The Basin Effect

I recently read an interesting article online which highlights some poignant issues effecting our inshore fish species. I do recommend that you take a few minutes to educate yourself on these issues. For ease of reference I have copied the article here below for you:

‘The Basin Effect’, a common phenomenon that fools us all: Towards an understanding of the

plight of coastal fishes in South Africa

By Dr Nadine A. Strydom and Ms Sandrini Moodley

Zoology Department, Nelson Mandela Metropolitan University

“The Bountiful Ocean” are words used by poets, artists, early mariners, fisher folk and even 

scientists once upon a time. We have all romanticized about what the ocean has to offer – those 

unseen riches, poised to take our carefully prepared bait, smash our surface plug or get snagged in 

our nets. Advancements in fisheries science have highlighted the fact that we are often under 

misconceptions about what we catch and how many there are out there. 

One of the amazing things about fishermen – whether they are recreational fishermen or 

fishermen by trade – is that they always seem to know where the fish are. This has been a 

characteristic of fishermen for hundreds of years and mostly comes from experience, and 

knowledge of the fishing areas. Fishermen pride themselves in this knowing but herein lies the 

problem. In recent decades, this skill has been replaced by overwhelming improvements in 

technology such as GPS, cellphones, acoustic technology etc. which allow fishermen and fishing 

vessels to detect target species and target fishing areas with pinpoint accuracy. The fact that we as 

fisher folk can figure these things out through ancient knowledge or our fish finder, tells us 

something about fish behavior. It is well known that fish tend to aggregate around structure for 

refuge, areas of high productivity for food or areas of significance for spawning. These are the 

areas that are known to fishermen as the ‘best fishing spots’. 

The fact that fish tend to aggregate in particular areas and that it can be predicted that the fish will 

be present in those areas at specific times of the year, tide state, moon phase, night time etc. also 

leads to a concentration of fishermen in these areas. This characteristic of fish behaviour means 

that fish populations are neither evenly nor randomly distributed through-out the oceans – fish 

have preferences as to the areas they occupy based on many factors such as food resources, 

protection or spawning. This being said, once the preferred habitats of a target species are known, 

it becomes much easier for fishermen to catch that species. Aggregations of fish also make it much 

easier to catch more fish. This makes fishermen very happy and leaves scientists around the world 

gravely concerned. Herewith follows the conundrum. 

In areas of high fish abundance, fishermen need to put in less effort in order to get higher outputs 

of fish than they would in areas of lower abundance. This means that when the catch per unit 

effort (CPUE) is calculated in these areas by scientists trying to manage recreational or commercial 

fisheries, it indicates that relatively low effort was required to gain high catches – ‘there must be 

many fish around’. The CPUE is traditionally used in fisheries science as a measure of fish 

abundance but the number of fish you catch per unit time is also used unknowingly by fishermen 

as a measure of the amount of fish around to catch. However, due to the high concentration of 

the fish in a limited area because of unseen benefits to the fishes to be there, the CPUE value is 

actually inflated. This is known as the ‘Basin Effect’ – the effect of the accumulation of fish in a 

localized area on fishing success. If the same fish population was to be randomly and evenly 

spread over a larger area, the number of fish caught applying the same amount of effort would be 

much less. This presents us with the basis of the misconception.

The elevated CPUE values caused by the Basin Effect leads to overestimations of stock size in the minds of recreational and commercial fishermen, often resulting in escalated quotas, and ultimately unsustainable fishing practices. It is therefore actually very hard to estimate the number of fishes in the sea without biasing our estimates. Most of the information used by fisheries managers around the work is fishery-dependent data – information coming from the fishermen themselves. Recreational and commercial catch records are biased because we know where to find our target species and how to catch them.

Fisheries evidence of this misconception can be found in the case of northern cod (Gadus morhua) 

populations in the Canadian town of Bonavista. In areas of the Bonavista corridor where the fish 

were known to be hyper aggregating (increasing in density while their biomass decreased), the 

CPUE increased between the years of 1980 and 1990. Interestingly, in the region of the corridor 

where the fish were not hyper aggregating, the CPUE decreased during this period. Overall, the 

population was in decline, but the inflated CPUE at the site where the fish were hyper aggregating 

masked this crisis. 

