Friday, 28 April 2017

Crabs, Anemones and Cornish Suckers (Shore Clingfish)

If you keep up with the Skomer Island Blog, you'll have already been introduced to one of the Long Term Volunteers, Thom. I am the other LTV for the April-July period, I'm a 21 year-old Marine Biology graduate from the University of Liverpool and my name is Ruby Temple-Long. Having the amazing opportunity to gain experience working on the high profile nature reserve of Skomer Island coincides with my year out from study, before I head off to Scotland and the University of Edinburgh to complete an MSc in Marine Systems and Policies.

I have volunteered with a wide range of organisations before the Wildlife Trust of South and West Wales including; Greenpeace EU Unit, Wildlife Sense Kefalonia and Gloucestershire Wildlife Trust (Snows Farm Nature Reserve and Stroud Wildlife Surveys).

The experiences mentioned above have all been extremely interesting but they aren't comparable to the unique four weeks I've already spent on Skomer. I was attracted to the island by so many things, but the parts that stood out the most were the vast array of species that can be found here and the numerous elements of practical research you can get involved with. Having a passion for marine species, my interest was sparked when I discovered the diverse range of seabirds and marine mammals that you may encounter on the island. I had been told that Atlantic puffins could be an almost everyday occurrence in the right season (and weather), and that nearly half the world’s population of Manx shearwaters come here to breed!

I arrived with little knowledge of birds but would like to think that I am learning more about the species we see passing through each day, and by the end of my three months may even be a budding amateur ornithologist! Already I have seen (or been shown) the common species on Skomer such as; Puffin, Chough, Kittiwake, Fulmar, Peregrine falcon, Short-eared owl and Swallow. In addition to the more unusual species such as Black redstart, Cuckoo, Snipe and Common sandpiper.

Black redstart at the Farm

The island is starting to get a little busier now with more researchers arriving and therefore more surveys to complete, but a few highlights from the past week were as follows. Each year the Trust undertakes a whole island Puffin count and on our first survey we found a record number of individuals, an astonishing 25,000! Thom and I were really pleased to be treated to a trip out to The Smalls with one of the trustees and on our voyage were greeted by a pod of Common dolphin that rode the bow of our rib for a while, with a small calf leading the way! Recently we were able to help some PhD students from Oxford University collect data for their study of Manx shearwaters which they return to Skomer each year to continue. The students are looking at the changes in the bird's body condition over the breeding season which includes monitoring a number of the same burrows each year and weighing certain individuals. They are particularly interested in those with geolocators as they are able to track their movements at sea and can learn more about how parents coordinate their foraging trips to feed the chicks.

With my main interest being ocean dwelling species, I often spend my time around the coastal cliffs and get down to North Haven beach wherever possible. Those who have visited Skomer will be familiar with the seals of North Haven beach that cover the rocky shore and the one particularly cheeky male that often commandeers our Zodiac! They are likely to have even been one of the first animals you saw as you pulled into the landing! Because of the dense seal population on North Haven, access to the beach is restricted to avoid disturbing a visitor favourite! However, from the short periods time I have been able to explore the intertidal zone I have found a variety of exciting coastal British species which I thought I would tell you a little more about...

North Haven beach 

An impressive 62 species of crab have been recorded in waters surrounding the British Isles. To be called a crab, an animal has to have ten legs, two of which have evolved to form to powerful pincer-like claws (or chela) for feeding and fighting! and all but one species (Chinese mitten crab) are marine. Unlike us, crabs have an exoskeleton and therefore don't have bones, they grow by forming a soft shell beneath their current 'skeleton' which causes their hard shell to shed and when this happens they are much more vulnerable, so tend to stay under the cover of rocks and thick clumps of seaweed. I've come across the following species of crab on my rocky shore explorations; spider, broad-clawed porcelain, edible and shore.
Edible Crab
  I've also seen a number of anemones, which most of you will already know because of Finding Nemo! Anemones are relatives of jellyfish and coral and stick themselves to rocks waiting for prey to pass through their tentacles armed with barbed stinging cells (nematocysts). There are over 1,000 species of varying colours and sizes inhabiting oceans across the globe at a range of depths. Although some species can grow up to 1.8 metres across, the smaller species such as Beadlet, Snakelocks and Strawberry have been found on North Haven. Some Twin fan worms were also observed in a rock pool as was a Shanny beneath a large boulder at the waters edge! All of which are being taken down in my notebook and will be added to bird log under the 'other' section at the end of my stay.

Strawberry Anemone

Another animal that has been particularly abundant on my rocky shore visits is the Shore clingfish, which is the focal species for my personal project that I will undertake during my stay. The Marine Conservation Zone team from Natural Resources Wales suggested that I look at this fish as it is particularly abundant across the Pembrokeshire coast however, little is known about its seasonality and breeding cycle here. All of the team has been helpful, answering any questions that I have had about the important work they do collecting data in the surrounding waters of the Skomer Marine Conservation Zone (MCZ) and have given me some really useful guidance for my research project.

Shore clingfish
The clingfish is cryptobenthic, meaning it hides in crevices on the seafloor (beneath and between rocks). It's easily identifiable by its duck-like mouth and two blue spots (which remind me of opals) on the top of its head, on the bottom side it has specially adapted pelvic fins that form a sucker which is incredibly strong and anchors the fish to the surface of the rocks it inhabits. I will be looking at where the fish can be found across the shore and what time of year they are observed as well as life history traits such as spawning and egg development which has not been looked at on the shores around Skomer before.
Shore clingfish eggs

Shore clingfish and eggs

It has taken no time at all to settle in on Skomer with such lovely staff and so many people to learn from, in addition to the masses of wildlife that we are lucky enough to see there is never a dull moment. I'm looking forward to getting stuck into my personal project and Razorbill productivity survey now that Julie the Seabird Field Worker has arrived and hopefully I'll be able to give you more of an update on everything soon!

Ruby (LTV)

1 comment:

  1. Good luck, Ruby, for your season! I was fortunate enough to visit Skomer in Sep'15 as a Birthday present given I am a Rabbit nut! Having seen the short BBC documentary 'The Rabbits of Skomer', to see the rabbits wild on Skomer quickly became Top 3 on my bucket list! Hope to come back soon & chill with the buns.