SMSG Blog

By Judith Brown

To get as complete a species list as possible we need to survey different habitats, different seasons and also during the day and at night. Some species remain well hidden during daylight hours when the plethora of fish predators make leaving the safety of the crack or crevice hazardous. When night arrives the seabed is littered by the sleeping bodies of the black fish and out comes a different array of animals. The striking red reef lobster, the small red scorpionfish, giant stretchy yellow banded sea cucumbers, many species of shrimps are just a few who we don’t see through the day. To quantify the difference in species diversity and abundance the SMSG team prepared for some day night comparison surveys.

[caption id="attachment_979" align="alignleft" width="300"] Day Transect


[caption id="attachment_980" align="alignright" width="300"] Night Transect

The survey method was adapted slightly (to compensate for reduced visibility at night) and involved three transects each 1m x 50m survey all along the rocky reef just off Wigan Pier. During the early afternoon Judith, Paul and Martin conducted the first set of transects – leaving the tape measures in situ with activated glow sticks on each end. As darkness fell the divers returned to the pier – Judith with a dive torch strapped to her head to allow her to count and write. This worked well except for that many small amphipods and worms which were attracted to the light at night meaning she had a constant swarm of critters buzzing around her head for the entire dive. Longspine black sea urchin were the most abundant to count with several hundred on each transect but the most exciting critter was an orange nudibranch – usually only found well hidden under rocks. After an 84 minute dive the team were all happy to return to the dive club to a pot of traditional St Helenian pilau cooked by Elizabeth on the BBQ.

[caption id="attachment_978" align="alignnone" width="300"] Reef lobster

By Dr Vladimir Laptikhovsky

Most us that have dived in tropical seas have seen parrot fishes. You might have heard them crunching and munching corals before you see them, they are amongst the most common fish in coral reefs all over the World. But not only coral reefs… some species in the genus Sparisoma managed to cross huge oceanic spaces and settled around the small oceanic islands of the Mid-Atlantic ridge, like the Azores. One of them, Sparisoma strigatum, is known to be endemic to Ascension and St. Helena. Around St. Helena, according to Dr Judith Brown, it is a very common species in shallow waters. Occasionally it occurs in groups in rocky areas between 5 and 20 meters depth. Juveniles might be distributed slightly deeper, amongst weed and rubble patches on sand at 15-18 m depth. The species was known around Ascension Island and even pictured on local postage stamp. However, our previous expedition that covered most of shallow waters around this island did not find it. Why are its numbers so low that it is virtually unnoticeable? This SMSG/SAERI expedition of is looking to answer to this question.

Eventually this mystery species was found, south of Catherine Point where a single specimen was seen and photographed by Steve Brown. It was found together with the white spotted filefish (Cantherhines macrocerus), also recorded on our last trip in August 2012. This was indeed quite an unusual site as it had a remarkable abundance of the endemic Ascension Island wrasse too.

The team returns to Shelly Beach

We mentioned in one of our early posts that two of our team members had been fortunate enough to be shown a very special site here on Ascension, the small rock pools at Shelly Beach where two very rare and vulnerable species of shrimp are found.

Yesterday a large number of the team enjoyed a return visit to the pools, escorted by Stedson Stroud and Jolene Sim of Ascension Conservation. This time we were loaded with all the equipment we would need for a survey of the site, including underwater cameras, devices to measure salinity and temperature, GPS units to map the site and, most excitingly, special permission by the Ascension Island Government to collect a small number of samples for further study.

Enjoy this short gallery of images taken at this exceptional location.

[gallery orderby="title"]

Last night the Ascension Island community were invited to a presentation by the team about their previous work in Falklands and South Georgia, as well as talks about the current expedition.

The talk was held in the Saint's Club, here in Georgetown, which is one of the centres of night-life in this small town. It's a great place to unwind at the bar, have lunch or watch a game of skittles!

Everyone enjoyed the images of undersea life, some of which have already been loaded to this blog as well as some detailed information about some of the methods we are using to capture some animals for further study.

Throughout our stay in Ascension the group has very much appreciated the great interest in the expedition by island residents. As we reluctantly prepare to leave soon, we remind all that anyone who would like to chat about the project will be most welcome to corner any member of the team while we're still here!

[caption id="attachment_559" align="aligncenter" width="584"] Paul Brickle introduces the talk with some information about the work of the Shallow Marine Surveys Group.


[caption id="attachment_562" align="aligncenter" width="584"] Peter Wirtz entertaining the audience with an impromptu talk about the various animals found in Ascension waters.


[caption id="attachment_561" align="aligncenter" width="584"] Simon Morley provides details about his settlement plate experiments.


[caption id="attachment_560" align="aligncenter" width="584"] Jude Brown explains the survey methods used by the team to count sealife underwater.


 

[caption id="attachment_563" align="aligncenter" width="584"] Frithjof Kuepper wraps up the presentation with some information about the search for new algal species.


 

This morning Drs Judith Brown and Wetjens Dimmlich woke early to go back to school. They travelled up the hill to Two Boats school to show the children there a selection of images from Shallow Marine Survey Group's work in both the Falkland Islands and the current Ascension expedition.

[caption id="attachment_441" align="aligncenter" width="584"] Jude speaks to a full room during morning assembly.
Image: W Dimmlich

Jude spoke to the entire school who were gathered in the gym and managed to maintain the interest of all ages during her talk. She showed images of different species of animals found in the cold Falkland waters and the tropical Ascension waters and challenged her audience to pick which came from where.

She also described our unsuccessful attempts so far to entice an unidentified shrimp from his hole and received some very useful tips for the audience on how to entice the creature from its burrow. During the drive back to the Conservation offices we had some discussion about finding a source on the island for parsley!

[caption id="attachment_442" align="aligncenter" width="584"] The kids enthusiastically offered suggestions on how to capture elusive sea creatures.
Image: W Dimmlich

Yesterday, Drs Paul Brickle, Jude Brown and Simon Morley gave a talk about the project to a gathering held in the Ascension Islands magistrate's court.

The island's Administrator, Mr Colin Wells, attended along with other Ascension Island government representatives including councillors, service heads, Ascension Conservation members and the RAF base commander.

[caption id="attachment_430" align="aligncenter" width="584"] Paul Brickle presenting the work of the Shallow Marine Surveys Group, while Simon Morley and Jude Brown wait for their turn in the spotlight.
Image: W Dimmlich

After the talk the team was very grateful for the words of support offered by the audience and the enthusiasm with which the work was received as well as a desire for the continuation of studies of the marine environment by local participants in the future.

[caption id="attachment_431" align="aligncenter" width="584"] Simon explains the objectives and methods used in his climate-change related experiments carried out during the expedition.
Image: W Dimmlich