‘ fish, just ‘fish, just how far are we prepared to go? the global trade is worth billions. some countries like china centre a fleet halfway across the world. they don't leave much behind. resentment is growing. foreign trawlers are destroying what should be one of the richest marine ecosystems on earth. the ecosystem is disturbed. when thatis the ecosystem is disturbed. when that is destroyed, it is almost impossible to restore it again. we have come to sierra leone in west africa, home to nearly 8 million people. it is one of the poorest countries in the world. it is not such a long time since civil war tore it apart. then there was a bowler. but another crisis has been growing under waterfor years. bowler. but another crisis has been growing under water for years. in villages up and down the atlantic coast, whole communities depend on

the sea. this is an area reserved for local fishermen. we are unhappy for this because it isa we are unhappy for this because it is a small catch. he smaller says trawlers are to blame. what would you like the government to do? we would like the government to take these people away, to stop fishing in this country. part of the problem now is nobody knows what is out here any more. sierra leone has had so many other things to think about. after a bowler, we are looking to getting a new set of estimates that the government can use. are you worried about what those estimates will show? yes. foreign trawlers should be a great source of revenue for countries like sierra leone. but

what happens when they don't follow the rules? are they getting away with that? is someone turning a blind eye? this is a story about africa, but the trail starts probably in the english countryside. south of oxford the latest technology is being used to monitor the world's oceans. we are looking ata map the world's oceans. we are looking at a map of the world and each of these triangles that you see is a vessel that is transmitting and we are picking up that transmission using satellites. that is probably only have the picture. lots of boats switch their transmitters off, especially when they have something to hide. these waters are very productive fishing grounds off sierra leone. they are heavily targeted by trawler fishing vessels. the boats, from all over the world, from russia and the european union, with three quarters of them from china. we are looking at several pairs of vessels here, aren't we?

yes, this is an image taken off the coast of sierra leone. what we can see are vessels side by side, travelling in parallel. this is typical. two boats fished side by side to several hundred metres apart using a large net. it is efficient but destructive for a fragile ecosystem. is that legal? it is not legal in sierra leone. back in freetown, we board a sierra leone's are only patrol vessel. we are leaving in the dark because we have been told that there are people here in freetown who will tell the trawlers a vessel is on the way. we wa nt to trawlers a vessel is on the way. we want to track down suspected trawlers. is there a danger that they will know we are looking and move out? it is like a game of cat and mouse. as soon move out? it is like a game of cat and mouse. as 500" as we move out? it is like a game of cat and mouse. as soon as we leave, we hear from natalie back and mouse. as soon as we leave, we hearfrom natalie back in and mouse. as soon as we leave, we hear from natalie back in oxford that foreign trawlers are running

away, heading further into sea. someone has tipped them off. we chase them all night and into the following day. the trawlers stay well ahead of us. what is the latest on ourfriends? well ahead of us. what is the latest on our friends? you appear to be 35 miles north—east. wide so we have closed the gap? you have closed the 93p- closed the gap? you have closed the gap. the patrol boat only goes out every couple of months. we get updates from freetown but nothing on the boats we are interested in. and the boats we are interested in. and the radio doesn't always work. we are at least 100 miles offshore. finally, we catch up. are these the pair trawlers we first heard about backin pair trawlers we first heard about back in england? it has to have doors on the back. this one doesn't. that is already very strong evidence. it is from china. we think it is one of the boats we have been

looking for. the boat has a valid license. it is allowed to fish in these waters but not as a trawler. every boat must have a government adviser to report on everything the trawler does. but they are poorly paid and have no real power. when was the last time a trawler was caught in the act? before my time. i have been working for seven years. in the seven years you have been working on your currentjob you have not seen a pair trawler arrested? no. 0k. trawlers in sierra leone are catching phenomenal amounts of fish. even though this method has been illegal here for nine years. the following morning, we visit the

second chinese trawler. it is another filthy, rusty hawk. second chinese trawler. it is anotherfilthy, rusty hawk. it's ha rd to anotherfilthy, rusty hawk. it's hard to believe it is even seaworthy. the law states have the crew must be local. their living conditions are appalling. he says he is on board nine months a year at just he says he is on board nine months a year atjust $100 a month. it is a pittance but there is no other work. it looks as if the boat has been pair trawling. the inspector seems to agree. you continue fishing... why did you not right then, why we were on board, take enforcement action? the vessels are stationary. they are not

