OUR BURNING PLANET
Decision time: Will Barbara Creecy put an end to fishing around dwindling penguin colonies?
The African penguin is an endangered species. To see if ending fishing around penguin colonies in the Western and Eastern Cape would help protect these birds, islands were closed in an experiment. However, conservationists and the fishing industry assess the results differently. It’s now in the hands of the government.
Environment minister Barbara Creecy has a decision to make – does she allow fishing to continue around endangered penguin colonies or not?
Daily Maverick recently reported on the endangered African penguin and how conservation groups like the Southern African Foundation for the Conservation of Coastal Birds (Sanccob) and BirdLife SA believe the biggest threat to colonies is prey availability, which is likely influenced by a combination of both environmental variation and resource competition by the pur-seine the fishing industry.
They want Creecy to ban fishing within a 20km radius of the six major penguin colonies – Dassen Island, Robben Island, Stony Point and Dyer Island in the Western Cape, and Bird and St Croix islands in the Eastern Cape.
Their recommendation is based on results of the island closure experiment that ran from 2008 to 2019. It was put in place to see if closing fishing around penguin colonies had a positive effect on penguin populations.
Sanccob, Bird Life SA, World Wide Fund for Nature and some individuals from Nelson Mandela University like Professor Lorien Pichegru and the University of Cape Town like Professor Lynne Shannon endorse the recommendation of the ban, based on marine ecologist Dr Richard Sherley’s interpretation of the results of the island closure experiment.
Sherley found that “fishing closures improved chick survival and condition, after controlling for changing prey availability”.
While the results are out, so is the jury.
The South African Pelagic Fishing Industry Association (Sapfia) does not support a ban. Their position is based on UCT’s Prof Doug Butterworth’s recent assessment of the experiment – that closing fishing around colonies had no significant effect on halting the decline in penguin numbers.
Butterworth, who was contracted by the fisheries branch of the DFFE to do this research, and the Marine Resource Assessment and Management Group (MARAM) from UCT hold this view, but there are opposing views from other UCT groups including the FitzPatrick Institute and the Marine Research Institute and some individual academics like Professor Lynne Shannon who endorse the closure.
Earlier this year, Creecy initiated a process whereby Fisheries, Oceans and Coasts and SANParks would work together to come up with recommendations and scenarios.
“She is going to use what comes out of that process to make a decision on the way forward in terms of island closures. She is taking this issue very seriously, which is great,” says Sanccob’s Lauren Waller.
But who and what should she believe?
The pelagic fishing industry’s perspective
Sapfia agrees that the penguin breeding population is much reduced from what it was at the beginning of the previous century, and that the current rate of decline is a serious concern.
However, based on Butterworth’s assessment of the experiment, they do not think that prey availability caused by consumer fishing is the biggest threat to the birds. Butterworth, a leading international authority in fishery assessment, was contracted by the government to do this research.
Butterworth told Daily Maverick that “the 12-year island closure experiment – carried out at non-trivial expense to the fishing industry – has led to results that show the impact, if any, on the penguins of stopping fishing around some penguin colonies will, at best, be to increase their annual growth rate only by about half-a-percent.”
Conservation groups maintain the biggest threat to the African penguin is lack of prey availability, which is caused by fishing. However, Sapfia disagrees for two main reasons.
First, “the proportion of pelagic fish biomass harvested in South Africa is low compared to small pelagic fisheries elsewhere in the world”.
And second, “the stock biomass is at 60-80% of its potential unfished level. These findings are based in part on credible biannual hydroacoustic surveys carried out by the research vessel, the Africana”.
The African penguin mainly feeds on anchovies and sardines. The pelagic fishery in South Africa is a purse-seine one based predominantly on anchovy, sardine and redeye herring.
Mike Copeland, chairperson of Sapfia, told Daily Maverick that the average catch numbers for anchovies, for the years 1984 to 2020, was about 230,000 tonnes a year.
