Asking whether fishing was better in the good old days presumes that the things being compared will have changed with time. I doubt there would be many who would argue there has not been change in fishing, both recreational and commercial, not only in NSW but throughout the world in the last sixty years. As change has occurred, governments have been required to adapt their attitudes to the continuously increasing competition for access to all ecosystems, including marine ones, and to the resources, including fish, that these ecosystems support. Fisheries management is far more prominent in local, national and international debates now than it was in 1960.
Fisheries are managed by governments for the stated purpose of optimising benefits for the collective of civil society from the conservation and use of aquatic ecosystems and resources. From a fisherman’s perspective, the primary purpose of fisheries management is to optimise the number, size and mix of species that are available to be caught sustainably year after year. Sustainability is key at all levels. But as human populations continue to grow, the allocation of those resources, and the ecosystems that support them, between the many competing users becomes progressively urgent. There are simply not enough fish to enable everybody to take what they want. And then there are the competing users of fish habitats, including those who do not want some habitats, and the resources in them, used at all.
The need for restraint when exploiting isolated pockets of fish, particularly in fresh water, has been acknowledged for centuries, but right up to the middle of the twentieth century the world’s oceans were popularly accepted to be limitless. This was most obviously expressed by the almost universal acceptance of dumping sewage in the ocean, where it supposedly disappeared. Escalation in the development of fisheries science, which accelerated following the Second World War in particular, progressively destroyed the tranquillity provided by ignorance.
Rejection of the concept that fish in the ocean did not need management was catalysed by acceptance that fishing reduced the abundance of all species that were captured. If not controlled, too much fishing could reduce catches, even if only temporarily. The hypothesis that marine fisheries needed to be managed was gaining acceptance even before the Second World War. The obvious recovery in several major stocks that had avoided exploitation during the war prompted more analytical and mathematical approaches to the science of fisheries assessments.
It was accepted that significant reduction in abundance was an inevitable consequence of heavy fishing pressure, but this reduction was accepted by most fisheries scientists to only be a problem if it was excessive and unmanaged. The progressive decline in populations of heavily fished species immediately after the war, most notably North Atlantic cod, left little doubt that control was necessary. The work of scientists such as Gulland, Beverton, Holt, Schaefer, Ricker and many others confirmed that if exploitation could be adequately controlled sustainability could be fostered. Precise, adaptive management, later championed by scientists such as Walters and Hilborn, could result in considerable benefit not only to seafood consumers but the fishermen themselves. By manipulating the levels of predators and prey, good management could stabilise yields at optimum levels and actually increase the sustainable productivity of selected populations.
Appreciation of the incredibly high reproductive output of most fish species, coupled with the knowledge that in depleted populations growth rates of individuals could increase as more food and space became available for those that were left (density dependent changes), were the basis of these conclusions.
Although great caution is necessary when comparing the management of oceanic fish populations with the management of their terrestrial counterparts, the analogy of the production of beef from a population of cattle in a paddock can help many non-experts understand the principles. To maximise the continuous yield of beef from a given paddock there is an optimum number, age and sex ratio of cattle in the paddock. This number is obviously less than the maximum that could be crammed into the paddock. In even moderate-sized paddocks it is equally obviously more than the minimum number necessary to ensure the sustainability of the species. The optimum number will vary between seasons and years and the size and quality of habitat. There will, therefore, be considerable variability in the numbers that the managers—the farmers—should leave in the paddock and the yield they should take for optimum returns.
Fisheries science established that in most situations there was a level of harvest that would maximise the yield that could be taken repeatedly while ensuring that the total population remained sustainable. In even more simple terms, the number of fish in a population could be reduced without negatively impacting not only the survival of the species but also the ability of the population to replenish itself. If this reduction was skilfully controlled year in and year out, the productivity of the population that is surplus to that needed to ensure its sustainability could be optimised. Outcomes such as Maximum Sustainable Yield (MSY), Optimum Sustainable Yield (OSY) or Maximum Economic Yield (MEY) became realities where fisheries were well managed. These outcomes were seldom achieved if fishing was not tightly controlled.
I am mindful of how a good fishing yarn can be destroyed, or at least distracted, by diversion to the minutiae of scientific assessment. I therefore leave the science, even if only for a moment, to recall being involved in a televised debate on the very serious problems of the overfished gemfish (a relatively deep-water species that was trawled in unprecedented, and confirmed to be excessive, quantities) fishery off the coast of NSW in the early 1990s. As the chairman of the committee responsible for assessing the status of this fishery I was in the debate to present the science, including the catch data and the statistical analyses that underpinned the assessment. On the panel was the noted chef and media personality Bernard King. Bernard understood he was there to provide detail on how to make culinary masterpieces from gemfish, not to listen to detailed explanations of the numbers of gemfish that might or might not be in the ocean. After I had provided what the moderator and I thought was no more than the minimum necessary level of detail, Bernard’s frustration rose beyond his limit. He addressed the audience: ‘Can you die of statistics?’
As mentioned above, when a population of fish such as jewfish is fished for the first time the total abundance begins to decline; there is at least localised depletion. If you take one fish out of the water, there is one less, at least temporarily. If you are fishing 2 yards upstream from your colleague, the absence of this one fish you just caught could have a significant impact on his/her chances of catching a fish of that type and size. This becomes particularly significant if the one you took was a relatively rare individual, such as an unusually large jewfish, and that is what your colleague is fishing for. For example, if Billy Smith and I were fishing side by side on The South End of the Kingscliff rocks, the chances of either one of us hooking a jewfish in a given period of time was approximately halved by the presence of the other. The chances of either one of us catching a jewfish would definitely go up if the other went home. The same principle would not necessarily apply if we were fishing in The Alley for tailor. In fact, the chances of catching a lot of tailor in the short term is commonly increased by having at least one extra fisherman, particularly if they are using the same bait, thus increasing the amount of bait as burley that can help keep the school on the bite. The fishing power of each individual tailor fisherman can be increased by the presence of another, at least in the short term and within the limits of saturation numbers of fishermen. But the long-term, broad impact of more tailor fishermen differs significantly from the short-term, localised one.
