Living with the oceans.


> The Glossary explains the meaning of specialist terms which are parti­cu­larly important for an under­standing of the text but which cannot be defined in the indi­vi­dual chapters due to space con­straints. Glossary terms are printed in bold in the body of the review, making them easy to identify.


The mechanical wear or removal of rocks in the surf zone. A variety of mechanisms contribute to abrasion. Soft rocks can be worn away by the wave energy alone. Harder rocks can be abraded by loose material such as sand that is transported to the shore with the surf. Another type is weather abrasion, which is the washing out of rocks by rain or frost wedging. The latter is a term for the phenomenon whereby water that has penetrated into cracks expands upon freezing, and causes the rock to chip or flake.
Acidification  (ocean acidification)
A large proportion of the carbon dioxide that enters the atmosphere through combustion processes is taken up by the ocean, causing the seawater to acidify. Strictly speaking the seawater remains basic. But when the acidity, or pH value, of the water decreases in the direction of less basic, it is referred to as acidification of the water.
Algal bloom
A massive reproduction event by algae and other single-celled organisms in rivers, lakes or the ocean triggered by an increased input of nutrients. Algal blooms are a natural phenomenon. As a result of overfertilization, however, especially pronounced episodes occur today in many marine areas. When the algae die, they are broken down by bacteria, which consume oxygen. This produces “dead zones” in severely overfertilized waters.
Plants and animals that can live both in water and on land are called amphibious. The term comes from the Greek amphi (two-sided, double) and bios (life).
Antarctic Bottom Water
Oxygen-rich, highly saline ocean water that sinks to the bottom in the Antarctic and flows northward along the bottom around the globe, all the way to the North Atlantic.
Antarctic Polar Front
This term is sometimes used as a synonym for the Antarctic Convergence, and it designates the northern boundary of the Southern Ocean. In this 30- to 50-kilometre-wide zone, cold, northward-flowing surface water from the Antarctic region meets warmer, southward-flowing surface water from the temperate latitudes of the Atlantic, Pacific or Indian Oceans. Because the cold Antarctic water, at around two degrees Celsius, is more dense and heavier than the warmer eight-degree water from the north, it sinks in the convergence zone and flows ­northward at a depth of 800 metres. The specific location of the Antarctic Convergence depends on the longitude, weather and season. Its position may shift to the north or south by up to 150 kilometres, but as a rule the Antarctic Convergence is at about ­50 degrees south latitude. The sharp increase in surface-water temperature within the Antarctic Convergence forms a barrier to the northward dispersal of many polar marine organisms. These are practically non-existent north of the Antarctic Polar Front because the water is too warm for them there.
Changes in nature caused by humans, such as the increase of CO2 concentrations in the atmosphere, are referred to as anthropogenic.
The gaseous shell that surrounds the Earth. Its major compo­nents are nitrogen and oxygen. The carbon dioxide content is only around 0.038 per cent. This gas, however, apart from water vapour, is the most important cause of the greenhouse effect.
North Atlantic Current
warm surface current that is a continuation of the Gulf Stream extending from Newfoundland to Europe, and that transports its heat to north-western Europe. The Gulf Stream and its extension, the North Atlantic Current, are driven by winds and thermohaline circulation, i.e. by differences in salinity and temperature of the sea water. On its northward path, the waters of the North Atlantic Current release large quantities of heat into the atmosphere, thus contributing to the mild climate in north-western Europe.
Azores High
An atmospheric high-pressure area that regularly forms in the central North Atlantic near the latitude of the Azores. Cold air sinks here, is warmed by the Gulf Stream, and is transported eastward toward Europe.


Ballast  water
Water pumped into special ballast water tanks in the hull to stabilize ships. Ballast water is transported over long distances primarily by cargo vessels. The organisms contained in the water, such as algae, larvae or bacteria, can easily cross great ocean expanses in this way. If they establish themselves in a new habitat they can displace native species.
Organisms living on the bottom of a water body are called benthic.
The biological variety of the Earth. This includes not only the species as such, but also the genetic variability present within the individuals of a species, or the variability of habitats in a region.
Substances produced by living organisms such as plants, animals, fungi or bacteria are referred to as biogenic.
Biogeochemistry is an interdisciplinary scientific field that encompasses chemical, biological and physical processes and their interactions. Many processes in nature can only be understood when all three of these aspects are taken into account. One accordingly refers to biogeochemical phenomena or processes.
The part of the Earth’s crust inhabited by living organisms. The biosphere also includes the ocean.


