These pages have been put together to address some of the concerns of rec fishos about the impacts of MPAs, and in particular sanctuary zones, on their lifestyle and fishing future in Western Australia. Despite the controversy, there is a lot of evidence supporting the view that sanctuaries will actually solve many of the problems facing us as fishos in Western Australia, a lot of which is presented here.
Sometime in 2010 the Federal Government will put in place a network of marine parks around the south west (that is roughly Kalbarri to Kangaroo Island). These will only be in waters managed by the commonwealth, i.e. 3nm from shore to 200nm from shore (the EEZ). Howard started this by signing up to an agreement with the UN to manage Australia’s waters for use and conservation and it has been done twice before around Victoria and Tassi, and at the Great Barrier Reef.
You might already have seen the first signs of this process in the paper. Last year DEWHA released 7 of what they called Areas For Further Assessment – meaning areas they are thinking are important for conservation. It’s an important time to get clued up about how these changes might benefit and impact you and your fishing.
The WA marine parks and recreational fishing pages are written by Fishers For Conservation member Adrian Meder
A Note From the Author
The reason I have put this information together is that I have considerable personal experience fishing, working and studying around no-take marine reserves, and am aware of a lot of misleading information surrounding their effects on recreational fishing. I am not a marine reserve scientist (I work primarily in fish farming research), but I have some scientific knowledge (a masters degree in marine biology) and know people that have conducted some important research in sanctuary zones. I also love fishing and getting on the water (its why I got into the field in the first place, like many others – to keep near the sea), and will not let anyone take fishing away from me, either through over-regulation, or overfishing. As many of the loudest voices in the debate have not actually experienced large, no-take marine sanctuaries in their backyard, there is a lot of misinformation out there. So why would a recreational fisho support sanctuaries? Because they can protect your local fishing from getting any worse in the long term, and provide outstanding fishing around their edges.
Caption: Catching big Pink snapper in shallow water – an experience worth preserving
Adrian Meder 20/02/10
How Do Sanctuaries Affect Fishing?
Scientific Surveys of Sanctuaries – More Fish, Bigger Fish
The chart below shows the effects of sanctuary protection on numbers and size of rec fish target species from existing sanctuary zones in WA, across Australia and in New Zealand where sanctuaries have generally been in place longer.
These figures were taken from scientific surveys that counted the number of fish found inside the sanctuary area, and compared it to the number of fish found over identical habitat in nearby areas open to recreational fishing.
In a couple of examples like Blue Cod and Butterfish at the Kapiti Island sanctuary zone in NZ, fish were not more numerous compared to surrounding fished waters, but were 25 to 30% larger— in fact, up with the biggest sizes recorded anywhere for this species. This is explained by the highly territorial habits of these species – where bigger fish have bigger territories. Everyone knows bigger fish are better breeders, so areas with bigger fish provide a bigger benefit to the fishery – especially when we know some of them are not being caught. In the overwhelming majority of sanctuary zone surveys in published journals, fish were larger and more numerous inside sanctuary zones.
This chart shows evidence from sanctuaries already in place from WA that they are highly effective at increasing fish numbers. For example, 34× more Western rock lobsters, and 10× more Dhufish were found in a small sanctuary at Rottnest Island (Kingston reefs) established in 1986. It was estimated that the lobsters there, as they were so numerous and much larger, could produce around a hundredfold more eggs per unit of area than fished populations outside the sanctuary. It is not hard to imagine that a sanctuary zone like this could compensate greatly for the loss of fishing area by the sheer quantity of eggs that would be ‘exported’ to areas open to fishing! More eggs means more catchable lobsters 5 years down the track. For comparison, it would take an enormously large and expensive fish farming operation to generate that many juvenile lobsters in a year.
The fishable areas immediately around sanctuary zones in Florida are now (in conjunction with other management changes) responsible for producing the majority (50-62%) of IGFA world-record fish for 3 species caught in the state despite encompassing only 13% of the Florida coastline.
What Do the Fishos Think?
