JR161: Food webs in Antarctica


 JR161



Question time!

The JR161 cruise has now finished.
Questions received by the team (and answers!) are posted below.



Q

Christine Pequignet from Paris asked:

Do you have to kill the animals you collect to study them or they stay alive? If you kill them, do you eat them? If you don't eat them, what do you eat?

A

Excellent question. My work involves the study of phytoplankton, tiny plants in the oceans, and so is not directly related with the collection of animals.  However, small animals are collected by other scientists aboard using a variety of towed nets.  Animals caught in the nets are identified, weighed, measured and a sample is preserved for study in laboratories back on land, the rest of the catch is thrown back into the sea, where it is eaten by sea-birds that follow the ship.  The nets are small (compared with commercial fishing nets) and are designed to catch only a representative sample of the animal populations in the oceans, occasionally a fish large enough to eat is caught and can be prepared by the chefs on board the ship.  There is, however, enough food on the ship to last the entire cruise – tonight we had pâté to start followed by spicy chicken and a cheesecake desert (there was also a veggie option, but I can’t remember what is was).

Tom

Q

Vicky, Age 13 from London asks:

How many objects of great scientific importance (and which are doubtless irreplaceable when so far out at sea) has Tom Bibby broken since you set sail?

A

So far, none, but there is a long way to go on the cruise yet!  We hope that we’ve brought enough spares and there is a lot of expertise on the ship (engineers etc.) to help us fix things.  As we’re working on a moving ship with salt water and electrical instruments, we’re lucky if we don’t have to fix something.  For example, our ‘towed-fish’, an instrument that we tow alongside the ship to collect uncontaminated sea water, was slightly damaged by ice but is repairable. 

Tom

Q

Marcus Pye, age 5 from Dorset asks:

Do you ever get seasick living on a boat? I get seasick standing on a pier!

A

You Landlubber!  Thankfully I don’t suffer too badly from sea-sickness – most people feel a bit queasy on the first day or so, but we all take sea-sickness tablets before we leave and that tends to help.

Tom

Q

Heather, age 16 from Portesham asks:

Would it be possible to use phytoplankton to combat global warming and in some way soak up CO2 emissions, eg. have large lakes of it next to power stations etc?

A

Phytoplankton are already combating global warming. Indeed, if it wasn’t for phytoplankton in the oceans, the concentrations of CO2 would be much greater and rising at a faster rate than they are today.  Much of our work involves characterising how efficient phytoplankton are at taking up carbon, and some work has even considered fertilising the oceans so that they are more biologically active. But solving a man-made effect with another one is a dangerous way to go, especially as there is still much that we don’t understand about such a complex system.

Tom

Q

Audrey, age 14 from London asks:

How big is a phytoplankton and who would win in a fight with a zooplankton?

A

Phytoplankton are small and range in size from microns (10-6 metre) to several millimetres (10-3 metre) (this is a much larger size range than for land plants).  Zooplankton are much bigger and feed on phytoplankton, so it’s a bit like asking who would win in a fight between cows and grass. 

Tom

Q

Kilkina, age 9 from Hawaii asks:

Are you growing a beard to keep you warm?

A

I’m growing a beard for a few reasons, but not to keep warm (I have enough hats and scarves to do this).  The main ones are (1) I’m lazy, (2) I want to look the part, and (3) my girlfriend won’t let me grow one back home.

Tom

Q

Amy, age 10 from Honolulu asks:

If phytoplankton is so small, how can they still perform photosynthesis?  Don't you need large leaves for photosynthesis?

A

Good question. The chemistry of photosynthesis happens at the level of individual proteins, so can happen in very small cells, and the photosynthesis process is the same in plants and phytoplankton.  Leaves increase the area that plants can capture sunlight but each leaf needs to be physically supported, eg. by the tree.  In the open ocean such a structure would sink, so phytoplankton need to be small to stay at the surface and capture the sunlight.

Tom

Q

Timmy, age 12 from Alabama asks:

Hi Tom!  How do you stay fit and active on the boat?  Is there much food to eat?

A

Hi Timmy. There is too much food on the ship – we have three meals a day breakfast, lunch and dinner all cooked for us by the chefs on board, as well as this there is a midnight meal for people on night shift (so if you are greedy you can have four meals a day!).  As the ship is only 98 m long, its hard to do much exercise and burn off the calories – there is a small gym, but I fear I’ll be a bit bigger when I finish the cruise.

