Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.

To humans, cold has a distinctly positive quality. 'Frostbite', 'a nip in the air', 'biting cold', all express the concept of cold as an entity which attacks the body, numbing and damaging it in the process. Probably the richness of descriptive English in this area stems from the early experiences of a group of essentially tropical apes, making their living on a cold and windswept island group half way between the Equator and the Arctic. During a scientific education we soon learn that there is no such thing as cold, only an absence of heat. Cold does not invade us; heat simply deserts. Later still we come to appreciate that temperature is a reflection of kinetic energy, and that the quantity of kinetic energy in a system is determined by the speed of molecular movement. Despite this realization, it is difficult to abandon the sensible prejudices of palaeolithic Homo sapiens shivering in his huts and caves. For example; appreciating that a polar bear is probably as comfortable when swimming from ice floe to ice floe as we are when swimming in the summer Mediterranean is not easy; understanding the thermal sensa tions of a 'cold-blooded' earthworm virtually impossible. We must always be wary of an anthropocentric attitude when considering the effects of cold on other species."

It is generally agreed that animal life originated in the sea and that adaptive radiation subsequently led to the colonisaHon of other environments - shores and estuaries, streams and lakes, bog, mountain and desert. In their invasion of these habitats animals left the equable, relatively stabl.e surroundings of the open sea and subjected themselves to the rigours of temperature fluctuations and extremes, a variety of ionic backgrounds, areas of depleted oxygen or the possibility of aerial exposure and potential desiccation. The spur for this radiation presumably lay in the prize of access to unexploited habitats and sources of energy. The survival of these more adventurous species has depended upon them evolving mechanisms to protect the integrity of their cellular constituents. Protoplasm can only exist within physiochemical limits which are quite narrow for each species. Water activity, salt and gas concentrations and temperature all have to be appropriate for enzyme catalysed processes to function properly within cells. Except in the open sea, environmental conditions regularly vary outside these limits. To take a familiar example; humans can only remain conscious (and hence functional) if their core (Le. deep tissues - brain, heart, liver, etc.) body temperature is maintained between about 30 and 43 DegreesC.

This volume presents a representative sample of contributions to the 41st European Marine Biology Symposium held in September 2005 in Cork, Ireland. The theme of the symposium was 'Challenges to Marine Ecosystems' and this was divided into four sub themes; Genetics, Marine Protected Areas, Global Climate Change and Marine Ecosystems, Sustainable Fisheries and Agriculture. The world's marine ecosystems face multiple challenges, some natural, but many resulting from humankind's activities. Global climate change, driven by influences of energy usage and industrial practices, is a reality now accepted by most of the world's scientists, media and political establishments. Warming seas and rising sea levels are regarded as threats, while visionaries consider deep ocean carbon disposal as a technological opportunity. Exploitation of the seas continues apace, with repeated concerns over the impact of over-fishing, plus reservations about the environmental effects of marine aquaculture. We need to understand how resilient organisms and ecosystems are to these challenges, while responding by protecting biologically-meaningful areas of the oceans. The subthemes of the 41st European Marine Biology Symposium address all of these matters.

To humans, cold has a distinctly positive quality. 'Frostbite', 'a nip in the air', 'biting cold', all express the concept of cold as an entity which attacks the body, numbing and damaging it in the process. Probably the richness of descriptive English in this area stems from the early experiences of a group of essentially tropical apes, making their living on a cold and windswept island group half way between the Equator and the Arctic. During a scientific education we soon learn that there is no such thing as cold, only an absence of heat. Cold does not invade us; heat simply deserts. Later still we come to appreciate that temperature is a reflection of kinetic energy, and that the quantity of kinetic energy in a system is determined by the speed of molecular movement. Despite this realization, it is difficult to abandon the sensible prejudices of palaeolithic Homo sapiens shivering in his huts and caves. For example; appreciating that a polar bear is probably as comfortable when swimming from ice floe to ice floe as we are when swimming in the summer Mediterranean is not easy; understanding the thermal sensa tions of a 'cold-blooded' earthworm virtually impossible. We must always be wary of an anthropocentric attitude when considering the effects of cold on other species."