Overfishing means thatalmost half of European stocks are now below safe limits, and if we continue fishing like this, fish stocks around the world could collapse by 2050.
Fishing removes not just target species but also other creatures caught in nets (by-catch). Some fishing methods threaten other wildlife such as dolphins, turtles and birds, which become entangled in nets and lines
Bottom trawling can cause extensive damage to the sea bed, significantly changing the structure of the animal communities that live there.
If we want our fishing industry to become sustainable, we will need to assess stocks thoroughly and manage them more effectively.
Human activities have introduced a wide range of contaminants and nutrients into the environment.
Contaminants like mercury can enter the food chain and be found in the fish and seafood we eat, with obvious dangers to health. Nutrients like nitrates can lead to rapid algae growth. When the algae decompose, this uses up the oxygen in the water, leading many species to die.
Marine litter or “plastic soup” is a threat to wildlife as seabirds can mistake fragments for food. It can also trap sea creatures, e.g. turtles get ensnared in lost fishing gear.
Non-indigenous species are species which are not native to a region but have either got there accidentally (from ballast water in ships, for example) or have been introduced deliberately. Some then multiply and become 'invasive', out-competing native species.
One example is the comb jellyfish Mnemiopsis leidyi. This carnivorous animal was introduced into the Black Sea in 1982 and has proliferated enormously. It feeds on zooplankton and fish larvae and is a top predator at the end of the food chain.
As Europe's climate warms it will become easier for tropical species to survive here, bringing new threats to Europe's seas.