Monday, 25 April 2011

The big fish review (part 2)

Last time we looked at a few less well known or more unusual types of fish. Many people could probably read the last article with a pretty clear conscious. Orange Roughy isn't really eaten very extensively outside of America, eels only feature in one sushi dish over here in the West (unless you like jellied eels) and shark is rarely ever on the menu outside of Chinese fine dining. Monkfish might have hit a little closer to home but is an expensive treat for most rather than a day to day fish meal. Now its time to turn up the heat! In this article the selection of fish are the ones we eat in our daily lives, these are the tasty guys that are driving the industrial fishing machine. They are the most important fish that we should reconsider and change our buying and eating habits. With this in mind I will suggest some viable and sustainable alternatives to each fish. So here is the next rogue gallery of the underwater wolrd:

5) Atlantic Cod: Fish, chips and crippled ecosystems

Above, Modern day expected sizes for adult and juvenile cod and below the large size that the fish historically were capable of reaching.

Gadus morhua the staple of British fish and chips, alongside salted cod dishes in northern Europe, Spain, Portugal and just about everywhere else. The cod are a member of the Gadidae family, distinguished by their awesome goatees. These chin barbels are used to help feel out (and also taste) the sea floor for crabs and shellfish that cod are fond of eating. Historically cod have been both large (2m+) and abundant (tales of being able to walk from Scotland to Iceland on the backs of cod abound) and today that is definitely not the case.

The history of cod is long, it has been a key part of the British diet and culture for many hundreds of years. To try and sum it up in a few short paragraphs would be foolish. I recommend reading the book Cod by Mark Kurlansky for a full overview of the history of this species. Instead I will review some of the recent scientific evidence showing why buying North Sea and even north Eastern Atlantic cod is a very bad idea.

Turn your attention to figure 1:

This shows the steady decline of north sea cod from the 1960s up until 2000. The key part is the blue line, starting at around 15000 tonnes the total stock of the fish has fallen to 5000. That means in 40 years the stock is now 1/3 what it used to be.

On top of this the bars show the numbers of new juveniles entering into the fishery at age one. This has strong yearly cycles, which is very normal for oceanic fish, but notice how year on year the number of new recruits (fishery term here) is falling. We no longer get the good years where there are 700000 recruits, it is now a bad year every year. This is because the good years (where food is abundant and the climate is good) are best exploited by the larger older females. These old girls are super breeders, they pump out many more eggs than younger females and they are of a higher quality. When times are good they are able to exploit this and produce lots of young, sadly there are virtually none of these old girls left.

The vast majority of cod caught in the North Sea is what I would call undersized. Cod only breed after 2-4 years. The average age of capture in North East Atlantic is 2 years, the majority of the fish captured will never have had a chance to reproduce. If you think back to your childhood or ask your parents, the size of fish in fish and chips was much, much larger than it is today. Nearly all cod sold in fish and chips shops will be about 1 year old. These are the last remnants of a stock on the brink of collapse.

Here in figure 2 is what might happen next if our stocks go the same way as the Newfoundland cod fishery:

There was a steady increase in fishing effort peaking in the 1960-70s this resulted in increased catches and then a mighty crash. The population was decimated, the last few undersized and juvenile cod huddled together for safety in small family groups in the 1990s. This may work against predators but it made them even easier to target with nets and as such the local population was virtually eradicated. The ecosystem here is decimated, the grand banks economy has collapsed. This population may well never recover, the loss of such an abundant top predator has shifted the entire ecosystem structure, many scientists predict it may take 200 years for a similar ecosystem to emerge.

It pains me to see information like this, and I hope that we act in time before our ecosystem is totally decimated in the same way. As of early 2000 we were still removing more than 60% of our fishable stock every single year. Urgent call were made by scientists and managers to radically reduce catch limits or even place a moratorium on North Sea cod. So far there have been small reductions in the length of the season and marginal catch limits (300 tonne reduction in the UK out of 2700).

Please DO NOT BUY Atlantic cod, I recommend the vastly more sustainable pollock if at all possible. Pollock is a little flakier than cod, but has slightly stronger taste. Fish fingers are a good sustainable food choice as they are made from pollock. Sainsbury's have recently tried to re brand the fish as Colin in an effort to boost sales, pollock was traditionally used in cat food so the new name is designed to get away from its less savoury past. Pollock decimates cod in the sustainability front, stocks are healthy, they breed younger and produce many more eggs.

