In October, a trip was planned for the eighth-grade students of Phoenix
Country Day School. We went to Catalina Island, which is about twenty
miles of the coast of Los Angeles. We had been anticipating it for a while,
but nothing could have prepared us for the astonishing experience off
exploring the kelp forest. The most provocative part of the trip was the
four snorkels. Catalina Island is a kelp forest preserve, which made it
fascinating to find that there was little or no kelp left there. We wondered
how most of the kelp could disappear in just one year.
Given this short prologue, we were able to form an interesting thesis.
Kelp is a very fragile plant that needs its living conditions to be precise.
In order to prove this, we decided to look into kelp life in Two Harbours,
Catalina Island. Our first step in the demonstration of our thesis was
to research the kelp.
In order for kelp to survive, simple but specific conditions are necessary.
First it needs a rocky benthic habitat, so it can root its holdfast. Even
in rocky habitat, the root system of kelp is not sturdy enough to withstand
strong currents or waves. Nutrients are also vital for its survival, and
as it is a photosynthetic creature, the water needs to be clear and shallow,
allowing sunlight to penetrate. Currents bring other nutrients. Without
nutrient- rich cold water, kelp lacks the nutrients it needs. Sea urchins,
kelp’s main predator, are the last threat to its survival.
We found most of our information from books about kelp’s living
conditions and necessities. We downloaded information from websites and
transferred it to Geographical Information System, a computer program
that uses data to create maps and charts that are helpful for scientific
study. From this program, we used a sonar image layer that allowed us
to examine a picture of the seafloor, a layer that showed us the benthic
habitat, and another for the bathymetry, as well as another for sea swell
in Two Harbours. On top of all of this, we put layers of kelp from the
years of 1980, 1989, 2003, and 2004.
Now, we were ready to take a close-in look at Two Harbours. The benthic
habitat there is mostly muddy. Along the coast, the habitat is generally
consolidated cement. However, there are some strips of hummocky volcanic
rock, which is an ideal habitat for kelp. The biggest forests of kelp
were found in the hummocky volcanic rock, but some grew in the mud. The
depth of the water increased as we moved further out shore. Along the
coast, the average depth was about 0-20 feet. Since kelp thrives in water
that is 5-30 feet deep, this is where we found it. As we examined the
different kelp layers, we saw a considerable difference between the layers
so we decided to look more closely at one small point on the map. We discovered
that in 1980 there was a large, abundant circle of kelp right on top of
a hummocky volcanic rock area. In 1989, there were scattered pieces of
kelp on that same point. The kelp had completely disappeared in 2003.
The biggest surprise was that in 2004, the biggest band of kelp we had
seen so far appeared. This probably has to do with the aspects of kelp
survival that we did not study, like El Nino, which warms the water in
the ocean, sea urchins, temperature, etc…