The aggregating behaviour of Orange Roughy (Hoplostethus atlanticus), a deep-sea perch has also 

resulted in a population collapse off Australia. This species was heavily exploited in a fishery in the 

area since the 1970’s. The fish were caught in large numbers and soon the species was showing 

major decline in areas off Tasmania. It was not known at the time that the large numbers caught 

where large proportions of the population that were aggregating to spawn. Overfishing on 

spawning grounds has now left this long-lived, slow growing species highly threatened. These fish 

have been aged to 149 years and in 20 years the population has been reduced to a fraction of 

pristine stock.

Fortunately, once these types of problems were identified in fisheries, scientists could recalculate 

and management strategies were put into place to curb the decline of populations in some cases. 

These included reductions in total allowable catches (TACs) and individually transferable quotas 

(ITQs) to monitor catches and populations sizes, as well as gear restrictions to reduce fishing 

mortality. Less emphasis was placed on CPUE in fisheries management, and more reliable methods 

of assessment such as fishery-independent acoustic surveys were employed to ensure the stability 

of population numbers in these fishes. Unfortunately not all fishing sectors have these safeguards. 

The recreational fishery in South Africa suffers major population declines in recent decades.

The slow growing, late maturing coastal fishes in South Africa face the quagmire of the Basin Effect 

in the minds of their captors. Many of these species are resident in their habitats, some migrate to 

spawn, some gather in large numbers to spawn and many use estuaries as nursery areas. The 

Basin Effect causes major misconceptions amongst fishermen about the abundance of common 

angling fish engaging in aggregating behaviour. This misconception impedes the success of 

education of fishermen on the plight of angling fishes now facing major population collapse off the 

South African coastline. Many shore anglers ignore fishing regulations deeming them an 

unnecessary nuisance. Many anglers believe they cannot do damage with a rod and line and often 

pass the blame to the subsistence or offshore sector – another misconception. The subsistence 

sector is a relatively small component of the fishing force in South Africa targeting coastal species 

and the large fishing fleets of the country don’t have access to the shallow-water species that are 

heavily exploited.

Populations of Baardman, Dageraad, Dusky kob, Englishmen, Galjoen, Garrikc, Geelbek, Redsteenbras, Red Stumpnose, Riverbream, Scotsman, Seventyfour, Silver Kob, Squaretail Kob, White Musselcracker, White Stumpnose and White-edge rockcod are all officially collapsed in 

South Africa. These species are shallow-water, coastal species that are available to the recreational (Rock and Surf or Estuary sectors), ski-boat and subsistence fisheries only. All these 

species grow slowly; reach sexual maturity only after a number of years; have complex biology in 

that many change sex after a number of years; and most are harvested below breeding size. For 

example, Dusky kob reaches sexual maturity at about 1m in size (5-6 years of age); yet fish are 

harvested below this size and are unfortunately regulated as such (Minimum size is 60 cm). Many 

species that undergo sex change, especially late in their lives, are now subject to skewed sex ratios 

in the wild. Poenskop or Black Musselcracker only become male after 18 years of age, now that 

most large individuals are fished out, the population is mainly female dominated and these too are 

harvested with such pressure that few live long enough to change sex and become males. Many 

species are legally harvested at size of sexual maturity (White Musselcracker) yet their population 

status suffers the same fate as the kob. Shear harvesting pressure dictates their population status. 

All these species suffer the consequences of the Basin Effect by virtue of spawning behavior, 

feeding strategies, migration, estuary nursery use or reef residency. They aggregate and their 

young are trapped in the ‘safe refuge’ of estuary nurseries, a fishing hotspot around South Africa. 

The problems are multifaceted but fishermen behaviour and fish behavior are at the core of the 

problem. 

The only solution is angler education and government legislation in support. A ban of all kob catch 

retention is long known by fish biologists as the only solution to save this species from local 

extinction off South Africa. How well received would such a ruling be? Firstly, would it be 

supported amongst the various fishing sectors in South Africa and secondly, would it be enforced 

in South Africa given the extent of enforcement issues affecting our marine resources. The only 

solution in the interim is angler education and higher penalties for the illegal trade in recreational

fish species. Recent fish poaching along the entire South African coast by members of the 

recreational sector who sell to restaurants and overseas markets has become an epidemic and 

exacerbates the problem. In the Eastern Cape, perpetrators who fish under recreational permits 

are also known abalone poachers with convictions or pending cases against them. Marine 

resource crimes coupled with the general lack of education in resource users is decimating coastal 

fishes in South Africa.

