June 19: University of Queensland

I visited Brisbane for two main reasons: the biodiversity and the University of Queensland. Queensland is Australia’s most biodiverse state. It has 70% of Australia’s mammal species and 80% of the bird species. Also, located here are 13 terrestrial bioregions, 14 marine bioregions, and 3 marine biogeographic zones. The University of Queensland has numerous professors who do research with the wildlife and Great Barrier Reef. 

The University of Queensland

David Booth and I

           Today I visited the University of Queensland for the day. This University is known for their research efforts on conserving wildlife and specifically on the Great Barrier Reef. I met with one of the professors and research leaders here, David Booth. 

            

      He showed me what his research involves and what the team of people exactly do. His research relates directly with the Green sea turtle, one of the seven species located on the Great Barrier Reef.

           

  There are two nesting islands for the Green sea turtle, one in the southern Great Barrier Reef and one on Heron island. More recently they have been doing their research on the far northern end of Raine Island and this is claimed to be the biggest green turtle rockery in the world. Their main interest of research is looking at the incubation environment and the quality of the hatchlings. By quality, they look at the size of the hatchlings, the physical attributes, and the hatchling success. This includes how many eggs are produced and the fitness to get out of the nest. For a hatchling to be successful, they work in numbers. For one individual, they need 20 other individuals to get out of the nest and it takes around 2-4 days for the group to get out. This is important to look at when populations are decreasing and the eggs are becoming less successful.

            For each hatchling, the more energetic and faster they are, the better chance of survival the individual has. So other factors about the hatchling become important at this stage such as crawling speed, trackway, flipping time, and swimming ability. The researchers look at the quality of swimming by putting a little Velcro suit over the animal and placing them in tanks full of water. They use a light to attract the animal to the other side of the tank to measure how often they stroke and how forceful those strokes are.

            Over time they have found out that the nest temperature is extremely important. At lower temperatures (around 26 degrees Celsius) in the nest, the performance characteristics are less optimal. At higher temperatures (28-32 degrees Celsius), the hatchlings have the best performance qualities.  Above 32 degrees, the performance qualities also begin to suffer. Past 34 degrees Celsius, the performance characteristics have a drastic falloff and there is a decrease in hatch emergence success. Because of global warming, there appears to be a warming of the sea and therefore, nest temperatures. This is significant since the sea turtles are temperature dependent. The sex of the turtle is also dependent on the temperature. For Green Turtles, the nest is all male at 26 degrees Celsius, between 26.5-29 the nest is a mixture, and above 29 the nest will be all female. Currently, the nests appear to be producing mostly females and a few males. If global warming continues, they will produce only females and no males. Therefore, long term disastrous effects will happen, but the effect won’t be obvious for another 10-30 years. This is because sea turtles live for 70-80 years and don’t return to the same area to nest for 30-35 years after escaping the nest. Within the last ten years though, it has been noticeable how little of males are being produced.

            At the biggest Green Turtle rockery in the world, Raine Island, there can be anywhere from 5,000- 60,000 females returning to nest within one year.  Each female produces 4-8 clutches of eggs and because of the mass amount of females, the area is becoming too crowded. It could take a female 6-8 nights in a row before she is finally successful.

            Late 1990s and onward, the hatching success appears to decrease dramatically. Another reason for this is because of the reshaping of the beach. The island is not as high above sea level and as a consequence, the water rises and drowns many of the nests. Because of this, they tried to help by reforming the island so the nests would be safely above sea level. This only helped a little in the incubation success. They noticed that there was still a large portion of unsuccessful nests, so they figured there must be another problem.

            It appeared that the nests are density dependent as well. They are actively trying to discover the reason for the density dependence and the mortality within the first week of incubation. They expect that they are dying because of low levels of oxygen and high levels of carbon dioxide are within the nest due to large population of nests in the same area. When turtles are maturing, the embryos consume lots of oxygen and give off a ton of carbon dioxide. Usually they are tolerant to this, but they suspect that the new eggs are quite sensitive to the different levels. David and the other researchers are actively researching this at the moment.

            If the ocean loses a species such as the Green Turtle, it could affect the Great Barrier Reef tremendously. The turtle’s diet affects the algae from over running coral reefs and they are an important part of the overall ecosystem. If the ocean loses the Great Barrier Reef, then the food supply for turtles will probably be overran by the wrong kind of algae. The bacterial type of algae that dominating the area might spread and affect the quality of food for the green turtle; thus, they won’t get enough nutrients to make the migrations or survive.

            Although many suspect that the Great Barrier Reef could be lost within the next 20-30 years, there is still a ton of speculation. The coral reef could possibly spread south, but it’s hard to tell since its all happening so quickly. Since there have been a couple massive bleaching events within the last years, there is a fear of another third warm summer and the coral will not be able to grow or spawn. If the Great Barrier Reef does disappear though, there is one thing for certain. The ocean will lose a massive amount of biodiversity and it will affect various different factors.

            In addition to climate change, there are a couple of major problems such as increase runoff in the water and a certain species of starfish that eats the coral. These starfish are becoming more common because of the runoff. The coral does not respond well with more nutrients in the water because of the runoff. Photosynthesis gives them nutrients but because they become stressed, they kick the algae out of their system and they cannot receive the nutrients needed.  The algae are what gives the coral their actual color. The immediate solution at the moment would be to decrease the nutrient runoff in the water. Global warming is obviously a factor as well, but that’s not something they can address since it is a global problem not locally.

            After this interview with David, he recommended scuba diving the Great Barrier Reef to see the biodiversity firsthand. Also, scuba diving the Great Barrier Reef is more beneficial than harmful since there are strict laws and it raises awareness and appreciation for the reef.

           

     Once I was done at the University of Queensland, I ended my night by going to Kangaroo Point to see the sunset over Brisbane and then rode the Ferris wheel there to get a different perspective of the city.

Sunset at Kangaroo Point