Troublesome trawling: how New Zealand's fishing industry hid the truth about by-kill

I recently signed a petition to reduce by-kill in New Zealand waters by installing cameras on all commercial fishing vessels. Forest and Bird and World Wildlife Fund New Zealand are jointly campaigning for this monitoring, as only a small percentage of boats as yet have cameras. The previous New Zealand government agreed to the wider introduction, but Fisheries Minister Stuart Nash is considering reversing this due to industry pressure. Considering that the current administration is a coalition involving the Green Party, this seems highly ironic. Is this yet another nail in the coffin of New Zealand's tourist brand as 100% Pure?

Despite requests from the fishing industry not to release it to the public, on-board footage shows the extent of the by-kill. High numbers of rare and endangered species have been drowned in nets, from seabirds such as wandering albatross and yellow-eyed penguins/hoiho, to cetaceans (there are thought to be only fifty or so Māui's dolphin/popoto left), seals and sea lions.

Many of the cameras already installed on New Zealand boats failed in the first three months due to inadequate waterproofing; when allied with the fact that the supplier of the technology was an integrated part of the seafood industry, there's more than a whiff of something fishy going on. Although official statistics are often considered to be of dubious quality, Occam's razor can be used to decipher the by-kill figures as they have been reported in the past decade. Only three percent of New Zealand's set net boats are officially monitored, yet they account for the vast majority of the recorded by-kill. Given a choice between sheer coincidence (i.e. only monitored vessels are catching large numbers of non-target species) and severe under-reporting from unmonitored boats, it is obvious that the latter hypothesis follows the law of parsimony.

Sadly, widespread deception by New Zealand's fishing industry isn't something new. A third-party report involving undercover operatives stated that between 1950 and 2010 up to 2.7 times the official tonnage of fish was actually being caught, peaking in 1990. All this comes from an industry that is laden with checks and measures, not to mention sustainability certificates. Killing marine mammals within the country's Exclusive Economic Zone isn't just a minor inconvenience: since 1978 it's been illegal, with severe fines and even prison sentences for those convicted. Small wonder then that the majority of by-kill has been undeclared.

What is equally sad is the lack of interest from the New Zealand public in resolving the problems. After all, over ninety percent of the population are not vegetarian, so we must assume the vast majority enjoy seafood in their diet. The rapid replacement of over-fished sharks with Humboldt squid in the Sea of Cortez off Mexico's Pacific coast shows how the removal of a key species can severely affect food webs. If New Zealanders are to continue to enjoy eating fish with their chips, the sea needs better protection.

Over the past decade, other nations have shown commitment to reducing by-kill and lessening waste. In 2010 the British celebrity chef Hugh Fearnley-Whittingstall launched the Fish Fight campaign to stop the discard of about half of the European Union's catch (due to it being either undersized or from non-quota species). Immense public support over the subsequent four years led to phased changes in the European Union's Common Fisheries Policy, proof that citizen action can make fundamental improvements.

Incidentally, it wasn't even a case of division along party lines; I was living in the UK at the time and wrote to my Labour Member of Parliament, who replied in a typically circumlocutory fashion that she would look into the matter! Even the then Conservative Prime Minister David Cameron agreed that EU policy needed a radical overhaul, a rare instance of cross-party sense and sensibility over pride and prejudice.

So what solutions are there to reducing by-kill? After all, installing cameras would only be the first step in assessing the scale of the problem, not removing it. Since Australia started monitoring its long-line tuna fleet, there has been a whopping seven hundred percent increase in the reporting of seabird and marine mammal by-kill. Some seaboard states in the USA have already banned set netting, which is still in widespread use in New Zealand. Several areas around the New Zealand coast such as between Kaipara Harbour and Mokau already prohibit this method of fishing - in this case to protect the few remaining Māui's dolphin - so there are precedents.

In addition, there are programmes currently testing new technology that may provide the answer. In 2002 the now charitable trust Southern Seabird Solutions was created to reduce by-kill of albatross and other endangered pelagic species.  This alliance of fishing industry leaders, recreational fishers, researchers and government analysts are trialling wondrously-named devices such as the Brady Bird Baffler, Hook Pod, tori lines and warp scarers.