When fish populations are reduced, deliberately or otherwise, the total area that they occupy is also usually diminished. This phenomenon is termed ‘range contraction’. Fish species that are relatively sedentary preferentially occupy the areas that they like most; in other words, they first fill up the areas that are best for fish of their species and size. All animals, including humans, tend to do this. They then tend to only occupy areas beyond the best when the areas that had been the best are occupied by such large numbers of their species that the disadvantage of excessive competition overrides the inherent attractiveness of that particular area, or series of areas.
Moving around, to at least some degree, is a feature of most marine fish species. Marine systems do not have rigid boundaries in all directions. Many of what ‘boundaries’ there are, are variable in themselves, particularly those that are influenced by water temperature. Characteristics of fish populations, such as spawning and seasonal migrations to and from areas, also impact generalisations about their occupation of preferred areas. Highly migratory species, by definition, move through areas. They tend, however, to spend proportionately more time in areas that have above average attraction. Such attraction can come from greater food availability, superior water quality or temperature being more favourable, or the area being a genetically determined spawning ground. As a result, the abundance of a fish species, total or relative, in some areas of its total distribution will be different to that in other areas. This difference can be temporary or long term.
One example of the enormous scale of the shift in the attractiveness of areas to fish is provided by skipjack tuna in the Pacific Ocean in times of El Niño or La Niña events. In response to these alternate events, the area of highest concentration of skipjack can move from the waters of Papua New Guinea to those of Kiribati, a distance of more than 6000 kilometres, even though the total skipjack population remains of approximately the same size: millions of tonnes. Individual fish will not all have moved such a huge distance, but the areas where the population is densest, and hence catch rates highest, will have shifted a long way.
Then there is the complication that most fish are extremely social. They can realise benefits for survival from being with mates who are of approximately the same size. These benefits are manifest in a wide variety of ways. For example, for constantly mobile species, such as the tunas, there is considerable hydrodynamic advantage in swimming in relatively tight schools with individuals of the same size and swimming style, preferably, but not exclusively, of the same species. Competitive athletes find a similar type of benefit by tacking on to the slipstream of others. Cyclists in a peloton are notable examples.
For smaller, less mobile and highly preyed upon species, such as pilchards and anchovies, there is relative individual safety in numbers. Schools of huge numbers of the same size individuals of the same species are the norm; there is a serious disadvantage to those that cannot keep up. For individuals of species whose schools are heavily preyed upon there is also a disadvantage in being too big and standing out in a crowd.
For species that are swimming relatively fast for extended periods, such as mullet when migrating long distances, the tolerance for variation in size quickly diminishes from that which might be the norm in the slow-flowing, upstream reaches of rivers where they spend most of their lives. Being surrounded by individuals of the same size is also a distinct advantage for an individual when predators are of immediate concern. I first became aware of the social behaviour that facilitates the maintenance of size specificity in schools in January 1963.
I was on the beach just south of the Kingscliff rocks. A moderate southerly for the last week had maintained a very consistent run of hard-gut mullet. Relatively small schools of irregular size were coming past every couple of minutes. The size of fish in these schools was also somewhat variable, but they were all classical ‘hard-gut’; that is, they were all large enough to migrate but still smaller than spawning-run sea mullet. The hard-gut migration is not for spawning. It is to relocate fish to the north to balance the impact of the net southerly displacement of their eggs and larvae by the dominant current off the east coast of Australia, the south-flowing East Australia Current. If the effects of current were not countered by migration, the species would quickly disappear off the southern edge of the continent. Many inshore and estuarine species on the east coast of Australia, such as tailor and bream, have similar, but less obvious, migrations.
On the Kingscliff beach that day there was a prominent hole about 100 yards from the rocks in which about 200 mullet had holed up. As I was watching, another fifteen or so mullet came up the beach and entered this school. In the time it would have taken these fifteen to cover the distance, had they continued at the same speed, about ten mullet emerged from the other end of the school. I wasn’t certain, but I felt that the ten that had emerged were bigger than the average that remained in the base school. I was intrigued. A minute or two later another pod of about ten arrived. Six came out the other side; these were definitely above average size. Shortly after, about eight entered the school: almost twenty came out the other side; these were definitely smaller than average. Similar comings and goings went on for at least the next twenty minutes or so that I watched. I lost track of time. I was fascinated.
I quickly realised that the school was obviously constantly restructuring itself based on the size of its constituents. The variation in the size of individuals within the school was getting relatively tighter with each entry and exit. The school was at the same time gradually getting larger. Then a much bigger school, of predominantly similar size fish to those already in the hole, arrived. This school did not slow down and all of the mullet in the hole joined the new arrivals in continuing the migration north.
The moving school now represented a very large brown mass; in commercial fishing terminology it would be measured as at least twenty boxes (a box of mullet was traditionally 50 pounds but more recently is 20 kilos). I followed it as it approached the rocks. It made no attempt to slow down as it reached the first of the rocks and turned seawards, picking up most of the few hard-gut mullet of varying sizes that were bunched up in the corner. I ran out onto the rocks to observe. I anticipated action. Indeed, there was. As soon as the school reached the edge of the foam, its constituents rose to the surface. As they continued seawards their backs came out above the foam. They began swimming faster. They were clearly agitated. Suddenly many of them were airborne. They scattered at speed in all directions, including back to the beach, but the kernel of the school continued on its path. It soon made it into the clearer, deeper and less foamy water of Snapper Hole. Here the mullet regrouped, most circling once or twice. Individuals slowed down to migration speed. They then bunched up and headed north, out around the reef.
