For the North Sea it appears that the numbers and richness of species (invertebrates and birds) have increased. The turnover of species has decreased in the North Sea, which means that the appearance of new species has not been at the expense of existing ones. In itself positive news, compared to (in fact in contrast to) the frequently heard negative trends about biodiversity (i.e. a decline in species richness). This is evident from a large-scale study in 21 countries with 161 time series for 6200 species over an average period of 20 years, in which our HuFoSS chairman Herman Hummel, along with 64 other scientists, took part. The study is published in Nature Communications.
There is also a positive or stable picture for Europe as a whole, but it must be taken into account that there may be strong regional and taxonomic differences. For example, in the Atlantic land region there is a decrease in the numbers of terrestrial invertebrates (including insects), while in other regions the wealth of bird species is increasing. In general, it has also been found that in Europe the numbers within species and the wealth of species increase with a higher temperature (e.g. due to climate change) and with greater naturalness (less disturbance) of an area.
More information can be found in the article at https://rdcu.be/b5AkH