Tom

Q

Lyndsey, age 12 from Rugby asks:

Do you think that the hole in the ozone layer is affecting the biology you are interested in?

A

The ozone hole definitely affects the scientists studying the biology here as they have to ware high factor sunscreen, hats and sunglasses.  Many science programs are focused on the impact of the ozone hole on biology, but these programs have only recently started and it will take time before we understand the impact.  These questions can only really be answered by long-term monitoring programs that are underway and run by organisations such as the British Antarctic Survey.  One problem is that man-made influences on Antarctica happen very quickly and it is unlikely that the biology here, which grows very slowly will be able to adapt quickly – for this reason, the biology of Antarctica is very fragile.

Tom

Q

Anay, aged 15 from New jersey:

I love the penguin picture and I think your sense of fashion is awesome! (especially the skidoo helmet).  I think you should definitely market a line of Antarctica wear after your trip.

A

Thanks – I may stick to the science - Tom

Q

Tristan, aged 10 from Edinburgh asks:

How can changes in the microscopic phytoplankton affect penguins?

A

Although small phytoplankton are at the base of the food chain in this region, they are the ‘primary producers’ – the same as plants on land.  They convert energy from the sun into food for all the animals.  Phytoplankton are eaten by krill, which is the main food of many penguins.  If there are lots of phytoplankton, there are will be lots of food for the penguins.  

Tom

Q

Delyth, aged 14 from Bangor asks:

Do icebergs get biofouling like boats?

A

In a way yes, but you shouldn’t think of it as biofouling.  Icebergs create environments for phytoplankton that can colour the bottom of the ice (greenish brown), and then, as the icebergs drift, larger animals feed of the phytoplankton as they provide some shelter and protection – as they drift they can be an oasis of life.  The icebergs obviously don’t worry about how fast they go, so its not really biofouling.

Tom

Q

Amy, aged 13 from Bristol asks:

How low will the temperatures get on your trip and is it very cold living on the ship? Also, do you get seasick and if so, is there anything you can do to prevent it?

A

It pretty cold outside of the ship, the air temperature is normally around minus 3 and the sea temperature is minus 1 (because the water is so salty it is still liquid below 0).  Its OK as long as you wrap up warm and don’t spend too long outside on deck – this can be hard as the scenery is so spectacular.  I don’t really get seasick – there are seasickness tablets that we can take, but the best thing to do is to lie down with your eyes closed.

Tom

Q

Joe, aged 13 from Crewe asks:

How did you become a scientist? Do you enjoy it? It sounds very exciting.

A

I’ve always tried to work on subjects I enjoyed and found interesting and, as a result, ended up doing this.  I’ve been lucky in that there was always a position for me to move into and, so far, all is going well. 

Tom

Q

Helga, aged 17 from Norway asks:

How many scientists on the ship are logging whale movements?

A

Most of the science on the ship is focused on lower down the food chain, but one scientist from the British Atlantic Survey (Ewan) is on the bridge during daylight hours logging numbers and movements of higher predators, including birds, penguins, seals and whales.

Tom

Q

John, aged 29 from London:

Do you get bored of eating hard biscuits with weavils in and limes to avoid scurvy?

A

There are some hardships associated with working at sea but none as bad as you think.

Tom

Q

Guy asks:

How big is the ship and how many crew, scientists etc. are on board? Also, how many teams of scientists are there and what type of work is each team doing?

A

The ship is almost 100m long, there are about 20 scientists and 30 crew. In oceanography, a multidisciplinary approach is taken to studying the oceans and scientists are divided into biological, chemical and physical teams.  Depending on the emphasis of the cruise these aspects can be differently weighted. This cruise is biology-heavy but there are still some scientists characterising the physical and chemical parameters of the waters we are in. At the end of the day, all the data is combined in an effort to understand a specific question – in this case, describing the food-web dynamics in the Scotia Sea.

Tom

Q

Gareth, aged 9 from Exeter asks:

Do penguins get cold feet?

A

Excellent question. I had to get expert advice on this one as my penguin knowledge is slim. In the winter, penguins do get cold feet but have a specialised circulation system to minimise heat loss. However, penguins have excellent insulation, and when active (feeding), they often use their feet to cool down by standing in melt water from glaciers.  (Thanks to scientists at BAS for this answer).