Those that had chosen to run back towards the beach continued in that direction. When they reached the beach they turned south. I followed. As a bunch of disjointed stragglers they made their way back to the hole they had occupied earlier, where they quickly settled down and assumed their previous station. More mullet kept coming up the beach and the school selection process began again as though nothing had happened. They were well adapted to a disjointed journey. They had a strategy. Obviously, the plan was to build numbers and then have another go at getting around the rocks. The rocks themselves were no problem: it was the shelter they provided for marauding jewfish that was the issue. But migration had to continue. These mullet were ‘hard-wired’ to do so. It was simply not a good idea to attempt to pass the obstacles either on your own or standing out in a group like the proverbial.
I observed similar schooling behaviour by migrating mullet numerous times over the next seven or more years. On few occasions was selectivity by size as clearly demonstrated as it had been on this particular day; seldom were conditions as good for observing fish at close range and seldom was the mullet migration as consistent as it had been on this day. While the memory remained large, the significance of what I had witnessed to my overall assessment of fish dynamics did not become apparent until a similarly picture-perfect day in, I think, 1980.
I was tuna spotting off the northern tip of the North Island of New Zealand with that country’s best fish spotter, Graham Bell. There were five American tuna purse-seine boats working the area. Graham was under contract to them to find skipjack schools and direct the boats to the best of them. I was there at the invitation of the New Zealand Ministry of Fisheries as a research scientist observing the efficiency of tuna purse-seiners in catching skipjack.
The sea was glassy calm, there were lots of skipjack about and the visibility from our high-wing Cessna was excellent. We had found nine or ten schools of between 30 and 50 tonnes each. Following Graham’s direction, all of the boats were now ‘in set’, about to set their net, or approaching a school that had been identified as a priority target. We had time to have a look around while listening on the radio to the progress of each set, the completion of which would take several hours.
As we circled a school of about 40 tonnes I saw six or seven skipjack swim out one side heading almost due north. I was most surprised that a small number of fish would just leave a school like this out in the middle of nowhere. Graham and I discussed the occurrence. He hadn’t noted it before. We began a search for similar pods of skipjack. It was only when we looked closely that we realised there were lots of them. We hadn’t noticed because we had been looking for big schools, not individual fish. We quickly realised the pods were headed to all points of the compass. If it had not been such a fabulous day for fish spotting and had there not been more than enough schools to keep all of the boats busy, we probably would never have noticed this phenomenon. From different perspectives, we both had great interest in finding out more about the behaviour of skipjack schools.
We watched one group of eight skipjack swim up to our school from the west. These eight fish swam right in to the middle of the school. Seconds later five swam out the other side on exactly the same trajectory. We observed at least ten interactions in the next half hour or so. Sometimes more came out than went in. Sometimes less. Occasionally none came out. One feature really surprised me: we could not detect a pattern in the directions they were going or coming. As far as we could see it was completely random.
We flew around the general area and now that we were looking for them we found small groups of skipjack everywhere. Never individual fish, not even twos, but three was not uncommon. Twelve was the maximum in a group. The moving pods tended to go in very straight lines. They did not even seem to change direction much when a big school of skipjack was nearby. If a school was in their path, they would collide with it and apparently ‘test it out’. They did occasionally deviate a little to do so. If, when they were out in the open, their paths crossed with another small pod they may or may not link up with it. The big schools remained relatively stationary with fish moving about within them. Individual schools remained about the same size as the day went on. The degree of movement within schools was difficult to assess as the density of similar sized individuals was high and they were stacked on top of each other to a depth of several fathoms. There were ten to fifteen thousand fish in a school. The range in the size of the schools, which Graham was proven by purse-sein catches to be able to estimate with an accuracy of better than plus or minus 10 per cent, was such that no two schools could coalesce without exceeding the maximum school size in the area on that day. What was the reason behind this behaviour? What was its significance?
Quantification of the school restructuring we had observed off New Zealand was provided a few years later. As part of the Skipjack Survey and Assessment Programme that I established in Noumea, New Caledonia, in 1977 we tagged more than 150 000 skipjack and almost 10 000 other tunas in a three-year period in a 40-million-square-kilometre area of the broader western and central Pacific. From the results of the recoveries of more than 4 per cent of the tags we were able to prove that skipjack schools did indeed restructure throughout the day. One of the Programme’s scientists, Dr Ray Hilborn, published an estimate of the half-life of a school as almost exactly one day. In fisherman’s terms, a 50-tonne school of skipjack at the beginning of the day could well be the same size at the end of the day, but only half of the fish in it at the end would be the same ones that were there at the beginning of the day.
This finding was one of the many that came from this tagging, the most important of which for fisheries assessment was that the biomass of skipjack in our study area was a staggering 3 million tonnes. To put this in perspective, the total Australian commercial fish catch all species combined is considerably less than 200 000 tonnes per year. Even more surprising was that the sustainable catch that could be taken each year from this skipjack population we estimated also to be 3 million tonnes; such is the productivity of this short-lived, highly fecund and fast-growing species. Eighty-seven per cent of the enormous number of skipjack in the central and western Pacific die of natural causes each year. This includes from heart attacks and disease and being eaten by marlin and other predators. But no other species eats more skipjack than skipjack do. Juvenile skipjack are a popular food item for the adults. And as there are hundreds of millions of adults they account for a lot of juveniles. If the adult skipjack population is reduced, a higher percentage of juveniles survive. In a public address in 1979 to fisheries scientists and tuna fishermen I predicted that if skipjack were a million dollars each it would still not be possible to seriously overfish them with known technology. With the passage of time this statement has been proven correct. I just wish jewfish were like that!