So what do rec fishos that already have sanctuaries in their back yard think? These are probably the best people to ask about the real impact of sanctuary zones on recreational fishing. The Great Barrier Reef has had 33% of its waters in sanctuary zones (called ‘green zones’) since 2004. A survey of recreational anglers (more than 13,000 of them) there four years later showed that “73% of fishers said that the zoning plan (of new sanctuary zones and rec fishing only zones) had either no effect, or a positive effect on their recreational fishing activity”. 66% said the new plan increased the protection of marine life in the area. Just four years down the track (given that fish numbers in sanctuary zones take a while to rebuild), a clear majority of rec fishos themselves report there is no impact on their fishing, and that protection of their fishing area is improved. So why would they be so bad in WA?
Around 33% of the Ningaloo Marine Park (or ~86000 hectares) was closed to fishing in 2005. 30,000 recreational anglers were thought to visit the park that year. A survey of visitors soon after the sanctuary zones were put in place showed general dissatisfaction with the process of implementing the parks, and that 80.1% of campers were impacted by the fishing closures (so that the majority had to go fishing somewhere else). Crucially, 99% of campers stated that they would return again. Five years later, with 11 million hectares closed to fishing, people still visit the Ningaloo to fish in droves. Of 179,000 visitors, 37% (or around 60,000) rated fishing as an important activity in 2008.
Sanctuaries mean a healthier marine environment producing more fish and bigger fish in and around the sanctuary. Furthermore, large networks of marine sanctuaries have been shown not to negatively affect recreational fishing in Australia – and in some cases, make it better.
How Can We Know Sanctuaries Produce More Fish for Fishing?
It would be stating the obvious that fishos prefer fishing in areas where fish are plentiful and easy to catch, and spend more time at the better fishing spots than at average or bad ones. If sanctuaries actually produced better fishing by generating ‘spillover’ fish from inside a sanctuary zone to outside – then overall fishos might be expected to devote more fishing activity around the edges of the sanctuary zone (where the spillover would be most likely to occur) where they are able to fish freely. This is called ‘fishing the line’. Why are there so many craypot floats dotting the edges of existing sanctuary zones in WA (and everywhere else) if crayfishers do not expect good catches there? A good international example is the Georges Bank bottom fishery, off the northeastern coast of the USA. This was one of the most productive fisheries in that country, until its decline and near collapse mid-last century. In order to regenerate this fishery, huge MPAs including sanctuaries were established (some 20,000 square kilometres worth) along with stricter management controls. Today, as the fishery regenerates, most fishing activity is concentrated at the borders of these MPAs. For the commercial fishers there – where more fish for less effort equals more money – it makes economic sense to spend more fishing time there.
Introducing sanctuaries means losing some areas and gaining others where fishing is not only better, easier, and effectively guaranteed in the long. Smart planning and implementation of sanctuary locations could also reduce the need to travel ever further from the boat ramp to find good fishing, by restoring productive fishing to areas closer to shore. Given rising fuel costs, and the breezy and exposed nature of the coast in WA, the creation of a network of sanctuaries along the coast would also make sense from an economic and safety perspective for Western Australian fishos.
The Science on Sanctuaries and Benefits to Fishing
There is no longer a debate among scientists that marine sanctuaries provide conservation and biodiversity protection. There is still a strong debate around the potential benefits of marine sanctuaries and fisheries management. The majority of these issues remain unresolved primarily because science in the sea is much more difficult than on land. There are very few species among those that we fish heavily where we have a clear understanding of where they go, where they spawn, and how well they reproduce. An important point to make is that there is a much greater demand for scientific justification for specific issues around marine sanctuaries than there is for the management of many of our fisheries.
There are literally hundreds of peer reviewed scientific reports that provide concrete proof that sanctuaries are delivering benefits for recreational fishing, conservation and protecting against fishery collapse. Harder to find; however, are credible scientific reports that show sanctuaries which do not have benefits for conservation and management, though of course there are a range of valid opinions and evidence on the issue. Most evidence for sanctuaries that do not provide some benefit comes from areas where sanctuaries are too small or placed in areas that do not feature or cannot support a particular fishery.
There is plenty of theoretical evidence (based on computer modeling) that sanctuaries do not produce more fish overall when fisheries management is good and stocks are under no threat of overfishing. However, those same computer models predict that sanctuary zones enable faster recovery of overfished stocks. Where management is good there is not a compelling argument that sanctuaries improve the numbers of actual fish. What sanctuaries do provide fisheries managers with is a baseline of unmodified fish populations to base their research on – this is considered of great value. It also provides insurance – “money in the bank” for when fisheries management gets it wrong. Is it worth it to catch a few less fish in the best of times to avoid the worst of times altogether (after all, we have accepted many bag limit reductions under existing management)? In a few years time, many West Australians may be asking this question.
