Climate Change Research
A lot of work is underway to understand how our climate is changing and how these changes might affect our marine systems. This is a controversial subject but there is good evidence that the climate is really changing and that the behaviour and distribution of marine animals is altered as a result.
For example, fish have preferred temperature ranges and can often move to stay within this range. Some of the species affected are fish that we eat (e.g. cod and plaice). Recently, Icelandic claims that mackerel distribution has changed due to climate change have caused a dispute with Scotland. Changes in the numbers of locations of fish can cause major hardship, particularly in developing world countries where other food sources are limited.
Some animals are unable to move because they live attached to the seabed. These species are more vulnerable to rapid changes but in many cases are able to release eggs and larvae into the water so that they can settle in places where conditions are more favourable. Some species lack this ability or have very specific habitat needs that can only be met in particular places, or live in places like Antarctica where there is nowhere cooler to go. These species are thought to be the most climate change effects.
Discovering how the distributions of animals are changing and what environmental factors drive these changes is critical to understanding how climate change will affect marine biodiversity.
If the surface waters of the sea warm up this could also affect how easy it is for different layers of the ocean to mix together (warm water floats on top of cold water). This mixing is vital to the ocean because it allows nutrients to come to the surface to feed the microscopic plants called phytoplankton who need to live in the sunlit surface waters.
Like other plants, phytoplankton take up CO2 and turn it into food. If the growth of phytoplankton is reduced it affects the whole ocean food web and has very powerful effects on the deep ocean animals living below. See the page on “Getting to know the abyss” for more information on this. The rain of dead phytoplankton to the seabed is a poorly-understood part of the global carbon cycle. Because the oceans take up at least 1/3 of the CO2 released into the atmosphere, the processes that trap and move this carbon are likely to be very important.
A new report has just been released by the Marine Climate Change Impacts Partnership (MCCIP). It summarises our current knowledge and is designed to be understandable and useful to the public. If you are interested in the subject this would be a great place to start.
MCCIP have looked at what areas are really uncertain and where the “data gaps” are. For deep sea habitats they said “There is a lack of baseline data on the distribution and structure of deep-sea biological communities in UK waters and how they vary in time. Understanding the responses of these systems to climate change requires good baseline information”
This is certainly true and the main aim of our expedition is to help solve this problem by developing new and better ways of collecting ecological information in deep water systems. If you want to get into the background material you can read the detailed scientific reviews online . The papers are all “open access” so you don’t need a subscription to the journal in order to read them.
Marine Conservation Research
This is a very exciting time in marine science. All around the UK, decisions are being made about what areas of the sea need protection in order to conserve our natural resources and biodiversity. In the seas around England these protected areas will be called “Marine Conservation Zones” (MCZs).
|A map of the proposed MCZs around England and Wales |
which can be found at http://www.mczmapping.org/
The orange shaded areas are locations where MCZs have been proposed.
These MCZs will need to be surveyed and checked over time to see whether they are working and successfully protecting the environment. This can be difficult and expensive, especially for the deep water areas to the south west of England and to the north west of Scotland. Autosub provides a possible way to carry out this monitoring work.
During the expedition we will use the Autosub to survey candidate MCZ s in the very South West of the UK’s waters (red circle on the map). Here the seabed drops down from the edge of the continental shelf through canyons and across slopes towards the abyss.
The History behind the expedition
Researchers in the 1960s and 70s discovered very large numbers of species in the deep ocean, with some estimates going as high as 100 million species. We still don’t know whether they were right, or what might allow such a large number of species to co-exist. Here is a short review paper on the subject by Prof Alex Rogers of Oxford University.
The Porcupine Abyssal Plain (PAP) has a special place in the history of deep-ocean exploration as it is one of only a very small number of places that has been studied over several decades. This has provided many important insights into the workings of the deep ocean and its role in the world’s climate.
Because the PAP has been studied over a long time and in many different ways it is possible to see how the community of animals there changes and to try and work out what the causes are.
In the past we thought of the deep ocean as a very stable place where nothing changed much over the years. We now know that this isn’t right. In what is now known as the “Amperima Event” the community of animals living on the PAP suddenly changed with huge numbers of the sea cucumber Amperima rosea suddenly appearing and taking over from the previous inhabitants. The reason for this is thought to have been a change in their food supply from the surface.
What we now realise is that even though the physical environment (temperature, pressure, light level) remains very stable, food availability and quality changes dramatically from one year to the next as a result of variations in our climate. Changes in food supply have massive effects on abyssal communities.
Future climate change is expected to alter the amount of plankton and other plants and animals living in the surface waters of the oceans. This in turn would change how much food reaches the abyss. Our work on the expedition will help us understand these changes.