Antarctic Glacial Retreat: Benthic Colonisation in Newly Ice-Free Coastal Areas
Latest update March 2, 2019 Started on January 1, 2018This expedition will study the responses of the benthic system to rapid environmental change following the climate-induced glacier retreat in the Antarctic Peninsula.
Greetings from Antarctica!
The loss of Antarctic sea-bed ice coverage due to climate warming, on the one hand has been affecting benthic assemblages, but on the other it is opening up new areas for benthic colonisation. Potter Cove (South Shetland Islands, Antarctica) offered the opportunity of assessing both processes. We recently published in Ecography journal (we went the journal cover!) an interesting reported about a sudden shift of benthic assemblages related to increased sedimentation rates caused by glacier retreat (https://onlinelibrary.wiley.com/doi/abs/10.1111/ecog.03018). This glacier retreat also uncovered a new island that presents a natural experiment to study Antarctic benthic colonisation and succession. We sampled the new island (see the photos here) by photo-transects taken up to 30 m depth. We report an unexpected benthic assemblage characterized by high species richness, diversity and structural complexity with a well-developed three-dimensional structure. Densities were also surprising! These values are at least an order of magnitude higher than previous Antarctic reports on early colonisation!!!. This finding challenges the extended idea of a slow and continuous recruitment in Antarctica.
However, it also opens the question of whether these complex assemblages could have been present under the glacier in ice-free refuges that are now exposed to open sea conditions.
We recently submitted an OpenROV project to apply at one of free Trident water drones to try discovering these Antarctic underwater secrets. Exploring near (and below!) the glaciers is one of the great challenges that Antarctic researchers have in the present to know the true impacts of the glacial retreat in the communities of the seabed.
Trident's ability to dive to 100m and fly smooth transects make it a perfect visual monitoring tool for this kind of fieldworks (https://www.openrov.com). Then we cross our fingers and hope to get lucky and get one of these incredible Trident's ROV to continue with our incredible adventure of Antarctic exploration! However, we require at least 25 followers or more to be eligible to win one. Please follow our project and help us make our dream possible!!!
Thanks wonderful people! Cristian
Recently I participated in the amazing Pristine Seas expedition to Antarctica. Chile and Argentina are working together to establish marine protected areas and protect one of the last pristine and wild places in the planet that belongs to all of us. The goal of this expedition was to provide political, scientific and communicational support, at a global scale, to the marine conservation proposal for the Antarctic Peninsula that has been put forward jointly by Argentina and Chile. By establishing fully protected marines reserves and effectively managing fisheries, we can also make the ocean great again and preserve this truly unique places for the years to come.
Antarctica is between the regions where climate change is happening faster. Massive ice losses, represented by glacier retreat, ice-shelves collapses and sea-ice reduction are among the main impacts of this regional warming. It’s a real threat for the future of most of the Antarctica species.
The frozen continent is one of the last pristine and wild places in the planet that belongs to all of us. We need to protect it now!
Here are some photos of this incredible adventure in the white continent:
Hello wonderful people and lovers of the sea! Here I want to leave to you some photos of our last campaign in the Antarctic Scientific Station of Chile "Yelcho", together with Dr. Cesar Cardenas, marine biologist expert in antarctic sponges.
In the photos you can see some of the diving sites where we made photo transects and videos to document the diversity of the seabed and how this diversity is affected by the retreat of the glaciers. However, many times we can not get much closer to the glacier because this is really dangerous for the safety of the divers that are in the water. The detachment of ice from the walls of glaciers can reach many meters of distance (and depth) and seriously hurt divers.
For this reason, I recently submitted an OpenROV project to apply at one of the Trident water drones to study the diversity very near to the glaciers without the divers being in danger. We hope to get lucky with this and be able to count soon on an OpenROV to expand our sampling tools in one of the most pristine and least studied places on the planet.
Due to the rapid retreat of tidewater glaciers on Antarctic Peninsula (AP) and the resulting melt-water introduction, the polar coastal system is now rapidly changing. In Potter Cove (South Shetland Islands, AP), the Fourcade Glacier shows an accelerated retreat affecting the hydrographical characteristics of the fjord and drives significant changes in the established benthic communities. In addition, this glacier retreat also opening new ice-free areas including rocky islands, providing an excellent opportunity to study colonization and succession processes in marine polar ecosystems. Surprisingly in these new ice-free areas we found an unexpected benthic assemblage characterized by high species richness, diversity, densities and structural complexity. These well-developed three-dimensional communities that in principle were developed in only few years challenges the extended idea of slow colonization and succession processes in Antarctica. However, it also opens the question of whether these complex assemblages could have been present under the glacier in ice refuges and are now exposed to open sea conditions.
Study the impacts of climate change on Antarctic benthic assemblages is crucial to understand this threatened ecosystem. Therefore, our main aim is to investigate the current status and its evolution over time of these benthic communities in the new ice-free areas of this Antarctic fjord. Analyzing community structures and relating them with environmental variables we expect to provide important insights on the possible responses of Antarctic benthos to the current warming especially experienced by the Antarctic Peninsula.
In this project we will study the diversity and the benthic community structure in the new ice-free areas in an Antarctic fjord and its evolution over time. This study expect to achieve new evidence on colonization in new ice-free areas in a glacial-marine fjord, not only at species level (pioneer species, rates of growth, mortality, etc.) but also at community level, analysing community structures and relating them with environmental variables.
In situ photographic and video techniques will be used to monitor colonisation in these recently exposed areas and its evolution over time. Photographic surveys in the new ice-free areas up to 30 m depths will be undertaken by SCUBA diving. Underwater video-transects will be carried out at deeper depths (>40 m) and beneath the front of glacier. For the video-transects we will use the Trident. The Trident images we gather will be used to determine species richness, abundance, taxonomic distinctness and functional diversity in depths never sampled before in this fjord. In addition, the Trident will be used to scan the seafloor in front of (and beneath!) glacier.
