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2020 Online documentation volume on Discussion No. 24 Global Biodiversity in Times of Crisis What can Germany and the EU do about it?


1 2020 online documentation volume on discussion No. 24 Global biodiversity in times of crisis What can Germany and the EU do about it? Detlev Drenckhahn Almut Arneth Juliane Filser Helmut Haberl Bernd Hansjürgens Bernd Herrmann Christoph Leuschner Volker Mosbrugger Thorsten Reusch Andreas Schäffer Michael Scherer Lorenzen Klement Tockner 1

2 Imprint Published by Deutsche Akademie der Naturforscher Leopoldina e. V. National Academy of Sciences President: Prof. Dr. Gerald Haug Jägerberg 1, Halle (Saale) Editor Prof. Dr. Detlev Drenckhahn, Dr. Henning Steinicke National Academy of Sciences Leopoldina Contact: Department of Science Politics Society (Head: Elmar König) Status: May 2020 Design and typesetting unicom Werbeagentur GmbH, Berlin Suggested citation National Academy of Sciences Leopoldina (Ed.) 2020: Global biodiversity in crisis What can Are Germany and the EU doing against it? Online documentation for discussion no.24, Halle (Saale) 2

3 Global biodiversity in crisis What can Germany and the EU do about it? Detlev Drenckhahn Almut Arneth Juliane Filser Helmut Haberl Bernd Hansjürgens Bernd Herrmann Christoph Leuschner Volker Mosbrugger Thorsten Reusch Andreas Schäffer Michael Scherer Lorenzen Klement Tockner Publications in the Leopoldina Discussion series are contributions by the authors mentioned. With the discussion papers, the Academy offers scientists the opportunity to provide food for thought or to stimulate discourse and to formulate recommendations for this purpose. This document is the online documentation for the discussion paper mentioned. 3

4 Contents 1 Global biodiversity crisis Introduction Significance of biodiversity for the earth system and the foundations of human existence Biodiversity loss and its consequences Impact of biodiversity loss on humans Drivers of the biodiversity crisis Land use Overfishing of the oceans Hunting and poaching Fresh water consumption Global nitrogen problem Phosphate problem Chemicals, pesticides (see Chapter 9) Climate change Invasive species Ecological tipping points Conclusions Significance of biodiversity for the human self-image The crisis of marine biodiversity Introduction Hotspots and loss rates of marine biodiversity Consequences of the loss of marine biodiversity Causes of the loss of marine biodiversity Fisheries and other direct use The direct destruction of habitats Alien species Pollution Warming and acidification of the ocean Measures to protect marine biodiversity Protection of marine wildlife Direct species protection Me Protected areas Recommendations for action Forests and biodiversity The forests of the world Biodiversity in forests Loss of forest area Degradation

5 4.

6 7.9.

7 Outside Europe List of Figures List of Abbreviations Bibliography Authors

8 1 Global biodiversity crisis 1.1 Introduction Since the beginning of the industrial age at the latest, mankind has caused enormous changes in the entire earth system, i.e. the networked and feedback compartments: The biosphere comprises all areas of the earth system in which diverse life occurs (biodiversity) and includes the hydrosphere (seas, Freshwater systems, ice), the atmosphere up to about 60 kilometers in height and the upper rock layers of the earth (lithosphere) (Fig. 1). Humans have become a dominant creative force in the earth system of geological dimensions (see also the current discussion of the Anthropocene 1) and create massive environmental problems and disruptions in energy and material cycles, so that, according to various authors, the safety limits of mankind's livelihoods (safe operating space for humanity 2) already partially threaten to be exceeded. 3: Fig. 1: The earth system with its interactions between anthropogenic influences (satellite image brightened at night), atmosphere, lithosphere, hydrosphere and biosphere. 1 Crutzen 2002; Subramanian Rockström et al. Steffen et al. 2015; Campbell et al

9 Explanation: The basis of the biosphere is biodiversity (diversity of organisms and ecosystems). Green arrows: interactions of the biosphere; red arrows: negative effects of anthropogenic influences. The hydrosphere covers 1.4 billion cubic kilometers (sphere with a diameter of 1380 kilometers), of which only 3 percent is fresh water (⅔ ice, ⅓ groundwater, 0.3 percent usable surface water). The global environmental problems of the Anthropocene include above all climate change with ocean acidification and warming, the considerable loss of biodiversity at species and ecosystem level (biomes, species diversity, genomic diversity), overuse of freshwater reserves, environmental toxins and overloading of global cycles with reactive nitrogen compounds. These are not separate phenomena. They are directly related and must also be seen with their diverse connectivities. This overuse changes dynamic processes that have evolved over time, so that people themselves are increasingly damaged. This does not threaten the survival of mankind in its entirety, but people are affected very differently in their life chances and their development opportunities and are already locally forced to leave certain home areas that have become unworthy of living due to food and drinking water insecurity and the resulting conflicts. 4 Structure of the biosphere area: The surface of the earth (510 million square kilometers) is around 71 percent covered by oceans (360 million square kilometers) and 29 percent by land (149 million square kilometers). The ice-free land area is 134 million square kilometers with a share of 4.6 million square kilometers inland waterways and rivers. Of the land area, 63 million square kilometers (47 percent) are currently agriculturally poorly to intensively used areas (arable land: 16 million square kilometers; pastureland: 47 million square kilometers), 40 percent closed forests (28 million square kilometers cultivated, 12 million square kilometers primeval forests) and around 25 Percent unused grasslands, wetlands, savannas, steppes and deserts (Fig. 2). For comparison: The World Food Organization (FAO) considers only 14.9 million square kilometers as (productive) arable land and 33.2 million square kilometers as (productive) pasture land, i.e. 36 percent of the ice-free land mass. 4 Ionescu et al. 2017; IDMC

10 Fig. 2: Land areas and land use of the earth's surface Explanation: Around 35-60% of the earth's surface is used agriculturally to varying degrees and 70% of the forests (21% of the earth's surface) are subject to weak to intensive forestry use. In addition to the grassland, which is mainly used as pasture, arable land does not serve to supply people with basic vegetable foodstuffs for more than 50% of its area, but rather to produce fodder for the production of meat and milk and increasingly also to generate energy and fuels (agro-diesel, ethanol) . The untouched primary (primeval) forests (11.5 12 square kilometers) only cover 9% of the land surface. However, they are home to around 50% of all animal and plant species on earth. The forests are still under considerable pressure, mainly because of the increasing consumption of meat and milk, the production of palm oil (e.g. as agro-diesel) and the increasing use of wood for energy purposes. 5 biomes, ecoregions: The International Union for Conservation of Nature (IUCN), subdivided according to Olson et al., 6 revised in Dinerstein et al., 7 the biosphere into 8 large biogeographical regions and the land area into 14 (terrestrial) biomes and over 846 Ecoregions (Fig. 3). Europe is divided into around 30 ecoregions. 5 sources: IPCC 2019; EU 2017; Eurostat 2019; OECD / FAO 2017; Carus et al. 2014; Jering et al. 2013; Bruckner et al Olson et al Dinerstein et al