Know your species, know its vulnerabilities but use the knowledge to understand how you have 

been misled and fish responsibly. Report environmental crimes against fish. Name and shame 

wrong-doers in public forums like Facebook & fishing sites. We don’t want them amongst us. Fish 

ethically and maybe your grandchildren will also have fishing stories about the same species to 

share with you in the future. 

The State Of Your Tuna Fishery

The International Sustainable Seafood Foundation (ISSF) recently published online a downloadable technical report outlining the current health of our 23 commercial global tuna stocks titled: The Status of the Stocks. The report provides a comprehensive summary of the recent scientific stock assessments as well as the current management measures implemented by the respective Regional Fisheries Management Organisations (RFMO's). The methodology behind the rationale of this report revolves around these three key main factors: Abundance, Exploitation/Management (fishing mortality) and Environmental Impact (bycatch).  

In 2012 the global total catch of the 23 commercial tuna stocks was 4.6 million tons with skipjack tuna accounting for a total catch of 56% of this volume. Whilst the total yellow fin and albacore are 28% and 6% only. Whilst these are large volumes, it is proposed that globally 52% of the tuna stocks are in a healthy level of abundance, 39% are overfished and 9% are at an intermediate level. In terms of exploitation, 43.5% of the stocks are experiencing a low fishing mortality rate, 17.4% are experiencing overfishing, and 39.1% have a high fishing mortality that is being managed adequately.

When viewed from the point of view of total catch, 86% of the catch comes from healthy stocks. This is due to the fact that skipjack stocks contribute more than one half of the global catch of tunas, and they are all in a healthy situation due to their high fecundity rate. In contrast, most bluefin stocks and 2 out of 6 albacore stocks are overfished, but combined they make a relatively small fraction of the total catch.

A foreign vessel offloads its catch of tuna:

There are three main albacore tuna stocks in the Atlantic Ocean ICCAT area namely: North Atlantic, South Atlantic and the Mediterranean. Albacore catches in the South Atlantic increased 2% in 2012 (24,600 tons) from the previous year. Long linging accounts for 67% of this and 26% for Pole and Line. In 2012, the Total Allowable Catch (TAC) was set to 24 600 tons with a Maximum Sustainable Yield (MSY) at 25 200 tons. Due to the respective scientific advice and recommendations, the TAC for 2013 was reduced to 24 000 tons by the RFMO ICCAT. The Pole & Line review notes the lack of information regarding the impact the live bait vessels inflict upon the small pelagics and therefore could possibly be upgraded in the future with adequate data collection.

Currently South Africa has a quota allocation of 4 400 tons only. Previously South Africa and Namibia had a sharing scheme but last year's ICCAT meeting it was generally voted to be split thereby Namibia's quota will be set at 3 600 tons. With the recent figures circulating around the Department of Agriculture, Forestry & Fisheries (DAFF), South Africa should reach and succeed our quota before the end of this year. This has major implications and repercussions with the most noticeable being a reduction in our quota by the volume of what was over caught for the 2016 season. (the quota will remain 4 400 tons for the 2015 season)

South Africa who has the second largest albacore quota (Chinese Taipei has been allocated 9 400 tons) will have to approach the other South Atlantic fishing nations and request additional quota from them should we exceed our limit. 

Ecomentaries: Paying the Price: the trouble with tuna

Ecomentaries.org recently begun production on a documentary titled: Paying the Price: the trouble with tuna, which explores the tuna pole fishing industry in South Africa and is well worth a viewing.

Their focus for this particular documentary is to create awareness for the general public as to the different catching methods and their associated effects on the respective ecosystems. Thus will in turn afford the local consumers an educated choice as to which retailer’s brand of canned tuna to choose. I believe that Food Lovers Market will become the first retailer to offer canned tuna with a more sustainable catching method. A simple you tube search result will provide you with ample videos of the various catch methods for purse seining, long lining and pole & line, if you would like to watch further click on the respective fishing method. As the cliché goes, a picture is worth a thousand words. 

