Thursday 26 June 2014

Seaweed invaders


Glaudine is still hanging around

On top of the normal data collection that we do here at the Marine Station, other projects are also done to examine specific aspects of the marine biology of Sherkin. For the last couple of days we have been collecting data for the ‘Sargassum Project’. Sargassum is an invasive seaweed species that originated in Asia and has been increasingly found in Europe (including Sherkin).

Sargassum spp invasion can be a problem as it can grow very quickly over large ranges of the shoreline (whereas lots of native seaweed species have a niche area that they mainly inhabit). This versatility enables Sargassum to affect lots of areas and unfortunately it can displace some local species and form large mats when it grows very tall – these large mats can cause all kinds of problems, for example: 
  • Large mats at the surface can block sunlight to other seaweed species growing below them preventing them from being able to photosynthesize as much and therefor reducing their fitness
  • By preventing growth of lower seaweed species that form habitats for other animals and plants Sargassum mats can reduce habitats for these epiphytic organisms
  • Sargassum mats can become so thick that they can damage boats and make the water impossible to swim in – this can increase costs associated with ship repair and can make areas less appealing to tourists
Invasive species can be transported from their original locations many ways, including:
  • Being deliberately transported for use in ponds
  • Being accidentally transported in ballast water of ships

Anyway, so Sargassum can be problematic.

The Marine Station has been monitoring the progressive abundance of Sargassum on the island for a number of years and it is really interesting to see how it has been gradually increasingly found in more and more sites around the island.

For the past couple of days we have been suiting up (in wetsuits) and snorkelling in Horseshoe Harbour sampling transects and reporting back the numbers and heights of any Sargassum individuals we see there.

Surveying in Horseshoe Harbour (one person in a little blow-up
 raft with two snorkelers either side of the boat)
The last Sargassum report from Sherkin was done a few years ago and it is INSANE to see how much more Sargassum is in the bay this year than in previous years – in 2011 they reported 7 Sargassum plants in the bay, this year we got into the water (a little chilly) and the moment we put our faces in we could see that the problem had definitely progressed – now we are finding that in many areas of the Bay we are reporting 100+ individuals completely covering the bottom and ranging from a few cms to many metres tall! (Tomorrow I will attempt to get a few pictures of Sargassum to show you what this invasive Asian alien species look like) - *I have collected some pictures!!*

The invasive seaweed - Sargassum!


So that is what I have been doing currently – viewing the problem of an invasive species firsthand. It is really interesting after spending 3 years learning bits about invasive species’ and the problems they can cause – I wish we had done a little field trip at University to observe an invasive species at work, I think that would have really hammered home the fact that invasive species are a very real problem that deserves more attention.

On a different note..

I found a nudibranch today!!!!! 


For those of you who don't know, nudibranchs are more commonly known as 'sea slugs' and are a marine mollusc. They are also SUPER EXCITING and are often stunning colours and crazy shapes. We named her Daenerys (because we've been watching too much Game of Thrones) and brought her back to the lab to examine/stare at/take a billion pictures of..

Daenerys looking stunning
Daenerys looking fabulous



















She can even crawl/slide along the underside of the water
surface!!!! Because she is awesome.

After taking a gazillion pictures of her we identified her and we believe her to be Facelina auriculata whose key characteristics are:
  • Propodial tentacles, long oral tentacles and annulate rhinophores present
  • Foot narrow, cerata short, in distinct bunches, long narrow tail
  • Cerata with red digestive gland and iridescent blue surface colour

We also found this rather large fellow who is a 'Devil-eyed crab'.
Although perhaps less delicate than Daenerys he is still
VERY fabulous









Tuesday 24 June 2014

Happy June 23rd!!

According to Maria, in Spain they celebrate the 23rd of June in a big way – with big fires and nice food and lots of drinking – to welcome the Summer. So that’s what we did yesterday, we collected lots of wood from around the place and had a big bonfire at the beach. The otter boys joined us for a couple of hours (there are 3 Dutch boys also staying on the island studying the otters) which was nice, although they didn’t bring any wood or food, and they made fun of our burnt sausages and homemade nettle beer.. (*A combination of: the length of the walk to the pub, the irrational cost of alcohol here, and our growing hatred for nettles, inspired us to experiment with home brewing*)



Incidentally the nettle beer was really rather nice (especially after adding honey) - and successfully alcoholic! So the otter boys were definitely missing out.