11 Fig. 3: Subdivision of the biosphere into 8 large geographic regions as well as 14 biomes (colored below) and 846 ecoregions (colored above, modified) Significance of biodiversity for the earth system and the foundations of human life Biodiversity / biological diversity encompasses the entire diversity of life all hierarchy and complexity levels. Biodiversity means above all the diversity of habitats (biomes, ecosystems), species (taxonomic units), locally adapted populations and their diversity of gene variants and the interactions between organisms and with ecosystems. Biodiversity in all its complexity is still considerably unexplored today. About 1.9 million animal and plant species are currently described. 9 Estimates of the actual biodiversity range from 5 million to 100 million animal, plant and fungus species; more recent, more conservative estimates assume 8 to 10 million animal, plant and fungus species. Currently, therefore, at most between 15 and 20 percent of the actual biodiversity is known. In the deep sea, probably less than 1 percent of the species are known. Around the world around new species are discovered every year Dinerstein et al. 2017; 9 Régnier et al (accessed: March 7, 2019). 11

12 For Germany about animal species are known (654 vertebrates, invertebrates, 3200 single-celled cells), 9500 plant species (including 3000 seed plants) and mushroom species and lichens (including approx. 11 Knowledge of biodiversity at other hierarchical levels, such as ecosystems, genes or the interactions between species, is still extremely poor. The overriding functions of biodiversity and ecosystems for material and energy cycles as well as the dynamics of the earth system, on the other hand, are broadly well understood. A central basis is the primary production of biomass through photosynthesis and the resulting material cycles. The current oxygen concentration of around 21 percent in the earth's atmosphere is exclusively due to (oxygenic) photosynthesis. Almost all near-surface processes and material cycles are strongly influenced and controlled by the biosphere, such as the concentration of gases, dust particles and aerosols in the atmosphere, soil formation, the cycles of water, carbon, nitrogen, sulfur and phosphate, but also the radiation balance of the Earth, the climate and the wind systems. The need for research for an overall understanding is still considerable. Fig. 4: Ecosystem services of biodiversity (simplified representation) 12 Explanation: The role of biodiversity as the basis of human existence is described by ecosystem services (Nature s Contributions to People), which in turn depend on ecosystem functions and thus on individual species (see Fig. 2 ). The global economic value of ecosystem services was estimated at 125 to 145 trillion (10 12) US dollars / year in 2011 BfN Based on MEA Costanza et al

13 1.3 Loss of biodiversity and its consequences Biodiversity is now extremely threatened. This documents inter alia. the IUCN Red List of Threatened Species, which records the degree of endangerment of various animal and plant groups. According to their investigations, animal and plant species are currently threatened with extinction worldwide, corresponding to 27 percent of all species examined. 14 The most comprehensive risk analysis for biological diversity was presented by the World Biodiversity Council (IPBES) in May 2019, 15 resulting from the collaboration of 145 experts from 50 countries and based on the analysis of around publications and official studies. Some selected findings from this and other sources are reproduced below: The average species population in most terrestrial (land) habitats has fallen by over 20 percent since 1900. More than 40 percent of amphibian species, almost 33 percent of reef-building corals and more than 33 percent of all marine mammals are threatened. The global biomass of wild mammals has declined by 82 percent since the beginning of the 20th century, and its distribution by at least 50 percent. At least 680 vertebrate species have been extinct since the 16th century. Three quarters of the natural terrestrial ecosystems and around 66 percent of the marine ecosystems have been severely affected and destroyed. In areas inhabited or administered by indigenous peoples and local communities, changes have been less pronounced or have not occurred. Currently, more than a third of the global land surface and nearly 75 percent of freshwater resources are used for food production. The timber harvest has increased 45 percent since 1970. Around 50 percent of this is used for energy (mainly incinerated). Every year around 60 billion tons of renewable and non-renewable raw materials are extracted from the earth, which is almost a doubling since Land surface productivity has fallen by 23 percent due to soil loss and the degradation of agricultural land. Global crop yields of up to $ 577 billion are potentially at risk from pollinator losses. For 100 to 300 million people there is an increased risk of flooding and cyclones due to the destruction of protective coastal habitats. In 2015, 33 percent of the marine fish stocks were overfished, 60 percent were fished at the maximum limit of sustainability and only 7 percent of the 14 (accessed on: February 15, 2020). 15 IPBES

14 fish stocks were fished less and 80% are not in good ecological condition. 16 Up to 400 million tons of heavy metals, solvents, toxic sludge and other industrial wastes as well as pesticides enter the world's waters each year, and the entry of fertilizers into coastal ecosystems has created more than 400 marine death zones with a total area of ​​more than square kilometers. In addition, there is an up to 10-fold increase in the entry of plastic, especially into the oceans, compared to 1980. These negative trends will continue in all political scenarios examined until 2050 and beyond, unless fundamental transformative changes in land use, fisheries and climate policy take place. The current extinction rate of animal and plant species is several 10 to several 100 times higher than the extinction rate known from fossil records of the past 10 million years, which continues to rise and gradually takes on features of the five geological mass extinctions. 17 Living Planet Index Since 1970, populations of vertebrate animals of all groups and 3700 to 4000 species have been continuously examined for their population sizes in an elaborate process. The determined declines were: total populations around 60 percent, of which land resources around 40 percent, freshwater resources around 80 percent, marine resources around 40 percent and vertebrate populations in South America almost 90 percent Fernandes et al IPBES 2019, Barnosky et al McRae et al. 2017; Deinet et al

15 Fig. 5: Population index (Living Planet Index) vertebrates 19 Explanation: The index is determined through extensive long-term studies of vertebrate populations worldwide since White lines: mean values; Color areas: uncertainty limits (95 percent). The global decline of all populations worldwide is 60 percent. In the freshwater biome and in South America the decreases are as much as 80 to 90 percent. Insect extinction The order of the insects has suffered an enormous loss of species and biomass in the last few decades. Land use, landscape fragmentation, eutrophication and pollution (including pesticides) are assumed to be the main causes. On a dry slope near Regensburg, butterfly species have declined by around 35 percent since 1840, and by as much as 60 percent in endangered species, although the species decline has accelerated significantly since the 1980s. 20 The Krefeld study shows a decrease in the biomass of flying insects, measured in 62 nature reserves in Germany over a period of 27 years, of around 75-80%. 21 A Germany-wide study found between 2008 and 2017 a further decrease in insects in grasslands by 67% of biomass and 34% of species numbers and in forests a decrease of 41% of biomass and 36% of species numbers. 22 Similar decreases have been described everywhere in Europe and in other regions of the world with a worldwide decrease of 19 According to Deinet et al Habel et al Hallmann et al Seibold