Tom

Q

Paul from New Jersey asks:

Are the phyotplankton that live in the Antarctic specially adapted to the cold or could they move to warmer places and survive?

A

Interesting question. To a first order, temperature is an important factor in determining the geographic distribution of certain phytoplankton. Psychophilic phytoplankton (with a requirement for low temperatures) have successfully adapted to live and grow in the cold and underpin the highly productive food chain in Antarctic waters.

Adaptive characteristics include cold-active proteins and maintenance of membrane fluidity. In addition, cold-tolerant phytoplankton display physiological responses to balance the temperature-independent reactions of light absorption and temperature-dependent reactions of electron transport and metabolism. This physiology is particularly important under high-light and low-temperature conditions.

Although successful in Antarctic waters, these strategies preclude survival in warmer environments in which other specialised phytoplankton successfully dominate.

Tom

Q

Shimi from Honolulu asks:

If global warming melts the ice will all the penguins fall into the sea?

A

Hi Shimi. Yes, but they can swim so it’s OK. Penguins rear their young on land or pack-ice and global warming is threatening the viability of some colony locations that have been established for thousands of years. Although the colonies could move it is unknown how well certain species will adapt.

Tom

Q

Britney, aged 15 from Brighton asks:

As all the ice sheets in the Arctic are melting and polar bears are drowning, why hasn't anyone introduced them to Antarctica?

A

Polar Bears would have a field day in Antarctica – the seas and ice is packed with polar-bear food (seals) that have increased in numbers since fur hunting was banned. The seals on the other hand would suffer. In addition, polar bears would bring with them diseases that could threaten many indigenous species – it is for this reason that husky-pack dogs are no longer used in Antarctica. The invasion of foreign species is a major problem threatening the unique Antarctic ecosystem – a problem that is made worse by increasing tourism and indeed scientific research. We must all tread carefully.

Tom

Q

Rachael, aged 15 from Dorchester asks:

Hi Tom - nearly finshed now - are you looking forward to coming home?! What home comforts are you missing the most? I'd also be interested to know who the trip is funded by and who decides what trips the ship will do and when and why?

A

Hi Rachel, Definitely looking forward to coming back, this is the longest I been at sea and it will be nice to get home although it is quite nice to be away from all the Xmas hype.  I’ll get into trouble if I don’t say I’m missing my girlfriend but other than that you can feel cramped on the ship – so I’m also looking forward to be able to stretch my legs on land and a bit of freedom.

The science cruises are funded by the National Environmental Research Council (NERC) – an organisation that dishes out the pot of money the government has decided to allocate to environmental research.  Scientists either as individuals or groups have an idea of research they would like to do and then apply to NERC for funding and, if required, ship time.  They have to justify the costs, the time and benefits of the work to the UK.   NERC then use other scientists in the field to decide if it’s worth funding (a process called refereeing).  It’s a long process and takes a lot of time and effort and isn’t always successful but that’s how it works.

Tom

Q

Guy asks:

How deep does the phytoplankton extend generally and is your sampling within that depth only ?

A

Light is absorbed by water and so light intensity declines with depth. At 100m there is approximately 1% of the surface light intensity - this is roughly a minimum amount for photosynthesis and so phytoplankton grow above this level. We sample to 140m to make sure we measure all of the phytoplankton.

Tom

Q

Clive Martin from Biscay Dolphin Research Programme/Marinelife asks:

I would be very interested to know which species of cetaceans you are having sightings of. Who is the onboard cetacean "expert" ? Are you linking in with the FerryBox Project and Dr David Hydes of NOCS?

A

My job on the cruise is to systematically record all air-breathing higher predators (i.e. seabirds, cetaceans and pinnipeds). As you can imagine that's quite a tall order, especially in an area as productive as the Southern Ocean. As far as cetaceans go we haven't seen a huge number of species so far but have seen a lot (over 50) of fin whales. We also saw a number of Antarctic minke whales around the ice edge, some long-finned pilot whales and a southern right whale near the Polar front and several groups of southern bottlenose whales. The bridge officers have also seen killer whales and 'dolphins' (probably right whale dolphins).The data from the cruise won't be linked directly to the ferrybox project but we're collecting equivalent data (SST, chl, salinity, etc.), as well as data on cetacean prey such as krill and shoaling fish. Hope that helps!

Ewan Wakefield (BAS & SMRU)

 
 


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October 2006
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