It’s Cephalopod Awareness Days again.
In fact, it’s Squid and Cuttlefish Day to be precise.
Last year we took this opportunity to ask ‘Where’s the love for the floundering population of Giant Australian Cuttlefish of Northern Spencer Gulf?’ Today, we return to this question and provide an overview of current and proposed threats and impacts facing the genetically distinct Sepia apama of the region. As many of you will already know, this year the population continued its decline towards local extinction, from an estimated baseline of around 250,000 in the late 1990’s to an official estimate of 13,500 this year. The accuracy of this current figure is a matter of expert and public conjecture. The bottom line is, the population is still on the A-train to oblivion.
The South Australian State Government claims to be investigating the decline, but how sincere is their investigation? In Fisheries Minister Gail Gago’s own words:
“A number of projects are underway, including monitoring breeding aggregation populations, assessing the potential for alternative spawning sites, research on preferred egg laying habitats, studies on movement patterns and population structure of cuttlefish.”
We don’t see anything there about impacts of any human activities, do you? Yet surely these would be the easiest to investigate, identify and manage? While the State Government has been boasting about money spent on cuttlefish research, the truth of the matter is that to date, the lion’s share of the $700,000 (distributed over the past three years) has been spent counting the animals, with precious little committed to studying the various threats and influences which surround and continue to mount around the fragile breeding aggregation.
Nutrient pollution implications for egg-laying and development
Nutrient inputs to the sea from nearby seapen aquaculture (Yellowtail Kingfish) in Fitzgerald Bay peaked in 2010 before ceasing the following year after experiencing animal health issues. This industry (and its pollution) scaled up significantly (pardon the pun) during the prior decade- the same period through which the cuttlefish scaled down.
In 2013, two cuttlefish breeding seasons after aquaculture in the region ceased, the State Government reported that the cuttlefish rate of population decline had slowed. Could the growth of this activity have impacted the cuttlefish population?
Nutrient load from seapen aquaculture (the result of fish feed and faeces entering the water) may indeed have implications for cuttlefish egg laying and development. Nutrient in the water fuels algal blooms. While algae photosynthesizes by day, by night it absorbs oxygen from the water. This dissolved oxygen is also critical for healthy cuttlefish egg development. So the competition begins.
This could prove to be particularly problematic for cuttlefish embryos during dodge tides, which occur each fortnight. Dense algal mats on the seabed may also limit the availability of suitable egg-laying habitat.
Northern Spencer Gulf is a naturally low nutrient environment by world standards. In such a system, who knows what impact hundreds of tonnes of nutrient annually from human industrial activities has had? Has anyone been looking? The Environment Protection Authority did not collect water quality data for the region for the years 2008 to 2011. We are told that their assessment of Upper Spencer Gulf’s condition conducted in 2012 will be released in 2014. What state will the cuttlefish population be in by then?
No research into the potential threat of nutrient pollution to the cuttlefish population is currently being undertaken. Meanwhile, aquaculture operations are rumoured to be returning to Fitzgerald Bay in the near future. The State Government and PIRSA are fully aware that nutrient pollution has the potential for ecological harm. In a press release in May 2013, Minister Gago announced $1.1 million dollars in funding had been committed to study the feasibility of farming seaweed “to complement aquaculture and safeguard the environment.”
Additional nutrient inputs from the Whyalla steelworks’ coke ovens are also ongoing. Ammonia (nutrient) enters the sea approximately 11 kilometres west of the cuttlefish reef. The map below shows the locations of the two major nutrient inputs. The cuttlefish are caught in a pincer move between these two inputs. The graph beneath shows relative inputs of nutrient from these sources during the three years for which data was available for both activities. Kingfish farm nutrient inputs for the intervening years are not currently available. The Whyalla Steelworks’ pollution data is listed on the National Pollution Inventory. The aquaculture industry remains exempt from the NPI’s mandatory reporting requirements, an issue we raised back in April, when discussing the harmful algal blooms and fish mortality events occurring around the State.
