UK Seas in Crisis : Will Brexit change things?

Note: This article was commissioned by The Marine Quarterly which has agreed to the publishing of an abridged version in its Summer edition.

The decline in both the health and diversity of life of British seas is a subject much reported upon. Yet in addressing the meaning of Brexit in this context it is first essential to ask: is this decline real, or is it simply another example of the human weakness of lamenting change and believing things were better in the past? So, we first need to know whether the crisis is real.

If you are familiar with The Unnatural History of the Sea by Prof. Callum Roberts (Island Books, 2007) you will be aware not just of documentary evidence of this decline, but also of a key concept in our assessment and appreciation of it.

This concept is that of a changing baseline. It rests upon the idea that each generation evaluates change on the basis of what it encounters when first coming into contact with a subject. Thus if something is common or abundant when first encountered, then this is perceived as the norm. If the reverse is true, then that is the norm. So if you were born into a world where computers are used by everyone, that seems normal. Whereas if you were born into a world where they had not yet been utilised commercially, then the change in the world they have created is profound. Perception of change therefore depends greatly on the baseline that is regarded as normal; similarly so for the reaction as to how to respond to that change.

So, what is normal in terms of the health and biodiversitybiodiversity Biological diversity in an environment as indicated by numbers of different species of plants and animals. of UK seas? Is there a genuine yardstick we can use to answer this question and, if there is, how does it affect what we can expect to achieve from Brexit ?

Statistics are generally employed to measure change, but we all know how fallible such a methodology is. Statistics can be twisted this way and that. Also, they are only as good as the method employed to compile them in the first place. Nevertheless when there is a degree of consistency in their compilation they can serve as a general guide.

Marine diversity (the range of species) and the abundance of their populations, both in terms of size and geographical location, are not easy to measure. Especially so when taking a long period of time, such as 1900 to the present day. Yet it is not impossible and indicators can be used. For example, statistics do exist for the catch size relating to fish stocks. They are a useful barometer of marine biodiversity based on the fundamental ecological principle of interdependence. Fish eggs and larvae are a staple food source at the base of the marine ecological structure; and, juvenile and adult fish are a food source at the top of the ecological structure e.g. seabirds, seals, dolphins and whales. Therefore if the abundance in fish stocks declines, so likely too will the abundance of other species all the way through the marine hierarchy.

If we take the North Sea since the beginning of the 1900s as a reference point for the health of UK fisheries we are able to access a fair bit of scientific data accumulated concerning fish stocks. Importantly too, this data has been assembled by scientists of professional standing based at the UK’s Centre for Fisheries and Aquaculture Science (CEFAS) and their data has been subject to peer review.

These scientists have reported on a North Sea scientific model to the International Council for Exploration of the Sea — ICES, based in Copenhagen, which assembles data on the size and condition of fish stocks in the North East Atlantic. This model of the North Sea’s ecosystem suggests that the total stock of fish in the North Sea has dropped from 26 million tonnes to 10 million tonnes in just over a century (CEFAS 2004).

Marinet has analysed similar data compiled by CEFAS and has been able to demonstrate the extent of the decline that has occurred in North Sea fish stocks between 1880 and 2010.

The date of 1880 has been chosen because, prior to this date, the use of steam had not been introduced into fisheries. The use of steam to power fishing vessels was a significant development, creating the capability for the use of larger nets by the introduction of steam powered capstans. Consequently the 1880 date and related stock levels is a benchmark, recording North Sea stock levels before intensive, mechanised fishing commenced. The 2010 date provides the most up to date stock figures available at the time of compilation. Stock levels are based on total biomassbiomass The amount of living matter. This is therefore a different measure to numbers of organisms. So, for example, there is much more biomass in 1 elephant than there is in 1000 fleas and there may be more biomass in 100 large cod than you would find in 150 small (because of over fishing) cod. estimates and thus include all fish in the stock, including juveniles.

Table: Estimated Total Stock in the North Sea in tonnes.

