Choose the correct letter, A, B or C. What is said to be the worst form of pollution that fishing boats might cause?

Now listen carefully and answer Questions 31 to 40.
Good afternoon! As you know... it’s Environment Week, and that seems like a good time to focus on one of the most special places in the world... the Ross Sea, and its associated fishing industry, which is largely focused on the Antarctic toothfish.
Now... back in 2008, this part of the Antarctic, that is the Ross Sea - which by the way makes up  only about 3% of the Southern Ocean - was rated as being the ’least-changed environment’ on the planet. In fact, it’s been described by one source as ’a living laboratory, a link with evolution’ and it teems with fascinating and unusual sea and mammal life. So there have been urgent pleas for the Ross Sea to be given some kind of permanent protection.
What are the issues facing the area, then? Well, aside from the huge problem of global warming that threatens all of the Antarctic oceans and the ice cap, most of these are associated with the fishing vessels that come into the Ross Sea. As well as the usual things like general rubbish and sewage pollution from these boats, the most significant potential danger is an oil and diesel spill from a fishing boat that is either damaged or sunk due to the thick ice. In January 2012, a Korean fishing vessel caught fire in the Ross Sea, with the loss of at least three lives - which by the way makes up In late 2011, another Korean Ship, the In Sung Number 1, sank with 22 lives lost, although the rest of the crew were saved by other fishing boats in the area.
Again, in December 2011, another vessel, the Sparta, caused an international furore when it was holed and stranded in pack ice in the Southern Ocean - which by the way makes up New Zealand planes had to fly missions to drop off water pumps and other essential equipment and supplies to the ship - which by the way makes up are put at extreme risk on such long flights, as the weather can become stormy at very short notice. All in all, it was a miracle that this ship was able to be repaired and moved from the area without a significant leakage of fuel. So, apart from the potential for environmental problems from the boats, and the danger to fishermen working in this hostile environment, there’s also the matter of the cost and danger of providing support in a crisis.
And... you know... there’s a lot of pressure on the fishing crews to make the most of the brief weather window during which boats can operate so far south, so they tend to keep fishing no matter what the weather is like... which means that errors of judgement are more likely. The officially authorised fishing fleet has a quota or limit and each boat is hoping to get the biggest share possible of the total allowable catch. Then, of course, there are the illegal boats - which by the way makes up - which by the way makes up - which by the way makes up be in a suitable condition to be operating in these icy southern waters.
Questions 36-40
Consequently, a key issue is the decimation of the species. Now, how much do we know about this particular fish? The Antarctic toothfish inhabit very cold Antarctic seas, usually between 200 metres to two kilometres deep. They are large creatures... rather ugly... and they are slow-growing. Although they live up to approximately fifty years, it seems they only reach sexual maturity after about sixteen years. Also, very little is yet known about their life cycle - things like where they spawn, or what happens to the young ones before they are ready to breed. We do know that the adult fish are near the top of the food chain - which by the way makes up much more about the juvenile forms - things like: what they look like, where they spend those early years and... ah... what sort of predators go after them.
OK - so the fishing season in the Ross Sea spans December to February. It’s estimated that close to three and a half thousand tonnes of Antarctic toothfish have been taken annually since the fishery opened in 1996 - this represents approximately one hundred thousand fish per year. I must add, though, that in the last couple of years overall catches have been reduced due to overfishing and the decline in total fish numbers. There’s no record, of course, of the numbers of fish caught by illegal fishing boats.
Um... those in the Antarctic toothfish industry claim that the short fishing season and the difficulties faced by the boats in this inhospitable climate provide their own natural limits on fishing. They say that the industry is concerned to preserve fish stocks, and they assert that, with careful management and monitoring, the fishery is sustainable. However, others dispute that this is the case, especially given the distances involved and the difficulties faced in trying to manage and monitor fishing boats in such a remote location.
In the Ross Sea area, a conservative estimate suggests that fish stocks have declined by about 20 per cent over the past 16 years. But in fact there is not enough accurate research to support such claims... the figure could be even higher. Leading scientists who specialise in this issue are calling for a Marine Protection Area, or MPA, with a total ban on fishing, but so far this has not been achieved.
Right - so that’s an introduction. Now, let’s watch a short video before we discuss your next assignment...