Author: Kris O'Keeffe
UTS and UTG personnel Selma Klanten (UTS) and Kris O’Keeffe (URG) undertook a repeat trip to Victoria on the weekend 15-18 Dec 2017, as part of an ongoing Weedy Sea Dragon population abundance monitoring program effort sponsored by Sea World grant awarded to Selma early 2016.
Sat morning 15/12 we got up with the birds and flew out of Sydney. We planned to get to our home in Dromana, Melbourne early to maximise our time for the day with a dive planned in the afternoon. We picked up our very big car and went and met Paul Sorensen owner of Diveline Scuba centre in Frankston, who kindly sorted out gear for us . Paul is very passionate about the ocean and is supportive of conservation programs like ours and is also studying marine science is his spare time. Paul has recruited one of the shop staff Tabatha Loughlan, to help with I3S photo identification of the local weedy Sea dragons. She has about 30-40 images in the database to date and keen to help more. Tabatha has just graduated with a marine science degree and keen on pursuing a career doing shark research.
In the afternoon we went and found our new accommodation and then made our way to Flinders Pier for our first survey. We met with Kade Mills of Victoria National Parks Association who kindly volunteered to help us with the surveys for the weekend. Kade runs the Reef watch and Great Australia fish count programs locally in Victoria and keen to get a local weedy citizen science monitoring program in full swing. Kade has also set up an I3s database to help with tracking of local weedy populations. We hopped into the water which was a pleasant barmy 19c, 10-15 m visibility and not much swell or current activity . We attempted to repeat similar survey track as last time around. Kade helped tow the dive marker buoy with GPS attached whilst I took weedy identification pictures for the Weedy Sea Dragon we encountered. We completed the survey area with a count of 4 weedies under the Pier and headed off in a north east direction for a bit of a further exploration and found another 8 Weedy Sea Dragon . The counts for survey were similar to last year’s Flinders’ survey where we had found 13 Weedy Sea dragons. Our survey photos were processed in I3S photo software but there were no matches with previous year records.
On Sunday 16/12/2017 afternoon we arrived at Portsea to meet Kade again to complete the scheduled Portsea survey. We had a little swell but conditions were generally fine with 8-10 m vis and water 19c. The Weedy Sea Dragons in Portsea were not as cooperative as those in Flinders for having their photos taken; perhaps less used to people as Portsea is not such a popular dive site anymore according to local divers who said it was once very popular as training site as it was so sheltered prior to dredging activities but now has increased wave activity. It has also been reported by locals that Portsea had a greater abundance of Weedy Sea dragons prior to dredging of the channel that resulting in sand cover of Portsea and some loss of habitat for the animal . The dive site is no longer that attractive for divers. Local container walls have been built to stop the on-going erosion due to increased wave activity resulting from the dredging.
An interesting comparison to earlier population reports can be found by referring to :
A report by Dragon Search: Public Report Summary of Victorian Sighting Data to April 2005. This report discusses the sightings recorded by Dragon Search divers and beachcombers in Victoria, between February 1997 and April 2005.
Here is a table from this report :
We encountered 6 individual weedy Sea dragons during the Portsea survey. One repeat from last year was found.
Interestingly we have found that visually the Weedy Sea Dragons in the Victoria region seem slightly thinner bodied than the Sydney ones and also seem to have larger and longer appendages.
We finished our successful surveying duties with a well-deserved celebratory beer at local corner pub.
On Monday am we ventured into the city to meet with Tereza Todd exhibit manager and Paul Hale curator, who also look after a Weedy Sea Dragon breeding program at Melbourne Sea World Aquarium.
We also had Kade present as well as Tabatha who works part time with Kade at Victoria National Parks Association. Tabatha is also doing some part time work for dive line scuba centre and helping manage a second Victoria weedy I3S identification database. We discussed our agendas with Tereza and learned some interesting things about their operations. They have been one of the only 3 aquariums in the world to breed Weedy Sea dragons in captivity. They have had 2 breeding successes to date; in 2011 and 2015. There are about 20 2-year old young Weedy Sea Dragons currently in the Aquarium from the 2015 batch. The Aquarium sends offspring to other Aquarium around the world which helps raise public awareness about the animal.
Tereza mentioned the breeding is a big hit and miss. They don’t know exactly the right conditions / environment yet to make it happen. She mentioned how the tail goes bright yellow on the male when it is ready to receiving eggs and its front abdominal blueish colour gets more pronounced.
Selma shared details on her genetic diversity study of the Weedy Sea Dragons; she plans to send the sequence data off to the U.S. for analysis in the new year. The Melbourne Aquarium as it turns out also has some samples preserved that they will share with Selma which will help with this study.
We talked about the potential of further Aquarium Weedy Sea dragon breeding programs locally in Sydney and potentially having more genetic diversity available for the species in captivity. Selma and Dave are keen to return to the Melbourne Aquarium in near future to give some talks.
The 3 days were a very productive collaborative effort to complete our surveys but also meet with other Victorian local who will be key to helping with a longer term weedy conservation program.
URG and UTS plan to do a repeat visit to Tasmania in Jan 2018 whilst URG plan to do continued monitoring of key sites around Sydney.