Carbon cycle
The cycle of the chemical element carbon. It includes the transformation of carbon chemical compounds within the global lithosphere, hydrosphere, atmosphere, and biosphere systems, as well as the exchange of carbon compounds between these systems. The carbon compounds can be in the form of gas (in the atmosphere), or bound up in solid material, for example, in water-soluble carbonate or in the solid biomass of plants in the form of carbohydrates.
Carrying capacity
The maximum number of individuals or species that can exist in a habitat. It is determined in part by the amount of available food and, in the case of fish, by the available spawning sites.
Microorganisms that produce energy for their metabolism from chemical compounds are called chemoautotrophic. Chemoautotrophic organisms are distinguished from photoautotrophic organisms such as plants, which prod-uce their energy from sunlight.
The portion of the Earth covered by ice. The cryosphere includes antarctic glaciers, mountain glaciers, sea ice and shelf ice.
CO2 Carbon Credits
CO2 Carbon Credits allow industrial enterprises worldwide to emit a certain amount of CO2. If a company reduces its CO2 emissions through technical measures, it uses fewer of its Carbon Credits, and can sell them to other companies. Measures designed to reduce CO2 output thus become more attractive economically despite the initial additional cost they entail.
Condensate  (gas condensate)
A mixture of relatively heavy hydrocarbons that can accumulate during natural gas production. The components of this natural-gas by-product include pentane as well as larger molecules, sometimes ring-shaped (aromatics and cycloalkanes). As a rule, because of its composition, gas condensate is a liquid at room temperature and mean sea level pressure. Because its makeup is similar to that of the light constituents of oil, it can be separated from the natural gas and processed in refineries to petrol, among other products.
A substance condenses when it transforms from a gaseous to a liquid state. The process of condensation is therefore the reverse of evaporation. The phase transition from water vapour to liquid water is one of the basic physical processes in the Earth’s water cycle. Without it the water vapour contained in the air would not form fog, clouds or raindrops. The condensation of water vapour, however, is dependent on to two conditions. For one, the air has to be at least slightly oversaturated with water vapour. For the other, it is necessary to have particles suspended in the air that act as condensation nuclei.
Continental slope
The area of the sea floor where the flat, near-coastal continental shelf falls more steeply into the deep sea.
In the context of the ocean or atmosphere, convection refers to vertical turbulent motion of the water or air, usually caused by density changes (for example,due to cooling or warming). Convection in the ocean plays a primary role in driving the thermohaline circulation.
Convention on Biological Diversity (CBD)
The Convention on Biological Diversity (CBD) was negotiated in 1992 in Rio de Janeiro, during the United Nations Conference on Environment and Development (UNCED). It pursued three primary goals: 1. conservation of biological diversity, 2. sustainable use of natural resources, and 3. assurance that the utilization of genetic resources and information (for example, for medically useful substances) is equally beneficial for all countries.
Coriolis force
The coriolis force or coriolis acceleration, caused by the Earth’s rotation, causes freely moving masses such as air and water currents to be diverted from straight linear motion. In the northern hemisphere, the coriolis force deflects linear flow to the right, in the southern hemisphere to the left, and at the equator there is no effect.
Customary  international law
A form of unwritten international law, which consists of rules that come from general practice accepted as international law. A further element of customary international law is opinio juris – a belief on behalf of a state that it is bound by the law in question. Examples are the prohibition of torture, recognition of air space, and recognition of the 12-mile zone as the sovereign territory of the coastal state. These rules are binding on all states under international law, whether or not they are the subject of a treaty. A key prerequisite is that the relevant opinio juris is accepted as law by the overwhelming majority of countries. Customary international law applies even if it is only relevant to certain countries. For example, customary international law holds that the 12-mile zone is sovereign territory, although some countries do not have a coastline.


