Monday 28 July 2014

More sarg-ing


So many secret beaches to graffiti!
Intertidal Sargassum dominating
a rockpool
So life on Sherkin is very warm at the moment - highs of around 29 (degrees C) recently - which is only a few degrees below the all time hottest temperature ever recorded in Ireland. The radio informed us that temperatures in parts of London reached 32 degrees! - Which I think is far too warm to be in London. I'm glad to be by the sea during this mini heat wave.

Sometimes the clambering
is a little more like rock
climbing.. I should've
brought my climbing
harness (and helmet)
A while back I did a post about the Sargassum survey that was happening - the one where we were snorkelling to survey sub-tidal Sargassum plants. Well there has also been an intertidal Sargassum survey taking place. The marine lab bods have been steadily working their way around the Island around the time of low tide and recording where they find Sargassum, how big the plants are, and other information about the rock pools that the invasive plant has been found in. Almost the entire circumference of the island has been surveyed! This hasn't been the easiest task though - as it involved clambering round the rocks surrounding the island (which are often incredibly sharp and slippery and awkward). Many injuries have been sustained from this clambering! Also, at some points round the island it is just impossible to get round on the rocks. At these points people have to climb up to the top of the cliffs and walk round to the next accessible bit of the shore - however at the hop of the cliffs there is no nice clear coastal path - in most places there is just an AWFUL LOT OF GORSE. super painful but also means that regular tick checks must be carried out.
Dragonfly

Glaudine keeping an eye on us?
I HATE TICKS. They are just the worst. And they magically appear! You will think you have removed all of them, but then you will check again a few minutes later and more tick will just appear - FROM NOWHERE. Also, horseflies, I hate these too.

But thats enough complaining about beasties. It has been really fun helping out with the Sargassum hunt, and it has meant that I have been outside in the sunshine - so thats an added bonus! And I am actually really looking forward to seeing the results of the survey and seeing how they compare to previous years.

Also, the other day we all went to see a one-man play that was being performed in the community centre. We were told great things about the play and we weren't disappointed! It was fab! It was very intense, but also very interesting and well-done. If you see it advertised anywhere and you get the chance to see it I would recommend it highly.



One pro of getting up at 5am for plankton sampling :)



Thursday 24 July 2014

More bloomin' information (see what I did there..)

After posting my last update I realised that I never really properly described why and when phytoplankton blooms occur. So i thought I would briefly try to outline these things.

Phytoplankton essentially need 2 things to survive and grow: nutrients & sunlight (as they are largely photosynthetic organisms). Without these things they cannot survive. When there is an abundance of both of these elements (due to natural or anthropogenic influences) phytoplankton can thrive and blooms can occur.

Naturally in many temperate regions there are 2 major bloom events - one in the Spring and one in the Autumn. During the winter the water column is well mixed due to storms, increased wind, and decreased stratification, so there are plenty of nutrients in the surface layers (where the phytoplankton reside). However, there is limited sunlight during the winter. This causes a build-up of nutrients in surface layers. When sunlight intensifies in the Spring, light is no longer limiting phytoplankton growth and large numbers of phytoplankton are able to grow due to the nutrients that accumulated in the water column over the winter. This is the major phytoplankton bloom of the year - the Spring bloom. Once the backlog of nutrients have largely been utilised by this bloom the nutrient levels return to a lower baseline level and phytoplankton levels also return to a lower level. Over the summer the water column becomes more stratified and nutrients in the surface waters get depleted and not replenished by deeper water nutrients. This leads to a smaller Autumn bloom when winter storms begin mixing the water column again - replenishing nutrients to the surface waters.

So that is a very very brief attempt at an explanation about when and why plankton blooms happen.


Zooplankton

Thus far on this blog I have only really talked about phytoplankton (the photosynthesising section of plankton). I thought I would take a moment to mention the non-photosynthesising fraction today.

Zooplankton can be animals that permanently remain in the plankton, or they can be the juveniles of animals and grow up and metamorphose out of the plankton phase. In other years the plankton team have also investigated the zooplankton in the waters here - but this year there aren't enough of us to manage both phytoplankton and zooplankton. However we are still collecting the samples for future years to look at.

Photographs of some zooplankton - juvenile stages of non-planktonic adult animals.
Some of these look nothing like the adult animals they grow into!
Photographs all taken at Sherkin Island Marine Station.


Unidentified worm larvae



Unidentified bryozoan larvae (the radio was
playing whilst I recorded this..)


In other news, the other day there was a rather large storm that passed over the island and we had to rush around unplugging everything possible as the lightning was very ferocious and impressive! I would kindof like to be here to see a winter storm now! There was also an amazing sunset and lovely rainbow that appeared just before ALL THE WATER FELL FROM THE CLOUDS.


  

Thursday 10 July 2014

Recent happenings on Sherkin

What’s been happening recently on Sherkin.. 

