Counting fish

An adult and a pre-recruit toothfish.  

The adults can reach over 2 metres in length

 and weigh in excess of 150 kg.

So, why are we way down here by the Ross Ice Shelf as far south as one can possibly fish?  We are now half-way through carrying out a research programme for CCAMLR.  This is a ‘pre-recruit survey’ (scientist-speak for measuring those fish that are too young to spawn) – the pre-teens of the Antarctic toothfish world if you like.  Now just to be clear there are two species of toothfish; Antarctic toothfish, which is what we mainly catch in the Ross Sea region, and Patagonian toothfish, which are largely caught in other fishing areas. Antarctic toothfish live further south and generally grow larger and Patagonian toothfish have a more northern distribution.  Most media coverage on Ross Sea fishing issues incorrectly report the catch as Patagonian toothfish.

Why are we doing this?  The most important reason is to get a handle on what the fishery might be like in a few years’ time.  The Ross Sea fishery is mainly based on adult fish and although we have a really good idea of the sizes (and thus the ages) of these, we know less about the population structure of the smaller fish which will replace them in the years to come.  We know from previous work that the younger and smaller fish hang out here in the shallower water in the southern Ross Sea (the shelf).  So we are fishing 65 different locations in order to collect these younger fish.  We catch them, and then measure many of their characteristics such as their length, weight, sex, and some organ weights - we remove and store their otoliths (to get their ages), and then take tissue samples for a raft of other projects ashore.

Drs Hanchet and Jo discussing the finer points 

of fish identification.  

What do we hope to understand from this work?  Firstly, whether there are differences in the numbers of young fish that survive after hatching from year to year - and if so how much this varies from one year to the next.  We might then then be able to determine what environmental factors influence this success.  It is also an additional insurance policy for the fishery, as this work will give advanced notice as to what we might expect in the adult population a few years down the track.

Who is doing it?  Well we have two scientists aboard – Dr Stu Hanchet from New Zealand (NIWA) who was one of the proponents of the work; and Dr Hyun-Su Jo from Korea’s National Fisheries Research and Development Institute (NFRDI).  There are also two of us from Sanford and our two scientific observers.  All vessels working in CCAMLR Exploratory fisheries like the Ross Sea must carry two observers at all times.  We work 24/7 with three of us on a watch doing the sampling.

Picking up our scientists from Cape Bird.

On 4 February we picked up our scientists from Cape Bird on Ross Island after we finished our normal season. Thanks to a great break in the weather and the much appreciated assistance and organisation of Antarctica New Zealand‘s Peter McCarthy we got them aboard without difficulty.  Most aboard also got their first view of Ross Island, Mt Erebus and Mt Terror as we rarely get close to the continent during normal operations.  I really hope the rest of our Our Far South crew get a similar day when they get down here.

Next blog – our fine vessel.

THE VIEW FROM MY OFFICE

The view of the Ross Ice Shelf
 from the bridge of the San Aotea II.

This is my first (ever) blog so I beg the reader’s indulgence – I’m feeling my way.

As I write this early morning I am having trouble seeing the computer terminal due to bright sunshine.  You learn quickly down here that 24 hours of sunlight comes with a hitch – the sun is always quite low on the horizon – very much like driving a car just after sunrise in the winter.  On fine days the glare is more hindrance than asset.   Looking out the bridge windows now I can see the Ross Ice Shelf (also known as the Ross Barrier) framed by a pale blue cloudless sky and stretching in front of me right across the horizon from east to west.  I sometimes wonder what James Clark Ross must've thought when he first came up against it in 1841 – it's nearly 50 metres high and stretches east 455 nautical miles from Cape Crozier on Ross Island, completely blocking his further progress south.  You cannot go further south than here by sea. As I look it’s a dazzling white ribbon with the sun contrasting and shadowing all the irregularities - caves, crannies, and bulges. The Ross Ice Shelf is where many of the southern hemisphere bergs are calved and out to starboard there is a new berg about four miles long. Flat-topped and pristine white it’s the definitive and unique southern hemisphere tabular berg – and I’ve got a great view of it from my ‘office’.

Me (left) and Peter Weeks the skipper of the Aotea II.
That's Mt Erebus in the background.

So, who am I and why am I writing this?   When asked, I define myself a marine science specialist -having spent much of the last forty-one years working at sea.  I worked for Government agencies for just over 20 years in the disciplines of fishing gear technology, exploratory fishing,  and then running research surveys mainly for stock assessment. Then I changed tack in the early 1990’s and spent a number of years as a fillet- boat processing manager for Sanford and moving to a diverse range of fishing related work .

Now I’ve come full circle and am again taking up some research work as an independent consultancy – mainly this time on Antarctic fisheries .  This started in the Ross Sea where I have spent every summer since early 2001 contracting to Sanford. Among other things I supervised the research carried out aboard.  The scope then widened to encompass the South Atlantic fisheries at South Georgia and the South Sandwich Islands. Over the past seven years I have attended annual CCAMLR Meetings as a member of the Fish Stocks Working Group and as an advisor to the New Zealand delegation to the Scientific Committee. I have written or co-authored a number of scientific papers chiefly on Antarctic toothfish biology, feeding, sea-bird mortality mitigation, and the long-line fishing methods used in Antarctic fisheries.

I feel very privileged to be able to take part in the Our Far South voyage. For those of you who don't know, it's a project where a group of New Zealanders from a wide range of backgrounds travel together to Antarctica and the sub Antarctic Islands to investigate the issues facing the region. Due to commitments and timing I will join them when they get down here in about a week and a half depending on weather.

Where am I?  Aboard San Aotea II - one of Sanford’s longline vessels in the Ross Sea carrying out a research survey on small toothfish at the very south of the Ross Sea.  More on the survey, CCAMLR and the boat next few blogs.