For species for which being with mates of the same size is critical, such as skipjack tuna or migrating sea mullet, re-aggregation by size is almost constant if the weather is relatively calm. Mullet school up, and the schools restructure, in the lower reaches of rivers in the weeks before they set off on their migratory runs.
In times of particularly rough weather selectivity in association becomes relatively less important for many species, particularly tuna. At such times ‘fruit salad’ schools become more common. If individuals of the same size are not available, there is still merit in being with those of the same species. If you cannot have the same species, the same size of mixed species is better than nothing.
Such is the strength of preference for certain locations and schooling selectivity for many species that the last few fish of a population of these species will tend to be together in the best area available to them, perhaps even in one school. It has been hypothesised that the last remaining school of skipjack tuna will still be a big one for as long as there are enough skipjack anywhere in the ocean to make up one big school. A fisherman who stumbles across that school, or the last remaining area where there are numerous schools, might mistake this local aberration for the species still being reasonably abundant!
Most species of fish aggregate to at least some degree at some time, particularly for spawning. Many species aggregate loosely virtually all the time. Jewfish are particularly social: juveniles have been forever called schoolies, for this obvious reason. Schools of flathead are not obvious; there is little hydrodynamic advantage in lying on the bottom in close proximity to each other. But there is no doubt that relatively dense aggregations of flathead do occur. There are many reasons and advantages, other than hydrodynamic efficiency, for fish being associated with similar size colleagues. There is, of course, also the natural selective attraction of some areas to fish of a certain size.
The relevance of this strong social behaviour by fish to the interpretation of the relative abundances of species now, compared to the good old days, is worthy of elaboration. When a species is fished down, albeit to levels that may be optimum for the long-term sustainable harvest of the species, individuals will concentrate, as they have always done, in the best areas, and preferably with individuals of the same size. If the total population is down to a target level of 30 per cent, there will not be 30 per cent of what there was historically in all areas. The relative density of the new population found in the most attractive areas can be anticipated to be more than what it is in the poorer areas. A species may even be completely absent in some peripheral parts of its earlier distribution. As a consequence, the total area of distribution will likely be reduced (‘range contraction’). Anglers fishing in the less favoured areas will have relatively poorer catches and will become disproportionately more concerned about the status of the species. They can then become critical of those anglers in the better areas who are opposing restrictive change to the management of the species, such as reduced bag and/or size limits. The more optimistic anglers, in the better areas, are not necessarily being selfish or even misrepresenting reality. The evidence they have of change in the abundance of their target species, correct thought it may be, is simply different to what anglers in less productive areas are observing.
What does all this mean for the assessment of the relative abundance of premium angling species such as jewfish now, compared to the good old days? There is little doubt jewfish populations in NSW are greatly reduced compared to levels of sixty years ago. Recent official assessments by NSW Fisheries suggest the total abundance across NSW is down to less than 20 per cent of unfished levels. How much below 20 per cent is a matter of conjecture. Even though current levels may be sustainable, largely because of the huge number of fertilised eggs the species can produce in good years, they are a poor reflection of the effectiveness of fisheries management in NSW. They also represent greatly diminished likelihood of the average angler encountering a jewfish of decent size, without modern fish-finding electronics. The chances are particularly reduced in areas outside those where the remaining population preferentially congregates.
From my experience, the centre of the jewfish population on the east coast was historically around the central coast of NSW, not the far north coast around Kingscliff, the obvious exceptions being in proximity of the mouths of the Clarence and other big rivers. The mouths of all rivers, and most creeks, have attraction for jewfish, but there is little doubt the lower reaches of bigger rivers can provide attractive habitat and food for larger numbers of individuals. While there is also little doubt that the abundance of jewfish in the mouths of the largest rivers, such as the Hawkesbury and Clarence, has been reduced, the principles of preferential fish distribution suggest it would still be relatively high compared to Kingscliff. Unless, of course, those particular rivers have become sites of disproportionate fishing effort, or pollution that is particularly damaging to jewfish. As well they may have!
The principles of range contraction and habitat preference would suggest that in an area such as Kingscliff the number of jewfish available to be caught would almost certainly be lower than the NSW average of less than 20 per cent of what they were in the very ‘good old days’. It would not surprise me if in 2020 there was actually something like 10 per cent, or even less, of the number of large jewfish in the coastal waters of the Tweed region, compared to what was there even in my good old days. I would be extremely surprised if there was more than the State average. Sadly, there is no guarantee the numbers will go up appreciably across NSW in the immediate future. It is, however, heartening to know that both the recreational and commercial fishing advisory councils to the NSW Government have supported a Mulloway (Jewfish) Recovery Program. The most recent discussions by both groups confirm the level of concern over the status of jewfish stocks and the need for much more draconian catch restrictions. These councils are accepting responsibility for the role fishing has played in the decline of jewfish populations, and NSW Fisheries is listening. But they are having much less impact on society’s acceptance of the need to address the non-fishing impacts on these population levels, such as pollution and habitat destruction.
Not only is there likely to be a disproportionate decline in the total size of the jewfish population on the far north coast but the local situation in Kingscliff could be expected to have resulted in abundance having been reduced to even less that the average for this region. The quality of the available habitat and food available for jewfish around the Kingscliff rocks, and even beaches, are both less than they were (chapter 8), and as far as I am aware, both continue to decline.
