SEA
"...like spun glass...illuminating the turquoise sea."
How Octopuses and Their Relatives Use Colors in Their World
Octopuses and their relatives, known as the cephalopods, are famous for their ability to communicate via pattern and color while being able to create their own camouflage as well. Unlike chameleons and some fish that employ hormones to change colors, cephalopods use electrical signals which activate organs in their skin. The colors are produced within reflective surfaces rather than pigment, and the animals can change colors numerous times per second. They can also contract muscles to change the contours of their bodies into bumps, ridges and frills to further blend into their surroundings.
Some species, however, use bright colors to advertise that they are toxic or have a venomous bite. Cuttlefish can use pattern to distract their prey.
Colors and changing body shapes can be used both for displaying to potential mates or when squabbling over dens. Male cuttlefish can display a mating pattern on one side of their bodies for females and a warning pattern on the other side to deter male rivals.
The Lives of Octopuses and Their Relatives was written by Danna Staaf and published by Princeton University Press in 2023.
Some species, however, use bright colors to advertise that they are toxic or have a venomous bite. Cuttlefish can use pattern to distract their prey.
Colors and changing body shapes can be used both for displaying to potential mates or when squabbling over dens. Male cuttlefish can display a mating pattern on one side of their bodies for females and a warning pattern on the other side to deter male rivals.
The Lives of Octopuses and Their Relatives was written by Danna Staaf and published by Princeton University Press in 2023.
Seagrasses and Mangroves
Seagrasses generally grow in sandy areas behind reefs where they provide a safe place for many reef species to breed or begin life. The roots of the grasses stabilize the sand, and erosion results if the seagrasses are extensively eliminated by pollution or boat anchoring.
Mangroves are trees that are capable of living in seawater. Their roots stabilize the sand or mud beneath them while also sheltering fish.
Seagrasses, mangroves, and reefs are reliant on one another: reefs protect the other two from the power of the ocean waves, while seagrasses and mangroves prevent sediment from smothering the reefs. If shoreline construction destroys one of these elements, the other habitats will eventually disappear.
Coral Reefs: A Natural History by Charles Sheppard was published by Princeton University Press in 2021.
Mangroves are trees that are capable of living in seawater. Their roots stabilize the sand or mud beneath them while also sheltering fish.
Seagrasses, mangroves, and reefs are reliant on one another: reefs protect the other two from the power of the ocean waves, while seagrasses and mangroves prevent sediment from smothering the reefs. If shoreline construction destroys one of these elements, the other habitats will eventually disappear.
Coral Reefs: A Natural History by Charles Sheppard was published by Princeton University Press in 2021.
Seaweeds of the World
Seaweeds "provide the foundations for life in coastal regions" by "creating organic matter out of inorganic matter." They grow in all the great oceans, but insufficient sunshine and nutrients limit the areas where they can grow.
Currents connecting the northern and southern Atlantic Ocean that flow into each other are called gyres. The rotation of the earth moves them in a clockwise direction in the northern hemisphere and in a counterclockwise direction in the southern hemisphere. These gyres act to separate the water and the kinds of species present in the two areas.
The Pacific Ocean is generally fresher, deeper, and colder than the Atlantic. The two Pacific gyres also separate the seaweed species between the northern and southern regions, but both areas have large kelp forests.
Most fish swim to inland waters to reproduce and approximately three-quarters of the world's fish begin their lives in areas of seaweed. Besides protecting them from predators, the seaweed serves as a source of food for fish, turtles, and other animals.
John H. Bothwell's Seaweeds of the World was published by Princeton University Press in 2023.
Currents connecting the northern and southern Atlantic Ocean that flow into each other are called gyres. The rotation of the earth moves them in a clockwise direction in the northern hemisphere and in a counterclockwise direction in the southern hemisphere. These gyres act to separate the water and the kinds of species present in the two areas.
The Pacific Ocean is generally fresher, deeper, and colder than the Atlantic. The two Pacific gyres also separate the seaweed species between the northern and southern regions, but both areas have large kelp forests.
Most fish swim to inland waters to reproduce and approximately three-quarters of the world's fish begin their lives in areas of seaweed. Besides protecting them from predators, the seaweed serves as a source of food for fish, turtles, and other animals.