“This represents about 11% of the average biomass for the same period (2,2 million tonnes),” said Copeland.
And for sardines, “the average catch of adult sardine for the years 1987 to 2020 was about 99,000 tonnes. This represents about 12% of the average biomass for the same period (0,86 million tonnes).”
Butterworth cites a baseline assessment of the SA sardine resource to demonstrate how fishing for sardines doesn’t impact the sardine biomass much: “Typically, fishing reduced abundance by about 20% – that’s way below the international norm for such species, and appreciably less than would be considered a safe (and larger) value to target.”
This study also shows how sardine populations are low now, but they would be low even without fishing.
Butterworth said “fishing is not responsible for the current low abundance – it’s environmental factors (not well understood) which at times can result in poor survival of eggs and larvae – something neither we nor the natural predators can do anything about”.
Butterworth said the abundance of anchovy is “only 20-30% below what it would have been in a no-catch situation”.
Conservation groups’ perspective
In contrast, Sanccob’s Lauren Waller and Alistair McInnes from BirdLife SA do not agree that fishing has no significant impact on prey availability.
“The problem is that there’s a concentration of fishing efforts in areas that are targeted by penguins as well,” said McInnes.
Waller said, “We feel, on the basis of the findings presented by Sherley, and indeed Butterworth, that there is sufficient evidence to justify island closures, particularly at Robben Island, Dassen Island and St Croix Island.
“The results from both modelling approaches are saying similar things – it’s how these results are interpreted that are key.”
McInnes agrees, saying, “Despite all these technical debates, the general results still hold, even in Butterworth’s results.”
The assessments might say similar things, but Butterworth’s shows that closing fishing around the islands will, at best, increase the penguins’ annual growth rate only by about ½%, but Sherley’s assessment showed that it exceeds 1%.
“It’s important to note that the 1% threshold was the pre-agreed threshold by the international panel and the working groups to be the biologically meaningful threshold in the experiments,” said McInnes.
But “there seems to be a dilution of that 1% now that it’s getting to crunch time”.
McInnes says Butterworth’s assessment, which was released in June 2021, “hasn’t had time to be challenged by Sherley’s results. And there are also some questionable methods used to integrate his outputs into that 0.5%”.
Despite the critique from Sapfia and Butterworth, McInnes still insists “there’s more evidence for an effect than no effect.
“The results to date show two to four times more positive results than negative results for island closures. Given the current decline of the birds, the prudent response by the government, in adopting a precautionary approach, would be to protect those waters until such time as there is unequivocal evidence to show the contrary.”
International review panel’s report
In 2020, an international panel reviewed some aspects of the island closure experiment, where they had to answer three questions relating to Butterworth’s and Sherley’s assessments, that considered whether there was merit to their approaches and if they could be used to support decision-making.
“The answer was that both sets of analyses could be used, with the caveat that further work should be done,” said Waller, adding, “this is always going to be the case – it’s the nature of models”.
However, Butterworth argues that “the approach used in the Sherley… article which [the previous Daily Maverick article] cites was wrong, and gave an inflated impression of the accuracy of its results.
“When Sherley corrected his approach to adjust for this, he carried out the computations incorrectly (as the 2020 panel pointed out).”
In response, Waller said, “There have certainly been model adjustments made by Richard Sherley since that publication, but even with these updated analyses that Richard has done, it is pretty much saying the same thing… in fact, providing stronger evidence.”
“Remember, all models are wrong,” Waller told Daily Maverick, citing the common aphorism in statistics, ‘All models are wrong, but some are useful.”
Andre Punt, who has chaired the international review panel for years, told Daily Maverick, “The panel has reviewed the technical details of the work done by Sherley and colleagues, and Butterworth and colleagues, and identified areas where further work was needed – for example, even though some of Sherley’s work had been previously published, we found that further work was needed because of a misunderstanding of the model structure that we advocated.