Sanctuaries are considered by many ecologists and fisheries scientists as valuable, and increasingly essential, tools in a toolbox of fishery management techniques. This is because they can increase fish stocks by protecting old fish and critical habitat, allow monitoring of changes to fish populations in the absence of fishing pressure, and provide a baseline for determining the holding capacity (numbers and size of fish that an area can support) when setting catch limits for an area.
Note that no one suggests that sanctuary zones can improve fisheries without additional management, or that they should replace good fisheries management; however, they can and do maintain and improve fishing and complement other measures where fisheries management is not achieving desired outcomes, and can effectively reduce the need for very harsh fisheries restrictions in surrounding waters.
The Role of Sanctuary Zones Within Fisheries Management
The major principle behind fisheries management is the Maximum Sustainable Yield – which is the maximum proportion of unfished, or ‘virgin’ stock size that can be taken yearly by commercial and recreational fishos without causing a major decline in that species’ stock in the following years. If there are NO large areas of unfished water, and NO known populations of targeted fish that have not been modified by fishing, how are fisheries managers supposed to know what an unfished population looks like?
Most fishery management in WA is based on the earliest reliable commercial fishery catch records available —in some cases this goes back to the 1950s – and make their estimates based on that. For example, in Western Australia a stock is considered healthy or sustainable if it has 40% or more of virgin biomass; and unsustainable if lower than 20% of virgin biomass. In the case of demersal fish in the west coast bioregion of WA, the first formal assessment of the condition of the fishery began in 2003. Too often, the existence and collection of reliable catch data occurs long after commercial fishing began for a particular fishery, so that even the best data cannot reflect the virgin state of our fisheries. Note that demersal fish in WA are not managed under MSY principles, as there is insufficient knowledge about these fisheries to support this approach.
Sanctuary zones provide managers with a window in which to observe unfished populations in an ongoing manner. Decisions can then be based on how much fishing an area can support right now, not how much we think it used to be able to support, and regardless of what the fishery used to look like.
Our ability to manage the sea is also made more difficult by changes in fishing technology—no one would pay for GPS or braided line if it did not make catching fish easier – but predicting how much easier is extremely difficult for fisheries managers. Changes in technology mean we are constantly underestimating our ability to catch more fish in a dwindling resource, and makes the use of historical catch rates (of fish caught with outdated techniques and technology) for management decisions more difficult.
Do fisheries managers make mistakes? In exactly the same way other resource managers do (financial managers have made a few lately) – especially when they have funding issues. Sanctuary zones provide insurance against those mistakes when implemented adequately by ensuring that stocks of large, mature breeding fish can remain in an area whatever happens. Fishos will insure their boat, but what about their lifestyle?
Fishing needs insurance from environmental change, from management mistakes, from politics, from population growth, and from overfishing. Setting aside areas in the form of sanctuaries ensures that heavily targeted fish can continue to have secure breeding populations in an area, for ourselves and future generations to catch.
Fishing is on the Rise
The above maps are taken from the WA Department of Fisheries publication “Fisheries Brief #1 West Coast Demersal Scalefish”, and show the increase in fishing effort and catches for Dhufish and Pink Snapper since the late 1990s. It is clear from the maps that fishing activity has moved out wider and into more remote areas away from population centres. It is unlikely that there is any other major reason for this other than the extra travel is required to find better fishing. Unfortunately, nowadays there is little left of the range of our favorite species like Dhuies and Pink Snapper in the West Coast Bioregion that is not under significant fishing pressure. Only 15yrs ago there was still plenty of areas left that had very low, if any fishing pressure at all and these areas helped restock our fisheries. In a sense, recreational fisheries management used to be supplemented by unfished areas created by distance from the boat ramp but this is no longer the case.
It raises a series of questions:
- What does fishing pressure look like in 2010?
- Does returning some areas to an “unfished state” now have any advantages for our fishing?
- Would it help fishos, or be of any advantage, to return fishing pressure and quality to that of say, 15 yrs ago?