16 an average of 9 percent of terrestrial insects per decade for at least 35 years. It is feared that up to 40 percent of all insects worldwide will become extinct over the next few decades. 23 Since insects, as the species-richest class of all animal groups, make up 70 to 80 percent of all animal species, insect extinction can be seen as a reflection of a serious systemic loss of the entire biodiversity. Insects are significantly involved in almost all ecosystem processes outside of the oceans, such as pollination of flowering plants but also soil formation (80 percent of all pollinators in Germany are already severely threatened, around 45 percent of all 561 wild bee species and over 60 percent of all ant species, both genera with a rapidly increasing trend 24 ).There are also other important benefits for agriculture: For example, 5 to 10 ladybirds and their offspring can keep the aphid population under control on 1 square meter of wheat field. 25 Insects are still indispensable as a food source for many bird species (including swallows, titmouse, nightingale), reptile species (including lizards) and many mammals (including hedgehogs, bats). The EU-wide decline in bird populations in the agricultural landscape of 31.4 percent between 1990 and 2014 particularly affected the insectivorous bird species Impact of biodiversity loss on humans The annual economic loss due to the current extinction of species is estimated at around 4 trillion () US dollars. 27 The growing number of environmental and environmentally-related food crises is not only caused by an increase in extreme weather events as a result of climate change, but is also linked to the growing destruction of ecosystems and their ecosystem services, which in turn is due to erosion (loss of fertile soils), landslides and floods , Dust storms and desert expansion. In the meantime, 25 percent of the agricultural land has become barren wasteland, 28 which has led to a growing number of environmental refugees (see above). The destruction of natural vegetation (biodiversity) in parts of the Sahel of Africa is exemplary of the loss of pastureland and the spread of deserts. Another example referred to as an ecosystem disaster is the drying up and salinization of most of the Central Asian Aral Sea and its fertile coastline, which was once the fourth largest inland lake in the world. The reason for this is the cultivation of cotton, which uses almost all of the water from the Amu Darya and Syr Darya rivers, mainly for irrigation of the cotton plantations. 29 The sea-like lake had a rich fish fauna with numerous endemic species and brought annual fish landings 23 Lister & Garcia 2018; SRU Sánchez Bayo & Wyckhuys 2019, van Klink et al Ries et al Freier et al EEA 2018b. 27 Costanza et al Nkonya et al Zonn et al. 2009; Létolle & Mainguet

17 of up to several tons with over fishing workers. The example illustrates the enormous ecological footprint (water footprint) of cotton and other agricultural products in arid areas: A cotton T-shirt consumes 4100 liters of fresh water (see section below). 1.5 Drivers of the biodiversity crisis The causes of the current loss of biodiversity are diverse and vary depending on the region and ecosystem. According to Sala et al. and Thuiller, land use by humans is the most important driver of (terrestrial) biodiversity loss. 30 Land use (clearing / burning of forests, emissions of greenhouse gases (GHG) from fertilizers and animal husbandry) also contributes to an average of 23 percent of global warming. 31 Climate change itself is the second greatest threat to biodiversity. 32 The direct anthropogenic drivers of biodiversity loss are closely related to the indirect drivers such as population and economic growth, consumer behavior or state action (governance) and subsidy policy, among others. of biofuels, fisheries and agriculture (e.g. Common European Agricultural Policy, CAP). The most important drivers of the biodiversity crisis are: land use and land use change such as deforestation and the conversion of natural ecosystems into agricultural areas, direct exploitation (hunting, fishing) of organisms, impairment of rivers and wetlands through excessive freshwater abstraction, nitrogen and phosphate inputs, input of pesticides and other environmentally harmful chemicals , Increase in greenhouse gases and climate change, introduced, alien (invasive) species Land use Through intensification and irrigation, agriculture has achieved large increases in yields in the last few decades and thus provided the food base of 7.7 billion people at present, albeit with large regional inequalities. At the same time, intensification of agriculture and land use change are the main drivers of climate change (23 percent) and of around 80 percent of biodiversity loss, 33 whereby 30 Sala et al. 2000; Thuiller IPPC CBD 2010a. 33 IPPC 2019; IPBES 2019; Dudley & Alexander 2017; Campbell et al

18 the demand for and production of animal products (meat, milk) plays a dominant role (> 50 percent). 34 It takes up 60 to 70 percent of global as well as European agricultural land, of which around 30 to 50 percent of the arable land for fodder cultivation varies from region to region. Soy meal and grain are the predominant (protein-rich) feedstuffs for poultry, pigs and cattle breeding as well as high-performance milk production. Until 2018, soy was mainly imported from South America, where it causes considerable GHG emissions through cultivation (fertilization, loss of soil carbon, deforestation) and conversion of forests, grasslands and savannahs into arable land (including from the Amazon rainforest, Cerrado, Caatinga and Chaco) (see below , Chapters 6 and 7). The global trade in agricultural raw materials 35 and other raw materials such as wood causes massive degradation of biodiversity, as exemplified by the rapid deforestation of tropical rainforests for the production of meat, soy feed and palm oil for the international market. For the import of agricultural products alone, Germany uses more land (approx. 18 million hectares) than its own agricultural land (17 million hectares), thereby damaging biodiversity and the global climate (see Chapter 7). The total land use of the European Union (EU) for agricultural and wood products is the second largest in the world at around 640 million hectares (see below, Section 7.5). Germany's contribution to global deforestation between 1995 and 2010 is estimated to be around 1 million hectares, primarily due to the consumption of animal food. Overfishing of the seas Commercial fishing is an example of the worrying overexploitation of biodiversity: two thirds of global fish stocks are at a maximum fished or already overfished. Estimates of the larger fish stocks in the open ocean, such as tuna species, assume a decline of around 80 percent. Overfishing has led to an almost complete collapse of the fish stocks in some marine areas that are very important for fishing, such as the Atlantic shelf area off Canada (cod, see Chapter 1.6) Hunting and poaching In many parts of the world, hunting is not sustainable and has in the past led to the extermination of especially large vertebrate species, also in large parts of Europe (including bear, wolf, bison). In the tropical forests, the local extermination of monkeys and other mammals (bush meat) leads to the phenomenon of empty forests with various consequences such as the lack of seed dispersal and forest regeneration (see Chapter 3). Bird hunting in the Mediterranean continues to be a serious threat to Palearctic migratory birds. Poaching and illegal trophy hunting for elephants, rhinos, 34 Crenna et al Kastner et al. 2014a. 36 Bruckner et al