I also recommend coley and pouting (or bib). Pouting especially has a very fast life cycle and gets high marks on the sustainability front. If you absolutely have to eat cod then I recommend you search for the North East Arctic or Eastern Baltic stock labels as these stocks are well managed, but good luck trying to find them!

So a big NO to cod and a huge hello to pollock, coley and pouting

This is pollock and chips, I bet you a pint (underage people and non drinkers are welcome to another appropriate beverage!) that you couldnt even tell the diference to cod!

6) Atlantic Flounder, Halibut, Sole and Plaice: Flat, trawled and not so common

These are the flatfish, strange because they start their lives swimming upright. As they mature, either the left or the right eye (depending on the species), begins to migrate around the head until both are on the same side. At this point they settle down on the sea floor and evade predators buy half burying themselves in the sand. These are well known food fish and are included on fish and chip shop menus and all the way up to very expensive fine dining.

Above, the young halibut swims around with both eyes on top and below, the adult skulks on the sea floor one eye now migrated around its head.

These fish we traditionally hard to find and required patience and practice to fish with traditional methods. The advent of the bottom trawl changed all this. Trawling uses a net anchored by a wooden beam or bar which is dragged along the sea floor. This not only catches pretty much anything that happens to be in the trawl but also smashes and destroys the delicate living structures such a corals, oyster beds and seaweed growth that are essential habitat for much marine life. These flatfish are caught by trawls and as slow moving bottom fish, have very little chance of escape.

These fish used to be very numerous. Now many are threatened or endangered. Atlantic halibut is considered and endangered sub population, overfished to the brink of extinction. Sole and flounder populations are at only 10% of their pre industrial levels. Plaice are now a fraction of the size that they were 50 years ago. Plaice are supposed to live up to the age of 40, it is very rare to find one over the age of 6 as they are simply all being caught.

These fish are both long lived and slow growing. On top of this they are caught usi9ng one of the most destructive industrial fishing methods, trawling not only indiscriminately targets a range of species but destroys the structure of marine ecosystems, preventing life from returning to overfished seas.

The North Sea is a good example of damage caused by extremely intensive trawling. If you look at the North Sea it appears to be a dark greeny brown soup. Of course as a British and European sea that has wind and rain throughout the year many people would not be surprised by this, the North Sea was never a tropical blue lagoon, but also it wasn't a dark green sludge. Historical records and plankton surveys show that the water was much cleaner and less loaded with planktonic algae before the rise of industrial fishing. So what happened?

This is an example of an otter trawl, less damaaging than a beam trawl, just two planks at each end of the net are dragged along the bottom. You can still see the potential for damage to the enviornment.

The combined trawling fleets of the E.U. Have scoured the North Sea and destroyed all of its cold water corals and most importantly huge oyster beds. These used to be so large that they would grow out of the sea to form oyster reefs that would endanger ships. The oysters were smashed to rubble and as such could no longer feed on all of the plankton, this built up in the sea and obscured the light reaching the sea floor, as such many corals and marine plants died off and entire chain of destruction reached back through the ecosystem. The ecosystem shifted, now the plankton is too dense to allow mussels and oysters to grow effectively and it will take many hundreds of years for the sea to recover, even if we stopped all trawling.

This shows the type of damage done by trawling to our marine environment

I strongly urge you to avoid eating any flatfish that is not explicitly pole and line caught. In addition any fish that has been caught using trawling I would recommend avoiding.

As for alternatives, there are some good ones here. Dab and megrim are the two that immediately spring to mind. These are smaller flat fish with shorter life cycles, and because they are virtually unknown they are often very cheap. The bad thig is they wont be at your local supermarket, you would have to go straight to a big fish market like Billingsgate (in London) to fins these guys. There is one drawback, they are still caught through trawling. If you want a cheap, tasty alternative that is fully sustainable I would recommend gurnard. These fish are really ugly but taste great, have virtually no bones and get thumbs up both from me and the much more respectable Marine Stewardship Council (MSC).

So flatfish of all kinds are off the menu and gurnard is back on.

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