One of the problems when assessing the health of fisheries is that we get used to how they are now or how they were when we started fishing them, we don’t view them in the context of their historical abundance. The baseline shifts, so instead of comparing the abundance of fish to the long term abundance of the stock, each generation redefines what “natural” or “healthy” fish stocks are as they continue to decline each generation. Daniel Pauly first introduced the idea of shifting baselines in fisheries management, showing that shifting baselines can mask drastic declines in fish stocks over the long term (his TED talk on the topic is worth watching if you aren’t acquainted with the idea). It can also effect how anglers think about fish stocks that are recovering, especially stocks that have drastically declined with only a small fraction of the pre-fished biomass remaining.
There are a number of fish stocks around the country that are well well below historical levels. Two that are most pertinent when it comes to how shifting baselines affect how we perceive fisheries that are in the process of recovering are the Southern Bluefin Tuna fishery and the Murray cod fishery.
In the case of Southern Bluefin tuna, less than a decade ago it was estimated that the stock was at a mere 5% of pre-fished spawning biomass. Thats LOW! In the last decade, reduction in quotas have seen the stock bounce back slightly. The stock is now estimated to be at 9% of pre-fished spawning biomass, with the biomass of 10+ year old fish increasing from 5 to 7% between 2011 and 2014. This is great news, there are signs that Southern Bluefin are making a comeback!
The problem comes from some within the angling and commercial fishing communities, seeing and experiencing this recovery first hand thinking that everything it now hunky dory, that quotas should be increased and bag limits upped (potentially stalling or slowing the recovery that has really only just begun). The low abundance of the fish now perceived as normal, the small recovery as a “boom”. This is shifting baselines in action. Southern Bluefin stock still aren’t in great nick, they are still ONLY at 9% of pre-fished spawning biomass. So while the fishing has improved and it seems that the fishing is the “best its ever been”, thats only because as a community, we’ve forgotten how good it was a generation ago, 30-40 year ago. The baseline has shifted. We have forgotten what we have lost. We have forgotten how good our fishery should be.
The same goes for Murray cod. Its estimated that Native fish populations in the Murray Darling basin are at less than 10% of their original levels. This is potentially a vast over-estimate, with scientist such as Paul Humphries suggesting that the real figure is likely closer to 1%, thats REALLY low (you can check out a video about his genius pub crawling “Stuffed Murray cod in Pubs” project here). You only have to look back at the commercial catch data and historical accounts to realise that our current Murray cod fishery is a sick emphysemic shadow of what it once was. A large commercial fishery for cod was established in the 1860s, with 75% of fish being sold at the Melbourne markets being Murray cod. Catches peaked in 1918, after which there was a decline in catches and populations to the point where by the mid 1930s the fishery had become uneconomic for many participants. Further declines followed, with commercial catches dropping by 85% between the mid 1950s and the closure of commercial cod fisheries in the early 2000s, suggesting a drastic decline during that 50 year period, on top of the declines that had already happened previously. To give you some an idea of the historical abundance of Murray cod, in 1862 a group of six men would send 2-3 tonnes of Murray cod to Melbourne a WEEK, all caught from the Murray river around Deniliquin. In 1926 on the Murray at Echuca, it was reported that the average catch for recreational anglers had been between 18-23kgs per angler every few hours in the preceding decades but had begun to substantially decline. To a modern cod fishermen, those numbers are almost unbelievable! Even with all the technological improvements that have been made over the years, which have made catching cod “easier”, those sort of average catch rates are something most cod anglers will never get close to experiencing. It would now only be a tiny handful of extremely lucky people who have experienced an absolutely red hot, “once in a lifetime” day on the water who would know what Murray cod fishing was once like. It used to be like that ALL OF THE TIME.
Over the last decade progress has been made. Wonderful programs like the Native fish strategy (which had its funding cut in 2012), stocking programs, work by the various government fisheries organisation (e.g. Victorian DEPI, NSW DPI), work by scientist and hard work by community and angler groups to improve habitat and fish populations have started to pay dividends. It appears that in some areas Murray cod (and trout cod in some, which is even more exciting) are making a comeback. Once again, you often hear “fishing has never been better”. Again, thats only because we have forgotten how good things were in the past. We are coming off such a low baseline, a baseline many now perceive as normal, that even very modest improvements in the stock make it appear like the stock is “booming”. That most definitely isn’t the case, something history makes abundantly clear.
Why is this important? Because as anglers, we owe it to our children to pass on healthy ecosystems, environments and fish stocks. We owe it to ourselves to fight for healthy fish stocks and improved fishing opportunities. If we forget about the past, we run the risk of doing a really really bad job of that. So while its great that the stocks of Southern Bluefin and Murray cod have started to recover, we shouldn’t be satisfied with these short term improvements. Doing so we sell ourselves short. WAY WAY WAY short. If we take the time look back at history, we can see that the fisheries that exist today are still only a mere shadow of their former selves. We have a lot of work to do to get back to something we can be happy with and we shouldn’t lose sight of that.
Fighting for that improvement is something that will be of huge benefit to anglers. Think of what the small improvements in fish stocks have done to improve angling in the examples used for this piece. Now think about what angling would be like if instead of being at 9 or 10% (or 1%) of pre-fished levels fish stocks were instead at 20, 30, 40, 50 or 60% of pre-fished levels? Thats the sort of fishing we need to be imagining, thats what we owe ourselves and our children. We may never get back to average catch rates of 18-23kgs an hour, but we might one day be able to achieve half that. That would be something we could be proud of. So while we should be excited about and welcome the small improvements that are happening, we need to remember that the job of improving these fisheries has only just begun.
This doesn’t apply just to Murray cod and Southern Bluefin, but to a range of different species, including Mulloway, Bigeye tuna, Striped marlin, Yellow belly, Trout cod, Silver perch, Macquarie perch, Australian bass, Estuary perch and many others, all of which have suffered significant historical declines. A number of our fisheries can and should be a lot better than they currently are.
If we want great fisheries for all these species, its important we don’t forget what we have lost, that we don’t forget how abundant they once were. Remembering the past is an important part of building a better future.
Thanks for reading!
Thanks to Simon Kaminskas for kindly providing the historical Murray cod photos and to Kurt Kiggins for unwittingly inspiring this post.
Further reading: A really interesting article on recreational fishing causing fisheries collapses in Canada. Once again, shifting baselines come into play, this time in the traditional sense, masking long term declines of fish stocks.