Single-celled, hard-shelled algae with a carapace of silica. Most diatoms in the ocean are a component of the plankton, and they are among the most important producers of oxygen in the ocean. They are also an important nutrient base for higher organisms. Diatoms also occur in freshwater and on the sea floor.
Drop-in sessions
Open advice and consultation sessions – especially in a university or neighbourhood setting – which people can attend without an appointment. Generally, an advisor is available for a given period to discuss a specific topic.


East Pacific Rise
A mid-ocean ridge located in the southeast Pacific.
A community of living organisms of various species in conjunction with their non-living environment (e.g. rock, mineral soil, humidity and other environmental factors). “Ecosystem” is a neutral scientific concept, although in a political context, it is often used to mean valuable physiographic regions which deserve protection. Forests, coral reefs and the Wadden Sea are all examples of ecosystems.
Earth history
An object of research in the field of geology. It encompasses the period of time from the origin of the Earth up to the geological present.
El Niño
An irregular climate phenomenon occurring every 3 to 8 years in the Pacific Ocean between Indonesia and Peru. The direction of the trade winds and ocean currents reverses due to atmospheric pressure changes. Off the coast of Peru this leads to a decline in the upwelling of cold, nutrient-rich water from the deeper layers to the surface. El Niño is Spanish for infant Jesus. The phenomenon was so named because it often occurs around Christmas time.
Plant and animal species that only occur in a particular and limited area of the world are called endemic. Endemic species are very susceptible to extinction due to degradation of their habitat.


Single-celled organisms that move through the water using a whip-like appendage called the flagellum. They are found in both freshwater and saltwater.


Group of 20 major economies, comprising 19 industrial and emerging countries plus the European Union. Germany, France, the United Kingdom and Italy are members in their own right. Countries are ranked in descending order by gross domestic product.
Technical measures that could influence the natural cycles on a grand scale, applied to counteract the impacts of climate change. These measures are broadly divided into two groups: Solar Radiation Management (SRM), and Carbon Dioxide Removal (CDR). SRM deals with the release of certain substances into the atmosphere to influence incoming solar radiation, while CDR generally refers to the large-scale breakdown or storage of CO2. The techniques are controversial because they severely intervene with natural processes, and because their direct consequences and side effects, as well as possible reciprocal impacts, are difficult to predict.
This term is commonly used in the fields of meteorology and oceanography, where it is used in the context of geostrophic equilibrium, a state of equilibrium that occurs in the atmosphere or in the ocean if only the Coriolis force and the horizontal pressure gradient force are taken into account and the two forces cancel each other out. As a result, a geostrophic wind or a geostrophic current is generated that is directed perpendicular to the pressure gradient force.
Greenhouse effect
Water vapour, carbon dioxide (CO2) and other climate-relevant trace gases in the atmosphere, including methane (CH4), initially allow short-wave radiation from the sun to pass through to the Earth. At the Earth’s surface these are transformed, and reflected back for the most part as long-wave radiation. Like the glass panes in a greenhouse, however, the gases then prevent the long-wave heat rays from escaping into space. The Earth warms up. The greenhouse effect is a natural phenomenon that protects the Earth from overcooling. With increasing concentrations of CO2 and other trace gases, however, the greenhouse effect is intensifying.
Greenland Sea
The Greenland Sea extends from Greenland to Iceland and Spitzbergen, thus forming the boundary between the North Atlantic and Arctic Oceans. Large water masses sink to greater depths in the Greenland sea due to convection.
Gross national income (GNI)
The sum of the income generated by all residents in a nation from employment and assets in a given year, whether received in the country itself or abroad. Prior to 1999, the term “gross national product” (GNP) was generally used.
Gulf Stream
A relatively fast, warm ocean current in the Atlantic. The Gulf Stream flows out from the Gulf of Mexico, around the Florida peninsula toward the northeast, and into the North Atlantic Current. It contributes significantly to the relatively mild climate in western Europe because it transports large amounts of heat.


