30.08.2008 Geology, flora and cultural heritage of LEI

Day Schedule:
7:00 Breakfast
8:30 – 10:30 Checkout snorkeling in shallows
11:00 – 12:30 Cultural and environmental history of LEI (Walk)
13:00 Lunch
14:00 – 17:00 Shore snorkel at Coral Garden
18:00 Dinner
19:00 – 20:00 Student talks from Anne U. and Henrike W.

Weather: first sunny and hot, cloudy in the afternoon
Tides: 8:07 high, 14:10 low

Details:
After a delicious breakfast we got our wetsuits at the Dive-Shop. Squeezing ourselves in, we were ready to go to the Lagoon where we had our introductionary snorkeling. The water was so shallow that we almost touched the corals with our bodies. We saw a huge diversity of animals like sandy sea cucumber (Holothuria atra), long skinny sea cucumber (Holothuria leucospilota), leopard spot sea sucumber (Bohatschia argus), branching coral, brain coral, blade coral, boulder coral, blue sea star (Linckia laevigata), cone shells and a lot of different fish like the triggerfish (Balistidae) and trumpetfish (Aulostomus chinensis).

After a short break we went to the education center. Lady Elliot Island (LEI) appeared as a coral cay about 3500 years ago, when sea birds started to rest on it. Their droppings contained seeds with which it was possible to establish vegetation. We saw the white capped noddy, the silver gull, the common noddy and many other birds.
Because of the guano, which is a good fertilizer, LEI was destructively mined in the late 1800's. 100 years later (1969), a program to recultivate the island was started. The first type of vegetation was grass, followed by bushes and trees. A bush that is using saltwater is the Octopus Bush, which occurs around the outside of the island, at the border to the beach. Costal She-Oaks are common on the island, as they are fast growing and need little water because the have optimized their leaves to prevent water loss. Other Trees are the Goats foot convolvulus, the Pandanus Palm, the Beach Spinifex as well as the Cotton Tree, with the yellow blossoms and the Sandpaper Fig. There are a lot of introduced species like the weed Iantana, that change the color of their blossom, the Mother of Millions, the Umbrella Tree and other plants. As we moved on we came to a dried out pond site. Dr. Loh told us that three weeks ago there still was water in there. The group ate some fruits from the nearby fig tree and everyone survived.

Later on, we were introduced to the history of LEI. In 1816 a vessel named Lady Elliot was wrecked on a reef off Cardwell in North Queensland that is now called Lady Elliot Reef. As mentioned before, Guano mining from 1863 till 1874 was the only commercial usage of the island. Up to 30 Chinese and Malayan workers cleared the top 60 cm off LEI. At the end of the mining-venture, the first Lighthouse was build in the northern part of the island. However, the native vegetation was completely destroyed by the guano mining and the island was barren and devoid of any plants. We also visited a well in the centre of the island, that was dug out by chinese workers through the coral rock (we could see coral debris of Acropora and Favia around the well) to supply the guano-workers with fresh water.
Imported from England, a 15m high lighthouse tower was assembled in 1873. Its kerosene-powered light could be seen by ships from approximately 30 km offshore. In 1995, a solar-powered 35m high lighthouse-tower was constructed next to to the old one and replaced it. Now in a 24/7 automatic operation its light signal reaches about 40km.
As we turned to the nearby graveyard, behind the old lighthous-keepers cottages, Dr. Loh told us two tragic stories. One about a girl who died of pneumonia because of lacking medicine and the other one of a Lighthouse keeper’s wife, named Suzannha , who committed suicide by drowning herself.
A short break for lunch paused our learning experience.
At 14:00 we walked to the Coral Gardens, where we expected to see some sharks. Buddy teams formed and we were informed about the currents and condition in the water. We snorkelled in three groups of four and one group of three, led by Dr. Loh and escorted by Dr. Reich and Prof. Wörheide. Outside the reef crest the waves were moderate with a decent swell, the water had a temperature of about 22 °C.
A white-tip reef shark (Triaenodon obesus) swam beneath us and a short time later a black-tip reef shark (Cacharhinus melanopterus) and a Smooth stingray (Dasyatis brevicaudata) followed. We saw also a lot of smaller fish like batfish, sweetlip (Haemulidae), cleaner wrasse, parrotfish (Scaridae) and rabbitfish (Siganidae). Turtles were also seen. The main corals on this low energy habitat are from the genus Acropora. These corals frequently build table-like colonies here. Other corals were the organ pipe coral (Tubipora musica, Octocorallia) and massive Porites.
At the end of the day, the last two student talks were given and helped us to understand the subject of the coral reef system located around the island. Henrike (it was her birthday today) informed us about reef geomorphology and zonation as well as the community structure of its inhabiting animals.
After that Anne U. informed us about the development of the tourism in the Great Barrier Reef (GBR) region. Tourism, growing industry, mining and agriculture increasingly threaten and pollute the environment and we were informed about the zonation of the Great Barrier Reef Marine Park to conserve the natural environment. LEI, for example, is a "green zone" ("no-take zone"), where no collection of animals, fishing and mining is permitted. The positive evidence of this full-protection can be observed around the island, with lot's of "charismatic megafauna" (sharks, rays, turtles, whales) abundant in nearby waters.