19 Lions and other large animals for the sake of the ivory trade, the extraction of horn and animal products for traditional Asian medicine, and for the purpose of appropriating trophies has increased significantly in recent years and may lead to the extinction of these large animals in the wild, including freshwater consumption, which includes the hydrosphere 1.4 billion cubic kilometers (sphere 1380 kilometers in diameter, Fig. 1). Of this, only 3 percent is fresh water (35 million cubic kilometers, sphere diameter: 405 kilometers), of which almost 70 percent is bound in ice and almost 30 percent in groundwater. Only 0.3 percent (approx. Cubic kilometers) is available to humans as surface water (lakes, rivers). Of all human activities, agriculture consumes 70 percent (one third of which is the meat sector through the cultivation of animal feed) 37 of the global water abstraction from rivers, lakes, reservoirs and groundwater (= blue water), primarily through irrigation measures and evaporation from crops and soil. The increase in livestock populations with increased production of forage on arable land and cotton production (preferred cultivation in sunny, dry areas) require particularly high water consumption. 38 A further increase in the production of biofuels will also increase the pressure on water reserves. 2.1 billion people had no safe water supply, 844 million people did not even have direct access to safe and clean water supply, one of the causes of child death from diarrheal diseases. 40 Although water availability is falling dramatically in many regions of the world, future global water consumption in agriculture will, among other things, be due to increasing meat consumption, will continue to rise by around 19 percent by 2050. 41 The emerging worsening of the water crisis in arid areas and the effects on biodiversity due to river engineering, drying out of wetlands, soil salinization or the contamination of waters with fertilizers, pesticides and other chemicals / plastics are worrying (see also below, Chapter 5) Nitrogen problem The overloading of global cycles with reactive nitrogen compounds (N r) is seen as a particularly serious exceeding of the earth's carrying capacity (planetary boundaries) 42 with a wide range of negative effects on biodiversity. Humans double the natural global nitrogen cycle with an additional 37 Godfray et al Destouni et al. 2013; Jaramillo & Destouni Destouni et al. 2013; Jaramillo & Destouni WHO WWAP Rockström et al. 2009; Steffen et al

20 entries of 210 million tons no. 43 The synthetic fertilizer accounts for the main part of the nitrogen overload (for more details see Chapter 7.7). It is mostly used inefficiently (over 50 percent is not absorbed by plants). In the EU27 member states, around 4.5 million tonnes of excess nitrogen are released into bodies of water (groundwater, inland waterways, seas) (in 2014 in Germany alone 0.5 million tonnes N r) 44 and there cause eutrophication, mass growth of partly toxic algae and oxygen poverty with dead zones in lakes and seas (see Chapter 3). German agriculture still falls short of the nitrogen reduction targets (the federal government's biodiversity strategy: 80 kilograms / hectare by 2010) by a massive amount (by over 20 kilograms / hectare) and in many places pollutes the groundwater (> 20 percent of the test centers) with excessively high, harmful nitrate concentrations (cf. . Chapter 7). A further 2.4 million tons of N r arrive as gaseous compounds, some of which are harmful to health (including tons of ammonia in Germany in 2015) and damage biodiversity in the immediate vicinity and over long distances (tele-effect) through eutrophication, acidification and ozone formation near the ground. 45 More than 48 percent of Germany's terrestrial, still near-natural ecosystems are affected by eutrophication, 8 percent by acidification through no input. 46 Laughing gas (N 2 O) is continuously increasing in the atmosphere (10 percent increase since 1985) 47. It destroys the ozone layer in the troposphere, which protects against UV radiation, is particularly long-lived (approx. 100 years) and as a greenhouse gas 300 times more effective than CO₂ phosphate problem Around 150 million tons of phosphate rock are mined annually and 20 to 25 million tons of phosphate are extracted from it, almost all of which is released into the environment as fertilizer. 49 Approximately 8 to 10 million tons of it find their way into inland waterways, rivers and oceans through erosion and rain, eight times as much as through natural geochemical processes. Phosphates create eutrophication, oxygen depletion and aquatic death zones. However, nitrogen input is currently the bigger problem in the oceans, as phosphate recirculates more quickly. From geological data it can be deduced that a 20-fold excess of phosphate in the sea could lead to mass extinction of marine life Erisman 2011; Fowler et al. 2013; Sutton et al UBA 2019a. 45 Bobbink et al. 2010; Bergmann et al. 2015; UBA 2018b. 46 SRU WMO 2018; UBA Fowler et al. Smil Steffen et al

21 1.5.7 Chemicals, pesticides (see Chapter 9) Chemicals are used, among other things, as pesticides (collective term for herbicides, insecticides, fungicides, etc.) 51 across arable land, orchards and thus into the environment in order to protect crops from harmful organisms (animals, Fungi, bacteria, viruses) and to remove unwanted wild herbs. In Germany, a total of tons of pesticide active ingredient (226 approved active ingredients) were applied to 13 million hectares of arable land (40 percent of the total area of ​​Germany) in 2017. In addition, there are around tons of biocides in the domestic and commercial sectors (disinfectants, protective agents, etc.), some of which are released into the environment via sewage and the air. 52 Pesticides have a toxic effect not only on harmful organisms, but also on non-target organisms directly through toxic effects or indirectly through the reduced food supply or reduced coverage. A well-known current example are the neonicotinoids, which are considered to be one of the causes of bees and insect deaths (see Chapter 9). The loss of natural enemies of the harmful organisms can make agricultural crops more susceptible to pests and pathogens. Through dispersal and via food chains, pesticides can affect organisms in neighboring or more distant areas. The continent-wide decimation (partly extinction) of certain birds of prey and other bird species was caused by the insecticide DDT. 53 This also applies to other substances, including Used in veterinary medicine: The pain reliever diclofenac was used to improve the work ability of cattle in India. Diclofenac (fatal uric acid accumulation), which is particularly toxic for vultures, has led to a 99.9 percent population decline in the great vulture species in India over the past 20 years, with consequences also on human health Effects on biodiversity. Examples are the CO₂ acidification of the world's oceans, the death of corals and the increase in forest fires as a result of periods of drought. The future consequences on biodiversity are likely to be even more serious (see below, Chapter 8). Land use (agriculture) currently accounts for around 25 percent and historically 33 percent of greenhouse gas emissions, around half of which is due to animal husbandry (see Chapter 7). Biodiversity protection is also climate protection, and climate protection is central to biodiversity protection. (For more details, see Chapter 8) 51 EU Directive 2009/128 / EC. 52 SRU Nakamaru et al Baumgart