A characteristic natural environment inhabited by a particular species.
Human history
The time period spanning the origin and evolu­tion of the genus Homo in Africa up to the present. Archaeology provides knowledge of the early development phases through the investigation of past remains.


Icelandic Low
A semi-permanent, low-pressure area over the North Atlantic. A large proportion of the precipitation in western Europe is transported in by this low. Interplay between the Icelandic Low and the Azores High is a significant factor in determining the weather in western Europe.
Ice shelves
Are large platforms of ice that float on the ocean but are still connected to the ice on land. Ice shelves can be hundreds of metres thick. They often form when glaciers flow from the land into the sea.
Ilulissat Declaration
a legally non-binding declaration signed by the five Arctic coastal states Canada, Denmark, Norway, Russia and the USA on 28 May 2008 in Ilulissat, Greenland. The countries promised to resolve intra-Arctic conflicts peacefully, to protect the Arctic environment, particularly from oil spills, to promote stricter environmental guidelines within the International Maritime Organization (IMO), to expand air and sea rescue along their Arctic coasts, and to cooperate more closely in research. Additionally, the five states emphasize in this declaration that ­there is no need for a new UN agreement to resolve intra-Arctic territorial disputes, but that the five Arctic coastal states will resolve all conflicts on the basis of the international law of the sea.
Interhemispheric dipole
A regular fluctuation of water temperatures in the Atlantic, occurring about every ten years. Scientists refer to this as a temperature anomaly.
Intergovernmental Panel on Climate Change (IPCC)
This is a United Nations body founded in 1988. It tasks hundreds of ­scientists around the globe with compiling, at regular intervals, the current state of research on climate change and assessing it. In other words, these scientists present the causes, implications and risks of climate change and identify ways in which humankind can mitigate and adapt to it. The three working groups of the IPCC publish their findings in Assessment Reports that are sometimes called World Climate Reports.
Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)
This is a scientific council established in 2012. It is an organization within the United Nations system. IPBES advises policy-makers on the issues surrounding the sustainable use of nature and its biodiversity and services, and publishes regular assessment reports on biodiver­sity-related topics. Its work is supported by more than 1000 scientists around the globe. They all contribute their expertise without pay and on a voluntary basis.
International Whaling Commission (IWC)
The International Whaling Commission (IWC) provides information annually on the status quo of the worldwide whale stocks, the establishment of protection areas, and on extensions of the whaling moratorium. It was established by the International Convention for the Regulation of Whaling (ICRW). This convention is an agreement created under international law whose aim is the preservation and management of whale stocks. The IWC comprises representatives from around 80 signatory nations.


Labrador Sea
The area of the North Atlantic between Greenland and Canada. As in the Greenland Sea, large water masses sink to greater depths here due to convection.
The solid rock shell of the Earth.


Marshall Plan
A US initiative to aid Europe’s recovery after the Second World War and consisting of loans and supplies of food, goods and raw materials. Officially known as the European Re­covery Program (ERP), it was named after its initiator, Secretary of State George C. Marshall. It began in autumn 1948 and ran for four years. By 1952, the US had provided around 13 billion US dollars in financial and material assistance to Europe – equivalent to around 120 billion US dollars today. The US’s motives for initiating the programme were humanitarian, coupled with a desire to build a strong and united Europe capable of standing firm against the ­Eastern bloc and trading with the US.
Mean sea level (NN)
Normalnull (NN) is a reference datum for the standardization of elevation measurements in Germany, Switzerland and Austria. It is equivalent to the elevation of the mean sea level. Normalnull is also the reference used for ­designating elevations of buildings or mountains. It was originally derived from the Amsterdam Ordnance Datum (Normaal Amsterdams Peil – NAP) that has been used conventionally in the Netherlands since the nineteenth century, and was at that time equivalent to the average water level of the Zuiderzee, a marine inlet that lay largely in the area of the present-day IJsselmeer.
Mid-ocean ridge
Ridges or mountain ranges on the sea floor similar to the seams of a baseball, extending around the entire globe. They originate in areas where continental plates drift apart beneath the ocean. Hot magma rises at these fracture zones in the central ocean regions, is cooled in the water, and piles up through time to form enormous mountains.
Monsoon (region)
A large-scale, strong and constant air current in the tropics and subtropics. The monsoon changes direction twice a year. This is caused by annual changes in the altitude of the sun. When the sun is high, the amounts of heat assimilated by the land and water masses are very different, which leads to distinct air-pressure differences and strong winds. When the monsoon blows from the sea it brings humid air masses and causes strong monsoon rains. This sometimes results in large floods.
Multispecies fishery
Fishing for multiple species of fish at the same time. Whether a fisherman catches a number of different species in his net depends on several factors, including the behaviour of the fish, the marine area, and the time of year in the case of migrating fish. In multispecies fishing, species are often caught that are of no interest to the fisherman, or that he is not allowed to sell. These fish are usually thrown overboard dead.


