Taking the great whales out of the southern ocean led to less Krill, their principle food. Whale shit is rich in iron; iron is the limiting nutrient in many ocean ecosystems. So whale shit was a major source of iron for Phytoplankton, which is eaten by Zooplankton, which is eaten by Krill and Fish. And Whales eat Krill and Fish. Fewer whales, less shit, less plankton and you've reduced the carrying capacity of the whole southern ocean.
The southern ocean is the world's shortest food-chain but the same is true (though with many more complex feedback loops) in richer ecosystems. When wolves were removed to from the Yellowstone ecosystem, the elk overgrazed the riverside foliage, which led fewer willow trees, which meant the beavers disappeared too, leading rapidly to a much less diverse ecosystem than the Beaver-dam Willow wetland that was there before. The effect, like that of removing great whales from the southern ocean, was the carrying capacity of the whole ecosystem was reduced.
No-one seriously thought the fox population would increase because of a fox-hunting ban; killing foxes isn't the primary purpose of fox hunting, and the hunt takes too few in any given year to be a significant cause of mortality. And so it turned out. Indeed there's some evidence the fox population actually fell following the ban. But hunting was still part of the management of the ecosystem, but in more subtle ways. It's also, by the by, the centrepiece of a rural way of life.
The English countryside is a wholly man-made environment. Even places like Dartmoor look nothing like they did before people got here. In the English countryside, Humans are the top predator. In the Autumn, "pre-season" or "cub" hunting the summer's litters of fox cubs, by then fully grown, were sought out, and scattered. Many, the weakest individuals, were killed. This reduced local concentration of foxes in individual coverts, meaning they don't over-predate their territory. It's the starving fox that usually goes after livestock.
Add to the lower likelihood of healthy foxes going after livestock, there's the rural taboo about shooting the landlord's quarry. Fox hunting made the fox valuable to farmers, while ensuring a higher fox population was less likely to take lambs. (You'll always need to protect your chickens). This meant that thanks to Fox-hunting, a much higher fox population can be found in England than in comparable ecosystems.
Foxes keep rodents down. Rodents eat birds' eggs. Higher fox population (thanks to hunting) means more song birds in the hedgerows, and a healthier ecosystem right down the food chain.
Fox hunting isn't cruel. While Lord Burns concluded a single shot from a rifle was the optimum kill, foxhounds never wound. Even the best marksman sometimes leaves a maimed fox. Furthermore shooting foxes doesn't discriminate between old, weak and ill animals; and healthy ones. Fox hunting does, mimicking the effect of lost, larger predators such as wolves and lynx which would once have carried out this role. Healthy foxes usually escape, weaker animals are killed.
Fox-hunting generates hysteria mainly because it's seen as a posh person's passtime. People feel uncomfortable at the idea of "taking pleasure in killing animals for sport", and the people who do it are in 18th Century fancy dress. It's easy to lose sympathy with people you don't understand. The fact is you'll hear more regional accents out hunting than you will almost anywhere else. There are toffs too, speaking with Marked Received Pronounciation, but they are not the majority. Most of those riding to hounds are the rural people who are closest connected to the land, retaining forms of speech long swept away elsewhere by the march of estuary English. But amongst them you'll find people from all walks of life. A passion for equestrianism is their uniting characteristic.
The "Sport" to most people riding to hounds is going hell-for-leather cross-country on horseback. It is extremely dangerous, exhilarating and primal. Watching the hounds work is also part of the enjoyment, something I found fascinating when I carried a whip for a pack of Basset hounds. I've followed hounds in pursuit of various quarry on horse, foot and by bicycle. Few if any people I've met out hunting enjoy the kill.
When people talk of "toffs" hunting, it's just evidence of ignorance and prejudice. Such a person could never have actually gone to a meet and still believe that. When people speak of "cruelty" I think of the barbarism of factory reared pork or chicken, not something remarkably similar to what would happen to foxes, were England returned to its primal state. If you think fox-hunting should continue to be banned, you might as well admit it - it's class war, not foxy-woxy that motivates you. Distaste for fox-hunting is rarely motivated by fox welfare, but by what people think the motivation of the those doing it might be. This is nothing more than brute, outgroup prejudice, given added justification by a mawkish sentimentality towards Vulpes vulpes. Issues of animal welfare are just window dressing for mere bigotry.
The SNP were going to veto a change to England and Wales law until it was pulled by the Government. This wasn't vicious Tories alone, it was supported by Plaid Cymru (not known as a party of the upper classes) as well as a handful of Labour MPs (including the only one I've ever voted for, Vauxhall's Kate Hoey). Despite the fact the change to the law was to bring England and Wales in line with Scotland, and didn't affect Scotland at all, the SNP opposed it. The SNP will be pleased to have linked 'English Votes for English Laws' to the divisive issue of Fox-hunting, and to have discomfited the Tories. But I think in the longer run, the breathtaking hypocrisy they have shown will yield a greater loss to their credibility. Their previous abstention on England's (and Wales's) legislation was an honourable self-denying ordinance which reduced the pressure for EVEL. Now the Tories will hammer it through, and will have the support of more of the house, because of the SNP's opportunism. The Ban of Fox-Hunting, never about the welfare of the fox, is the ultimate political football. No-one. Not farmers, not huntsmen, nor the fox benefits from this.