NH3

by Stanley Salmons

  “He’s right. That area of ocean is known as the Sargasso Sea. Now I’m thinking about it, it is exactly the sort of place you might expect a mutation like this to arise – very rich environment, full of algae and marine life of every sort. When did you say this incident was again?”

  “Last April. Almost exactly a year ago.”

  “Well just suppose that is the source of the organism, how did it get into your rivers by October?”

  “No idea.”

  Terry pulled a World Atlas off the shelf and busied himself with a ruler. Then he accessed an on-line encyclopaedia for some data and started to tap figures into a calculator.

  “Let’s see. It’s about five and a half thousand kilometres from Bermuda to Wales. The Gulf Stream comes from there and up to our shores as the North Atlantic Drift. It travels at a maximum of two metres a second at the surface. If bits of the organism travelled in the surface current they could arrive here in just over a month. Plenty of time.”

  She smiled. “You physicists and your numbers.”

  “What else is there?”

  “There are vectors.”

  “Vectors are numbers too. They just have direction as well as magnitude.”

  She laughed. “Not that sort of vector. Biological vectors. Animals or insects that carry disease. For example, the Anopheles mosquito carries the malarial parasite. It’s an insect vector.”

  “Right...”

  “So the organism wouldn’t have to be dependent on the vagaries of an ocean current. It could have been carried here.”

  “Carried by what?”

  “Birds? Manx Shearwaters travel those distances, and they nest on cliffs down the west coast. The organism could have been trapped in their feathers.”

  “There weren’t any birds around that weed mat.”

  “Well, all right, migrating fish – of course, why didn’t I think of it before? Eels!” She leant forward excitedly.

  He scratched his head. “Eels?”

  “Yes. Eels go to the Sargasso Sea in their millions to spawn.”

  He turned back to the computer. The encyclopaedia was still online. “It says here the larvae of the European freshwater eel hatch in the Sargasso Sea and then they travel back to their rivers of origin in Western Europe.”

  “There you are,” she said triumphantly. “And during that time they could be carrying the organism in their gills.”

  “That would explain a lot, wouldn’t it? Eels don’t just come up to the estuary; they come right up the rivers. According to this, though, it takes them about two and half years. That doesn’t fit.”

  “Perhaps the organism came on ocean currents, like you said, and the eels picked it up in the estuary. If they return to their rivers of origin it explains why some rivers are affected and others aren’t.”

  “Yes, that’s right!” He felt a sudden surge of excitement. There was a brief silence. A fleeting frown crossed her face and he realized he’d been gazing intently at her. To cover his confusion he said:

  “How did you know all that about eels?”

  She raised an eyebrow. “Come on, Terry. I am a biologist.”

  “Well if they are carrying this stuff it could be all over Western Europe. Not just rivers, either. Eels wriggle across fields so it could have reached other bodies of fresh water – lakes, reservoirs. And you said it can survive in soil, too. This whole thing’s much bigger than I thought.”

  Her face fell. “What are we going to do?”

  “I don’t know. We’ve got to do something, though. Right now everyone’s treating it as factory pollution. The real culprit’s under their feet.”

  CHAPTER 7

  It was just before lunch the next day when Terry gave Maria’s draft paper back to her. She thumbed through a few pages and looked at him in dismay.

  “Blimey, Terry, I’ll have to get you a new red pen. Sorry, I knew it was rubbish.”

  “It’s not rubbish – it’s very good for a first draft. I’ve marked the bits where I thought there are gaps in the logical flow and I’ve pointed out some relevant literature you haven’t cited. I think you could make a bit more of the spectroscopic data. Put the detailed maths in an Appendix. I’ve written it all down. Remember, anyone who heard you at the conference will want to read the full paper. You have to make it worth their while.”

  She looked again at the manuscript and back up at Terry, and screwed up her face. He smiled and added gently:

  “Don’t worry. It’s an excellent start.”