Nominal capacity
The maximum output generated by an energy installation in the long term without causing damage to the installation or shortening its lifetime. The nominal capacity is always stated for motors or generators. Day to day, technical installations often operate below their nominal capacity, not least in order to protect them from wear or damage. Wind turbines generally only reach their nominal capacity on very windy days.
Non-governmental  organization (NGO)
Civil-society interest group that attempts to influence policies. NGOs counterbalance the representation of governmental interests. NGOs are especially active on issues relating to social equity and environmental quality.
North Atlantic oscillation (NAO)
Refers to the fluctuation of the pressure relationship between the Azores High and the Icelandic Low. The NAO is especially important in driving the winter climate in Europe, but also in North Africa, Greenland and the eastern USA. Researchers believe that the NAO determines 30 per cent of the European winter weather. The NAO also exists during the summer, but during this time it seems to be less critical for climate. A systematic change in this air-pressure system has been observed in recent years compared to earlier measurements. One result has been an increase in warm winters in Europe with less snowfall.


Oceanic ridge
Ridges or mountain ranges on the sea floor that form where continental plates drift apart. At these plate boundaries, magma rises from the Earth’s interior, is cooled by the water, and over time forms enormous mountains.
Ottawa Declaration
a document signed by the eight Arctic countries Canada, Denmark, Finland, Iceland, Norway, Russia, Sweden and the USA that established the Arctic Council as an intergovernmental forum for dialogue and defined its basic functions and procedures. The Declaration was signed by the Foreign Ministers of the participating states on 19 September 1996 in Ottawa, the capital city of Canada.
Overfertilization  (eutrophication)
The input of unnaturally large amounts of nutrients from agriculture or from industrial or municipal effluent into natural waters. Overfertilization leads to increased reproduction of algae, called algal blooms. The problematic substances include nitrogen and phosphorus compounds from mineral fertilizers of from faeces and urine.


