Cluster Fisheries | Umweltbundesamt

On the relevance of the action field

From an economic point of view, sea fisheries (coastal and deep-sea fisheries) as well as freshwater fisheries (lake and river fishing, aquaculture, pond farming and angling) are only regionally of major importance in Germany. Germany’s own productive output from deep-sea and freshwater fisheries satisfies a proportion of roughly 11 % of domestic demand. Consequently, imports are of much greater importance to meeting the demand of the German market. As far as the productive output and the generation of revenues are concerned, aquaculture is the most profitable sector. However, in coastal regions deep-sea fishing is a major employer. Nevertheless, deep-sea and inland fisheries such as pond farming are considered cultural heritage and, last not least, of importance to tourism.

Both deep-sea and freshwater fisheries are currently faced with major challenges which include strict regulations in terms of nature conservation. Deep-sea fisheries are faced with the additional problems of unfavourable stock conditions and the loss of fishing areas resulting from Brexit. Climate change and associated changes in living conditions for fish and other aquatic wildlife are adding to the pressure on stocks and enterprises.

In the same way as agriculture and forestry, fisheries – in other words the catching of fish in the wild – are particularly and directly dependent on the availability and regenerability of natural resources. If there are changes – owing to climate change – in the size and location of fish stocks, and if there are changes in the species communities and the food supply, this will directly affect the (production) conditions prevailing in the fishing industry. The nature of pond farming and aquacultures dictates the species composition by itself. However, the species also depend on the availability of sufficient fresh water and other natural resources.

Sustainability at the European and national levels is a fundamental principle of fisheries policy. In this context, the principles refer not only to the long-term conservation of fish stocks but also to maintaining the skills involved in fishing. For example, it is one of the declared objectives of Federal government to conserve Germany’s relatively small deep-sea and coastal fisheries^{82 82}.

DAS Monitoring –what is happening due to climate change

The water in the seas, rivers, lakes and ponds is warming. Fish species – like all poikilothermic creatures – are very reliant on certain temperature ranges. Consequently, water temperature has a direct influence on the health and size of fish stocks. When a species’ thermal optimum is exceeded, fish and other aquatic organisms suffer stress. This makes them more vulnerable to diseases. Where migration is possible, animals will retreat to regions where conditions accord better with their thermal requirements. Migratory movements are also likely to occur when the food sources of fish and other seafood (edible marine invertebrates) shift their location, presumably when smaller species – according to their thermal optimum – migrate north with their predators following. Besides, it is possible for predator and prey to become decoupled or, in technical terms, ‘mismatched’. This occurs when, owing to increasing temperatures, the phenology of one of the species concerned is changed so much that the prey is no longer available at the point in time when they are needed by their predator.

Owing to the seas warming (cf. Indicator KM-I-1) the habitats of species will shift northwards. This applies in particular to the North Sea – an open sea on the edge of the Atlantic. To date, indigenous species in Germany’s fishing regions have been migrating to northern waters while species indigenous to southern waters – so-called lusitanian species (cf. Indicator FI-I-1) – have been moving into their habitat.

Species indigenous to the Baltic Sea are unlikely to be able to migrate anywhere else. As a rule, they are adapted to the specific conditions prevailing in this comparatively small enclosed sea. However, here too the increasing water temperatures are affecting stocks by decoupling the food chains. Herring stocks in the western parts of the Baltic Sea are threatened because the species now spawns earlier and its larvae are short of food (cf. Indicator FI-I-2). If these stocks were to collapse, the impact would significantly change the entire ecosystem currently prevailing in the Baltic Sea.

As far as watercourses such as rivers are concerned, water warming (cf. Indicator WW-I-10) causes migratory movements – prevailing conditions permitting – up-river rather than in a northerly direction. In this case, the losers of climate change are, above all, the psychrophilic species which already now colonise the upper reaches of rivers thus being unable to evade rising temperatures. The same applies to lakes and ponds, where the possibility of migration is per se either low or entirely absent. Thermophilic species, on the other hand, are able to benefit, as exemplified by carp living in Lake Constance (cf. Indicator FI-I-3).

As far as inland aquaculture is concerned, there is currently a focus on discussions regarding the impacts of climate change, especially with a view to bottlenecks regarding the availability of water required in the management of pond farming. Adverse effects can also be caused by rising water temperatures, heavy downpours and flooding. Especially the farming of salmonids such as brown trout (Salmo trutta) and char (Salvelinus spp) – which depend on oxygenated water that is free of suspended matter – is subject to potential problems as a result.