“I would emphasise that the closure experiment has been unique worldwide. It is somewhat unfortunate that, what I consider to be an excellent way to use science to understand how fishing near colonies impacts penguins, has seen some confused by the arguments about analysis methods.”
A ban’s impact on the fishing industry
A socio-economic study was done by consultants Mike Bergh and Philippe Lallemand to estimate the economic impact on the pelagic fishing industry if the ban were to happen.
Sapfia’s position was that “the monetary value of these losses at just two of the four islands involved in the experiment, Dassen and Robben Islands, was estimated to be R300-million (excluding the economic multiplier effect).
“The small pelagic fishery directly employs more than 5,000 staff in addition to seasonal workers. An increase in overall fishery output of R1-million would be associated with an extra 10.7 jobs in the country’s fishery sector and in the wider economy, and a loss in fishery production would be associated with a corresponding decline in employment.”
Mike Bergh, a scientific consultant to Sapfia, explained that if fishing was closed in a 20km radius around penguin colonies, the fishermen wouldn’t simply be able to fish elsewhere because anchovies are an “opportunity based fishery”.
“Anchovies have to occur in sufficient concentrations close to the surface to be fishable, and those conditions arise from time to time in certain areas.
“So, if you don’t take that opportunity, you may not have another chance. It may just be that this week, that opportunity exists within that closed area.”
Bergh estimates that 23.2% of anchovy catches and 30.1% of sardine catches would lie within the proposed closed area.
The value of the pelagic fishing industry
The pelagic fishing industry provides a cheap source of nutrition that many South Africans rely on.
“The fishery is a major contributor to food security through direct human consumption (e.g. canned fish) or indirect human consumption (e.g. bait or fish meal and oil) and employs a large workforce in fishing and related industries mainly in areas outside the major metropolitan centres,” said Sapfia.
Canned pilchards are an important part of the National School Nutrition Programme and “many of the companies have a contract with various school feeding schemes”, says Sapfia’s Mike Copeland.
“It’s estimated that every day over 800,000 cans of pilchards are consumed. And that is equivalent to about 3,2 million meals every day.”
Conservation groups like Sanccob believe that there would be significant economic loss to South Africa, if the sardine and anchovy stock is depleted and the African penguin (and other seabirds like the Cape gannet) goes extinct.”
In a study commissioned by the City of Cape Town in 2018, Dr Hugo van Zyl and James Kinghorn reported that in 2017, the African penguin colony in Simon’s Town alone brought in 930,000 visitors, created 885 jobs and generated R311-million.
However, Bergh says it doesn’t have to be an either-or situation.
“There is an opportunity for both fishing and the tourism sector to continue to generate revenue for the South African economy.”
Butterworth says, “What is urgently needed is to determine what’s causing this reduction in penguin numbers, and to take actions that (if possible) address those causes, rather than react in a way which will have appreciable negative socio-economic impact, but is very unlikely to result in any meaningful benefit to the penguins.
“Whatever is causing this decline, it almost certainly isn’t fishing around the islands.”
In an attempt to get to the bottom of the cause of the decline in penguin numbers, Butterworth has published a study which points at the loss of optimal breeding habitat and burgeoning Cape fur seal populations.
“The penguin population decline may therefore be predominantly the result of competition with seals for food, given that sardine and anchovy constitute important components of seals’ diets, and this competition might also be the primary reason hampering their recovery,” says Butterworth in the study.
However, McInnes says, “there’s been a couple of studies on the relative impacts of seal predation versus prey availability, and prey availability does come up as being more significant. And we are convinced that access to this prey is the biggest limiting factor for the species.”
It turns out science can be very ambiguous.
“You are seeing what I call management science,” said Andre Punt. “We need to make a decision, but there is more data that could be collected and more analyses conducted, but if we waited for all the data we would like, it would be too late.
McInnes said something similar: “We can go through these results with a fine-tooth comb for years, but every year that we delay taking action, we are losing between 5% and 10% of the penguin population.” DM/OBP
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