The Ecomentaries.org film group spent time on board the tuna pole vessel Hangberg which freezes its catch on board. They have recently aired on Vimeo a tailor of their up and coming documentary series which can be viewed at the link in my first paragraph. The film crew followed the tuna from whence it was caught, frozen, transported to Duncan Dock Commercial Cold Store where it was graded according to size and stored. From here it is exported to canneries and processing plants around the world ensuring full trace ability essentially from hook to can.

Below is some information about Ecomenatries.org which I extracted from their website for your information:

We are a production and media company who raise awareness for critical wildlife, community and environmental issues. We produce emotive mixed media content to provoke discussion, action and ultimately, change. 

We support businesses and NPO’s with their green agendas: developing creative conservation platforms to help them share their environmental initiatives with the world.

We tackle a wide variety of sensitive and important subjects and inject them into the public domain via our extensive distribution network, including broadcasters, print publications, social and online media.

From shark finning in Mozambique and Bangladesh's turtle mafia, to sustainability projects in the Amazon and protecting Madagascar's abused children,  we have shot ‘ecomentaries’ in some of the world’s most remote pockets

We adore green business, and specialise in developing creative content for socially responsible corporations. If your company takes conservation seriously, why not tell people about it?

More is being demanded from corporations than ever before. Consumers already make decisions based upon ethical standards, their carbon footprint, sustainability, and social-awareness. However, soon, even this may not be enough.

A company’s ethics are becoming the cornerstone of their success. Nike has already changed their production processes and Cadburys is now fully Fairtrade. Whether it’s employing local people, running off green power, using sustainable produce, or even developing an anti-poaching unit, consumers want to know about it.

Long gone are the days of traditional advertising; companies are looking for new avenues to reach consumers. We utilize our extensive network of distribution outlets to promote our work and the work of our partners.

What We Do:

Documentaries

Environmental films

Community awareness projects

Corporate productions

Mixed media exposure

David’s Sustainability VS Goliath’s Economies of Scale

These days, the press across the various mediums highlight the importance of sustainability and fishing for the future. Through this and other public awareness programs broadcast by organisations such as Green Peace, WWF and ISSF, the general public is being awakened to an interesting and complex industry that is - commercial tuna fishing. Whilst the likes of first world country consumers are already well aware and preferential to more sustainable practices, there is an ever lagging effect filtering down to the 3^rd world nations. In the UK for example, the various retailers shelves are well stocked with various produce sourced from sustainable fishing methods. However, here we don't see this and this is due to consumer awareness and price. Here it’s purely about economies of scale and price for food security and ultimately survival. We don’t have the luxury of affording pole and line caught tuna in Checkers and Pick n Pay just yet. The fact of the matter is that we are already mumbling about the Saldanha brand (a product range that was developed and initially imported on behalf of Saldanha by ourselves) costing around R18 per can for the flavor variants and R15 for the oil and brine variations. The simple matter is the South African Rand hardly ever fares well for imports such as canned tuna, which price will fluctuate like the proverbial tide in parallel with the exchange rate. We’re talking U.S. Dollars to South African Rands here which until recently slumped lowest since the year 2008. This is the main factor combined with the price of raw materials in Thailand. Bangkok sets the skipjack price which recently is at an all time low. However the rand weakening didn’t allow the importers to take advantage of the low skipjack price which is being traded around $1300/mt CFR Bangkok (cost and freight delivered to Bangkok main port). As a result the can on your shelf has been able to withstand this variable but only to a certain degree. Depending on when the retailers will place their orders for more stock, we can expect the price of canned to possibly increase should they look to preserve their margins as the skipjack price is bound to recover to higher levels.

Now let’s discuss pole and line…I’m not sure who would prefer to pay an estimated R25-R30/can of pole and line caught skipjack tuna…the general public apart from Woolworths wealthy can afford this and such… its easier for the more well off patrons to ease their conscious by insisting on sustainability from a pole and line caught degree and sleep well at night. There is sort of a price barrier in third world countries for sustainable fishing practices being canned for these nation’s shelves. The poor rely upon the canned tuna as a relatively cheap accessible source of healthy protein. In South Africa its more blikkie chilli vis that's been sold than canned tuna. In fact last week retailers in Argentina started securing cans of tuna with anti theft alarms as theft of canned tuna is literally out of control like their ailing economy. Imagine an anti theft clothing alarm tag usually reserved for garments now stuck to your can of No Name Brand shredded tuna? It’s literally happening around the world as we speak. Now there are cheaper variations (shredded tuna) finding a their way to the bottom of the shelves but at a more reasonable price? The fact of the matter is that the retailers have developed a cheaper product derived from the by product of tuna loin production. These shreds or flakes are then canned with vegetable broth/ additives which proteins bind the pieces together during the heat generated by the retorting process. (If I understand this correctly) So we end up with a far inferior end product but at more affordable prices.