22 1.5.9 Invasive species Introduced, alien species can cause severe damage to biodiversity either directly (invasively) or through the transmission of diseases. Invasive species (including domestic cats, goats, and brown rats) are blamed for about a third of the world's extinct species since 1600, particularly on islands. 55 For example, the tropical brown night tree snake Boiga irregularis, which was introduced by the military, destroyed almost all of the native bird fauna 56 on the Pacific island of Guam in a few years and is now also threatening the bird world on Hawaii and other islands. The comb jelly Mnemiopsis Leidyi, which was introduced into the Black Sea from the Gulf of Mexico, caused an almost complete collapse of the anchovy fishery due to food competition 57. The globally spreading chytridiomycosis (skin fungus Batrachochytrium dendrobatidis) is the cause of the extinction of at least 200 frog and toad species worldwide From what has been said so far, it follows that biodiversity is severely threatened at all its organizational levels and is subject to rapid change due to diverse (direct and indirect) drivers, which leads to the impoverishment and homogenization of species communities worldwide. One consequence is that change is constantly leading to new, human-made combinations of species and ecosystem conditions, the functioning of which is difficult to predict and highly complex, non-linear system transitions and tipping points can often occur. A well-known example of an ecosystem tipping point is the complete and apparently irreversible collapse of the Northwest Atlantic cod population off the east coast of Canada. The waters off Newfoundland have been among the most important fishing grounds on earth since the 19th century, with annual fish landings of several tons (even up to tons). The seemingly inexhaustible cod biomass collapsed suddenly to almost zero level in 1992/93 and has remained at this level to this day (25 years later) despite fishing bans. That has, inter alia. led to the loss of close to jobs in the fishing industry. The causes of the non-recovery of cod stocks (and many other overexploited cod stocks in the North Atlantic) are complex. Possible causes are the increase in capelin (Mallotus villosus), the former main prey fish of the cod (which now eat the eggs and brood of the few remaining cod) and the increase in seals, i.e. the predators of cod fry and young cod. Due to overfishing, tipping points are 55 IPBES 2019; Baillie et al. Savidge Kideys Reid et al

23, which have led to new marine ecosystem states ("alternative stable states") without the cod playing a significant role. 59 Another example of the consequences of overfishing are the fish-rich waters off Namibia. Over half of the animal marine biomass there is now made up of jellyfish. 60 Here, too, new alternative ecosystem conditions have evidently emerged through overfishing. Even the disappearance of a single species can have far-reaching consequences for the ecosystem and trigger tipping points: The local extinction of sea otters on the Pacific coast of North America has led to extensive deaths in the extensive kelp forests. A local population recovery (resettlement) of sea otters resulted in a regrowth of the kelp forests. The reason: The sea otters regulate sea urchins who eat seaweed as the otters' preferred prey. 61 climatic tipping points: Global warming is already leading to the thawing of permafrost in parts of the Arctic. In these permafrost soils, enormous amounts of biomass are conserved over large areas, mostly plant residues and peat, which are bacterially decomposed when thawed and release GHG, in particular the putrefactive gas methane (25 times more effective than CO₂) and nitrous oxide (300 times more effective). This will further accelerate climate change and the thawing of permafrost soils, potentially releasing several hundred gigatons of GHG and correspondingly serious consequences for the climate. 62 The hot period (> 5 in the Paleocene / Eocene) is attributed to permafrost thawing. Conclusions Biodiversity is a key component of the earth system and is the characteristic of planet earth. It is essential for the existence of mankind. However, man is currently causing great losses in the Biodiversity that resembles the mass extinction events known from earth's history, even if their extent cannot yet be precisely quantified. The consequences of the anthropogenic loss of biodiversity are systemic in nature, far-reaching and they will probably have long-term after-effects lasting over millions of years. Many consequences of the progressive loss of biodiversity are already visible, namely in the form of dwindling or disappearing ecosystem services, climate changes (due to their ecosystem-dependent drives) and a growing number of regional environs eltkrisen and from them 59 Sguotti et al and literature therein. 60 Lynam et al Estes et al IPCC DeConto et al

24 resulting poverty migration. The complexity of the effects of biodiversity loss and the prediction of ecological and climatic tipping points require intensive research. Direct drivers of the anthropogenic loss of biodiversity are in particular the conversion of natural / near-natural ecosystems (forests, grasslands, wetlands) into intensively managed and mostly over-fertilized agricultural areas (land use change), overexploitation, construction, eutrophication, contamination and construction of the land and freshwater systems as well as contamination, eutrophication , Acidification and overfishing of the seas. Climate change is accelerated by intensive land use, especially meat production, and in turn is driving the biodiversity crisis further. The necessary containment of the loss of biodiversity and natural / near-natural ecosystems requires coordinated programs at national and international level and decisive action. A significant expansion of the protected area system to 50 percent of the earth's surface and 40% in the oceans, an end to the ongoing change in land use, the reduction of meat production and the internalization of external (general) costs of biodiversity loss are important fields of action .. 24

25 2 Significance of biodiversity for human self-image The current global distribution of humans is the evolutionary result of an adaptation to geographic diversity gradients through species-specific diversification, domestication and use of elements of biodiversity. In the future, anthropological diversity, at least a part of the genetic diversity that secures livelihoods, will be deprived of the basis for adaptation by reducing biodiversity. The importance of the respective specific environmental diversity in the habitat of a human culture is to be recognized as a component, as a safeguard and reassurance of the collective identity for human populations. Since human cultures are functionally anthropogenic ecosystems, a sustained loss of biodiversity would seriously threaten the existence of non-globalized cultures and severely limit globalized cultures. Safeguarding biodiversity is not just a human right of indigenous groups, it is a general human right and as such is worthy of protection. The basic scientific question of today's biodiversity loss lies in the uncertainty in assessing the scope of its importance for the foundations of human existence. Regardless of the need for scientific clarification about the diversity-dependent, ecosystem functions, international agreements and decision-makers have named biodiversity loss as the second current threat to the earth system alongside climate change. In this they follow the absolute majority opinion of the knowledgeable scientists. According to human standards and needs, the loss of biodiversity is very likely to lead to serious impairments to health and security of supply, to the loss of the aesthetic experience of nature and to impairment of individual and collective well-being. The food supply for people is essentially secured by an anthropogenic diversity supply. However, this relies on recourse to the genetic diversity of the wild types. The wild types also ensure the intactness of the natural ecosystems and their buffer capacity as well as the existence and nutritional basis for all non-domesticated living beings. In the microbiome they also guarantee the existence of all living things. In terms of general preventive and insurance behavior, the possibility of negative consequences of the loss of biodiversity forces action to be taken. The loss of diversity that was believed to be possible has long since given way to a certainty of its existence. There is no need to resort to ideological constructs, systems of belief or emotion-based arguments - the application of common sense is sufficient to argue and act for the preservation of biodiversity and against further loss. The evaluation of the normative and descriptive parts of biodiversity requires the cooperation of scientific, legal and economic research 25

26 with the inclusion of moral-philosophical considerations. In addition to active political action to contain the biodiversity crisis, an important instrument for proactive action is the implementation of an educational program for all areas of education, for example based on the model of the educational offensive as part of the basic program for protecting the earth's atmosphere. It would create the basis for a general awareness of the impending biodiversity problems and bring about a broad biodiversity-promoting and protective position at all levels of society. 26