  She sighed. “Okay. Thanks, Terry.”

  He went back to his office and sat there, thinking. Had he skimped on that? Not really. It needed a broad brush approach at this stage and he was too distracted to do more than that at the moment. They could pick up the details – matters of style and English – on the next draft.

  He wanted to discuss things with Maggie again but he was supervising a practical class that afternoon and he knew she was trying to beat the deadline for a grant application. Perhaps he could suggest meeting over dinner tonight. It seemed like a good idea but he was hesitant to suggest it. Theirs was a working relationship and he didn’t even know if she had a partner.

  He took a deep breath and picked up the phone.

  After letting him stumble around for what seemed like an age, Maggie put him out of his misery.

  “I think it would be very nice to have dinner together, Terry. And if you’re trying to ask me if there’s anyone around who might object, the answer is ‘No’. Where would you like to eat?”

  They settled for The Village, an inexpensive restaurant close to the university which served a variety of vaguely South American dishes.

  They walked there together. Neither of them had had a chance to go home and change, and that was a relief to Terry, who wanted the whole thing to be as casual as possible. When they got to the restaurant he helped her off with her short coat and she hung it on the back of the chair. She was wearing tight blue jeans and a dark V-neck sweater.

  “The Village” was popular with staff and students. Too popular, as it turned out: it was crowded, and there was a group of boisterous students on the next table.

  Maggie said she’d prefer to skip the starter and just order a main course. Terry said he’d do the same. The waiter, a slim-hipped young man in tight black trousers and a short waistcoat, took the menu cards and went away with the order, leaving them looking at one another across the table.

  Terry said, “Did you get your grant application away?”

  “Yes, I should just about make the deadline. God, what a lot of work.”

  “Well I hope you get it. At least it’ll make all that effort seem worthwhile.”

  “To be honest, I had a job concentrating,” she said. “I couldn’t stop thinking about that organism.”

  “I know what you mean. The guys at the EA clearly haven’t grasped what they’re dealing with. Really I’d like to take the whole thing to a higher level – when we’re more certain of our ground.”

  The waiter arrived with a couple of beers which he poured far too quickly, leaving them with the bottles and two glasses half full of foam.

  “Are you all right to talk about it now?” he asked.

  “Of course.”

  “Well, let’s sum up where we are. We have a Welsh river that’s polluted by ammonia. We have solid evidence that the culprit is a freshwater organism – a species of cyanobacteria – that’s undergone some sort of mutation. It seems pretty likely that other rivers in Wales and Cornwall have been affected in the same way, but they aren’t next to each other so the origin has to be somewhere out in the Atlantic. All right so far?”

  “Yep, Go on.”

  “We have a candidate location for that origin in Bermuda waters – ”

  “Though that’s pretty speculative at this stage.”

  “All right, but consider the evidence in favour.” He began to count on his fingers. “One, the deaths. A boatful of people die with breathing difficulties, the air
is described as irritating and smelling of stale urine, and there are no sea birds – all consistent with ammonia. Two, you said it yourself: the Sargasso Sea is just the sort of rich environment where you’d expect a mutation like that to arise. Three, it explains why only selected rivers are affected. Eels migrate to the Sargasso to spawn, pick up the organism, and carry it back to their home rivers.” He opened his hands. “I’d say that’s pretty persuasive.”

  She pursed her lips and nodded. “Okay. Then what?”

  “Then it all falls apart. The polluting organism is a freshwater species, not a saltwater one. So how could it have survived in the ocean? Somewhere along the line we’ve gone wrong.”

  They looked up as the waiter arrived with their meals, which he placed without ceremony in front of them. For a while they ate in silence.

  He noticed that she was only picking at her meal. His wasn’t much good either. He tried the beer. It was all froth and no flavour. He wondered why the place was so damned popular.

  She put down her fork. “Something just occurred to me. Cyanobacteria are actually made up of thousands of individuals.”