* Maximum estimated stock level. Measuring stock sizes is an imprecise science, so there is a large measure of uncertainty around all estimates. The 1880 figures are extrapolations based on catch data recorded at the time. The extrapolations are calculated as a maximum, middle and minimum stock level, and thus cover a range in their estimation. The 1880 figures recorded above are the maximum figures in the range, and the middle and minimum figures are provided in a briefing on the Marinet website

Sources: The 1880 figures are from: S. Mackinson, 2002, Representing trophic interactions in the North Sea in the 1880s using the Ecopath mass-balance approach, ref. Table 1.16. In S. Guénette, V. Christensen, D. Pauly (Editors), Fisheries impacts on North Atlantic ecosystems : models and analyses. Fisheries Centre Research Reports 9(4). The 2010 figures are from the International Council for the Exploration of the Sea (ICES).

The North Sea is ICES Area IV (IVa, IVb and IVc). It covers an area of about 220,000 sq miles (570,000 sq km), with depths generally ranging from 120 to 300 ft (37 to 91 metres).

The decline in the UK fish stocks and associated marine biodiversity is all too evident from the foregoing historical figures, but the question is whether Brexit will fix it?

Two points need to be made at this point which will govern the subsequent discussion.

The first is that this decline is of a long-standing nature and predates our entry into the European Common Fisheries Policy (CFP) even if the CFP has, arguably, accelerated that decline. Some of the factors in that long term decline are examined below. Addressing them is a necessary condition for whether the changes that Brexit may bring will make any difference.

The second point is that Marinet has no idea as to what the actual terms of the fisheries Brexit agreement between the EU and the UK may be. Therefore speculating on those terms is largely a fruitless exercise. We do however list below changes we believe would be desirable.

So, onwards to a brief look at some of the significant issues which have led to the decline in the UK’s fish stocks and associated marine biodiversity. No emphasis is given to any one cause as it is the combination and cumulative effect of the various causes over time that is the more significant factor, but the list does seek to focus attention on what will need to be addressed if change following Brexit is to become meaningful.

The first factor to note is that the technological capacity of fishing vessels, both in terms of engine power (able to deploy larger nets and stay at sea for longer periods and over a greater geographical range) and detective ability (sonar) has constantly increased. This means that vessels have increased in size and fishing capability; and in terms of the fleet as a whole, unless this trend has been run in tandem with a corresponding decrease in “fleet capacity” then this increase in intensive fishing will inevitably lead to over-fishing.

The CFP has given compensation to owners to retire vessels from the fleet in order to reduce overall capacity but this effort has, arguably, been inadequate and defeated by associated “improvement subsidies” to the fishing vessels that have remained in the fleet thus maintaining the fleet’s overall capacity i.e. too many vessels continuing to harvest a continually declining resource.

Against this background, rationing has been introduced by the CFP. This means vessels have been limited in the amounts of fish they can catch via quotas. However when a vessel fishes a “mixed fishery” (more that one species is caught in the net) and finds that its quota limit for a certain fish has been reached, this excess has been returned overboard (and dies) or is now returned to land (CFP 2014 reform). Nevertheless in both circumstances, the “excess” from the over-fished stock has still been harvested and the over-fishing pressure has been maintained.

Next, these technological improvements have led to a change in the nature of the UK fleet, setting off long-term changes in ownership and vessel size. Ownership of CFP quotas (essentially, fishing rights) has become a vital factor. Before the CFP, the right to fishing was unrestrained and small boats (under 10 metres in length) in the UK fishing fleet were very numerous and prospered. Under the CFP small boats now have an entitlement to just 4% of the total UK quota allocation, making many boats uneconomic. Consequently a substantial portion of the UK quota allocation lies in the hands of large vessels and particularly the largest, allied to the fact that the ownership of these UK quotas is now often held by non-UK interests (Dutch, Danish and Icelandic) thus depressing the economic benefit to the UK fishing industry (Greenpeace 2013, Ocean Inquirer No.5 : A Wolf in Shrimp’s Clothing).

An additional factor of importance is the manner in which fish are caught. Two key features in the life profile of fish stand out. The first is that fish always return to the same areas to spawn. The second is that every time an adult female fish doubles in length so does its laying of eggs increase commensurately. Thus knowing where to catch fish is predictable (i.e. their spawning ground) and the oldest adults are the most fecund.

