Rockweed Geological, Chemical, and Physical Interactions

Geological - Rockweed inhabits all intertidal zones across all shores in the North Atlantic, ranging from North America all the way around Greenland to Northwest Europe. It uses holdfasts to attach itself to rocks along the rocky shores in these areas.

Chemical - Rockweed plays a major part in maintaining the quality of the water in its environment. It does this by removing nutrients as well as metals such as zinc, arsenic, and copper. In addition to this, rockweed converts inorganic nutrients like nitrate and phosphate, and converts it to organic matter using energy from the sun. This benefits the marine life that comes to graze on the rockweed so they can get vital nutrients, as well as live in good quality water. Rockweed also has a very high tolerance to temperature as well as a low tolerance to salinity. This is a determining factor in where rockweed lives.

Physical - Along rocky shores, parts of rockweed breaks off and gets deposited by the tides along the shore where it serves as a feeding ground for some bacteria as well as zooplankton and some invertebrates. This forms the basis of the marine food chain in the rocky shore environment. Rockweed also serves to provide shelter and protection to the organisms that use it as a home against predators, waves, as well as temperature fluctuations. In addition to this, rockweed is also used by humans as a fertilizer and a food source, and is harvested for these reasons.

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

Works Cited

Hori, Masakazu, and Takashi Noda. "Spatio-temporal variation of avian foraging in the rocky intertidal food web." Journal of Animal Ecology 70.1 (2001): 122-137. Academic Search Premier. EBSCO. Web. 5 May 2011.

Peterson, Roger. The Birds. New York: Time-Life Books, 1969. Print.

Pitelka, Frank. Shorebirds in Marine Environments. Lawrence: Allen Press Inc., 1979. Print.

Physical

• A major prey of marine birds are the sea-urchins that migrate from sub-tidal to intertidal habitat.
• The main factors that influence what the birds eat are:

Waves
Tides
Currents

• All of these combined determine where the bird will have to search for food, and when.
  

Chemical

• The supraorbital gland is used to deal with the salt the birds encounter from feeding on crustaceans. Like humans, these marine birds cannot have all of that extra salt in their bodies.
• This gland removes the sodium chloride from the bloodstream very efficiently. This gland is 5x more effective than the human kidney.
• The supraorbital gland is located above the birds right eye, and filters the salt out of the bird when it enters the body.
• The excess salt is secreted as a byproduct through its bill. This makes the bird appear to have a runny nose, and the bird may even sneeze to get rid of this excess salt.
  

Geology

• Marine birds can be found along the rocks of the intertidal rocky shore.
• The birds make their nests along these rocks for a few reasons. First, they provide a nice stable base and provide protection from the wind. Secondly, they help the birds to blend in with their surrounding environment, and protects them from predators.
• Building the nests along the rocks also provide an observation point for searching the water below for food.