John H. Bothwell's Seaweeds of the World was published by Princeton University Press in 2023.
Sea Levels
Sea levels vary across the globe. Because of the trade winds, the western Pacific is approximately three feet higher than the eastern Pacific, and the eastern Pacific is higher than the Atlantic. As the trade winds lessen in the Pacific during the El Nino years, the west coast also experiences higher sea levels. With its different densities and gravitational effects, the land is another variable affecting the movement of water. The Andes and Himalayas exert an upward force on the oceans while mountain ranges underwater force it downward.
Rain and snow can increase the volume of water entering the sea at the mouths of rivers, and the warming and cooling of surface water also affects the sea level. Spring and summer upwellings along the Washington and Oregon coasts cause a drop in sea levels.
The land is on the move at the same time. In the Los Angeles area, Laguana and Hollywood sank while Long Beach and Huntington Beach rose between 1991 and 2000.
Tides by Jonathan White was published by Trinity University Press in 2017.
Rain and snow can increase the volume of water entering the sea at the mouths of rivers, and the warming and cooling of surface water also affects the sea level. Spring and summer upwellings along the Washington and Oregon coasts cause a drop in sea levels.
The land is on the move at the same time. In the Los Angeles area, Laguana and Hollywood sank while Long Beach and Huntington Beach rose between 1991 and 2000.
Tides by Jonathan White was published by Trinity University Press in 2017.
Tides
Tides lose energy through friction which, in turn, slightly slows the length of the earth's day, causing the moon to be pushed away. According to Jonathan White in his book Tides, "Every whirlpool, every eddy, every dimple of tension is evidence of energy moving from the moon to the water and back to the moon."
We think that the division of the land and sea occurs by the beach, but for global tides, it is the outer edge of the continental shelf. Continental shelves can differ widely in width. On the west coast of the United States, it is approximately twenty miles wide, but most extend fifty to a hundred miles on the east coast, although the shelf in southern Florida is only a few miles wide. Shelves by Chile and offshore islands such as Bermuda, Tahiti, and the Hawaiian Islands are almost nonexistent, and the Chilean continental shelf plunges precipitously to the Peru-Chile Trench.
Tides by Jonathan White was published by Trinity University Press in 2017. John H. Bothwell's Seaweeds of the World was published by Princeton University Press in 2023.
We think that the division of the land and sea occurs by the beach, but for global tides, it is the outer edge of the continental shelf. Continental shelves can differ widely in width. On the west coast of the United States, it is approximately twenty miles wide, but most extend fifty to a hundred miles on the east coast, although the shelf in southern Florida is only a few miles wide. Shelves by Chile and offshore islands such as Bermuda, Tahiti, and the Hawaiian Islands are almost nonexistent, and the Chilean continental shelf plunges precipitously to the Peru-Chile Trench.
Tides by Jonathan White was published by Trinity University Press in 2017. John H. Bothwell's Seaweeds of the World was published by Princeton University Press in 2023.
Seaweed
Because seaweed is flexible, it can bend with the movement of water, enabling it to survive the immense power of currents and waves. During storms, waves can fling pebbles and rocks which can damage the plants, but waves and currents supply nutrients and herbivores are dissuaded from grazing by turbulent wave action.
The giant seaweeds can grow more than a foot a day and can attain heights of between 98 t0 164 feet tall.
Gels and thickeners derived from seaweed are used in foods, drinks, toothpaste, and medicinal creams. As well as being popular ingredients in Asian cuisines, seaweeds are used as animal feed and fertilizers. Red seaweed has been promoted as an inhibiter of methane gas emissions from cattle.
Seaweeds by David Thomas was published by Smithsonian Institution Press in association with The Natural History Museum, London in 2002.
The giant seaweeds can grow more than a foot a day and can attain heights of between 98 t0 164 feet tall.
Gels and thickeners derived from seaweed are used in foods, drinks, toothpaste, and medicinal creams. As well as being popular ingredients in Asian cuisines, seaweeds are used as animal feed and fertilizers. Red seaweed has been promoted as an inhibiter of methane gas emissions from cattle.
Seaweeds by David Thomas was published by Smithsonian Institution Press in association with The Natural History Museum, London in 2002.