To illustrate, a cod becomes sexually mature around 3 years and can live up to 25 years. At 3 years a female will lay 250,000 eggs, at 8 years 2.5 million eggs and another ½ million eggs ever time in gains a kilogramme in weight. Older fish are therefore not just the key to a stock’s reproductive potential and economic value when harvested, but also provide food to the marine ecological structure — from every 1 million eggs only two need ultimately to survive if the number of adults in the stock is to remain constant. This illustration is similar for all fish species.

Fishing practices exploit this. Not just by focusing on fish in their spawning grounds where they are easily caught, but also by using a net size which ensures that no adults beyond one year of sexual maturity escape. In the case of cod, this is 5 years. The consequence is that under CFP rules cod stocks effectively have no adults older than 5 years. The stock’s reproductive capability is thus severely restricted. This same reality applies to all other fish species.

CFP fisheries reforms now assert that stocks should not be fished beyond their “maximum sustainable yield” i.e. at a level that does not compromise the ability of the spawning stock to reproduce safely. Also, the EU Marine Strategy Framework Directive (whose purpose is to restore health to EU seas by 2020) has set a benchmark standard where “Populations of all commercially exploited fish and shellfish are within safe biological limits, exhibiting a population age and size distribution that is indicative of a healthy stock.”

However “within safe biological limits” is referenced to the current depleted levels of spawning stocks and not their historical levels (several times greater), and the need to rebuild stocks so that they are “exhibiting a population age and size distribution that is indicative of a healthy stock” is being wilfully ignored. This is true for all commercial fish species.

When fish stocks collapse due to over-fishing, the EU takes emergency measures. It closes fishing of the spawning grounds. However it recommences fishing of these areas when ICES says the spawning stock is once again at a “safe level”. This is the practical version of fishing at “maximum sustainable yield”. The consequence is stocks remain permanently depressed and the “food security” function and economic capability of the fishing industry similarly so.

Marine reserves (e.g. the UK’s Marine Conservation Zones) would seem to be an appropriate management tool for fisheries conservation, but the 2009 Marine and Coastal Access Act allows for fishing in MCZsMCZ Marine Conservation Zone.

So, will Brexit alter this reality? No one knows at the present time. However we have outlined below certain management actions needed if UK seas are to move from crisis back to ecological and economic health.

• UK to own exclusive rights to all fisheries out to 200 nautical miles.

• UK management of its stocks to be focused on how to maximise the gross national product of our fisheries, working in liaison with countries like Norway who pursue such an objective.

• The rights to the UK’s catch to be held by companies that are genuinely British rather than foreign owned.

• All fish caught in UK seas to be landed at UK ports thereby reinvigorating their local economy.

• UK fish stocks to be managed regionally, with a far higher proportion of fishing rights given to small boat fishermen.

• All UK fishing vessels to be fitted with CCTV with the Marine Management Organisation providing oversight from its monitoring centre. This will ensure compliance with fisheries regulations.

• Royal Navy enforcement capability against interlopers to be enhanced. It is currently one vessel operating for the equivalent of six months per year.

• The age and size profile of stocks must be increased, allowing all adults in stocks to survive at least 5 years of adulthood. This will improve both the economic and reproductive potential of stocks, uplifting marine biodiversity generally. This is achieved by enlarging the mesh of nets.

• Marine reserves to be created whose purpose is to improve fish stocks, with managers for these reserves drawn from the local fishing community.


David Levy and Stephen Eades
Marinet Limited, March 2018.

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One Response to “UK Seas in Crisis : Will Brexit change things?”

Carole Jacob
Comment posted on 5th September 2018

I agree totally with Marinet’s findings and submission to the consultation on marine management post Brexit. This response is totally without favour to any business but seeks genuinely to restore marine biodiversitybiodiversity Biological diversity in an environment as indicated by numbers of different species of plants and animals. to a sustainable level and justice for fishing industry in the UK, especially to those fisher communities who rely on fishing for the local economy.

Marinet’s response is well researched and carefully prepared. My hope and wish is that it will be seriously considered by the UK government.

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