caught in the act. if you do not have sufficient evidence, it might cause a lot of embarrassment. back on the patrol board the airwaves is full of chatter. observers are wondering just how useful they really are. you think you have done your best sometimes. and then when you get a t—shirt somebody will tell you something different. in a way back to freetown, another chase. a shrimp boat tries to have runners. when we catch up, they are holding up the nets. on deck, a shocking sight. the boat is allowed to catch fish other than shrimp, but most of these dying fish are useless and will be thrown away. it is destructive and in

sierra leone's row poorly regulated waters, it is unsustainable. this is frozen shrimp, packaging and spanish. it is destined for a dealer in gran canary. probably for the european market. west african fish ends up in markets all over the world, from europe to china. one recent study found that sierra leone earns less than 10% of the money generated by foreign fleets. as many as 70 trawlers are working around the clock in sierra leone's waters. the fishing never stops. back on shore, we show our evidence to the leading fisheries expert in the country. percy has been studying the country. percy has been studying the industry for nearly a0 years. for a licensed shrimp are to pull up this kind of catch, tells you what?

it is not encouraging. the net strips everything in its path. without any selection. even if you stop fishing for decades, it takes a very long time to recover. nets down the side like this... white of our suspected pair trawlers? how conclusive is the evidence? you don't need to catch them in operation. the fact you caught them without doors and alongside each other, you can conclude they have been working together. does that mean that the officer who was with us, should have taken some kind of action right then and there? he should have, yes. he should have, yes. he should have, yes. he should have. there is one more piece of the puzzle. the authorities

in freetown also have access to satellite data, just like natalie backin satellite data, just like natalie back in england. what do they know of are suspected trawlers? exactly the same. their tracks are identical. over the course of a month of the chinese boat have never been apart. if observers and inspectors can see what is happening and satellite data backs them up, why are these boats still fishing? the minister in charge has agreed to see us. the minister in charge has agreed to see us. she was appointed after a change of government last year. the pair trawling has not been reported. the minister calls in her top civil servant. he has worked in the ministry for decades. it is herjob to approve all trawler licences. we have observers on board and no observer has indicated to us that they are trolling.

the minister get him on the phone. we will get to the bottom of it, definitely. that is a promise to myself and sierra leone. we will definitely get to the bottom of it. two weeks later, we are sent of it. two weeks later, we are sent of theirs. the minister and her team have called the two chinese boat back to freetown. they have been tested to prove they are controlled by themselves, somehow they have passed. we show the footage to percy. what did you make of the test, from what you could see? well, it was unsuccessful. the net was out

there. it didn't open to operate. would you go so far as to say the test was a sham? yeah. yeah, i was trying to be a little moderate, you know, out of respect for my colleagues. yes, that was a joke. that is not the end of the story. we have learned the ministry is not renewing the annual licenses of the chinese fleet. they are not being accused of the pair trawling but poor sanitation. the government has banned all industrial fishing for the month of april. it is an unprecedented move. these are still small steps. the people of sierra leone can see a precious resource disappearing day by day. does this vulnerable country have

what it takes to avert disaster? good afternoon. for the most part more warmth and sunshine for the rest of easter monday. we are seeing su btle rest of easter monday. we are seeing subtle changes. more high cloud streaming across the sky, turning the sunshine a little hazy in places. the cloud doesn't show up much on our chart. do not expect necessarily blue skies all day long, but temperatures are still in the 20s. the small chance of an afternoon shower across the far south—west. this evening and denied the chance of showers for the south—west increases. some of those into wales and northern ireland at times. elsewhere, clearspells. tomorrow, for many, anotherfine —looking day with spells of sunshine. more cloud in the west. the art showerfor sunshine. more cloud in the west. the art shower for northern ireland. gray in aberdeen. temperatures back

to 12 degrees. elsewhere, still in the 20s. that as warm as it had been. the trend accelerated during the week. temperatures much lower with outbreaks of heavy rain to come at times.

this is bbc news. i'm lukwesa burak. the headlines at 2pm: police in sri lanka arrest 2a people as the government blames a local islamist extremist group for a series of co—ordinated bomb attacks. eight british nationals are now thought to be among the 290 people killed. police say more than a thousand people have been arrested arrested after seven days of climate change protests. dozens of firefighters are trying to control a moorland fire in marsden in west yorkshire. gun salutes have taken place to mark her majesty the queen's 93rd birthday yesterday. and click takes a look at how social media is being used