- How good do we want our fishing to be?
- How much more pressure, despite bag and size limit changes, can waters of the west coast handle?
Dhufish Recreational Management Changes Through History
There has been recreational management of Dhufish in WA since a minimum size limit of 13 inches was first introduced in 1958. Bag limits were introduced in 1975. It is clear from the chart above that bag limits for Dhufish and mixed species demersal limits have been steadily reducing for 25 years. Late 2009 saw the first introduction of the next phase in reducing our ability to catch these fish, with the introduction of seasonal bans and licenses. If the management methods and decisions were sufficient to maintain Dhufish stocks at the time of the changes, then bag limits should only fall at the rate that angling effort increases (as well as accounting for any environmental changes and possibly changes in commercial management), and that restrictions can potentially be relaxed following good recruitment events or periods of reduced effort. There are, unfortunately, few examples of recreational fishing restrictions being relaxed in recent times. There is no argument here that there are not problems with Dhufish stocks that require increasing tough restrictions. It is clear that these conventional management methods have not arrested the decline of such recreationally important fish stocks as Dhufish in the past. Perhaps it is time to adopt new approaches (that have been proven to recover overexploited fisheries) such as marine sanctuaries to supplement conventional management.
Sanctuaries? Are There Better Ideas?
Are there better ideas than sanctuary zones for recovery and management of recreational fishing stocks into the future in Western Australia?
Various recreational fishos and organisations have called for other ‘better’ ideas than sanctuaries. These include replacing commercial catches with fish farming, enhancing marine waters with farmed fish and creating artificial reefs to create more habitat. Other ideas for marine park management include ‘rec fishing only’ zones or allow some types of fishing (e.g. trolling) in sanctuary zones, or full closures of limited duration, before reopening zones to fishing once they have regenerated. These methods are described in more detail below:
Further restrictions via traditional fisheries management:
Western Australia is unusual in that is has very heavily regulated recreational fisheries relative to the other states. A combination of low bag limits, licensing, seasonal fishing bans and spawning closures are used to manage our targeted fish species. With the growth in the fishing population, and decline in our most prized stocks, these regulations can only be expected to grow tighter.
One of the major issues with traditional fisheries management is that changes aimed at protecting fish stocks must be politically appealing in order to be successful. For example, in WA we now (early 2010) have a two month ban for demersal fishing in combination with moderate license fees in an attempt to cut recreational effort on demersal species by 50% – although this decision appears to be have been made without consultation by a rec fishing lobby group, consulting neither scientists nor fishos. Note that the original proposal from fisheries scientists was to halve the recreational catch. Managers tried to achieve this with a 4 month ban. After proving unpopular with fishos this idea was dropped. The next idea was for the introduction of very costly licenses to limit the amount of fishing by restricting fishing to those who can best afford it. Again this idea had low political appeal and was dropped after it was widely criticized as a fishing tax grab. The restrictions that are in place now use less harsh bans and license fees (small enough to avoid public outrage, more so than large enough to reduce fishing effort), and gear restrictions. These new restrictions are unlikely to have the same effect as the harsher restrictions and so will probably lead to further restrictions if stocks continue to decline. What is clear is that they were introduced for their political workability rather than on the scientific recommendations of fisheries scientists. It is fair to say there has not been a high level of trust of fisheries management in the state in recent years by rec fishos, and that if longer bans and more costly licenses are required (if stocks continue to decline), they will be difficult to sell to the fishing public.
Aquaculture:
In an ideal world, aquaculture has the potential to replace wild harvested fishing effort. In reality, they are seen by the industry as two separate business opportunities. Fishing will continue to maximum sustainable yields in wild fisheries, and aquaculture will grow to as much production capacity and space as is allowed by government regulators. Aquaculture production has already grown to one third of Australian seafood production (in 2003-04), but there has been no effort by industry or government to reduce wild fishing pressure because of this. That this should happen in the future, for the sake of improving recreational fishing, is unlikely. Aquaculture activity in the ocean or rivers generally increases nutrient and chemical (parasite treatment, antibiotic) loads into surrounding waters and reduces the area available for fishing.
Enhancement and restocking of recreational stocks:
Many freshwater fish are successfully stocked into rivers, lakes and dams for the sole purpose of recreational fishing. Because these are essentially ‘closed’ water bodies, the fish have nowhere else to go but an angler’s hook, so there are clearly measurable outcomes for anglers.