Elsewhere, nocturnal experiments have been conducted using acoustic pingers to deter dolphins, although the results to date aren't especially promising. Equally dubious is the amended trawl net design for squid fishing vessels that incorporates the Sea Lion Exclusion Device (SLED); only today, it was reported that a juvenile sea lion had been found dead in such a net. Clearly, STEM ingenuity is being brought into play, but it will require further development and widespread introduction of the best solutions without industry interference in order to minimalise by-kill.

There are also some simple changes of practice that don't require equipment, only for the boat crews to be more aware of wildlife and act accordingly. Such procedures include moving away from areas with marine mammals present, not dumping offal, recovering lost gear, and changing the operating depth and retrieval speed of nets.

As usual, the financial considerations have taken precedence over the ecological ones. New Zealand has a comparatively small economy and as seafood is the nation's fifth largest export earner - over one billion dollars annually - it is hardly surprising that successive governments have tended to side with industry rather than environmentalists. However, could it be that there is now enough apprehension about the general state of the oceans to overhaul the sector's laissez faire practice? After all, in 2007 a fishing ban in New Zealand waters was placed on orange roughy, whose rapid decline caused huge concern.

There are of course plenty of other environmental issues affecting marine life: plastic pollution (including microbeads); increasing temperature and acidity, the latter especially drastic for shellfish; offshore algal blooms due to agricultural nutrient run-off; and numerous problems created by the oil and gas industry, from spillages to the far less reported exploratory air guns that impact cetacean behaviour.

The longer I've been writing this blog the more I'm convinced that science cannot be considered independent of the wider society in which it exists. Social, political and religious pressures and viewpoints can all adversely affect both what research is funded, what the time constraints are and how the results are presented or even skewed in favour of a particular outcome.

In the case outlined above, government ministries hid evidence to protect short-term industry profits at the expense of long-term environmental degradation - and of course the increase in public spending the latter will require for mitigation. New Zealand's precious dairy sector is already taking a pounding for the problems it has knowingly generated, so no doubt the fishing industry is keen to avoid a similar fate.

By allowing such sectors to regulate and police themselves and thus avoid public transparency, the entire nation suffers in the long run. We don't know what the decline or disappearance of populations of for example wandering albatross and Māui's dolphins might have on the (dis)appearance of snapper or blue cod at the dinner table, but as the alarming loss of Mediterranean and Californian anchovies and sardines suggests, negative cascades in the food chain can occur with extreme rapidity. Natural selection is a wonderful method of evolution but we are pushing it to the limit if we expect it to cope with the radical changes we are making to the environment at such a high speed. By-kill is something we can reduce, but only if industry and governments give science and the public a 'fair go'. Now isn't that something New Zealanders are supposed to be good at?

Sandy strandings: the role of contingency in the beach biosphere

At irregular intervals over the past fifteen years I've been visiting the east coast beaches of New Zealand's Northland between Warkworth and Paihia. Although it's frequently good territory for finding shallow marine fauna via rock pools or along the tideline, a recent visit was enhanced by exciting finds unique in my experience. I usually expect to see the desiccated remains of common species such as sand dollars, scallops, whelks and assorted sea snails, but coastal storms just prior to my arrival brought an added bonus. Two days of exploration along three beaches was rewarded with a plethora of live - but presumably disorientated - creatures such as common sea urchins (Evechinus chloroticus) and large hermit crabs (Pagurus novizealandiae), along with some recently-deceased 5- and 7-arm starfish. As you might imagine, several species of seabird, notably terns and gulls, were having a gastronomic time of it with all these easy pickings.

At the nearby Goat Island Marine Discovery Centre run by the University of Auckland I told our marine biologist guide about my two daughters' attempts to save some of the homeless hermit crabs from the gulls by offering suitable shells as new abodes. The biologist responded with a story of a visitor who had thrown live starfish back into the water after a mass stranding. Someone else commented that his actions wouldn't make a difference; our guide said that as he continued throwing them, the man replied "It made a difference to that one...and that one...and that one..."