Then there is the decline in the habitat and associated productivity provided by Cudgen Creek (chapter 22). The logical assessment of the impact of major declines in wetlands and seagrass distribution, coupled with the complete change in the quality of the water and its contents discharged from the creek, would be negative. The training walls themselves provided fish aggregation devices, which, like other such devices, made jewfish more vulnerable to the average angler, but did little, if anything, that was positive for the productivity of the species.
In summary, estimates of the size of the jewfish population of NSW in 2020 suggest that it is on the low side of 20 per cent of unfished levels B0 (biomass at time zero in fisheries science jargon). Some estimates have it being much lower. Thus, as the population is significantly below the MSY target of 30 per cent and also below the lower acceptable limit of 20 per cent, the species classification of ‘overfished’ (‘depleted’ in the modern classification) is not unreasonable. The rumours I hear are that the scientists see a few signs that give rise to some optimism that the population may be stabilising and a slow recovery might be possible; a few more wet years in the catchments of our major rivers is considered likely to be a great help. But holding your breath is not advised!
The almost continuous decline in jewfish populations up to the end of 2020 has been due, at least in part, to the complete lack of effective fisheries management in the good old days. The precedent was not inspiring. Habitat destruction, pollution and environmental degradation generally have undoubtedly added greatly to the problems (I discuss these factors below). Again, there is at least a little good news in recent years.
Civil society is now well aware that the oceans are not limitless resources. Governments have progressively appreciated the enormity of the threats to our marine ecosystems, particularly our riverine and inshore ones, which are the habitats of several stages of the life cycle of jewfish. They are under increasing pressure to do something about it. In NSW the creation of the Marine Estate Management Authority (MEMA) and the Threat and Risk Assessment (TARA) approach it has taken to identifying and then managing the threats to our marine ecosystems, no matter where they arise, is a huge leap in the right direction. This approach has a great deal more scientific merit than merely closing predetermined bits of areas to all fishing and calling them ‘protected’ regardless of what the problems are in each area and what action is necessary to address each. The public continues to be seriously misled by being told, even by numerous senior marine scientists, that closing areas to all fishing actually provides total protection. As most fish species are mobile at some stage in their life cycle, such closures do not represent total protection against fishing, let alone the plethora of other threats. It is significant that the threat assessment (TARA) initiated by MEMA identified twelve threats to coastal marine ecosystems that were ranked above fishing. The closure of areas to fishing in NSW has not been based on provision of identified protection against any of the twelve. The public, and fishers in particular, are being further misled by being told that that total fishing closures in areas that are selected on the basis of their geographic location and biodiversity content, and not the threats to each area, will result in a net benefit to fisheries. Modern fisheries science has provided mathematical confirmation that such an outcome is only possible if each fishery in the area is seriously overfished before the closure. It is statistically virtually impossible in an area with multiple fisheries for an indiscriminate closure to benefit all fisheries that are impacted. It is totally impossible to achieve a net benefit to all fisheries from the closure if there are multiple fisheries in the area and all of them are well managed before the closure. Ensuring that their key species are not overfished, and the public is aware of this, are effective ways of countering proposed total fishing closures.
A major impediment to protecting and restoring fish populations and marine ecosystems is the lack of accurate assessment of what has caused the declines and what is necessary to address each of those causes in the areas in which they arise. Most of the threats, other than fishing, arise on land and not in the ocean. All threats must be managed at their source, which even for the few that are not on land are not necessarily in the same areas that are impacted.
How much of the current decline in fish populations, jewfish for example, is due directly to fishing? How much of the problem is attributable to other factors, such as pollution in many forms, habitat destruction and reduced freshwater flows, particularly in estuaries? I am the first to admit that there is currently insufficient high-quality scientific evidence to support a definitive answer to these critical questions. But having been a senior fisheries manager, I am well aware of the need to at least debate the issues with as much information as can be garnered in the hope of informing the decision-making process. And hopefully stimulating more critical research. There is also a great need to make sure the public is aware of the truth, including the uncertainty in many of the projections. Management decisions need to be made on the best available science that is relevant to each carefully described problem. Waiting until the science is unequivocal will almost certainly result in further habitat destruction and deterioration of water quality and probably overfishing.
There is no doubt fishing reduces the abundance of target species. There is similarly no doubt habitat destruction and deterioration of water quality have negative impacts on fish abundance. They must. Closing areas to fishing is the common knee-jerk response by governments to problems with fish populations, even if it has not been established that fishing is the cause of the problem. It fosters the illusion that governments are doing something to address the issue. Closing rivers to fishing after acid sulphate-induced ‘fish kills’ is discussed under point 2 below. Responding to the problem of dangerous levels of the pollutant dioxin in the flesh of fish in Sydney Harbour, by closing the Harbour to commercial fishing, is but one of numerous other examples.
Accepting the limitations of the available scientific evidence, I suspect a combination of four major changes is to blame for the decline in jewfish populations and indeed the abundances of many coastal fish species. The order they are listed below does not assign priority. The relative impacts of each cannot, at present at least, be precisely determined.
In NSW serious destruction of fish habitat has occurred, primarily in estuaries and rivers. It continues in many areas. A 2014 review of the management of the threats to NSW estuaries concluded that there has been very serious destruction in most of the estuaries of NSW. Cudgen Creek at Kingscliff was one of the case study estuaries that was given detailed scrutiny in this study. Its decline as an ecosystem is discussed in chapter 22. You cannot destroy or degrade vital habitats and nurseries and not have a negative outcome for fish populations, at least for the populations that were there prior to the degradation: the good old days! The removal or degradation of fish habitat that had historically been provided by the Kingscliff rocks and the adjacent Cudgen Creek has been extensive (discussed throughout this book). The dramatic modification of Botany Bay for the development of airport and shipping facilities is a nationally more significant example of human population growth and increased affluence resulting in habitat modification and loss.