Paris Climate Agreement
The Paris Climate Accords, as the treaty is also known, form the first comprehensive and legally ­binding climate agreement by the international community. Adopted by 196 states on 12 December 2015 at the United Nations Climate Change Conference in Paris, the Agreement sets a global framework for combatting climate change. It aims to hold the increase in the global average temperature to well below two degrees Celsius above pre-industrial levels by means of drastic reductions in greenhouse gas emissions. In the best case, the ­temperature increase is to be limited to 1.5 degrees Celsius. Moreover, the developing countries in particular are to be assisted in efforts to adapt to the impacts of climate change. The Agreement entered into force on 4 November 2016 after 55 countries had ratified it which are jointly responsible for at least 55 per cent of global emissions.
Parts per million (ppm)
The expression parts per million (ppm) is used to designate one-millionth of a substance. 1 ppm of a substance thus represents a concentration of 1:1,000,000 parts.
The pedosphere is the part of the continental land masses that is referred to as soil. It is the interface between the atmosphere and the lithosphere. The pedosphere is a layer of loose, small grained rock material that is enriched in organic substance and usually contains some amounts of water and air.
Organisms that live and feed in open waters are called ­pelagic.
Pelagic system (pelagial)
The term pelagic system is used to indicate the main body of the open water (pelagial) including all of its inhabitants. Pelagic organisms comprise the plankton and the nekton. The nekton includes organisms such as fishes and whales, which, in contrast to the plankton, are able to actively swim against the currents.
Permafrost ground
Ground that is permanently frozen, year-round, below a particular depth. Among other areas, permafrost grounds are found in the arctic tundra, in northern evergreen forests, and in the high mountains. In these regions the sun’s energy is not sufficient, even in summer, to warm the ground to depth. Only the upper layers thaw out for a few weeks.
Planktonic plants that are mostly microscopic in size. They include microalgae. Planktonic organisms typic-ally have little or no power of self-locomotion, and thus drift with the water currents.
Organisms that feed on plankton (microalgae, fish and mussel larvae or krill) are called planktivores.
All free-floating organisms in the open water. Most planktonic organisms are microscopic in size. They include protozoans, microalgae, krill, and the larvae of fish and mussels. A distinction is made between plant plankton (phytoplankton) and animal plankton (zooplankton). Planktonic organisms are able to propel themselves, but only very weakly, so they are forced to drift with the water currents. In contrast to the plankton, the nekton includes all marine animals that can actively swim independently of the currents.
Plate-tectonic processes
the movements of the various continental plates that make up the Earth’s outer shell (lithosphere). These plates drift apart, collide with one another, or slide past each other, causing earthquakes and volcanism. Where two plates spread apart – like on the mid-ocean ridges – large quantities of magma rise up out of the Earth’s interior and form new basaltic crust, a new, solid rock shell. In regions where two plates move toward each other, long collision zones are created in which ­various processes take place depending on the composition and age of the two plates.
A group of individuals of one species that inhabit the same area at the same time. A population forms a reproductive community. One species can develop multiple populations at different locations.
Pore pressure
The pressure of the water that exists between the particles within a sediment body. Because water cannot be compressed, pore pressure increases when fresh sediment is deposited atop older sediment layers.
Precautionary principle
This is a guiding principle of interna­tional environmental policy. It calls for human societies to act in good time and with foresight when intervening in natural systems, in such a way that environmental hazards do not arise in the first place. Germany’s Federal Environment Agency notes that the principle has two dimensions: risk foresight and resource foresight. Risk foresight (also termed risk prevention) means that, in the event of incomplete or uncertain knowledge about the nature, extent, probability and causality of environmental damage and hazards, a precautionary approach must be taken that prevents such damage or hazards from the outset. Resource foresight means handling natural resources such as water, soil and air with a view to their long-term conservation in the interest of future generations.
Primary production, primary producers
The production of biomass by plants or bacteria. The primary producers obtain their energy from sunlight or from certain chemical compounds, and through their metabolism synthesize energy-rich substances such as carbohydrates. These substances, in turn, represent a subsistence basis for animals and humans.


