How much do you know about the splendid alfonsin?

No, me neither.

At first I thought he must be the mannish hero of some cheap boys' novella - a Pimpernel in the face of organised crime, a Zorro jumping on the cat-stroking villainry of world domination, a musketeer with liberty carved into his very eyeballs.

Somewhat disappointingly, in one sense, it's a fish.

And I know this: if trawlers used to catch 60 tonnes of them in a single hour back in the 1970s and now they catch only one tonne in an hour, something has happened to the alfonsin that he must consider entirely the opposite of splendid.

You or I might get to eat a splendid alfonsin (also known as splendid alfonsino, which is even more heroic); but we're unlikely to see one alive, as they generally live on or near the ocean floor at depths that can reach 1.3km.

For a long while after the dawn of commercial fishing, such species remained out of reach, out of sight and out of mind.

No more. As more accessible stocks dwindled, and demand continued to rise with the growing human population and affluence, ever more well-equipped fishing vessels began to target these deep-ocean species with a range of methods, the most destructive of which entails dragging five-tonne pieces of iron at the front of trawls over the sea floor - fine, if it's just sand and silt, but not so great if it's a deep-sea coral reef.

Three years ago, following a heap of pushing and prodding and repeated false starts, the UN General Assembly eventually acknowledged the possibility that soon some of these species might vanish out of sight forever unless steps were taken to protect them.

Deep-water bottom-dwellers are often slow to grow and slow to reproduce. The orange roughy can live to at least 149.

This makes them highly vulnerable to overfishing, unlike species that reproduce with great fecundity when they're barely out of the fry stage.

Conservation groups pressed the UN for a straightforward moratorium on bottom-trawling except in places where good management regimes were already established.

Enough member governments demurred to force a weakening, but what emerged was, by the standards of these things, not a bad set of measures: scroll down to "A/RES/61/105" at this research guide.

Governments promised to protect vulnerable marine ecosystems (VMEs), either by themselves or through regional fisheries management organisations (RFMOs). Where no competent RFMO existed, they would create one.

Countries would bar vessels that flew their flags from bottom-fishing in international waters where it had not been proven that no harm would come to VMEs. The precautionary principle was everywhere and most of these rules had to be put in place pretty quickly, by the end of 2008.

That 2006 resolution also instructed the UN secretary general to monitor the situation and provide a status report. It had to be ready for this year's UN General Assembly, which opens in the middle of next week.

At this moment, officials from UN member governments are in New York poring over the secretary-general's report [329Kb pdf] .

It's unlikely that any of the bottom-trawling countries will find much to keep them awake at nights.

The main reason is encapsulated in a couple of sentences so strangely juxtaposed in sentiment that they could belong to different centuries; you'll find them on page seven.

The first states that submissions for the report were solicited, and did in fact arrive, from member governments, RFMOs and non-governmental organisations - which in this case mainly means conservation groups such as the Deep Sea Conservation Coalition (DSCC).

The second states that the people compiling the report based it on submissions from governments and RFMOs, as well as unspecified "other relevant information".

So - er - what happened to the rest of the submissions?

The DSCC's take on this is that "the secretary general's report collated the information received on what has been done, but in doing so does not clearly show what has not been done".

For an example of what the coalition means, let's take the area managed by the North East Atlantic Fisheries Commission (NEAFC).

The report says that NEAFC decided to prohibit gillnets and entangling nets (which work pretty much as their name suggests) in water deeper than 200m; very good. It also agreed to "reduce all deep-water fishing effort" by one-third.

According to the DSCC, what the report omits is that gillnets and entangling nets are a minor source of catches, the majority coming from trawls - which are not banned; and that under the effort-reduction measure, the reported catch actually rose from 20,000 tonnes in 2004 to 90,000 tonnes in 2007.

And so on; there is more, much more of this.

The secretary general's report is long (67 pages), detailed and acronym-dense, and unless you readily know your PECMAS from your SIODFA you'll not find it easy going; nor will you the detailed DSCC submission [597Kb pdf] .

But what it really boils down to is this. The UN resolution three years ago said, in a nutshell, "don't fish the sea bottom unless you know you can do it sustainably".

What seems to have happened in many areas of the world is that member governments have put into place regimes that say "we don't have any information to say that's not sustainable, so we'll presume it's okay to continue".

Lobbyists for fishermen may at this point wish to express concern about livelihoods; two things are worth bearing in mind.

Firstly, all governments signed up to this; anyone who doesn't like it should complain to them.

Secondly, the resolution doesn't ban bottom-fishing; it just says don't do it unless you know it won't destroy deep-sea ecosystems, such as ocean vents, or the very fish stocks you're trying to catch.

UN member states don't have to accept the secretary general's report. They're discussing it this week, and it will come up again during the General Assembly (agenda item 77b, in case you're interested).

If they're serious about making fishing sustainable, they might ask how it is that catches can rise by a factor of more than four under measures that are supposed to cap them.

They might ask why it is that in the entire north west Pacific, fishing nations have agreed to protect just one part of one seamount among many that are likely to support vulnerable ecosystems.

They might ask why protocols designed to encourage captains to move on when they realise they're having an "encounter" with a vulnerable marine ecosystem stipulate they can bring up 100kg of live coral or 1,000kg of sponges before realisation has to dawn.

Then again, they might not ask any of this; in which case, we had better enjoy the splendour of the alfonsin and all its cousins while we still can.