27 3 The crisis of marine biodiversity 3.1 Introduction The ocean is often considered to be the last wilderness on earth. However, recent research has shown that only 13 percent of the total ocean surface can be considered untouched or near-natural, while undisturbed areas are disappearing at an alarming rate. 64 Since humans live on land, protective measures initially concentrated on terrestrial biodiversity, and instruments such as protected species or national parks were initially developed and implemented on land. This terrestrial focus is slowly being replaced by a more balanced perspective, which culminated in the United Nations' explicit goal of protecting underwater life as Sustainable Development Goal (SDG) No. 14 in 2016. This paradigm shift is more than overdue, also taking into account the fact that life at all originated in the sea around 3 billion years ago and decisive innovations in life such as the evolution of the complex cell (eukaryotes) or the "Cambrian explosion" with the Origin of many of today's animal building plans took place in the sea. The marine biodiversity thus contains the most original and unique branches of the biological tribal history ("tree of life") of our planet. In addition, marine ecosystems are also the largest on our planet. The deep sea (> 3000 meters depth) covers 54 percent of the earth's surface and thus exceeds, for example, the remaining areas of tropical rainforests by a factor of 25. Assuming a 40 meter high canopy and a root space protruding 10 meters into the ground, the volume is the deep-sea ecosystems are even 1500 times larger than that of the rainforests. At the same time, our knowledge of marine biodiversity at all levels, whether genetic, species-related or functional, is often still very sketchy. In particular, the largest ecosystem on earth, the deep pelagic ocean, and the polar regions have major research gaps. To date, only sample material has been taken from the sea floor deeper than 4000 meters, the area of ​​which corresponds to a few soccer fields. 65 extrapolations have shown that for each of the known multicellular marine species (i.e. without microbes) there are 3 to 8 times as many other unknown species. 66 Since marine biodiversity is so difficult to assess, it is all the more difficult to assess whether marine species are locally or even globally extinct or not. 67 Charismatic large species have so far been the focus of most conservation efforts 64 Jones et al. 2018a. 65 Ramirez Llodra et al Mora et al McCauley et al

28 in marine systems ranging from habitat-forming coral reefs to fish and large predators such as sharks, tuna and marine mammals. Although it is easy to convey, future conservation measures should take into account the functionality of the entire interaction network of marine ecosystems in a comprehensive concept of ecosystem-based management. 3.2 Hotspots and rates of loss of marine biodiversity In a 10 year international effort, the Census of Marine Life CoML project identified clear global patterns and hotspots, e. B. the Indo-Pacific region, coastal areas and the deep sea. The ocean is characterized by special habitats such as deep-sea hydrothermal springs or coral reefs, which, with only a small proportion of the sea surface, are home to disproportionately high numbers of species and probably also genetic diversity. It can already be observed today that mobile marine organisms such as fish and marine mammals follow the shifting climatic zones particularly quickly, which leads to a change in local species communities. 68 In addition, a loss of biodiversity is recorded in many marine regions and their ecosystems, which is mainly documented at the species level, 69 often with cascading effects on the entire ecosystem. 70 Although there are few documented extinctions overall, human activity on land was years ahead. 71 While it is often almost impossible to document extinctions of marine species, 72 there are well-documented cases of ecological (local) extinction on the coast 73 or commercial extinction, particularly from overfishing. 74 Sensitivities Compared to terrestrial species, the sensitivity of marine species is higher, at least where corresponding vertebrate groups on land and in the sea enable a comparative assessment of the conservation status. Many marine vertebrate species are among the most endangered today. Schipper et al. examined 120 marine mammal species and found 36 percent to be threatened worldwide (i.e. classified as critically endangered, endangered or vulnerable), 75 which means that the threat level is higher than that of terrestrial mammals. Likewise, Croxall et al. 346 seabird species and found that more than half of the seabirds were in decline, making them 68 Burrows et al McCauley et al Sala & Knowlton McCauley et al Roberts & Hawkins Lotze et al Frank et al Schipper et al

29 more threatened than land birds. 76 Among the fish species, large species such as sharks and rays and migratory fish such as salmonids and eels are most threatened Consequences of the loss of marine biodiversity In the past few decades, the ocean has made up around 25 percent of man-made excess carbon dioxide through physical dissolution and subsequent transport of organic Bound carbon absorbed into the deep sea. 78 This biological carbon pump has thus significantly reduced the ongoing warming caused by greenhouse gases. To sustain these important services, marine biodiversity, as in terrestrial ecosystems, is essential and plays a vital role in maintaining primary production, sequestering nutrients and carbon, ecological resilience to disturbance, and transferring biomass to higher tropical levels, including usable fish. 79 For example, various coral reefs recover more quickly after devastating hurricanes, while various macroalgae forests and reef fish communities are more productive and resilient. 80 In addition to the protection of the marine natural heritage, the preservation or restoration of biological diversity in itself is of direct importance for its services to human society, for example through the maintenance and restoration of productive fish stocks, through the provision of coastal waters without algal blooms and jellyfish mass occurrences or through coastal protection through mangroves, salt marshes and coral reefs. Portfolio effects are particularly important for fisheries in order to dampen the annual fluctuations due to climate-related recruitment. 81 Very little is known about these positive portfolio effects of biodiversity in marine systems, but these processes are likely to play an increasingly important role under the influence of climate change and more frequent climatic extremes. 3.4 Causes of marine biodiversity loss Fisheries and other direct use Fisheries and other forms of direct resource exploitation continue to represent one of the greatest threats to marine biodiversity, either through overfishing or through the resulting cascades of effects along the entire food chain. The latter effects are often observed when species at the top of the food pyramid such as large fish or whales are decimated, resulting in widespread 76 Croxall et al Fernandes et al Levin & Le Bris Worm et al Duffy et al Schindler et al

30 effects that spread through the entire food web. 82 The decimation of the large whale species by whaling by around 90 percent has presumably led to a reduced connectivity of the deep-sea fauna, since their stepping stones, the large whale carcasses, are no longer available in sufficient quantities today. 83 Heavy use of the sea has already been demonstrated in the earliest human settlements, but has intensified significantly over the past 100 years, 84 mainly through industrial fishing. Even in European waters, only a fraction of the fish stocks are within safe biological limits. 85 A comprehensive study based on 4,713 global fish stocks found that only 32 percent of all populations were in a satisfactory status, while all others were either below the critical biomass or above the critical utilization rate required by the concept of maximum sustainable yield. 86 In the ocean, overexploitation and the associated local extinction began long before industrialization, which has led to a changed ecological baseline (shifting baselines). This in turn makes it increasingly difficult to define the target state of the ecosystem that can be achieved again, which can be regarded as untouched if it actually has an already greatly reduced inventory of species. 87 In terrestrial ecosystems the extinction of large fauna took place much earlier and has already been caused by prehistoric hunter-gatherer cultures and climatic fluctuations. Overfishing also has a strong developmental aspect. B. in West Africa, are heavily dependent on marine protein sources, so that demand will soon no longer be met by the available catch, which will lead to malnutrition. 88 In addition, many fishing methods result in bycatch such as marine mammals, turtles and seabirds in the case of longlines or small or non-target fish in the case of trawls. Many fishing practices such as trawling also destroy important marine life communities (e.g. cold water corals, sponge reefs), with trawling taking place along the continental slope and around the ocean mountains at ever greater depths. 89 Some ecological regime changes due to overfishing have led to alternative ecosystem states with a dominance of jellyfish 90 or crustaceans 91.After a regime change, a return to the previously desired state is often not possible despite fishing moratoriums (alternative state). B. after the 82 Pauly et al. 1998; Utne Palm et al. 2010; Pauly & Zeller Roman et al McCauley et al Fernandes et al. 2017; Froese et al Costello et al Jackson et al Golden et al. 2016; Kittinger et al Ramirez Llodra et al Utne Palm et al Jackson et al

