The sea and the sky appear blue because of a phenomenon called Rayleigh scattering, where the shorter blue wavelengths of light are scattered more than the other colors by the gases and particles in the Earth's atmosphere. This scattering causes the blue light to be more visible, giving the sky and the sea their blue appearance. As for plants, they appear green because of the pigment chlorophyll, which is used in the process of photosynthesis to capture light energy. Chlorophyll absorbs red and blue light, but reflects green light, giving plants their green color. **

The yellow-green color of the inside of a sea bream is likely due to the presence of bile pigments. Bile is a digestive fluid produced by the liver and stored in the gallbladder, which helps in the breakdown and absorption of fats in the digestive system. The yellow-green coloration indicates the presence of bile in the fish's digestive tract, which is a normal part of its digestive process. **

The North Sea, Baltic Sea, and Mediterranean Sea are all partially enclosed bodies of water, while the open sea refers to the vast expanse of ocean that is not enclosed by land. The North Sea and Baltic Sea are located in northern Europe and are partially enclosed by surrounding countries, while the Mediterranean Sea is connected to the Atlantic Ocean but is largely enclosed by land. The open sea, on the other hand, refers to the unrestricted ocean waters that are not enclosed by land. **

It ultimately depends on personal preference and what one is looking for in a coastal destination. The North Sea is known for its rugged coastline, strong winds, and sandy beaches, making it popular for water sports and outdoor activities. On the other hand, the Baltic Sea offers calmer waters, picturesque fishing villages, and historic towns, making it a more tranquil and relaxing option for those seeking a peaceful seaside retreat. Both seas have their own unique charm and attractions, so the choice between the two would depend on individual preferences. **

No, the Baltic Sea is not a Wadden Sea. The Wadden Sea is a coastal wetland area in the southeastern part of the North Sea, known for its extensive tidal flats and salt marshes. The Baltic Sea, on the other hand, is a brackish sea located in Northern Europe, bordered by several countries including Sweden, Finland, and Germany. While both bodies of water are important coastal ecosystems, they are distinct in their geographical and ecological characteristics. **

Green is green because it is the color that our eyes perceive when they detect light with a wavelength of around 520-570 nanometers. This wavelength falls within the visible spectrum of light, and when it is detected by the cones in our eyes, our brain interprets it as the color green. Objects appear green when they reflect or emit light in this specific wavelength range, which is why we perceive them as green. **

While some North Sea fish species can tolerate the environmental conditions in the Baltic Sea and vice versa, there are differences in salinity levels, temperature, and other factors that may make it challenging for certain species to thrive in the other sea. Some fish may be able to adapt and survive in the different conditions, but others may struggle or not be able to survive at all. Overall, it depends on the specific species and their ability to adapt to the new environment. **

Hamburg is located on the River Elbe in northern Germany, near the North Sea. **