Cuttlefish prawn-trawler bycatch an unknown quantity
Prawn Trawling operations appear to have been unaffected by cuttlefish catch ban in Northern Spencer Gulf which was implemented ahead of the 2013 breeding season. Discarded bycatch reporting remains voluntary for this industry. It is known that cuttlefish are caught by prawn trawlers in Northern Spencer Gulf, but information on quantities or trends over time is unavailable. We have written to the Spencer Gulf Prawn Fishermen’s Association with a few questions regarding cuttlefish bycatch, and hope to receive some more information on this soon.
Shipping disturbs the seabed, increases turbidity and creates noise pollution
Whyalla harbor’s commercial shipping has reached record volumes in recent years. Proposed construction of another much larger iron ore export facility at Port Bonython (immediately adjacent the cuttlefish breeding reef) will see this increase dramatically.
Cephalopods (cuttlefish, squid and octopus) and cetaceans (whales and dolphins) are each known to be vulnerable to underwater noise. Noise pollution (such as that generated by ship’s engines and propellers) can impact cephalopods’ ability to balance, forage and feed. Some research has commenced in South Australia to study the impact of shipping noise and increased turbidity on cephalopods, but how far this has progressed is not known.
We are concerned that the results of this study are unlikely to affect the State Government’s plans to increase shipping movements from below 400 per year to over 1000 per year for this region, as stated in the Upper Spencer Gulf Marine Park Regional Impact Statement. This figure does not include additional necessary barge, tug and work-boat movements. The document also states that shipping will be unimpeded by the zoning or management of the marine park.
So what’s next, a new iron ore export port?
An Environmental Impact Statement for the proposed new Port Bonython Bulk Commodities Export Facility will remain open for public comment until November 18, 2013. The consortium responsible for the project proposes to construct a facility for the export of iron ore, commencing with an export capacity of 25 million tonnes per annum, with the view to increasing capacity to 50 million tonnes per annum should demand increase. To put this in perspective, Whyalla’s existing harbor was recently expanded to facilitate the export of 13 million tonnes per annum.
Ships will be loaded at berths on a proposed 3 kilometre long jetty through the cuttlefish reef at Stony Point. The world-famous ‘Fenceline’ cuttlefish dive site may be rendered inaccessible for the future of cuttlefish study and tourism.
What about the Olympic Dam desalination plant?
The State’s largest proposed desalination plant was approved for BHP Billiton to construct at Point Lowly in October, 2011. The company is yet to commence construction, and the planned Olympic Dam mine expansion remains under review by the company. BHP Billiton is investigating lower cost ways to access and process the copper, uranium, silver and gold rich ore body, which lies 350 metres below the earth’s surface. The current development approval requires the company to substantially commence construction of the desalination plant prior to 2023. The cartoon below summarises the cuttlefish’s predicament, with a few details on the proposed desalination plant. Studies conducted by BHP Billiton during the Olympic Dam EIS period showed that cuttlefish eggs could be killed, or embryo development stunted in the event of brine pooling around them. This hasn’t stopped several other industrial development proposals in Spencer Gulf including Port Spencer, proposing to build additional desalination plants returning even more brine to the gulf and risking even greater cumulative impacts.
So what can be done about all of this?
We maintain that alternative locations for these developments were not adequately considered, and that despite the company and State Governments efforts to downplay the environmental risks, the location remains unsuitable for its rich biodiversity and ecological uniqueness. To add insult to injury, the State Government has known all this for years- for much longer than the life of these various proposed industrial developments. Enter the Draft Spencer Gulf Marine Plan.
Back in 2006, after five years of development by a variety of stakeholders and experts, a Draft Spencer Gulf Marine Plan was released for public comment. The document has since been tossed aside, with the Giant Australian Cuttlefish effectively demoted from its former glory as the Gulf’s iconic species to the Government and mining industry’s sacrificial lamb. The waters surrounding Point Lowly received the highest Ecological Rating, recommending ‘negligible impacts’ only.
If you’re as disappointed as we are in the South Australian Government’s attitude towards this incredible marine species and their habitat, today would be an excellent day to sign and share our petition. We are calling for a moratorium on industrial developments on the Point Lowly peninsula until the causes of the Giant Australian Cuttlefish decline have been identified.