  He had to crane forward to hear her. The students at the next table had presumably had a few beers by now and they’d become very noisy.

  “Individual what?”

  “Individual bacteria.”

  “Right …?”

  She was silent for a while lost in thought.

  “Well?” said Terry prompting her.

  “Well... Maybe that gives us a route for the mutation to pass from a saltwater to a freshwater organism.”

  “You mean we could be on the right track after all?” He had to raise his voice to make himself heard.

  “Yes, there are mechanisms…”

  Now he could only pick out phrases between the gales of laughter from the next table.

  “…horizontal gene transfer… plasmid exchange…”

  “A plasmid isn’t the only possibility,” she said, during a brief interlude. “It could be a transposon.”

  “Did you say transposon?”

  “Yes. They’re very similar but a plasmid would stay as a separate entity whereas a transposon would incorporate itself into the chromosomal DNA. It would be much harder to find…” The laughter and shouting started up again and she glanced towards the next table. “Oh, let’s get out of here.”

  “My place isn’t far. I can rustle up some coffee. Sorry, I’m not trying to...”

  She smiled. “Thank you, Terry. That would be fine.”

  He lived in a late nineteenth century terraced house which had been converted into two self-contained flats. His was the one on the ground floor. There was no intercom at the entrance, just two bell-pushes marked “A” and “B”, and whichever occupant was summoned had to come to the front door to open it. He used his key and led Maggie through a narrow hallway into the sitting-room.

  “Make yourself at home. I’ll get the coffee on.”

  He retreated quickly to the flat’s kitchen-dining area. He hadn’t expected to bring her back here and now he was having second thoughts. The place was reasonably tidy but he was suddenly aware of things that would normally have passed him by: the cheap paper lampshade, the worn carpet, the shine on the armrests of the second-hand sofa. He didn’t have to live like a student; he could afford better now. It was just that replacing the furniture would require a lot of searching and comparing fabrics and styles and prices. There was always something else to do, something more urgent.

  He filled the kettle and switched it on. Then he opened a cupboard and out of sheer habit picked up a couple of mugs. He looked at them, replaced them, and went to the shelf above. The metal tray started to fill up: cups, saucers, teaspoons, cafetière, a jug of milk, a bowl of sugar – Terry didn’t take milk or sugar himself but he thought Maggie might.

  The kettle boiled. He rinsed the cafetière with the boiling water and put in two carefully measured scoops of ground coffee. Then he filled it to one of the lines he’d scribed on the glass with a spirit marker.

  He looked at the tray for a moment. It wasn’t very elegant but he hoped it would do.

  Maggie was sitting in an armchair, waiting quietly. She got up as he came in.

  “No, you’re all right, stay where you are if you’re comfortable there.”

  He placed the tray on a coffee table, plunged the cafetière, and poured the first cup.

  “Milk?”

  “That smells good – no, I’ll have it black, thanks. I do put milk in the lousy ‘instant’ we have at the lab. It helps, but it still tastes like mud. I really ought to get a decent coffee maker.”

  He poured his own coffee and sat down on the sofa, self-consciously placing his hand so as to cover the shiny patch on the armrest.

  With his other hand he vaguely indicated the room. “Sorry, it’s not very fancy, this place...”

  “It’s quiet and it’s comfortable, Terry, and that’s perfect.”

  “Okay, can we start again? – I couldn’t hear you properly over that racket. What was it you were saying about plasmids and transposons, and where do they fit in?”

  She sipped the coffee. “I’d remembered something. Those strands we were looking at under the microscope? They actually consist of bacteria – thousands of them, strung together in long chains.”

  “Yes, I got that much.”

  “Well, bacteria have some interesting quirks.” She paused to take another sip of coffee. “Think about super bugs.”

  “Like MRSA, you mean? Resistant to a number of antibiotics. Big problem in hospitals.”

  “That’s right. Do you know how antibiotic resistance spreads?”