31 Bottom trawling collapses off Newfoundland in the Northwest Atlantic. 92 Any meaningful implementation of marine protected areas must therefore reduce the current fishing methods or even prohibit them entirely. The direct destruction of habitats The direct destruction of marine habitats is increasingly affecting coastal ecosystems, as 50 percent of human lives are already in coastal regions, and the trend is increasing worldwide. 93 However, remote areas such as the deep-sea area are also increasingly affected, especially by the beginning of deep-sea mining. 94 Several studies have since documented that recovery from dredging or fishing activities in the last wilderness of the deep sea is extremely slow, 95 which requires that conservation measures to protect these sensitive habitats be stepped up. Alien species Another threat to local biodiversity is the arrival of aliens Species mainly via ballast water and marine aquacultures, which lead to a worldwide homogenization of species populations, 96 especially in estuaries and coastal regions. Examples are the comb jelly Mnemiopsis Leidyi (sea walnut) from the Gulf of Mexico, which contributed to the collapse of coastal fisheries in the Black Sea 25 years ago. 97 The Pacific oyster, Crassostrea gigas, which has spread to Europe, America and Australia via aquaculture, is another alien species with strong environmental impacts such as displacement of native species Pollution Plastic Pollution Without a doubt, plastic pollution has a negative impact on marine organisms. This applies in particular to macroplastics (particles> 1cm) and ghost nets, in which turtles, birds and marine mammals can become entangled or which are mistakenly mistaken for food particles. However, there is currently no evidence as to whether microplastic pollution has a negative impact on the survival of entire populations, and there is currently no evidence to support the extinction of regional species. 98 Since there are huge marine areas and no waste removal methods are conceivable 92 Frank et al Lotze et al Ramirez Llodra et al Jones et al Capinha et al Kideys Rochman et al

32 that would not kill both neo-tonic (living on the water's surface) and planktonic species at the same time, the only sensible approach is to reduce plastic input into the oceans, i.e. H. in the confines of the source on land. Noise pollution This form of pollution from an increase in shipping traffic (90 percent of global trade takes place via cargo ships) 99 is largely unobserved, but can affect the communication of marine mammals. It can be considered certain that targeted underwater detonations caused by military or industrial activities damage the inner ear and thus the orientation of marine mammals and can lead to their death. 3.5 Warming and acidification of the ocean The warming of the oceans mainly affects tropical species that are at the upper limit of their thermal tolerance, such as reef-building corals. Polar species that can no longer move further towards the poles in order to remain in the cold conditions that are essential for them under the accelerating warming of the polar waters are particularly affected. Subtropical areas will experience a tropicalization due to the movement of species from tropical areas. Cold temperate species are increasingly moving towards the poles, where they are competing with polar species, such as the polar cod, which is increasingly being replaced by the cod stock off northern Norway and the Barents Sea. 100 Extreme climatic events are also increasingly occurring in marine ecosystems and will play a more important role than slowly increasing mean values, as is the case on land. Massive death of key species in temperate latitudes (e.g. kelp forests) 101 is more frequently observed as a result of summer heat waves, the frequency of which is increasing. 102 Repeatedly occurring extreme water temperatures have led to massive coral bleaching in the Indo-Pacific region over the past 10 years, which endangers the existence of large reefs. 103 At the poles, the Arctic sea ice is disappearing at an alarming rate, endangering charismatic species such as seals, walruses, sea birds and polar bears, but also the arctic food chain associated with the sea ice. 104 Ocean warming interacts with other undesirable processes 99 Kaluza et al Descamps et al Wernberg et al Frölicher et al Hughes et al Post et al

33 such as eutrophication and the associated lack of oxygen, 105 which not only threaten soil diversity, but also lead to the spread of oxygen-poor zones in open water. 106 Warming also favors heterotrophy compared to autotrophy in food webs. It also promotes the growth of small plankton species, which leads to longer food chains and consequently reduces the efficiency of transmission to usable fish populations. 107 Direct physiological warming effects, which essentially lead to smaller fish, are also predicted for many fish populations. 108 Ocean acidification A particular threat to marine biodiversity is ocean acidification, which is caused by the dissolution of excess anthropogenic CO₂ in seawater, 109 which is associated with lower pH values ​​and a decrease in the carbonate saturation of ocean water. These processes increasingly affect not only the surface zone of the world's oceans, but also the deep-sea water masses. 110 The susceptibility of key species such as echinoderms, snails, coccolithophores, calcareous algae and corals to ocean acidification is well documented. 111 There are also alarming experimental studies documenting an immediate decline in recruitment in commercial fish species that urgently require further investigation into whether evolutionary adaptation to future conditions is possible. 112 Since the dissolution of CO₂ in seawater is a simple physicochemical process, progressive acidification is inevitable as long as the CO₂ emissions continue and the atmospheric CO₂ content rises. Another problem is that the acidification of the ocean and the warming of the ocean in sensitive species such as corals have a negative effect Ecosystems, there are a number of regional measures that can increase the resilience of ecosystems to these globally occurring disturbances and that should be pursued with vigor and require fundamental changes in the functioning of important economic sectors, 105 Diaz & Rosenberg Stramma et al Daufresne et al Baudron et al Doney et al Levin & Le Bris Kroeker et al Stiasny et al Hoegh Guldberg et al

