Ecomare

After breeding season, some seabird species stay the entire year in the vicinity of their nesting area. Others move elsewhere due to the change in seasons and food supply. The distances can vary between short and long. Many gannets and puffins leave the North Sea area after their chicks leave the nest, around the end of July. In the following spring, the birds return to their nesting grounds. There are four species that stay the entire year in the North Sea: fulmar, kittiwake, guillemot and auk. They do not participate in long migrations, but they migrate within the North Sea region. The guillemot nests in the spring along the English and Scottish northern and eastern coast and a part of the population departs in August with its young chicks to the eastern of southern part of the North Sea. In the early spring, the birds return to their English and Scottish nesting rocks.
The southern North Sea is particularly important for seabirds as foraging area in the winter. Especially the Frisian Front, an area north of the Wadden Islands, attracts many seabirds. The tidal currents are so weak here that nutrient-rich mud can settle to the bottom. Therefore, there are lots of benthic fauna, fish and seabirds
There is not much seabird migration to see in general along the Dutch beaches. The birds fly along the coast, but too far away to observe easily. Only with stormy northwestern winds do they fly closer to the coast. This is when unusual seabird reports are made. During such conditions, warmly dressed bird watchers with telescopes can be found scanning the rough seas.

Seabirds are not only interesting for people to observe. For centuries, island inhabitants on both sides of the North Atlantic Ocean have been catching fulmars, gannets, puffins, auks and guillemots and gathering seabird eggs. During winter months, these people were sometimes cut off from the rest of the world. The eggs gathered in the summer and the caught birds were used for consumption. The island residents regulated their harvest in such a way that the seabird populations (which became their food supply) were not in danger.
The great auk had a different story. This seabird of the northwestern Atlantic Ocean was slaughtered on a large scale in the 19th century to serve as food for the seal hunters and fishermen. The great auk had adapted so well to hunting underwater, that it was unable to fly, just like penguins. This made it extra vulnerable and the last specimen was killed in 1844.
People still eat seabirds. On Iceland and the Faroa Islands, where seabirds used to be an essential source of food, the residents still eat puffins. The birds are caught with the help of nets on poles. This 'fleyging' happens on boats, or even more often, by standing on steep cliffs of the nesting colony. The birds are caught in the air when they fly close along the cliffs on the way to their nest.

The pollution of the seawater with all kinds of toxic materials is also a big threat for seabirds. Toxic materials are found in many variations: heavy metals, pesticides, PCBs, PAHs, UGILECs, etc. All of these harmful materials flow in from the rivers, through accidents, discharges and incineration at sea, and even via precipitation from the air. Via the links in the food chain, they are carried up the line to the seabirds, where the materials accumulate in their fatty tissue. In extreme situations, a seabird will eat into its own fat reserves: the poisons are released into the blood and thereby attack all kinds of the bird's life functions. Extra deaths of seabirds therefore occur during breeding season and the winter months, when the birds address their fat reserves. It is known that the hormone balance is disturbed by the pesticide DDT (and its degraded product DDE): the production of calcium decreases. Calcium is found in egg shells. Because of DDT, these shells are thinner and break more readily. In Florida, breeding pelicans sagged through their own eggs as a result of DDT pollution.
It has been proven that PCBs disrupt the reproduction of birds and mammals. They are also harmful for the immunity system whereby the animals grow less resistant to infectious diseases. In the meantime, the amount of PCBs in the fatty tissue of some seabirds has grown to tens of thousand times higher than in the seawater itself. It has been shown experimentally that such figures are extremely harmful for the seabird's anti-bodies against parasites and other diseases.

Oil is the best known and one of the biggest threats for seabirds. Every year, many thousands of seabirds die from oil pollution in the Dutch section of the North Sea alone! Only a fraction of these victims can be saved in the coastal rehabilitation centers, such as Ecomare.

Seabirds and marine mammals drown regularly in the nets of the standing rigging fisheries. By the Norwegian coast, it has been established that around 30,000 guillemots die in fish nets per year.
In the 1980s, an end seemed in sight for the growth of the seabird population in the North Sea due to the arrival of the industrial fisheries. This sector catches small fish such as lesser sandeel and sprat, which is food for many of these birds. The catch is ground to fishmeal and used to feed livestock, in fish farms, in cans and dry-food for cats and dogs and even as fertilizer. Before 1950, this form of fisheries on the North Sea was more or less unknown, but grew in the 1970s to a yield of two million tons of fish per year (compared to one million ton of fish for human consumption). Lots of industrial fish come from Danish and Norwegian fishermen, which make frequent use of giant ring nets in the North Sea. In addition to lesser sandeel and sprat, lots of young herring are caught.
The first consequences of all that fishing are already apparent. On the Lofoten, a group of islands off the Norwegian coast situated at the very most northeastern part of the North Sea, only one out every thousands of parent pairs of puffins were able to bring up their young in the early 1990s. Lesser sandeel and young herring is food for juvenile puffins, and that had disappeared. The puffin population of the Lofoten grew old. Younger generations were lacking. Guillemots and kittiwakes found themselves in the same situation.
Such problems also began elsewhere in the North Sea. After 1982, the lesser sandeel around the Shetland Islands declined in number. There were a lot of fishing activities taking place around this group of islands: from 1974 to 1982, the yields of lesser sandeel grew extremely rapidly from 8,000 to 52,000 tons per year. Since 1983, the Arctic terns in particular, but also the Arctic skuas, kittiwakes, puffins and fulmars had poorer nesting results due to the food shortage. In 1988 and 1989, the colonies of the great and Arctic skuas, the fulmar and the kittiwake did not produce even one young. The number of Arctic terns had declined by 70%.
It cannot be proven from the above figures that the fisheries are the direct cause of the problem. It is possible that the problems by the Lofoten and Shetland Islands was caused by a change in the current pattern of the water. Changes in the direction of the current, salinity or temperature can have a major influence on fish stock. However, one can set major question marks as to why the situation deteriorated so badly for the seabirds.
There are even more signals in which it appears that the birds in the North Sea have problems finding sufficient food during the nesting season as well as in the winter. The numbers of dead guillemots, auks and kittiwakes which washed ashore increased in the Netherlands during the winters in the 1980s, partially due to starvation, partially due to chronic (oil) pollution and partially because more birds overwinter in the southern North Sea. There seemed to be a slight improvement during the 1990s, as far as oil victims were concerned.

A number of environmental groups, such as Greenpeace, North Sea Foundation and the Wadden Sea Society, have been concerned about the future of seabirds in and around the North Sea. The Society National Committee Seabirds Oil-free - a joint program between the Dutch Bird Society, the Dutch Society for the Protection of Animals and coastal animal kennels, supports bird sanctuaries with funding for good accomodation and food during disasters involving birds. These groups attempt to educate politicians and public via campaigns and lobbying as to the deteriorating living situation for seabirds in the North Sea region.

There is not very much known about the distribution of seabirds around the North Sea, their choice of food and the best way to protect them. Observations during sea expeditions from people counting birds must supply more clarity.
The scientists are also looking at the effects of pollution in the North Sea environment. Such studies are very important because the governments of the North Sea countries want to see proof. Only then can something maybe change. The Dutch Workgroup for oil victims (a division of the Dutch Seabird Group) studies the effects of oil pollution on seabirds. This study makes use of data from oil victims counts, that have been taking place since the Second World War. Oil victims are also examined internally in the Netherlands and other countries around the North Sea. In this way, addition data is obtains, concerning the cause of death, body condition and the affect of oil and other materials on birds.