Enhancement in the sea involves growing juvenile fish on a fish farm and then releasing them into the sea. This is a problem because fish cannot be contained in an area for fishing. Marine enhancement could be great, if it made economic sense for more species than salmon (note they return to the fresh water river they were released into, thus making them much easier to catch), scallops, and possibly abalone – but there are no examples in the sea where recreational re-catch rates justify the expense of artificially producing the fish. To quote the marine enhancement advocacy website www.stockenhancement.org “the effectiveness of stocking is not well understood and techniques for ensuring success have not been developed. To realize the potential of stock enhancement to rapidly replenish fish stocks, better science is needed about stocking juveniles into the sea”. That better science is still required after more than 100yrs of enhancement research and restocking attempts, suggests other methods may be more cost effective at rebuilding depleted marine fish stocks.
The following question was asked to WA Aquaculture Development Unit head Greg Jenkins at the Western Australian Dhufish Workshop 2004 organized by the WA Department of Fisheries and Recfishwest.
Question 12: Are there issues regarding restocking dhufish?
Response 12: (Greg Jenkins) “Restocking is problematic for many species. There is a struggle to get 10 per cent survival for dhufish compared with up to 80 per cent survival for black bream. Dhufish aquaculture would require large amounts of money to pursue restocking and there would be no guarantee of success”.
Marine enhancement requires very fast growing fish, as the greater the time spent in the hatchery, the less cost effective an enhancement program can be. Very fast growing fish like Mulloway or Yellowtail Kingfish may be more suitable. A trial Kingfish enhancement program in New Zealand (“Kingfish go Wild”) involved the release of 20,000 tagged juvenile (average 2kg) fish at 5 sites. The trial cost $30,000 dollars (well below production cost of over $40,000 dollars), raised by the recreational fishing community. After 2 years, a total of 8 fish were recovered. Note that this project was enabled at less than production and transportation cost, and delivered a net recapture rate of 0.0004% at $3750 per fish. This is, arguably, not cost effective enhancement of fishing for the recreational fishing community.
Note that fish restocking programs into closed water bodies (dams, rivers, and some estuaries) are an entirely different proposition to restocking the open sea, and have shown much greater measurable success.
Artificial reefs:
Some recreational fishing groups in Australia have argued that the addition of artificial reefs in depleted waters can produce better recreational fishing, and artificial reefs have been placed in areas around marine parks (such as the Great Barrier Reef MPA) as a means of compensation for lost fishing grounds to recreational fishos. A reef itself does not produce more fish unless there is a severe shortage of available habitat; but aggregates existing fish so that they are easier to catch. A review of scientific research shows that artificial reefs can potentially reduce reef fish populations. If making the existing fish stocks easier to catch is desirable, then artificial reefs can benefit recreational fishing. This could do more damage to dwindling stocks in the long term because it is only making it easier to catch the remaining fish.
WA is unusual in that it is blessed with an abundance of perfectly good reef structure, compared to eastern states (think of the area between Perth and Rottnest, or Jurien Bay). There are even substantial existing artificial reefs in the ship graveyard off the back of Rottnest, which hold spawning aggregations of Samson fish. These fish probably moved there from somewhere else rather than being added to the population because of it. Currently fishos are running over miles of perfectly good but empty reef to find some that still hold fish. If there are not enough fish on those reefs, there is not likely to be more on any new ones we put in.
Recreational fishing only zones
Almost all multi-use marine parks contain recreational fishing only zones. These may deliver improved fishing, but there isn’t much evidence to show that they actually hold any more fish, deliver greater protection to targeted fish populations or improve fishing compared to general use zones. They may be most effective where recreational take is very low and commercial take is very high. This is the case for many fish species (including Pilchards, Western Rock Lobsters, some Tunas), but not so much for fish like Pink Snapper or Dhufish (where the recreational take is estimated to be 20% and 50% of total catch respectively) in WA. Bear in mind that almost the entire Perth metropolitan area is now a rec fishing only zone. Has the fishing improved in the time since that change was made in 2007—if so, will it be enough to restore fish stocks into the future?