Common sea urchin (Evechinus chloroticus)

Of course we cannot hope to make much of a difference with such good intentions: nature, after all, is essentially immune to human morality and empathy, with survival at a genetic level the only true sign of success. But do small-scale events whose aftermath I recently experienced - in this case a few days of stormy weather and the resultant strandings - have any long-term effects on the local ecosystem?

Apart from a mass marooning of the large barrel jellyfish Rhizostoma pulmo on a North Wales beach around thirty years ago, I haven't experienced anything similar before. But then until three years ago I didn't live near the sea, so perhaps that's not unlikely! There are fairly frequent news stories from around the world about mass whale or dolphin beachings put down to various causes, some man-made such as military sonar. But as these events involve animals larger than humans they make it onto the news: for smaller creatures such as the crabs and urchins mentioned above, there are unlikely to be any widely-disseminated stories.

Australian southern sand star (Luidia australiae)

It may seem improbable that the balance between organisms could be profoundly altered by local events, but it should be remembered that a few, minor, outside influences over the course of less than a century can wipe out entire species. For example, although the story of how a single cat was responsible for the demise of the Stephens Island wren around the start of the Twentieth Century is an oversimplification of the events, there is evidence that current human activity is inadvertently causing regional change.

One well-known recent illustration is from the Sea of Cortez, where too much game fishing, especially of sharks, may have led to the proliferation a new top predator, the rapidly spreading Humboldt squid. Estimates suggest that the current population in the region is over 20 million individuals (which suits the local squid-fishing industry just fine), but extraordinary considering none were known in the region before about 1950. Two-metre squid may not sound menacing compared to sharks, but the Humboldt squid is a highly-intelligent pack hunter with a razor-sharp beak and toothed suckers on its tentacles, so diving amongst them is probably not for the faint-hearted.

The TV series Cosmos: A Spacetime Odyssey contained a good introduction to the five mass extinctions of the past 450 million years, but it isn't just these great dyings or even El Niño that can upset ecosystems; we may find out too late that relatively minor, local changes are able to trigger a chain reaction at a far wider level. The evolutionary biologist Stephen Jay Gould repeatedly emphasised the importance of historical contingency and the impact of unpredictable, ad-hoc events on natural history. The modern synthesis of evolutionary biology includes the notion that speciation can result from isolation of a population within an 'island'. This latter differs from the strictly geographical definition: a lake, or even an area within a lake, can be an island for some species. If, for example, local changes cause a gap in the ecosystem, then this gap might be filled by an isolated population with the 'fittest' characteristics, in the sense of a jigsaw piece that fits the relevant-shaped hole.

Hermit crab (Pagurus novizealandiae)

Back to the beach. American marine biologist Rachel Carson's 1951 award-winning classic The Sea Around Us contains an early discussion of the recycling of nutrients within the oceans, but we are now aware that the sea isn't remotely self-contained. My favourite example of an intricate web of land, sea and even aerial fauna and flora centres on the Palmyra Atoll in the Pacific Northern Line Islands. Various seabirds nest in the atoll's high trees, their nutrient-rich guano washing into the sea where it feeds plankton at the base of the offshore food chain. The plankton population feeds larger marine fauna, with certain fish and squid species in turn providing meals for the seabirds, thus completing the cycle. Such a tightly-knit sequence is likely to undergo major restructuring of population densities if just one of the players suffers a setback.

I appear to have followed Stephen Jay Gould's method of moving from the particular to the general and may be a little out of my depth (okay, call it a feeble attempt at a pun) but it certainly gives food for thought when local shallow marine populations appear to suffer after only a few days of mildly inclement weather. If there’s a moral to any of this, it’s that if natural events can affect an ecosystem in unpredictable ways, what havoc could we be causing, with our pesticide run-off, draining of water tables, high-energy sonar, over-fishing and general usage of the oceans as a rubbish dump? The details may require sophisticated mathematics, but the argument is plain for all to see.