It is not possible to build a tropical island in the Baltic Sea due to its geographical location and climate. The Baltic Sea is located in a temperate climate zone, characterized by cold winters and mild summers, which is not conducive to the growth of tropical vegetation. Additionally, the water temperature in the Baltic Sea is much cooler than that of tropical seas, making it unsuitable for the development of coral reefs and other tropical marine ecosystems. Therefore, it would be extremely challenging, if not impossible, to create a tropical island in the Baltic Sea. **

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. **

Beauty is subjective, but one of the most popular and beautiful North Sea islands is Sylt. Known for its stunning sandy beaches, picturesque dunes, and charming villages, Sylt offers a perfect blend of natural beauty and luxury. The island's unique landscape, with its rugged cliffs and vibrant heathlands, attracts visitors seeking a peaceful and scenic retreat. Sylt also boasts a rich culinary scene, with many Michelin-starred restaurants and local seafood delicacies to enjoy. **

Beauty is subjective, but many people consider the island of Sylt to be the most beautiful North Sea island. Known for its stunning sandy beaches, picturesque dunes, and charming villages, Sylt offers a diverse and breathtaking natural landscape. The island also boasts a rich cultural scene, with art galleries, gourmet restaurants, and luxury spas. Whether you're looking for relaxation or adventure, Sylt has something to offer for every traveler. **

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. **

Hisoka is on Green Island because he is a player in the game Greed Island, a rare and exclusive video game that only a select few have access to. Hisoka is drawn to the challenge and excitement of the game, as well as the opportunity to test his skills against other powerful players. Additionally, Hisoka may be on Green Island to search for rare and valuable items that can enhance his abilities and further his goals. **

The smallest island in the North Sea is Heligoland, also known as Helgoland. **