Insidious and continuing pollution from industrial, urban and agricultural sources
A huge and complex array of damaging chemicals continues to enter our waterways. The impacts are many and varied. Most are not seen; extremely few are measured. Their impacts are certainly not fully quantified or appreciated. One aspect of this problem that is extremely critical but is inadequately understood, and certainly not directly managed, is the impact of pollutants on fish eggs and larvae.
Eggs are a vital component of the life cycle of most mammals, birds and fish. The evolution of species confirms the singular importance of the protection of eggs. In humans, eggs are encased in the deepest and most sheltered part of the female body, as they are in most mammals. Birds girt their eggs in an impervious shell and commonly guard them further by sitting on them in nests. In extreme contrast, most fish eggs, which are usually small, are simply spawned directly into the water, frequently in or near areas of high productivity, such as the mouths of estuaries where nutrient levels are high. So also, in modern times, are the levels of pollutants. These individual eggs have no active defence and little innate protection against any unusual events or substances, such as pollutants.
Before human intervention, there was little need for fish to protect individual eggs, or all of their many eggs, against pollution. The many species had evolved in relatively pristine environments. They had developed an obviously extremely successful reproductive strategy that was largely dependent on laying many millions of unprotected eggs, commonly millions per female, and broadcasting them widely, often several times in the spawning season. Prior to human pollutants, nothing could get to all eggs. Even selective predators or scavengers could not scoop up all of them. The prominence of the strategy is confirmation of its effectiveness in marine systems; the great majority of the world’s oceanic fish species rely on it. It has been proven by the persistence and evolution of a huge number of species using it successfully over millions of years.
But this very strategy, which has been part of the core of the health and sustainability of our marine ecosystems, is itself being progressively exposed by increasing human intervention. Fish eggs are by their flimsy and unprotected nature inordinately vulnerable to chemicals. Many chemicals can, and do, disperse throughout entire marine ecosystems. The increasing distribution of visible plastic demonstrates the ability of even large pieces to disperse to at least most parts of the world’s oceans. Soluble pollutants can therefore potentially affect all fish eggs, or at least the great majority of them. Do we know they don’t already?
The impacts of pollutants are much more all-pervading and relentless than those of predators, including fishermen. Human by-products such as herbicides, insecticides and other pesticides are particularly concentrated in estuaries, but they diffuse throughout the entire marine system. In the absence of evidence to the contrary, it is reasonable to assume that they have the same type of impact on fish eggs and larvae that they are designed to have on other animals and plants: in even moderate concentrations they kill or deform them. As do anti-fouling paints on the bottoms of the ever-increasing number of boats moored in our bays and estuaries. These paints by definition and design interfere with the reproduction and growth of marine organisms.
Hormones in sewage from the expanding human population also continue to act in water as nature designed them to do in bodies, particularly on unprotected cells with which they come into direct contact. What is the impact on fish eggs of human oestrogen or testosterone? What about drugs, legal and illicit, that are flushed into the ecosystem? How does an egg or larval fish respond to methamphetamines, or blood-pressure medications, or Viagra?
Episodic and catastrophic major pollution events, such as chemical spills
An example very relevant to Kingscliff and jewfish is the many discharges of huge quantities of acid-sulphate water into many NSW estuaries. These discharges were greatly concentrated following modification of river catchments and wetlands associated with increased riparian drainage, mainly for agriculture and urban ‘development’. These activities were deliberately misleadingly labelled by governments and regional bodies as flood mitigation schemes. They resulted in periodic kills of enormous quantities of living organisms in many NSW rivers and creeks. At their worst, these discharge events killed all biota in extensive reaches of rivers. They were total biota kills that were inadequately described as ‘fish kills’. Yes, millions of fish were killed, but so was everything else in the water. By calling them ‘fish kills’ the governments of the times misled the public into thinking that fishing closures represented an appropriate and meaningful response. Had they, from the start, been correctly described as total biota kills, governments could well have been forced to take more appropriate action to address the full dimensions of the problem!
These kills have been particularly devastating in the Tweed and Richmond rivers since they began more than fifty years ago. I carried out a survey, including the collection of water samples, for the University of Queensland of the Tweed River at the time of the first of these major kills, in 1968. What I saw was incredible. Not only were there huge piles of dead fish, crustaceans and worms on the banks, in places more than 3 feet deep, but the water in the river was crystal clear with a pH approaching that of vinegar or lemon juice. It was even lower in some of the offending drainage canals. There a copper coin would dissolve. From our survey boat I could see every pebble on the bottom of the river, even in the deeper holes. The alumina-silicates that had washed into the river as part of the discharges from the many drains are extremely powerful flocculants; they are what is used commercially to clear the water in swimming pools.
There was not a sign of life in the river; no birds, no dragonflies or other aquatic insects, nothing. It was eerie. There was a lot of media attention in 1968, but in spite of the fact that the cause was obvious not a lot of action was taken back in the good old days to prevent it happening again, which of course it did, numerous times. And the problem followed the spread of ‘flood mitigation schemes’ to other rivers further south.
Science cannot yet determine exactly what the long-term impacts of these episodic indiscriminate total kills are or will be. For example, we do not even know whether species such as jewfish are like salmon and return to the area of their birth or larval development to spawn. If they do and these areas include rivers or estuaries, then the whole reproductive cycle could be even more seriously impacted than the mere removal of one, or two, year classes by these episodic mortalities. Then, of course, there is the perennial impact of acid sulphate chemicals in periods when levels are not high enough to kill everything and are therefore not readily visible. They can maim or kill small percentages of many species, or all of some species, or all of batches of fish eggs, and still go undetected, or at least remain inadequately managed.
