Climate change is changing the habitats in seas and inland lakes. It therefore also poses economic risks for the fishing industry. A sustainable approach to fisheries and the implementation of marine protection measures can relieve the burden on the ecosystems concerned and increase their resilience. If the fishing and nature conservation measures are adapted early on, there is a chance to secure the future of fishing in the long term.
Technical measures in sea fishing
There are various technical possibilities to make the fishing industry more sustainable. Selective fishing techniques, such as predetermined mesh sizes for nets, help to protect juveniles and species that should not be caught at all from accidental removal from the water. New rules in EU fisheries policy regarding bycatch or fisheries surveillance support this development.
- By-catches of commercially used species may no longer be thrown back into the sea from 2019. However, exceptions are possible for certain species.
- More effective monitoring of fisheries (e.g. through automatic detection and identification of vessels) and the introduction of dissuasive penalties for infringements are envisaged.
- In addition, financial support for the modernisation of smaller fishing vessels will be given priority.
This is intended to reduce disturbances in the marine habitat; endangered species would not be further decimated by by-catch.
Real-time monitoring of catches could support the establishment of closed areas and times. Seasonal and area restrictions on fishing could be well justified.
Ecosystem measures for inland waters and fisheries
Ecosystem measures are necessary to preserve, restore and stabilise the natural habitats of many fish species in the long term. The establishment of nature reserves and resting areas can increase the resistance of populations to climate change.
The networking of migratory watercourses such as streams and rivers helps to preserve the biological diversity of fish and small organisms. Renaturation of natural watercourse, bank and bed structures promotes good spawning conditions and creates habitats for native fish typical of the watercourse. With the help of recolonisation, endangered fish species can also be preserved and fish stocks typical of the water can be protected.
The use of adaptation strategies may require considerable investment. For example, in catch fishing these could be the conversion to other target fish species and in aquaculture adapted procedures to reduce dependence on rainwater. In the inland area - and especially in aquaculture - it will be crucial in the future to ensure a sufficient water supply all year round. It is therefore necessary to further develop water-saving processes. Efforts to make watercourses passable or increase the size of the riparian strips also fundamentally increase the ecological and climatic resilience or the resistance of aquatic ecosystems.
Legal, political and management measures
The change in marine fishing potential at higher latitudes will initially also create new opportunities for fishing. In order to participate, fisheries management would have to integrate such opportunities into the management of resources in a timely manner and address the capacity adjustment of the fleet.
The effects of climate change on fisheries cannot yet be quantitatively predicted. This still requires a considerable amount of research, also in order to derive concrete options for action. Part of this is a precise observation of spatial shifts of fish stocks and changes in species communities.
Within the framework of the "German Small-scale Bottom Trawl Survey" (GSBTS), standardised catches are made annually in defined areas of the North Sea. They estimate the natural variability of the catch rates of various fish species and of recording medium to long-term changes in fish communities.
On the basis of good data, it is possible to develop sustainable management and recovery plans for fish stocks that take adequate account of their climate-related processes of change and vulnerability. The management plans should include adapted fishing quotas and closed seasons and also take into account non-target species. It is also important to include climate-related failures and to specify in the management plans when to intervene in the event of stock declines. The plans shall be continuously reviewed and updated as necessary.
Targeted official controls at national and European level are necessary to ensure compliance with fisheries regulations, both at sea and in port. In addition, it is important to further develop international monitoring of fishing and the allocation of quotas for fishing.
A decisive milestone on the way to ecosystem-compatible fisheries is the implementation of fisheries management measures in the nature reserves of the German Exclusive Economic Zone (EEZ). The measures shall be designed to avoid negative impacts of fishing on protected species and habitats. Marine protected areas primarily serve to protect endangered species and habitats. If appropriate management measures are implemented, they could simultaneously act as retreats and ultimately also as recreational areas for threatened and overfished stocks. However, such fishing measures have so far only been implemented to a very limited extent in the German marine protected areas.