25.08.2008 Low energy rocky shore, mudflats, seagrass beds

Day Schedule:
07:00 – 08:00 Breakfast
08:00 – 11:30 Activity: Low energy rocky/sandy shores and mudflats; collection of
invertebrates starting at Polka Point
11:30 – 13:00 Activity: Identification of the invertebrates collected
13:00 – 14:00 Lunch
14:00 – 14:45 Lecture: Ecology of Moreton Bay
15:00 – 16:00 Activity: Fish identification (seine netting)
16:00 – 18:00 Free time for developing ideas for individual projects
18:00 – 19:00 Dinner
19:00 – 20:45 Individual group projects
21:00 – 21:35 Lecture: Students talk about whales

Weather: Fine to partially cloudy, light to moderate SW to SE winds, 22°C
Tides: 09:57 – Low tide, 16:53 – High tide

Details:
Low energy rocky/sandy shores and mudflats; collecting invertebrates starting at Polka Point
Starting at Polka Point we searched for invertebrates. The area was first very rocky with a cliff. Then turned into sandy shores and subsequently into seagrass meadows. The area around Polka Point was built by sedimentary rocks and the soil became anoxic close to the surface. The prominent rocks eroded from the cliff are red in colour due to iron oxides. Animals adapted to tolerate partially dry conditions during low tide could be found between the rocks, animals requiring more moist conditions were found in the wet sand and small water holes. While walking around, the students collected different invertebrates (Crustacean, different Mollusca, Worms, Echinoderms and different corals). Other animals like fishes or birds could be seen.

Species list of animals collected an photographed:
Sponges: Haliclona sp.
Anemones: Macrodactyla doreensis (Purple-tipped Bay Anemone), Cnidopus verater (Green Anemone), Stichodactyla haddoni (Haddon’s Anemone), Cerianthus sp. (Tube Anemone)
Sea Pens: Virgularia sp.
Bivalvia: Pinna muricata, Pinctada maculata (Spotted Pearl Oyster), Cardiidae sp., Fragum unedo (Strawberry Cocle), Globivenus embrithes
Snails: Cymatium parthenopeum (Broad-ribbed Triton), Fusinus sp., Cellana tramoseriea (Common Limpert), Nerita sp., Cypraea sp. (Cowrie), Hydatina physis (Rose Petal Bubble)
Nudibranchia: Armina sp., Pleurobranchus peronii, Hypselodoris obscura
Cephalopods: Hapalochlaena fasciata (Blue-lined Octopus)
Sea Squirts: Endistoma elongatum
Crustacea: Mictyris longicarpus (Soldier Crab), Clibanarius talniatus (Yellow-striped Hermit), Macrophthalmus carssipes (Orange-spined Sentinel Crab), Thalamita crenata (Green Swimming Crab), Clibanarius virescens (Yellow-footed Hermit)
Polychaetes: Phyllodoce novaehollandiae (Green Paddle Worm), Chaetopterus variopedatus (Parchment Tube Worm)
Brachiopoda: Lingula sp.
Sea Stars: Astropecten polyacanthus, Nepanthia sp., Pentaster sp.
Sea Cucumbers: Holothuria scabra (Sandfish), Holothuria pardalis, Holothuria notabilis, Cladolables perspicullum, Synaptula recta

Lecture Ecology of Moreton Bay
The main information given to us was that the reason for the high diversity in this area is caused by two water regions mixing up. So coldwater fish and tropical fish are meeting here. Also three main habitats of sea are located in Moreton Bay. The open ocean, high energy shore at the outer coast and low energy shore also with mangroves in the bay. A couple of rivers are entering the bay, so the nutrient and sedimentary entry is quite high. This fact causes seagrass meadows in the bay.
Fish Identification (seine netting)
After the lecture we went out to the beach to try to catch some fish. We tried to trap the fishes with the help of a net. We surrounded the fish with the netting and pulled it onto the beach, where we could have a look on the trapped fish. We did this twice, but the catch was rare both times.
Fishes: Sillago maculate (Diver Whiting), Tetractenos hamiltoni (Common Toadfish),  Atherinomorus ogilbyi (Ogilby’s Hardyhead), Hyporhamphus regularis ardelio (Garfish)

Individual Group Projects
We discussed our first ideas for the individual group projects and formed groups.
Group 1: Felix, Iris, Reinhard
Group 2: Xenia, Kristin, Julien, Sebastian
Group 3: Sabine, Jamil, Christian, Anne D.
Group 4: Henrike, Anne, Stephan, Mark

Students talk about whales:
The talk was about the evolution of whales in general and Humpback Whales in detail. Marc informed us about adaptations whales developed due to their environment – water. We also learned about travelling routes and their communication.