Australia has had a long history of introduced species and pathogens. Most of the species were deliberately introduced from European settlement onwards. The great majority of the animals and birds we eat are introduced species, as are more than 95 per cent of the vegetables, fruits and grains we cultivate. Most of the agricultural practices that we consider to be necessary for our well-being are to the considerable detriment of native species and Australian ecosystems, including our waterways and eventually oceans.
While the impact of introduced species of terrestrial animals and plants has been overwhelming the marine environment has not been immune. By 2008, 429 exotic marine species had been recorded in Australia. Most were not deliberate introductions. Many others have gone about their destructive business without being recorded. Then there is a great number of introduced pathogens. Ones that have been identified that fishermen will remember include the Californian herpes virus that devastated Australia’s pilchard populations, beginning in March 1995. There are also the numerous diseases that wreak intermittent havoc with oyster species, including Pacific oysters, which are themselves a deliberately introduced species that has effectively displaced native oysters in many places.
The impact of the huge number of these introductions on Australia’s marine biodiversity and the management of fisheries needs to be considered in the context of there never having been a single species of marine fish recorded as having been fished to extinction in Australia. Numerically the number of introductions has had infinitely more impact (429+ introductions compared to zero extinctions) than fishing on biodiversity as measured by species richness (a popular metric, particularly in international forums). Perhaps even more telling is that problems that are caused by excessive fishing are usually relatively easily fixed, as they have been in almost every case a fisheries recovery plan has been implemented in Australia (jewfish in NSW currently remains a notable exception). In contrast, introduced species have mostly proven impossible to eradicate, even when we try, which we do not do conscientiously very often. The tendency is to wait until we learn to live with the problem; as we have done with Pacific oysters.
In 1960 there was no regulation of the magnitude of marine fish catches by commercial or recreational fishers in NSW. Size limits had been imposed on many species, but impacts of these limits on fish abundances were not assessed; they were not intended to regulate the total biomass of fish that was taken. No marine species had been assessed to be overfished, certainly not to the extent that anything serious needed to be done about it. Even whales were still being hunted in Australia. (Whales are not fish so they never were fished, but their plight was always attributed to fishing). But then no marine fish species had actually been accurately assessed anyway. Up to the mid-1980s, the executive of NSW Fisheries was still basking in the ignorant belief that the oceans were limitless resources, at least from a fisheries management perspective. The prevailing management paradigm was that if a species of fish, or an area, was overfished, fishermen would simply move to another area or exploit another species: a commercial fishing licence of the time entitled its holder to fish for any species anywhere in NSW with any legal gear. This concept had been internationally discredited in 1958 but it remained in vogue in NSW until 1986. In the absence of effective management of fishing and environmental degradation, several species, including jewfish, had begun to be depleted at a rate that subsequent research was to demonstrate was beyond the capability of the population to sustain itself at optimum levels.
As discussed above, the contribution of environmental degradation from many causes had not been described in the good old days. Its impacts still have not been adequately assessed. Quantification of the problems was seldom attempted. This in turn has made accurate assessment of the contribution of fishing to environmental issues virtually impossible. However, evaluation of the relative impacts of the two major types of fishing, commercial and recreational, in 2020 is still valuable for assessing what has changed since the good old days. Evaluation is also necessary for future planning.
Commercial fishing
It has been popular, particularly among recreational fishers, to blame commercial fishing for most of the problems with fish abundances in NSW. The evidence, however, does not always support this hypothesis. That prawn trawlers cause excessive mortality on juvenile jewfish is high on the popular list of complaints by anglers. Numerous environmental groups have managed to demonise all forms of trawling, everywhere. Yes, there is no doubt prawn-trawling has, over time, killed worrying numbers of juvenile jewfish in the waters of NSW. This mortality must, however, be considered in the context of the total time in which jewfish populations have declined and the impacts of other threats on them. Trawling is currently only allowed in three of the approximately 150 estuaries in NSW; even in these three the number of vessels has been considerably reduced and there are major seasonal and area closures.
Fishing effort in the NSW oceanic prawn trawl fishery has been reduced to approximately a third of historical levels, and areas where catches of juvenile jewfish were highest have been either totally closed or subjected to major seasonal restrictions. Additionally, the improvements in by-catch reduction technology have been impressive. NSW Fisheries scientists deserve considerable credit for this latter internationally acknowledged achievement. Total catches of juvenile jewfish by prawn trawling in NSW are a great deal less than they were when the total jewfish population was far more robust than it is today. Yes, trawling is an issue that needs to be monitored and managed when necessary. Perhaps it needs to be even more stringently restricted. Perhaps less. But it is currently far more strictly managed than many of the other impacts on jewfish populations. It is also far more effectively managed than it was in the good old days.
Mesh netting in estuaries is another commercial activity that many recreational fishers take great exception to, particularly if it takes place in their favourite estuary. All catches of a target species have the potential, at least, to impact somebody else’s catches. The closer geographically and in time the catches occur, the more likely the impact. That is why the allocation of our limited fisheries resources between recreational fishers and the seafood-consuming public, who approximate 90 per cent of the population and include most recreational fishers, has become such a vexing and complex issue. But mesh-netting of jewfish has, like trawling, also been increasingly tightly constrained across NSW. It has been eliminated in many estuaries. The catch using this technique is certainly a great deal less than it was in the good old days. As currently restricted, it is most unlikely it would, of its own, restrain an increase in the total NSW jewfish population.