Examples from New Zealand show that a recreational fishing only marine park actually held less Pink Snapper (because everyone went fishing there, assuming it was a rec fishing utopia) than surrounding unprotected areas, and lobsters became 11 times more abundant in a nearby no-take marine reserve over the same time period that lobster numbers declined (at the same rate as unprotected areas) in the rec fishing only marine park.
There may be scientific evidence out there that recreational zones are effective – and intuitively, they should improve recreational fishing – in enhancing catch rates, but this author has not been able to find any.
Short term fishery closures
This idea is similar to crop rotation on land, and is used in some commercial shellfish fisheries. For finfish (that are longer lived), the buildup of fish stocks can take much longer, up to 15 years. In the few studies that have looked at fishing effects of temporary closures, evidence suggests that fishing pressure does not take long to strip those extra fish back out of the system. For example, the temporary closure of Bramble reef on the Great Barrier Reef for 3 1/2 years resulted in Coral Trout numbers increasing by 4 1/2 times pre-closure levels. Upon reopening, 60% of those fish were gone after 8 weeks (and back to normal levels everywhere else). That is not much of a return for several years without fishing, and it should be noted that this approach has not been tried again, or officially requested by recreational fishing groups on the GBR since.
Spawning closures have been used successfully to rebuild and protect fish stocks, including in WA. It is important to understand that they are only effective for fish that aggregate to spawn in a known area, over a predictable and short period of time (to minimize impact on rec fishing). A good example of this is Pink Snapper in Cockburn Sound. For other species, like Dhufish, thought to spawn throughout their range, and over a period of up to 6 months, an effective spawning closure would mean not fishing their entire range for 6 months. Use of sanctuary zones could allow a measurable number of all species found in them to spawn throughout their entire lifespan without losing fishing access to the majority of their population at all through the spawning season.
Other annual closures are introduced to reduce the ‘effort’ of recreational fishing, such as the current 2 month ban on demersal fishing. They are directly intended to reduce the time you can fish (and therefore the number of fish you can catch), and work in a broadly similar way to a sanctuary zone. Unlike a network of sanctuary zones – that allow you to fish all year but not everywhere– they do not protect or create a pool of the largest breeding fish that contribute the most to the long term health of a fishery.
Is Fisheries Management Enough?
Recreational fisheries management using traditional bag and size limits and gear controls is very difficult to get right. Even at its best we can expect our catches to get smaller and smaller as populations grow, fishing technology improves and more boats get out on the water. If bag and size limits were all that was needed to manage recreational fish stocks, and these methods were working well, bag limits should only drop at the rate that populations increase, and that technology available to fishos makes fishing easier. It’s probably fair to say that bag limits have dropped a bit faster than that!
Often opponents of sanctuary zoning say that not enough research has been done for specific areas to justify sanctuary protection. Unfortunately a lack of research has been a feature of all our extractive activities in the marine environment. Many fisheries (i.e. Orange Roughy) have crashed before the necessary research was done to tell us that heavy fishing was never a good idea. This is a very political argument. It is fair to say that if such a high level of research was required before opening a fishery as is demanded before implementing a sanctuary zone, we wouldn’t be fishing for very many species. Bear in mind that the first formal stock assessment of demersal fish in WA began in 2003. This is a very late start for science based fisheries management on a global scale – for example a quota management system (which is currently being considered for some WA fisheries and is based on stock assessment) was introduced for key stocks in New Zealand in 1986, 1988 in Victoria, and 1998 in Tasmania.
Once bag limits fall to say, one fish per angler per day, then there isn’t much scope left for further control using traditional methods for that fishery that allow fishos to remain ‘on the water’. This is when things like bans and license fees come in that are aimed at taking fishos off the water altogether – and this is becoming the reality of rec fishing management in WA. Sanctuary zones are a type of ban—one that allows fishing all year, and actively improves fishing in surrounding areas where stocks are under heavy fishing pressure already, by ensuring populations of large breeding fish are maintained in an area. Many of those that argue sanctuary zones have no benefit for fishing, do so when fish stocks are not being overfished. Fair enough! In WA, unfortunately, it looks like fishing pressure is at least very heavy, if not overfishing, for our favourite fish right now. That pressure is growing with increasing population and wealth.