  “I thought it was a kind of natural selection: most are killed by the antibiotic, but if any are resistant they continue to divide.”

  She nodded. “That’s right, but there’s another process as well. The bacteria that have the gene for survival can transfer it to other bacteria. They pass it in a small package of DNA called a plasmid.”

  “Clever. So you think that could be how this mutation is travelling?”

  “I can’t be sure, but it’s a distinct possibility. And if that is what’s happening it explains the way it’s spread. The freshwater organism in your rivers could have picked it up from a saltwater species that was carried into the estuary.”

  He put his cup on the table. “Hang on, let me understand this. This plasmid thing passes the mutation from a saltwater species to a freshwater species? Then presumably there’s nothing to stop the freshwater species passing it to another freshwater species.”

  “I suppose that’s right. Shit.”

  “Quite. An innocent lump of slime in a pool or on a rock suddenly starts generating ammonia. And then that one passes the mutation on in turn. It’s a chain reaction. It’s worse than the bloody eels.”

  She bit her lip. “I can’t be sure that’s the mechanism, Terry. I just haven’t been able to think of anything else.”

  “All the same, we’ve got do something before the situation gets completely out of hand.”

  “What was it you said in the restaurant – about taking it to a higher level?”

  “Seems to me there’s no choice; we have to tell someone. We can’t rely on anybody else flagging it up. If I can arrange something will you come with me?”

  “Of course. But who are you going to see? And are you sure they’ll want to see you?”

  He scratched the back of his neck. “Good point. I don’t know, actually, I’ve never done anything like this before – I’m not a political animal, never have been. I suppose I could start in the university, talk to someone with the right connections…”

  “The Vice-Chancellor?”

  “It’s a possibility. I’m not happy about that, though. He’s a Chaucer scholar, isn’t he? Mention The Miller’s Wife and he’ll give you chapter and verse. But say ‘cyanobacteria’ or ‘plasmid’ and the shutters will come down. I’d sooner approach a scientist in the first instance.”

>   “What about CaSE – the Campaign for Science and Engineering? They lobby the Government all the time.”

  “Do we know anyone on the Committee?”

  “Isn’t Professor Barlow on it?”

  “Hugh Barlow? Chemistry? That’s more like it: a chemist would see the point. I’ll give him a ring tomorrow. Nice thinking, Maggie.”

  She smiled and sat back. Suddenly the immediate business was over, and a silence settled on them. Terry broke it before it became oppressive.

  “More coffee?”

  “Thanks.”

  “You know, if Prof. Barlow does take it on board and arranges a meeting at some Ministry or other we’d probably have to go down to London, and I shouldn’t think we’ll get much choice about the time. Is that all right with you?”

  “I suppose so. If it clashes I’ll just have to reschedule my teaching.”

  The silence fell again. She sipped her coffee.

  “Um, where do you live, Maggie?”

  “Actually I’m a warden at Eden Hall – you know, it’s one of the Halls of Residence.”

  “Sounds good. What’s the accommodation like? A lot nicer than this, I bet.”

  “Not really. More modern, of course, but a bit austere. You put a few pictures up and it still looks like a very plain room with just a few pictures in it. But it’s cheap and it’s walking distance from the Department so I don’t need a car. The duties aren’t onerous. I’ve been thinking of getting my own place, just the same. The kids are all right but I feel like I’m never off duty.”

  Terry nodded.

  “I suppose I should run you back there, then,” he asked, a little awkwardly.

  “Thanks,” she said. Was that a fractional hesitation on her part? It was too late, he’d said it now and she was standing up.

  There was no further conversation in the car. Perhaps he’d been a little too correct but he wasn’t used to this sort of thing. Right now what he needed was her help. What he didn’t need was to make a fool of himself with misguided romantic advances.

  He swung into the drive leading down to Eden Hall, stopped near the entrance, and switched off the engine. She turned to him.