Recreational fishing
The recreational catch of jewfish exceeds the commercial catch in NSW. By how much is a matter of conjecture. This in itself is a worrying admission. The most comprehensive recreational fishing survey suggests that even little more than a decade ago the recreational catch could have been as high as seven or eight times the commercial catch. Several more recent but less comprehensive surveys have suggested that the recreational catch may be closer to two times the commercial take. But numerous scientists have serious reservations about the conclusions that have been drawn from the more limited recent surveys.
The progressive reduction in the recreational bag limit and increased size limit must have had an impact on the recreational catch. But so would the continuing restriction of the commercial catch impact that fishery. In any case the evidence currently available to confirm that the two types of fishing must both have had a significant impact on jewfish populations may be compelling, but the accuracy of the conclusions being drawn remains highly questionable.
The ever-growing efficiency of recreational gear, in the case of jewfish particularly lures, including soft- and hard-bodied plastic ones, and the ability to detect individual fish with modern fish-finding electronics, which now include impressive side-scanners and ‘live scope’ technology, are major issues for future conservation and allocation. As, of course, is the number of anglers and the accumulated knowledge of how, when and where to fish and how to get to the exact spot using GPS. These are the reasons why much tighter management of the recreational catch has been necessary. They will continue to be so.
The most immediate threat to the chances of most anglers catching a jewfish at any point in time often remains the other fisher in their boat, or the one fishing a few metres from them off the rocks or the beach. This is particularly so if all parties have excellent gear, lures and/or very fresh bait. The factors that contribute to the good fishing experiences in the modern era, such as fabulous equipment, unfortunately contribute to the fundamental contrast in fish abundances with those in the good old days.
There can be little doubt that the collective fishing power of recreational fishers in NSW has increased greatly in the last sixty years. The individual modern angler is a much more potent unit of fishing power, and there are many more of them. The total recreational fishing power is still increasing. In contrast, commercial fishing effort, at least as measured by the number of fishers and the total area fished, has gone down measurably in the same period. The average recreational fishing boat in the waters off Kingscliff today is a hugely more powerful fishing platform than was the one commercial boat there in the 1960s; Chookie Fowler’s 14-foot, 20-horsepower-driven wooden boat did not even have an echo sounder of any sort, and GPS had not even been dreamt of for fishers in 1960.
There is little doubt the building of the walls at the mouth of Cudgen Creek has, by causing sand to cover a great deal of the marine ecosystem, reduced the productivity of the habitat that historically helped support the jewfish population around Kingscliff. It would have at least negatively impacted the number of jewfish that visit the area. These walls have also effectively created fish aggregation devices and platforms that make lure fishing much easier. In combination, these changes have given recreational fishers easier access to a greatly reduced jewfish population. The walls are much higher than any of the pre-existing rocks and therefore much more easily fished at any tide or sea condition. This has undoubtedly increased the vulnerability of the smaller number of jewfish that now inhabit the Kingscliff area. One of the early results of this phenomenon is that the total annual catch of jewfish around Kingscliff went up considerably immediately after the walls were constructed in the mid-1960s. While the catch rate may have declined in recent years, the total recreational catch may still be higher than it was in 1960. Even if it is not, there can be little doubt that the percentage of the greatly reduced jewfish population in the region that is being captured each year by recreational fishers is a great deal higher than the percentage that was taken from the much greater jewfish population in 1960.
In summary: yes, there are many fewer jewfish in the waters of NSW than there were in the good old days. And what is there will need to be more tightly rationed between more and more fishermen with better and continuously improving gear and information. But fisheries research and management, including of recreational fishing, have improved considerably since the 1960s and particularly so since the 1980s. There is now at least recognition that stocks need to be managed and that recreational fishing effort and anglers’ aspirations need to be included in that management. Considerable attempts have been made to do so. There is reason to be optimistic that the negative impacts of fishing on the total jewfish population will be effectively restrained. But I, for one, believe this will not happen without more pain for both recreational and commercial fishers. Equitable allocation of the recreational share of the resource between the growing number of anglers capable of catching a jewfish will likely result in even more restrictive size and bag limits.
Stocking of greater numbers of aquaculture-bred juvenile jewfish may well offer some artificial boost to jewfish populations that would be welcomed by most anglers and commercial fishers, but may not be beneficial to wild populations in the long term. The impacts of such stocking on the sustainability or genetic integrity of the natural jewfish stocks remain uncertain. The real issue with stocking artificially bred fish is that it usually constitutes a beneficial allocation to fishers and is therefore popular, but its benefit to the underlying natural ecosystem, beginning with the species itself, is far more uncertain.
These principles of allocation versus conservation are similar to those that affect the closure of inshore areas to all fishing. Groups other than fishers, in particular swimmers and divers, unquestionably benefit from such actions. The risk of getting hit on the head by a sinker is removed and the numbers and average size of marine species that would normally be taken by fishers commonly increase and become more visible. The benefit of this allocation is real, making it easy to justify the decision. Swimmers and divers are entitled to a share of the marine estate. This is a good way of delivering that share. But the benefits of appropriate allocation must not be misinterpreted as representing adequate conservation. The mere closure of an area to fishing does not deliver the broader package of conservation outcomes inherent in the title of ‘marine protected area’. Closure of an area to all fishing certainly does not constitute provision of total protection, as has been claimed by numerous scientists. How can it when it does not provide protection against the higher priority threats even to that area, let alone to the broader marine estate?
The real imponderable is whether impacts other than fishing on jewfish populations will be addressed as conscientiously and effectively as that of fishing. Can they be while so many of the non-fishing impacts on fish populations remain inadequately described, ineffectively managed and, currently, apparently irreversible?