Future climate risks – outcomes of KWRA

As mentioned in the findings section of the 2021 Climate Impact and Risk Analysis (KWRA, cf. Reading Aid, p. 7) regarding the action field Fisheries, a high climate risk is expected to arise – with a high degree of certainty – by the middle of this century, and this is likely to cause the decoupling of food relationships in the Baltic Sea. In this case, too, the main focus is on herring. The risk for fisheries may also become high if, by the middle of this century, the distribution of fish species in watercourses changes to a relevant degree. A high climate risk is also forecast – albeit with very low certainty – for the end of this century, owing to stress from pests and diseases in inland water bodies and aquaculture facilities.

According to the KWRA, there is a medium risk for the middle and end of this century in terms of losses to fisheries from an increased migration of thermophilic species to the North Sea thus bringing about changes to the ecosystem. Likewise, the KWRA study argues that there is a medium risk of damage to inland aquaculture operations.

Where do we have gaps in data and knowledge?

The impacts of climate change on fish stocks are currently being researched, and there are numerous questions left to be answered. Individual stocks or regions are being researched with particular intensity, such as herring in the western part of the Baltic Sea. However, to date no comprehensive overview has come to light. The indicators illustrated in the monitoring report are therefore to be seen as exemplifying various effects paths associated with global warming: the shifting of habitats, decoupling of food relationships, and the climate favouring thermophylic species. Given the great variety of marine ecosystems and ecosystems of inland water bodies, the existing illustrations in indicators provide only a partial insight into potential climate change impacts.

As far as the inland realm is concerned, there is so far a lack of nationwide surveys, for instance on the temperature requirements and distribution ranges of species indigenous to German rivers. Likewise, the incidence of fish diseases has not been centrally documented to date. Consequently, it has not been possible either to develop a nationwide indicator on these subjects for inclusion in the current monitoring report. The same applies to damage due to incidents of fish ponds drying out or being flooded. The absence of data in a centralised form – which might indicate climate change impacts on fisheries and aquaculture operations – is to some extent also due to the heavily decentralised and small-scale production structures prevailing in this economic sector.

A similar situation prevails with regard to deep-sea fisheries. Especially in coastal fisheries, the prevailing production structures are mostly very small-scale. Besides, sea fishermen/-women active in the North Sea are less closely tied to particular target species or fishing grounds than their colleagues elsewhere. This is an additional impediment to assessing climate change impacts on the fishing operations concerned.

There is a lack of response indicators in the ‘Fisheries’ action field which is, in part, due to the less than centralised capture and maintenance of data. As far as deep-sea fisheries are concerned, the prevailing strongly politically oriented regulations complicate matters. For example the outcomes of international negotiations – which take place on an annual basis – decide where and how much fish the German fleet is permitted to catch. This makes it difficult to plan a targeted adaptation of fishing operations and thus also to develop a response indicator for the illustration of specific adaptation responses.

What’s being done – some examples

In fisheries, the adaptation to climate change can be implemented in two ways: on one hand increased protection of fish stocks; and on the other, adaptation of enterprises to changed production conditions. For the protection of fish stocks, a distinct reduction of anthropogenic pressures is crucial. This means primarily that fishing activities are curtailed. However, it also means that any other burdens such as the input of pollutants or eutrophication as well as revitalisation measures in inland waters are reduced.

In deep-sea fisheries, fishing quotas dictate where and how much fish is permitted to be caught. The quotas result from a political negotiation process at European level. As mentioned above, the fishing opportunities in the North Sea and the North-East Atlantic are the outcome of international negotiations, above all with the United Kingdom and Norway. On an annual basis, the International Council for the Exploration of the Sea (ICES) publishes scientific recommendations – prior to the determination of fishing quotas – on the question how high these quotas should be for specific stocks in order to safeguard conditions for their sustainable reproduction. Scientists working at the Thünen Institute (TI) of Sea Fisheries and Baltic Sea Fisheries are among the members of the scientific advisory team. Their research involves marine ecosystems, thus allowing these scientists to obtain important insights which form the basis of scientific recommendations. The political responsibility for Germany’s deep-sea fisheries is in the remit of the Federal Ministry of Food and Agriculture (BMEL). Consequently, the BMEL represents Germany in negotiations on fishing quotas. The principle of Maximum Sustainable Yield (MSY) and the precautionary principle have constituted the core objective for fish stock management since 2013. Overall, the sustainability of fisheries has improved, especially in the North-East Atlantic. However, the fact remains that not in all cases the scientific recommendations on the allocation of quotas are adopted; as a result, many fish stocks have so far not been able to recover from the impacts of overfishing. This is true, in particular, for the Black Sea and the Baltic Sea. In addition, there are problems with data deficits and climate change impacts, for instance, regarding the availability of fish species available as prey.