Spanish tradition is that at midnight people burn a list of bad things that have happened in the previous year and a list of hopes for the next year, so that’s what we did, and it was actually quite fun, I might have to adopt this tradition!

After burning our lists we finished off the nettle beer and well-done sausages and played a very silly chicken game that was great! – bwuk bwuk BAKAAAAW!


Then we went for a quick (quite cold) swim. It was the first time I’ve ever swum in bioluminescent water! (some plankton emit flashes of light when the water near them is agitated). It was SOOO PRETTY. Moving through the water made it sparkle and glitter like little water fireflies. But that’s enough of me trying to be descriptive I think. Basically it was awesome. I want to go back at night and skim stones to see if you can see the bioluminescence from the beach!

All in all it was a great night! (Although this morning I was feeling a little worse for wear..)


There is a large beach party planned for a bit later in the year and I’m now super excited for that!

On a separate note - I seem to have become severely allergic to the outdoors. Which is rubbish. How is it possible that this ailment has developed?? It is completely ridiculous to be allergic to being outside!!
My hayfever is refusing to be tamed by tablets and I am now sneezing 100+ times each day which is very very annoying - I imagine the other people that work in my lab are probably getting very sick of my sneezes by now.. oh well, only the rest of the WHOLE SUMMER to go..

This seal has been hanging around the Marine Station a lot lately.
Maria has named him Glaudine.



Monday 23 June 2014

Dolphins!


On our plankton-collecting trip the other day a large pod of dolphins joined us as we were travelling between sites. There must have been 50+ common dolphins swimming along with the boat jumping in the waves and playing. They stuck around the boat when we stopped to collect our samples in the sun, I think we may have accidentally encountered a feeding frenzy as loads of gannets had also gathered and were plummeting into the water around us (apologies for the picture quality - screenshotted from a video).




When we returned to the lab we discovered that we had managed to capture a very unfortunate jellyfish in the nansen bottle and then in one of our tiny tubes! 

Poor little guy!


He/she is a comb-jelly (or sea gooseberry) and is part of the group 'Ctenophore'. You can't see in my picture (which is actually quite poor) but they have rows of comb-like structures down their sides that show iridescent colours when they reflect direct sunlight!

Sunday 22 June 2014

The Plankton Team

A number of people have asked me exactly what ‘being part of the plankton team’ entails so I thought I would write a brief description of what we do here:

The plankton lab!!! (where the magic happens)
  • We go out on the boat to a number of different sites in the waters around Sherkin Island where we collect samples of water from different depths using a nansen bottle, we analyse these samples on the boat for temperature, conductivity, and salinity using a probe
  • We collect additional samples using a plankton net, which we drag through the water column to collect a sample of all the plankton through the range of depths covered by the bottled samples to get a quick idea of what species are in the area
  • Environmental parameters such as tide time, weather, wind direction, swell, secchi disk depth (how clear the water is), are taken and noted down
  • These samples are later analysed in the lab under the microscope for species composition and number of plankton present
  • We enter this data into a database that contains data stretching back to 1978!
Tubing station
·      The data can be useful for many things: firstly just to see if anything has changed over the years, for instance perhaps due to climate change or anthropogenic introduction of nutrients. Another use for the data is that some species of plankton can be harmful to fish, crustaceans, and even humans. If a bloom of one of these species of plankton occurs then it may be better to not eat the shellfish produced in nearby areas, so the plankton monitoring can be a useful early warning system for these Harmful Algal Blooms (HABs). There are a number of oyster farms around the island so monitoring the plankton in the area is a good idea.

·      We have boat trips regularly and when we are not collecting our samples we are in the lab analysing them and trying to work through past samples that need to be processed. We also have to clean our sample tubes and make new tubes for plankton analysing which takes time as making the tubes involves sticking together pieces of plastic with Vaseline.

So that explains what I am doing here most of the time.