Changing biodiversity

Changing biodiversity

Start date
1 July, 2012

Long-term science

How will Antarctic biodiversity change in future years?

West Antarctic seas are rapidly changing and one of the big questions is how marine biodiversity will respond to climate change.   Antarctica is one of the last regions of Earth to remain largely un-impacted by invasive non-native species.

These are focus areas of the BAS Grand Challenges: Polar Change. To enable us to tackle these questions, we first need to establish comprehensive baseline data on how many species are found in the ocean around the Antarctic Peninsula and in the shallow waters around the Rothera Research Station, where they are and how they vary with habitat (e.g. soft sediments versus rocks) and season.

BAS Marine Assistant Terri Souster, diving close to Rothera Rothera Point in Antarctica
BAS Marine Assistant Terri Souster, diving close to Rothera Rothera Point in Antarctica

We have implemented a series of long term biodiversity monitoring experiments and studies at Rothera which include:

  • characterisation of soft sediments
  • characterisation of hard sediments
  • ROV (Remotely Operated Vehicle) studies

All animals sampled have been grouped into morphologically identical “species” with voucher specimens maintained at Rothera. Any excess material has been sent for taxonomic analysis with collaborators and subjected to DNA barcoding. A reference database is in preparation, but interim data will be available from the Polar Data Centre.

Antarctica: the final frontier for marine biological invasions?

Antarctica is one of the last regions of Earth to remain largely un-impacted by invasive non-native species.  The number of known introductions is increasing, and is recognized as one of the greatest threats to Antarctic biodiversity.  As climate changes and the number of people and ships visiting Antarctica there may be increased risk to the biodiversity of this frozen world.

Our studies into the ‘final frontier’, investigate the implications and impact of increased shipping activity on Antarctic marine biodiversity. This research is an important step in the quest to understand whether invasive species will find the Antarctic marine environment more hospitable as Antarctica’s climate changes.

An isolated continent

The Antarctic continent is isolated from the rest of the world by the Southern Ocean and successful natural colonization events are rare. As a result, terrestrial biodiversity is low and comprised of simple plants (e.g. mosses, lichens, liverworts) and animals (e.g. flies, mites and springtails). There are no native terrestrial mammals, reptiles, amphibians, freshwater fish, trees or shrubs.  Microorganisms dominate at climatically more extreme inland locations.  In contrast, large seabird and marine mammal populations breed on the coast and marine ecosystems are biologically diverse and rich.

Hull surveys of the RRS James Clark Ross have been undertaken at Rothera Research Station since 2007. These surveys are crucial for helping scientists understand the potential impact of biofouling as a mechanism for introducing non-native species to Antarctica. Photo credit: Calum Stronach.

Antarctic Treaty System agreements on non-native species are amongst the strictest in existence globally. These have been enacted into UK legislation through the Antarctic Act (1994; 2013). The introduction of all non-native species and non-sterile soil is prohibited, unless in accordance with a permit.  Antarctic Treaty Parties must plan and conduct their Antarctic activities to avoid non-native species dispersal and to ensure Antarctic biodiversity is maintained.

Scientific research and tourisms are the dominant activities within BAT.  Around 18 nations, located in Europe, Asia and North and South America, have established over 50  research stations and facilities in Antarctica. Each Antarctic summer around 50,000 tourists, predominantly from cruise ships, land at visitor sites .

Thirteen of the known non-native species within within British Antarctic Territory (BAT) have been found in the vicinity of research stations and tourist visitor sites.  Recent eradications of introduced plants mean that most remaining macroscopic Antarctic non-native species are terrestrial invertebrates.  There is still only a poor understanding of the rate of non-native species arrival and establishment and levels are probably greater than currently known.

Climate change and biodiversity

BAT has experienced substantial climate warming since the middle of the 20th century, resulting in the retreat of glaciers and complete or partial collapse of the region’s ice-shelves. Despite a recent pause in the warming trend, global ‘business as usual’ greenhouse gas emission scenarios suggest that BAT will be subject to rapid warming by 2100.

Resulting warmer and wetter conditions will make it easier for introduced species to established and become invasive. It could also result in a substantial increase in the area of ice-free ground in northern BAT.  Consequences of ice loss may include greater connectivity of existing biological communities, possible local extinctions of less competitive species, and the increased distribution of non-native species.

Within the marine environment, climate change has resulted in a regional decline in seasonal sea ice cover, glacier retreat and ice shelf collapses. These changes open up considerable new areas and habitats (e.g., fjords) for colonization, and thus increase the diversity of opportunities for potential invaders.

Science and policy in action

The Antarctic Treaty Consultative Meeting has made non-native species one of the highest priority issues in its Five-Year Work Plan and its Climate Change Response Work Programme (see: http://www.ats.aq/e/cep.htm). Work to gain an understanding of the level of biosecurity employed by National Antarctic Programmes operating continues. British Antarctic Survey employs comprehensive biosecurity practices (see: https://www.bas.ac.uk/wp-content/uploads/2019/01/BAS-Biosecurity-Handbook-January-2019-FINAL.pdf).

The Antarctic tourism industry, through the International Associate of Antarctica Tour Operators (IAATO; https://iaato.org/home), has been proactive in the development and application of biosecurity procedures. However, the overall risk of introductions may increase if the number of tourist visitors increases or biosecurity practices are not employed adequately.

The UK has already taken a leading role in undertaking research, developing policy and implementing practical steps to reduce the risks from invasive species. For example, the UK:

 

Our aim is to:

understand how marine biodiversity will respond to climate change and to do this we need to conduct baseline studies and characterise the biodiversity at different depths and in different habitats. We are doing this via an on-going series of projects which are listed chronologically below.

Soft sediments

A home-made suction sampling device was used to extract sediment from ¼ M2 quadrats from three sites in each of South Cove and Hangar Cove. Seasonal sampling was carried out along across 2 winters and two summers. In one set of seasonal experiments, 30ml sediment cores were also taken to enable the metagenomic analysis of meiofauna and microbial communities. Marine Biologist (2012 – 2015): Belinda Vause

Hard sediments

In 1998 a biodiversity survey was carried out on a transect running south from Cheshire Island, which mainly comprised hard rock substrata. A key element of this project is to compare current biodiversity with that recorded 15 years ago to investigate patterns of long term change in community structure. There will also be a seasonal comparison. Furthermore, understanding the dietary habits of marine invertebrates is central to studies of food webs, ecological processes and energy budgets. Measurement of metabolic rates and molecular analysis of gut contents from a range of marine invertebrates will also be conducted to allow the flow of energy within the marine ecosystem to be investigated. Marine Biologist (2014 – 2016): Terri Souster (PhD student registered with the Open University).

Remotely Operated Vehicle (ROV) surveys

To date our collections have been restricted to diver collected material working at depths down to 25M. To expand the depth range we have instigated an ROV trial which will initially revisit the hard sediment transects to validate the capabilities and limitations of using an ROV. All analyses will be conducted on macrofauna filmed from video feeds. Further surveys at more remote locations, not often visited by divers, will be conducted after this initial trial. Marine Biologist (2015 – 2017): Ben Robinson.

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Rothera Research Station

The largest British Antarctic facility is a centre for biological research and a hub for supporting deep-field science.