In view of the critical situation regarding Baltic Sea fisheries, the BMEL launched a commission charged with providing a mission statement in November 2020 for the future of Germany’s Baltic Sea fisheries. The commission is tasked to develop a model for sustainable and future-proof Baltic Sea fisheries and to propose concrete measures for the implementation of relevant principles and proposals⁸³. The back story to this is the persistently critical stock situation regarding cod and herring and the consequential loss of important fishing opportunities. The BMEL considers that the tradition of Baltic Sea fisheries requires reorientation in order to keep it going. To this end, the TI for Sea Fisheries and Coastal Fisheries in the North Sea and the Baltic Sea is conducting research on the structural change required.

The BMEL addresses deep-sea fisheries, inland fisheries and aquaculture with its ‘Agenda – adaptation of agriculture and forestry as well as fisheries and aquaculture to climate change’ (AMK)⁸⁴ and the associated programme of measures⁸⁵. Politically speaking, the latter are in the remit of individual Länder. However, the BMEL intends its Agenda to promote explicitly a closer cooperation between Federal and Länder governments. The Agenda is part and parcel of the DAS Adaptation III Action Plan (APA III); for instance it is promoting new breeding objectives such as the adaptation to higher temperatures or the reduction of health risks arising from changes in pressures from parasites and pathogens. Furthermore, there are ongoing discussions on shading as a potential adaptation measure for inland waters and aquaculture facilities. The adaptation to climate change of deep-sea fisheries and the inland fishing sector is to be supported nationwide by means of the transfer of scientific knowledge to practical applications; and a national information and data portal is to be installed and managed at both Federal and Länder level. It is also proposed to establish a permanent task force with representatives from Federal and Länder authorities in order to review the regulative and funding policy aspects of framework conditions for adaptation to climate change, and to develop proposals regarding implementation.

Given that freshwater fisheries are in the Länder’s remit, several Länder operate scientific institutes which, among other aspects, look into the impacts of climate change on fish stocks in watercourses and also deal with the inland fishing sector in general. However, it must be said that the endeavours to develop a nationwide overview of this subject are still in their infancy. The AMK (see above) may provide a starting point for intensifying cooperation in this field.

Ultimately, it is up to fishing operators on the coast and inland to prepare for any changes in production conditions, to deal with them appropriately and to make adequate in-house decisions for adaptation measures. This may affect fishing methods, timings and (to a limited extent) fishing locations, as well as the target species and the management of aquaculture facilities and pond farming. Nevertheless, it is expected that the public purse will be willing and able to provide favourable framework conditions in this respect.

^{82 - Bundesregierung (Hg.) 2021: Mehr Fortschritt wagen. Bündnis für Freiheit, Gerechtigkeit und Nachhaltigkeit. Koalitionsvertrag 2021 – 2025 zwischen der Sozialdemokratischen Partei Deutschlands (SPD), BÜNDNIS 90 / DIE GRÜNEN und den Freien Demokraten (FDP). https://www.bundesregierung.de/resource/blob/974430/1990812/04221173eef9a6720059cc353d759a2b/2021-12-10-koav2021-data.pdf} 

^{82 - Deutscher Bundestag (Hg.) 2022: Antwort der Bundesregierung auf die Kleine Anfrage der Abgeordneten Stephan Protschka, Peter Felser, Frank Rinck, weiterer Abgeordneter und der Fraktion der AfD. Erhalt der Fischerei an Deutschlands Küsten. https://dserver.bundestag.de/btd/20/007/2000788.pdf}

^{83 - BMEL – Bundesministerium für Ernährung und Landwirtschaft / Leitbildkommission zur Zukunft der Ostseefischerei: https://www.bmel.de/DE/themen/fischerei/leitbildkommission-ostseefischerei.html}

^{84 - BMEL (Hg.) 2019: Agenda Anpassung von Land- und Forstwirtschaft sowie Fischerei und Aquakultur an den Klimawandel. https://www.bmel.de/SharedDocs/Downloads/DE/_Landwirtschaft/AMK-12-04-19-Agenda-Anpassung-Klimawandel.pdf}

^{85 - BMEL (Hg.) 2020: Maßnahmenprogramm zur Umsetzung der Agenda Anpassung von Land- und Forstwirtschaft sowie Fischerei und Aquakultur an den Klimawandel. https://www.bmel.de/SharedDocs/Downloads/DE/_Landwirtschaft/Klimaschutz/ma%C3%9Fnahmenprogramm-klimaanpassung.html}