James Haddy - the Bream DoctorBream'in with passion - by Dan Clifton
Passion for bream? Well if you have ever had the chance to just watch a bream do its thing, you will start to understand why they are the most addictive small fin fish in Australia. Not only are they tough on light gear, they are extremely intelligent and mysterious. Bream, like many species, proffer many questions. It is when you start to search for answers that you start to realise the truth behind the fact that we know more about the moon than we do ocean, and it is in our backyard.
We have very little knowledge of bream movements. And many questions arise such as are they a resident species, are they migratory species, or do they just move at their own accord?
Well I was asked to go and talk to a man who has more than just an interest in bream in Tasmania, he loves to fish for them on a recreational level, and he has the most passion of any bream fanatic I have ever seen. So much so he has invested his lifes work into understanding the physiology and ecology of the black and yellow fin bream across Australia.
Dr James Haddy first started studying black bream biology in 1995 for his PhD at UTAS in Launceston. This work concentrated on the reproductive physiology of black bream and the development of spawning techniques to breed bream in captivity. After completing and publishing his PhD work in international science journals, he relocated to QLD to work as a fisheries biologist to investigate the biology of by-product species being retained in the Queenslands east coast trawl fisheries. It is here James found himself making a difference by proposing management changes for the fishery based on sound biological knowledge on a variety of species such as threadfin, bream, pipefish, crabs, cuttlefish, lobsters and bugs. With his recommendations new laws were placed into the management strategy of these fisheries. Once his QLD work was finalised he moved to NSW to be involved with a research project on yellow fin and black bream in the NSW estuary systems. James undertook a long research project that has given a massive amount of new information about the fragility of the bream population if not managed correctly.
James is currently researching the movements of black bream in Tasmania to find out where they are from and when and if they move estuary systems. These questions are being answered by the use of genetics and tagging, and already providing some very interesting results indicating that some population mixing is occurring in Tasmanian bream stocks, and that Tasmanian bream are found in the ocean. However the extent of these movements need more research.
After talking to James and getting to see what research he has already done I find myself deep within his passion to help preserve bream stocks in Tasmania. James took me though a lecture he had given in Tasmania about the spatial and temporal trends of black bream spawning activity in intermittently opening estuaries. The lecture was a summary of the research that James did with bream in NSW estuaries, and shows the demise of bream in one such location due to bad commercial and recreational practices. Commercial practices can also be managed to provide a robust fishery. It also demonstrated the trends which spawning bream require from Mother Nature to successfully spawn. Bream are broadcast spawners, whereby they release their eggs and sperm into the water column, but in order for these eggs to have high fertilization and hatch rates, conditions need to be almost perfect. The conditions that need to be in perfect synchronisation are a suitable habitat e.g. a creek with water temperature between 15-26C, salinity levels between 15-35"°, and oxygen saturation levels above 5 mg/L. It is a fine balance because if the salinity is too high, then oxygen levels can become low, and fresh water from rainfall can decrease the salinity allowing for higher dissolved oxygen and then water temp generally falls.
Bad fishing practices do not help. When these spawning conditions are favorable bream will be venturing into the creek and river systems on the estuary to find the optimal environment to spawn. It is at this time the fisherman, in the past placed nets over the entry and exit points of estuarine creeks, removing a considerable amount of the large adults. This activity results in the age structure of heavily fished estuaries being dominated by many small young bream. This situation is worsened if repeated years of environmental recruitment failure were to occur. Poor water quality, as a result of low environmental river flows, also affecys how long the estuary would take to re-establish a new population.
James's research is providing helpful information to fisheries in Tasmania and this may prevent similar issues arissing in our Tasmanian estuarine systems.
James is working on locating distinct families of bream in Tasmania and taking small fin clippings from the fish caught. DNA analysis is taken to see which family they belong to, and to see if these families migrate or are located in a specific area.
Other information James has been obtaining from his research is to see how many of our Tasmanian black bream are true black bream or hybrids with yellowfin bream from the mainland. James told me that from his research from the DNA samples, Tasmania probably has the only pure strains of black bream left in Australia.
I asked James what he plans for his future research on black bream in Tasmania. With a smile he told me of his desire to start a community based project to breed bream and snapper for replenishing the depleted stocks such as the current situation in the Tamar River. Other waterways may also gain some extra help in re-establishing healthy populations.
Dr James Haddy is a well published name in the International and Australian fisheries literature, and has made great changes in the past to recreational fishing laws as well as commercial fishing regulations. This should help preserve fisheries within Australia for many years to come. After my meeting with the "Bream Doctor" I believe Tasmanian are privileged to have someone so dedicated to making our fisheries better for the future.