THE RESEARCH –Morton Bay Research Base 26th-31st august 2013
TEACHWILD: A JOURNEY OF MARINE DISCOVERY
Marine debris is a global threat to biodiversity of immense proportion. For instance, more than six million tons of fishing gear alone is lost in the ocean each year. Despite this staggering amount of marine waste, fishing gear forms only a small percentage of the total volume of debris in the ocean, not even making the list of the top 10 most common items found during coastal cleanup operations.
Backing the boat in for the turtle work the impacts of this threat on biodiversity are both broad and deep. Marine debris has been reported to have direct impacts on invertebrates, fish, amphibians, birds, reptiles, and mammals. These impacts are known to be a significant threat to the persistence of several threatened or endangered marine species, and likely to be affecting many others.
For example, up to 40,000 fur seals are killed each year by entanglement in debris and entanglement and ingestion are major causes of population decline for some marine mammals. As the volume of refuse humans release into marine systems is growing at an exponential rate due to the global increase of plastics and other single-use products increases, the impacts from debris in the marine environment are likely to be intensifying. The timeliness of marine debris research is apparent.
One of our main aims is to collect data in a standardized rigorous way to tackle the marine debris issue as ultimately we would like to see policy decisions based upon scientific evidence. Analysis of data collected will provide essential information for addressing the impact of debris on wildlife, as little is known about the rate of encounter or its impact on marine wildlife, in Australia or elsewhere in the world.
Data collected for this project will contribute to addressing the four fundamental questions one marine debris:
1) What are the sources, distribution, and ultimate fate of marine debris?
2) What is the exposure of marine wildlife to debris?
3) When wildlife are exposed to debris, what factors determine whether animals ingest or are entangled by
4) What is the effect of ingestion or entanglement on marine wildlife populations?
THE STORY RESEARCH AIMS
About North Stradbroke Island, Qld
North Stradbroke Island, one of the world’s largest sand islands, is situated at the southern end of Moreton Bay, one hour from Brisbane and accessible by vehicular ferry or water taxi from Cleveland. The island’s sandy white dunes and beaches are sparsely vegetated and can be extremely fragile. The eastern side of the island contains the Blue Lake National Park, while the southern part of the island is closed to the public due to sand mining. This sand is high in silica and used for glass and ipad applications. The centre of the island contains a series of ecologically important wetlands and freshwater lakes, which are not regularly flushed out, and consequently are particularly sensitive to pollution and artificially increased nutrient levels. The waters off North Stradbroke Island have a unique mix of colder southern waters and warmer northern waters. This combination provides a home for manta rays in the summer and other marine life including sea turtles,dolphins, eagle rays, barracudas and Spanish mackerel throughout the year.
Between June and November humpback whales pass the island on their annual migration from Antarctica to their calving grounds near the Great Barrier Reef. While the calves are still quite young, they make their return journey passing close to the island where they can be easily spotted from various lookouts.
Arrived at Cleveland at 10 pm on Sunday the 25th august and checked into the motel BayAir. At 8.00am the following morning I walked down to the jetty at Cleveland where I met Geraldine and the other seven teachwild fellowship members. There were representatives from all of the eastern states. While on the vehicle ferry we spotted a pod of dolphins and a dugong which was a sign of good luck. We travelled by bus to the research base which is operated by the university of Queensland where we had a briefing and introduction session and met the chief scientist Denise Hartely who showed us the catalyst program she made with the ABC called plastic oceans.
In the afternoon we were divided into two groups and I did the boat trip with a marine biology student doing her honours to check her experiment on how long decomposition takes for a dead green turtles once caught in a net. She had dead turtles in purpose built pots and we went around lifting them out of the water, photographing and recording the changes in the carcases. This was a very smelly job. This research has been undertaken as there are many turtles caught in live fishing nets as well as ghost nets and floating debris to understand better the problem of non target species being caught. It was great out on the water, sunny and just right.
In the morning my group began with necropsy’s on four Prions and two Gulls with one gull having a large fish hook and line stuck in its guts which was obviously the cause of its death. Out of the six necropsies we found one bird with small white plastic particles in its gut, interestingly most birds had small stones in their gut and bits of shell grit. Some species of seabirds such as shearwaters(mutton birds) are very prone to plastic ingestion when feeding. small bits of plastic can look like food but also cigarette lighters, glowsticks, circular disks from balloons and even toothbrushes. we watched a very interesting DVD called ‘Bag It’ which every body should watch
In the afternoon we went out on the boat to check how the decomposition of the dead turtles in the pots were going. this process involves lifting the buoys which the turtle cages attached. the turtles are more bloated and losing scutes(sections of the turtles shell) and gelatinous.
Day 3 -
We drove to the ocean side of the island to Naree Budjong Djaca beach. here we did three transects. a transect is a measurable line which runs from the water up past the high tide line. two people on either side of the line walking along a meter either side of the tape collecting all rubbish which meticulously recorded and included polystyrene, foam, different hard types of plastic, drink bottles. it was amazing the amount of rubbish particularly polystyrene and other plastics on a seemingly deserted and little used beach. there seems to be a correlation between the amount of rubbish on a beach and the access of vehicles travelling along beaches particularly by fishermen
We were in the lab this morning analysing the plastics that had been removed from the necropsied sea birds. we made observations about type and colour and with callipers we were required to measure length ,width, depth then we weighed them and were able to identify the types of plastics by a buoency test. from one of the pelicans there was an empty condom box and a large plastic wrapper, and from another pelican we analysed the three fish hooks with one hook still having line attached. this was very interesting and disturbing as the statistics are showing that some species particularly the shearwaters are more vulnerable to plastic ingestion and generally plastics entering the food chain. phthalates and bisphenol-a(bpa) are chemicals used in the manufacture of plastics and are known endocrine disruptores. in the afternoon we were back in the boat checking the green turtle pots which shows there condition is deteriorating at every pot lift.
Back to adam’s beach to conduct three more transects where I was the scribe for the first time. not much rubbish on this section of the beach, then after lunch we went to north point for a swim. I went for a walk around the point and saw two dolphins playing and some whales a long way out breaching and a surf life saving club helicopter practicing life saving drops. back for lunch then out in the boat on Morton bay lifting turtle pots. now many turtles have lost all their shell and most of their guts and in severe decomposition, lost facial definition and exposed rib bones and returning to the research base for the last time on a ripper of an afternoon at nstraddy