population then we sea an uncontrolled kelp population which causes addition environmental issues.

REFERENCE:

Spatio-temporal variation of avian foraging in the rocky intertidal food web.

Authors:

Hori, Masakazu¹
Noda, Takashi¹

Source:

Journal of Animal Ecology; Jan2001, Vol. 70 Issue 1, p122-137, 16p