Rare-earth metals
A group of 17 metals that are located adjacent to one another in the periodic table of the elements and have similar chemical properties. The unusual name comes from the fact that in the past these metals were mined from minerals (“earths”) that were thought to be very rare. In fact, however, many of the rare-earth metals are relatively abundant in the Earth’s crust. But large deposits with high concentrations are not common. The ­largest occurrences are found in China and Mongolia. Rare-earth metals are used in many key technologies. Among other uses, they are needed for permanent magnets in magnetic resonance tomography (MRT) and in wind turbine generators, as well as for the production of storage batteries, LEDs and plasma displays.
Rated capacity
The maximum output at which energy-driven equipment can run over extended periods without being damaged or subjected to a decreased lifespan. The nominal power rating is always specified for motors and generators. In every-day application, technical equipment usually runs below the rating, generally in order to extend its lifetime. It is not uncommon, however, for wind turbine generators to reach their rated capacity on very windy days.
Ratified, ratification
Formal and binding validation of an international convention or treaty. Various countries may conclude a treaty but this does not automatically make it valid or legally operative under international law. Nor is it enough simply to sign the treaty document. Each state must, in addition, make a formal declaration expressing its intent to be bound by the relevant treaty. This is known as ratification. As a rule, the head of state or a high-ranking politician signs an instrument of ratification. The prerequisite for ratification is generally a legal act adopted under national law, such as an act of Parliament, in which Parliament assents to the provisions of the trea-ty. In Germany, for example, treaties concluded by the Federal Republic must be approved by the Bundestag. Only then can the instrument of ratification be deposited.
Representative Concentration Pathways (RCPs)
The term refers to four selected scenarios that were utilised in international climate modelling and in the Fifth IPCC Assessment Report to facilitate simulations with diverse climate models and render their outcomes comparable. Scenarios set certain parameters for the climate models and thus define a certain scope that would otherwise need to be determined at considerable cost and effort. The scenarios consist mainly of numerical tables. These combine times series of the potential future trajectories of greenhouse gas emissions, aerosol concentrations in the atmosphere, land use and vegetation – all to the year 2100. Furthermore, they take account of assumptions concerning the trajectories of population growth, economic development and fossil energy consumption. On this basis, the RCP scenarios provide time series of anticipated greenhouse gas concentrations and of the radiative forcing that results from each concentration.
Red List
Plant and animal species as well as habitat types are classified into several categories in red lists according to the degree of threat, for example, from “near threatened” to “extinct”. The most important worldwide Red List is issued by the International Union for Conservation of Nature (IUCN). Individual countries or regions also have their own lists that are released by various public authorities. For the Baltic Sea, for example, there is the Helsinki Commis-sion, HELCOM. The classifications can differ from list to list. On the IUCN List, for example, the small-spotted catshark is classified as “least concern”, because it still has a wide distribution. In the Baltic Sea region, however, it is now very rare and is therefore classified as “endangered” in the HELCOM List.
Residual soil
Degradation of rock resulting in accumulation of low-solubility material, in part due to biological processes.
The United Nations Conference on Sustainable Development (UNCSD), which was held in Rio de Janeiro in 2012, exactly 20 years after the 1992 United Nations Conference on Environment and Development (UNCED), which also took place in Rio and is still known as the Rio Summit. In June 1992, representatives of 178 countries convened at the Rio Summit to discuss environmental and development issues for the 21st century. The Summit established sustainable development as the guiding vision for the international community. At Rio+20, the Sustainable Development Goals (SDGs) were elaborated and defined in more detail.


Seagrass meadows
A group of flowering plants which typically grow in sandy sediment in coastal waters and on tidal flats. They have long, herb-like fronds and thus resemble – but are unrelated to – the grasses that grow onshore. They are important habitats, providing young fish with food and protection from predators. ­Various species of fish lay their eggs directly on seagrass, so these meadows are often described as nurseries for fish. They are also a vital foraging ground for birds, such as Brent geese, during their autumn migration across Western Europe’s Wadden Sea.
An undersea mountain, formed on the sea floor through volcanic activity and reaching at least 1000 metres while re­maining beneath the ocean surface. Studies indicate that some seamounts host biotic communities with numerous rare or unique species. Seamounts exist in various areas of the sea, and there are thought to be many thousands of them worldwide.
Shared Socioeconomic Pathways (SSPs)
are selected scenarios that were produced to supplement the Representative Concentration Pathways (RCPs) and are thus slightly more recent. They take socioeconomic factors into account, depicting five different societal development trajectories – ranging from a future ­characterised by active climate policy to one in which there is no climate or environmental protection policy at all. In the latter ­trajectory, termed SSP5-8.5, humankind puts its faith entirely in market forces, technological progress and fossil resources such as coal and mineral oil. In other words, the SSP scenarios can be employed to test the climate impacts of policy decisions. The SSP scenarios provide a basis for calculating the future development of temperatures in a manner complementing the RCP scenarios.
Shelf area
The near-coastal, shallow part of the sea floor. The shelf falls gradually to an average depth of 130 m. The shelf ends at the continental slope.
A natural reservoir that can hold large amounts of a given substance, such as carbon dioxide. For example, carbon sinks include forests, the deep ocean, and even corals, because of the carbon dioxide bound up in the carbonate.
Soil erosion
The wearing away of fertile and humus-rich topsoil by the natural physical forces of water and wind. Human communities can worsen soil erosion through their farming activities. After harvesting, harrowing and ploughing, for example, the soil is un- protected and erosion can easily occur. Deforestation can have a similar effect by leaving soil exposed. In the long term, soil erosion causes the loss of precious arable land.
Stratospheric, stratosphere
The stratosphere is that area of the atmosphere that lies at an altitude between around 15 and 50 kilometres. Within the stratosphere at around 20 to 40 kilometres there is a band with higher ozone concentrations. This „ozone layer“ blocks a large portion of the ultraviolet solar radiation that can be harmful for living organisms.
A stock is a self-sustaining population of a fish species that occurs within a limited marine region. As a rule, the different stocks of a fish species are so far isolated geographically from one another that the individuals of one stock do not mix with those of another, even though they belong to the same species.
The material that an organism lives upon, for example, stones to which barnacles are attached.
Individuals of different animal species that co-exist in such a way that one organism profits from the other are called symbiotic.