Well there was a wedding a few days ago! I think the whole island plus another couple of hundred people must’ve been at the pub for the celebrations (also we were all there)! The pub and the marquee outside looked beautiful decorated with candles and fairy lights – with the view of the sea and mainland Ireland across from the pub it was a really stunning place for a party. There was an excellent band and there was much drinking, dancing and merriment!

On Sunday we went rockpooling (for fun) at one of the nearby beaches and we bothered many sea beasties.

Aside from that it has been work as usual in the Marine Lab – Maria is back from her holiday back home in Spain and she has returned with yummy things and wine! (I’m sure the wine is also going to be yummy). Her return brings the Plankton Team back up to 3 people, which will make washing tubes a LOT faster, and pulling up plankton nets from 50m depth will be nicer with 3 people also.

Also another bod has arrived! Her name is Jess and she is a new addition to the Rocky Shore team (the 2nd best team here). Hopefully this will 
mean that the Rocky Shore people will be able to sleep a more normal amount each night now!

In other news, a villainous horrid meddling devil creature (a cat) broke into the plankton lab (probably jumped through a window) a few days before the wedding and proceeded to cruelly vandalise (walk over) our precious, delicately positioned, beautifully and painstakingly prepared sample tubes – ruining them all and leaving cat hair everywhere. It also menacingly tore some of our posters off the wall and threw some books on the ground. Finally this mean, dangerous animal decided to pay us the ultimate disrespect, and defecated next to our tube table. It also weed somewhere unidentifiable – leaving our lab smelling like cat wee no matter how many windows and doors we left open. We later identified the wee location when we took our kit box onto the boat and found that this made the boat smell like cat wee. So we have now washed ALL OF THE THINGS, and are on the lookout for the culprit feline..

LOOK AT THE DESTRUCTION!!
 We may all become expert Bogglers by the end of the Summer as Boggle is a major evening activity - some people are better at using predefined words, whilst others are better at finding as-of-yet-undefined words..

"My precious.."

For Caz.


Thursday 3 July 2014

Hidden danger..

I mentioned in one of my previous posts that one of the reasons for examining and identifying plankton is to monitor for Harmful Algal Blooms (HABs) - much larger than usual aggregations of harmful algae species. I will attempt to describe what is meant by 'HABs' a little further:

When algae blooms, the larger numbers of phytoplankton are broken down by bacteria in the water. These bacteria utilise oxygen to do this and this can result in dramatic depletion of dissolved oxygen in the water column which can cause problems for other animals that require this oxygen. Sometimes large algal blooms can lead to huge fish die-off as the bacteria steal all the oxygen to break down the algae.

HAB species can also cause several health conditions among a number of animals - notably humans, fish and shellfish. The conditions can be divided into a number of classes:

Amnesic shellfish poisoning (ASP)
This is caused by domoic acid accumulating in shellfish - this can then be transferred via fish to humans and can cause gastrointestinal and neurological disorders including (as the name suggests) loss of memory.
One of the species of plankton that can cause ASP when it blooms is the diatom Pseudo-nitzschia.


These are photos of some of the diatom species we commonly find in our samples and have to
 identify - sounds easy? Its not. Often they don't look quite as perfect as in these pictures and can be at
 strange angles as we are looking at them in a 3D environment. Many of the plankton that resemble
lines all look very VERY similar so it takes a little practise to distinguish between some of the species..
also, they are often quite small..
 Pseudo-nitzschia is labelled with a red star because it is a HAB species
Diarrhetic shellfish poisoning (DSP)
This causes gastrointestinal disturbances in humans including some throwing up, abdominal cramps, and (as the name suggests) some other unpleasantries.. people usually recover from this within a few days though. Some species of plankton that can cause DSP when they bloom are Dinophysis and Prorocentrum.

Neurotoxic shellfish poisoning (NSP)
This causes gastrointestinal and neurological disturbances and can also cause some asthmatic symptoms in humans but these usually subside after a few days. This can be caused by Gymnodinium.

Paralytic shellfish poisoning (PSP)
This is the super bad one! PSP can be life-threatening and has neurological effects. There is no known antidote. Apparently there is a 15% mortality for people who catch PSP! This nasty one can be caused by several species - but mostly by Pyrodinium and some species of Alexandrium.


These are photos of some of the dinoflagellate  species we commonly find in our samples here. As with the diatoms the ones labelled with red stars are known HAB species! The dinoflagellates are less common in our samples and are
far more exciting in my opinion. My favourites are the grenade (Dinophysis) and the sorting hat (Neoceratium) - yes
I have favourite plankton now.. 
Sometimes you can see public notices at beaches warning people of Harmful Algal Blooms and advising people to avoid swimming in these areas or to avoid fishing in these areas. You should pay attention to these! They are important!!


Here is an example of what a Dinophysis bloom can look like under the
 microscope - ALL THE GRENADES!!

'HAB' can also stand for
'Happy Algal Bloom'*
Here is a little zooplankton
picture - possibly a little baby
jellyfish


 














On a separate note - the rocky shore team found another sea slug today! I LOVE NUDIBRANCHS!




*this is not particularly true - sorry