34 especially in the areas of agriculture, coastal development and transport. Reduction of coastal eutrophication While primary production in the open ocean can decrease due to the lower nutrient supply from the deep sea, the opposite is true for many coastal areas. Ecologically valuable ecosystems such as coral reefs or marine vegetation suffer from high local nutrient pollution, mainly due to intensive agricultural practice, but also due to diffuse inputs from traffic and shipping. Decades of research have shown that the protection of coastal regions extends far inland and that the entire catchment area of ​​rivers and not just the coastline must be part of a comprehensive management system. Many of these concepts are well developed and essentially mean that agricultural practices must be fully sustainable in order to minimize nutrient loss. Where this is the case, slight improvements were observed and ecologically important coastal vegetation was able to expand again (examples: Chesapeake Bay, 114 Baltic Sea 115). However, as soon as the obvious, easy-to-implement reduction targets for nutrient loads have been achieved, a further reduction in nutrient inputs requires a comprehensive and large-scale restructuring of agricultural production towards closed nutrient cycles, which requires corresponding political will and far-reaching social rethinking. In the case of the Baltic Sea, the oxygen content in deep waters is still unsatisfactory. In addition, blue-green algae blooms regularly in the summer season for several years. Overall, therefore, a good environmental status (GES) according to the EU Marine Strategy Framework Directive (MSFD) cannot be achieved. Fisheries management In the field of fisheries management, the solution is primarily to catch less fish first, and then later to be able to catch more fish overall when the stocks have recovered. Sustainable fishing practices can be implemented almost instantly, provided the political will is there. There are positive case studies in which stocks have recovered and which demonstrate the remarkable resilience of marine (fish) populations. 116 The return of fish populations to their possible population size means more, not less, fishing. It also makes the fishery more profitable as it takes less effort to catch the same amount of fish. 117 Aquaculture (sea, fresh water) 114 Ruhl & Rybicki Reusch et al Worm et al Froese et al

35 Aquaculture, as the fastest growing food sector in the world, cannot replace sustainable fisheries management. On the contrary, most current aquaculture practices are currently unsustainable, rather depriving people in economically less developed countries such as West Africa, who often rely on fish protein to avoid malnutrition, important protein resources. 118 The large-scale conversion of small pelagic fish into feed for aquaculture and also for animal husbandry in the form of fish meal and oil disrupts the marine food chain and threatens the food supply of many marine predatory fish and seabirds. Recent efforts towards greener aquaculture practices, such as increasing plant food substitution in feeds for aquaculture 119 and the development of multi-trophic aquaculture, can help mitigate the negative ecological effects of intensive aquaculture. The conversion of coastal vegetation such as mangroves / seaweed to produce seafood such as shrimp, 120 the recording of fodder fish to produce fish meal and the widespread use of antibiotics are also problematic. 121 Another issue is the flight of alien species and pests from aquaculture, which is the second most important source of species introduction into marine ecosystems worldwide. Spread of Alien Species With the Ballast Water Agreement of the International Maritime Organization (IMO), which came into force in 2017, this problem is handled satisfactorily, albeit with too long transition times for full compliance with the regulations of the member countries. 122 Further studies are needed to monitor the effectiveness of the various management options, in particular ballast water exchange and ballast water treatment in ports. Improvements are also needed in ballast water treatment both on ships and in ports. The unwanted introduction of alien species and diseases from aquaculture must also be more strictly controlled. Worldwide e-commerce with aquarium species is an increasing threat that must be controlled by appropriate laws. 3.7 Protection of marine fauna Direct species protection Such measures have proven their worth in the past if they are implemented consistently and based on international agreements. One of the best examples is the moratorium on whaling, another example is the stabilization of certain 118 Golden et al Froehlich et al Boone Kauffman et al Defoirdt et al Wan et al

36 turtle, seal and seabird populations, which in some cases also resulted in populations recovering. Another notable positive example is the recovery of the seal populations in the North and Baltic Seas. 123 A lot more needs to be done by banning products from particularly endangered species, such as sharks. So is z. For example, the finning of sharks is not permitted within the EU, but the import of such products is permitted. The same applies to some ornamental species (e.g. dried starfish, tropical mussels and snails). Likewise, the European eel, a species on the IUCN Red List, is still marketable and can be fished. Marine Protected Areas In addition to efforts to protect individual charismatic species, entire marine ecosystems are increasingly being protected by Marine Protected Areas (MPAs). 124 The prioritization of suitable areas is a great challenge, since the knowledge about the species composition in many marine areas worthy of protection and their spatio-temporal distribution (tropics, deep sea, polar regions) is very incomplete. Another special feature, also compared to the situation on land, is the openness of marine ecosystems. Since many marine species have larvae that reside in plankton for weeks, flow patterns and oceanographic connectivity are important considerations in the development of marine protected areas. With the rapidly shifting climatic zones, suitable protected area locations can change quickly, especially if the current spread patterns change due to warming and salinity. Novel modeling approaches provide the tools to assess the natural boundaries of water masses in order to describe the optimal design of MPAs and thus maximize larval retention within their boundaries. 125 In order for the MPAs to have a positive effect on biological diversity, the establishment of effective protective measures and their implementation is absolutely crucial. Although the EU announced in 2018 that it had achieved the Aichi target (No. 11) 126 with 10.8 percent of protected European marine areas, 127 most marine protected areas so far only exist on paper, as a current study for European waters by Dureuil et al. shows. 128 The authors found that the fishing pressure from trawling is higher inside the European MPAs than outside, reflecting the relatively good habitat status of the reserve. Globally, 94 percent of all MPAs continue to allow human use, including fishing, which significantly affects the effectiveness of their protection Reusch et al Edgar et al Cowen et al CBD 2010b. 127 EEA 2018a. 128 Dureuil et al Costello & Ballantine

37 Five conditions for marine protected areas MPAs that meet the following five conditions have the strongest positive effects on biodiversity both within the protected area itself and as spill-over effects on adjacent areas: 1. The removal of organisms is completely prohibited, 2. Protection requirements are consistently enforced, 3. The area has been established for some time (10 years old), 4. Sufficient size (100 square kilometers) and 5. There is a certain degree of isolation. 130 These conditions are in line with the general IUCN guidelines for protected areas in general, but are still too seldom taken into account, which applies in particular to most European marine protected areas. 131 How large should the proportion of the oceans be that are protected under MPAs? The Convention on Biological Diversity (Aichi Targets) has set itself the goal of protecting 10 percent of the sea surface, 132 which is probably too little for various reasons: (1) Many large open sea animals such as turtles, sharks, Tuna or whale migrate thousands of kilometers between their feeding and breeding grounds. 133 At the same time, many of them are among the most threatened species today. (2) The migratory movements of many mobile species with the climatic zones are considerable and faster than on land, 134 so that they are mobile targets for the species and populations to be protected. (3) Many marine species have large dispersal capacities, 135 so that the MPAs must also be expanded accordingly in order to effectively protect processes within the MPAs. 136 The definition and implementation of protected areas on the high seas is an open topic and requires more research, 137 so that, for example, migration corridors for migratory species such as turtles, large predatory fish (tuna, sharks) or whales can be effectively included in the planning. Many highly migratory species use entire ocean basins and cross many territorial waters during their feeding or reproductive migrations. 138 In the open ocean, novel concepts must be developed that enable dynamic management when the distribution areas of mobile species shift rapidly.139 Real-time satellite tracking data in connection with advancing miniaturization by 130 Edgar et al Kelleher 1999; Dureuil et al CBD 2010b. 133 Lascelles et al. 2014; Harrison et al Burrows et al McCauley et al Krueck et al Krueck et al Harrison et al Hazen et al