Tru Blu Prawn Farm and Palmer Island Mulloway

     The aquaculture department of the center is studying the convertibility of prawn hatcheries to fish hatcheries, especially looking at differences in Australian and Taiwanese designed hatcheries.  In response to the collapse of the prawn industry primarily due to low cost (but low quality) imports and lack of government support of the industry as a whole, researchers are hoping to find a different outlet of profitable production for the hatcheries.  There is potential for hatcheries to raise fish for the New South Wales government for recreational fish stocking or fish farming.  One interesting thing to note is that in Australia all the hatcheries are private regardless of whether they raise for recreational fish stocking or private production, hatcheries just have to undergo an accredidation process.   

     This past Thursday we went to 2 different farms with prawn hatchery facilities in Yamba.  Neither of the hatchery facilities on site are currently in operation however both are actively farming using purchased eggs instead of rearing their own.  Tru Blu continues to farm prawns while Palmer Island Mulloway uses their ponds for Mulloway (Jewfish). 

Tru Blu Farm

Tru Blu Hatchery Facilities (Australian Design)

The facilities have only ever been used for 3 runs of prawns, as the industry collapse occured shortly after the Tru Blu hatchery was built, most consider it to be the best hatchery in all of New South Wales

algae rearing tanks

More of the farming ponds

(Tru Blu has cut back to only farming half of their total ponds )



Some of the praws they sell in their shop





Product Ready to go to the market



Feeding the prawns

Palmer Island Mulloway Hatchery Facilities (Taiwanese Design)





Urchins

     Recently in Tasmania there has been an invasion of centro (long-spine) urchins, that have over grazed and  thus developed ocean barrens, unable to support much marine life.  The Eastern Australian Current has washed them into areas they have never before inhabited , probably due to increased strength of the current due to climate change factors.  Consequently this has nearly depleted rock lobster and abalone populations and poses a serious threat to shallow reef ecosystems as a whole.  The centro urchins are a keystone species in their native habitats, however have many detrimental effects when they invade other areas and there is great potential for them to continue spreading southward of Tasmania.  In order to not only better understand the grazing / feeding habits of these urchins but also how they respond to climate change conditions, Symon has developed an experiment in the ocean acidification lab that will examine these various factors and will be one of my main projects for the next 8 or so weeks.  We have approximately 140 baby urchins (varying in weight from .05 to .11 grams) each in a microhabitat in the larger flow through system.  The treatments consist of combinations of 3 different temperature treatments, 3 different acidification levels of the seawater, 2 different types of algae (encrusting and sargassum) and of the sargassum treatments some are allowed unlimited access to food and others have limited access to food.  We weighed and measured the urchins at the beginning of the experiment and will continue to do so weekly.  Wednesday begins week 2 so more to come as the experiment progresses.  

The babies

Flow through system

I think science programs should start offering a 'photographing scientific specimens' class!!!

   

Some photos of the urchins with the microscope camera, the scale is 1 mm and we use image J to set the scale to our the scale in the photos and measure the diameter and spine lengths of the urchins.

My very first kangaroo sighting!

The Research Vessel!

With the tropical storm finally clearing up on Friday we got a chance to take the NMSC research vessel out to collect some various specimens from Split Solitary Island.  Underwater visibility was only about 4 to 5 meters but still got some great stuff which will stay in quarantine for a couple weeks to make sure they aren't bringing in any disease that could have the potential to spread.

Solitary Islands Underwater Research Group

Last night, I attended a Solitary Islands Underwater Research Group (SURG) meeting to learn what some of the groups that work with the NMSC do and more about the partnerships they have.  The SURG is a group of volunteers who collect research to aid in the management of the Solitary Islands Marine Park.  The SURG is funded by government grants and has been around since 1985.  Surg is currently collecting ongoing research on how ocean acidification and warming is affecting both the corals and fish of the area.  For coral surveys, volunteers are taken out to dive in groups of 2 with one experienced scientist and one less experienced individual eager to learn.  Belt transects are run and every coral that lies within the transect is identified by the family of coral, and the lightest and darkest colors on the coral are recorded according to the color identification cards the divers carry with them.  Water temperature, depth, and location are also recorded.  The difference between the lightest and darkest color on each coral is what is critical to determine the level of bleaching and potential for recovery.  See the link to the Coral Watch website below for more information.  Fish surveys become a little more complex because the divers must be able to quickly identify any of the 50 species of concern before the fish leave the sampling area.  Video cameras are also used to ensure that no fish are left unrecorded.  The number of each of those 50 species present within the transects are recorded to determine if a shift of marine fishes range is occurring and how they respond to bleaching corals.  Below is also the link to the SURG website. 

http://www.coralwatch.org/web/guest

http://www.surg.org.au/surg_research.php