This graph below was taken from the 2013 4th European Tuna Conference which was held in Brussels and illustrates the volumes imported by the EU and USA of canned tuna. This should give you an idea on the shear volumes that is produced globally for these two markets.

This is where the Goliaths of the fishing industry find their way into the market and respective arguments. Without the purse seining fleet operating, we wouldn't be able to catch enough of this resource to meet the global demand for an affordable canned protein. With a shelf life between 1-2 years, depending on the brand, which doesn't need refrigeration. In Africa canned chicken, tuna and other products are on the rise as this continents largest imports due to the lack of infrastructure and refrigeration. The problem with purse seining is the environmental impact it has on the species which it is targeting as well as the by catch. With the use of FAD's more by catch, sharks, sea turtles other marine life is being directly impacted. I will go into this in a future blog entry.

However, it is the most affordable method to catch large volumes and thus their economies of scale far out weighs that of the pole and line method. As a profitable company, purse seining makes perfect sense. However, one hook one fish such as poling is the most scientifically sustainable method for wild caught tuna. How to find a balance is the predicament we find ourselves in today. Whilst the operational expenses per metric ton of purse seining is drastically less than that of pole and line with their respective carbon foot prints in favor of purse seining?

The Regional Fisheries Management Organisations (RFMO’s) control the tuna in each respective ocean and due to public awareness and pressure brought upon by scientific data, they have had to make drastic measures. Such measures would include but not limited to a  100% closure of some waters within the Pacific, FAD free zones, FAD closure seasons, fleet capacity  and TAC limitations, to name a few. But the industrial wheels of economy and trade keep turning and such we find for instance with regards to the cap on fleet capacity, the larger purse seining companies scrapping their smaller vessels for more ultra modern vessels which hold in excess of 2,200 tons and can maneuver at 18 knots. One would think that they are defeating the purpose by reducing the fleet when all that is being done is the effective fishing efforts being increased exponentially. We are seeing more 2,000 ton plus vessels being built in Spanish shipyards such as the vessel "Gijon" which was launched a short while back. This behemoth will be commissioned for the Mexican tuna fishery with a further 2 more being built. We have now seen some canneries insisting that by the end of 2014, they will only purchase from fishing vessels with fish holds of less than 350 tons. But is this enough?

 Whilst the likes of my company comply with Earth Island Institute and Friend Of The Sea annual audits to ensure sustainability and tractability, it is a mere spoke in the smallest cog that is the industry of tuna fishing. (MSC would have cost too much) Following the international trends, the local retailers have made pledges to only stock MSC certified pole and line caught tuna on their shelves by the end 2015. Where will this be sourced from? One of the only MSC certified skip jack fisheries globally is that of the Parties to the Naru Agreement. They have nicely created a monopoly by forming the marketing company Pacifical to exclusively sell all their MSC certified tuna. And this is a purse seine fishery as well!!! Seems we can't bake our fish cake and eat it just yet. The retailers such as Woolworths are making large strides to encourage sustainability and one should read up on their website about their corporate responsibility in doing so here: Fishing For The Future - Canned Tuna

Unfortunately its not possible to export our local albacore catches in 40ft containers to a cannery half way around the globe in order to be canned then shipped back. (wouldn't like to calculate that carbon foot print) This simply isn't viable, so what about canning it locally? We did just that and in 2011 we concluded an assessment by international experts and found that labor would become this projects biggest headache, partly due to the labor unions and their effect on suitable labor costs. The subsequent cost of production would have been to expensive and it was decided to scrap this project all together. Until then we will have to place our sustainable support on to the retailers and may they continue to make progress for their 2015 deadline.

Take a look at TUNA IN SOUTH AFRICA AND WHAT YOU CAN DO