a subdiscipline of physics that deals with the relationships between heat and other forms of energy, as well as their possible transformations. Important parameters include pressure, temperature and mechanical work, as well as changes in volume, density and physical state, which also play a role in the origins of currents in the ocean and atmosphere.
Thermohaline circulation
A global system of near-surface and deeper ocean currents that is driven by density differences between water masses with different salinities and temperatures. Convection is an important motor for thermohaline circulation.
Tidal zone
The area of the coasts defined by the limits of high and low tide. The water level falls and rises here in phase with the tides. This creates some areas that are periodically not covered by water. Characteristic biotic communities often colonize these areas.
Trades/ trade winds
winds that blow steadily in the tropics and are thus a driving force of marine currents. The trade winds prevail between around 23 degrees latitude north and south of the equator. The northeast trades occur in the northern hemisphere and the southeast trades in the southern hemisphere. The direction of the trade winds is primarily controlled by the deflective force of the Coriolis force.


United Nations Conference on the Law of the Sea (UNCLOS)
Between 1973 and 1982, three United Nations Conferences on the Law of the Sea (UNCLOS) were held with the aim of establishing internationally enforceable maritime law. This was accomplished with the third Convention (UNCLOS III) in 1982. The result was the adoption of the UN Convention on the Law of the Sea. UNCLOS has defined the rights of nations with respect to the sea since 1982. For this purpose it divides the seas into various zones. For example, under UNCLOS every nation-state has the right to manage the fish stocks in its Exclusive Economic Zone (EEZ), which extends to a distance of 200 sea miles from its coast. Beyond the EEZ, the high seas freedoms apply under UNCLOS. Fish may be caught here by any country. In addition, UNCLOS regulates shipping, marine environmental protection, and the production of oil, gas and other resources in the ocean. UNCLOS is the legal foundation for the International Tribunal for the Law of the Sea. By 2010 the Convention has been ratified by 157 nations.
United Nations Statistics Division (UNSD)
United Nations (UN) division responsible for compiling and disseminating global statistical information, developing global standards and norms for statistical activities, and promoting cooperation between national statistical services. The UNSD’s work is overseen by the United Nations Statistical Commission as the apex entity of the UN’s and the world’s statistical system.
Upwelling region
Usually near-coastal marine regions where cold, nutrient-rich deep waters rise to the ocean surface. The motion is commonly driven by trade winds blowing parallel to the shoreline. The winds force the surface water away from the coasts and deeper water rises to replace it. Biologically, upwelling regions are highly productive, and are thus very important for fisheries, which are often concentrated at the western margins of continents, particularly off the coasts of Chile, California and Namibia.


Warsaw Pact
A Soviet-led political and military alliance, which existed from 1955 to 1991, between the USSR and several Eastern European countries as a counterbalance to the North Atlantic Treaty Organization (NATO). The founding treaty was signed in Warsaw in 1955 by the USSR, Albania, Bulgaria, Czechoslovakia, the German Democratic Republic, Hungary, Poland and Romania.