The Western Rock Lobster fishery is hailed around the world as being one of the best examples of sustainable fisheries management. Yet even it is having some severe troubles, with the industry itself calling for closures. Nobody would have predicted a few years ago that this might happen, and it is fair to say that either someone has got it terribly wrong, or that management has failed to predict or protect against the changes now occurring. Either the fishery is on the verge of collapse in the medium term, or the managers have got their system (the one lauded as being world’s best practice, and used to manage the fishery for more than 40 years) completely wrong. Everyone knows which case they would prefer it to be, but it doesn’t change the fact that even the best traditional fisheries management has shown some major flaws, with the potential to collapse fisheries and destroy jobs and communities.
Why ban all fishing in a sanctuary zone?
Surely, if a sanctuary zone is in place to protect demersal reef fish, there is no need to stop us from catching a few tuna, salmon, Samson fish or other highly mobile pelagic fish? Surely, if a sanctuary zone is in place to protect habitat on the bottom, there is no need to stop us from catching a few pink snapper or crays?
This argument is based on the idea that fish in a particular area have little effect on other fish in that area. Ever noticed how there tends to be good snapper fishing near the bottom right below that school of salmon or bonito working the baitfish on the surface? For almost all of the ocean where sun light does not penetrate (which is a lot of ocean), marine life on the bottom is entirely dependent on the ‘rain’ of dead, half eaten fish and nutrients from near the surface – and this half eaten fish comes from the activity of pelagic fish, mammals and seabirds near the surface. So without the presence of these highly mobile fish at the surface, there may be less demersal fish on the bottom.
Ever since scientific study began in areas where fishing pressure was removed, examples have been found where the numbers of top-order predators (many of which are our target fish) heavily influence the ecosystem as a whole. Research in sanctuary zones in New Zealand shows that ‘keystone’ predators like Pink Snapper and Lobsters indirectly support the presence of kelp forests. This is because large, legal sized Snapper and Lobsters can eat the large sea urchins that graze the reefs (while smaller ones – below legal size – cannot). Because these larger fish have been removed by fishing over most of their range, areas known as urchin barrens dominate where there are plague proportions of sea urchins that prevent the formation of kelp forests. Kelp forests are a critical nursery habitat and shelter for a range of non-targeted fish and shellfish. When fishing pressure was removed, through sanctuary protection, fish grew large enough to eat these urchins – allowing the kelp forests to regenerate to the extent that the ‘urchin barrens’ were reduced back to pre-fishing levels. In one sanctuary zone it was estimated that total primary productivity of the reef area was increased by 58% – all because the return of the big Snapper and Lobsters allowing the kelp reef to grow back. There is even evidence that small lobsters and big lobsters may play different roles in the ecosystem – almost as if they were different species – as they contribute to their ecosystem in different ways. In this way, more fish means even more fish. Because there are no large marine sanctuaries in the South West of WA, we simply have no idea whether any of these fishing-induced changes have taken place here.
Furthermore, sanctuaries could improve the fishing of highly mobile pelagics – if they do not stick around for long – but their prey bait fish are protected in an area, then they should be likely to remain in an area longer or return more often if food is plentiful. They may not receive much protection from a single sanctuary zone, but a representative network of large sanctuaries would still offer protection from overfishing, as they would spend enough time away from fishing as they move up and down the coast. However, there has been little conclusive research in this area because it is difficult to research fish that widely disperse and networks of marine reserves are still relatively rare.
Another argument is that sanctuaries cannot protect fish that are not totally sedentary (i.e. don’t remain in the same spot their whole lives). For example, juvenile Pink Snapper are thought to be highly mobile in most Western Australian waters (the exception being Shark Bay). They were also thought to be highly mobile in New Zealand waters, until research in sanctuary zones (in fact it would be impossible to do this research without Sanctuary zones) that tracked individual fish showed that Pink Snapper could remain in the same area for over 3 years, and that big fish, while not being territorial, could spend up to 30% of their time in as little an area as 20 m2. We do not know if this is the case in Western Australian Pink Snapper populations, though it would be highly valuable information for fishery management. Without sanctuary zones to ensure protection of large adult fish, gaining this knowledge (even performing the research) is almost impossible. It may even be that the establishment of sanctuary zones with higher productivity of food and fewer threats will encourage more sedentary behavior from these species.