"Ninety per cent of the biomass in this river is in two spawning spots," he says.
With Barker joined by Fulton Mackay's gurning guard and Richard Beckinsale's wide-eyed cellmate, it ran for three series in the mid-70s, spawning both a feature film spin-off and disappointing sequel Going Straight.
More torrential rain worsened flooding in the American midwest, spawning high water that swept away an Iowa teenager, caused a traffic nightmare near one of the nation's busiest airports and threatened to swamp a Missouri town for the fifth time in less than a decade.
Najaf, say the clerics, already bustles with 3,000 students.America's overthrow of the Baath is spawning a Shia renaissance, not entirely to America's liking.
There are the risks of running down supplies needlessly and, also in the case of antibiotics, of spawning bacteria resistant to anything doctors throw at them.David Heymann, head of infectious disease at the World Health Organisation, urges calm.
Fish do not.Introduced in Arkansas in the 1970s, Asian carp have swum up the Mississippi River, eating and spawning ravenously.
In particular, the valley will become even less of a location, and even more of a process: a way of spawning new ideas and young companies.There are two kinds of threat to Silicon Valley: from outside and from inside.
The biggest worry, though, is exchange-traded funds (ETFs), investment vehicles that trade on stock exchanges and hold assets such as shares, bonds and commodities.These funds have mushroomed of late, spawning all manner of innovations, some of which may be destabilising and worry regulators.
Of the former, almost 33m belong to health clubs, spawning a multi-billion-dollar industry of sports shoes, fitness foods, exercise videos, heart monitors and personal trainers.It was not always thus.
Most important, transport and telecoms networks, and social media, are spawning new data as a free by-product.This has triggered new research.
Meantime, the internet is spawning new forms of accountability.
