Gulf of Guinea

Let’s travel to the eastern side of the Atlantic Ocean, right off the coast of Africa. Between Cape López, near the Equator, and Cape Palmas lies a body of water known as the Gulf of Guinea.

The Volta River and the third largest river in Africa, the Niger River, are the major rivers that feed into the Gulf of Guinea. Because of the runoff from these two rivers, and the high amounts of rain along West Africa, the gulf’s water is lower in salinity than other parts of the ocean. This warm water is separated from deeper, colder, saltier water by a shallow thermocline.

A thermocline is a thin, distinct layer in a body of water that marks when the temperature of the water rapidly changes with depth. In the ocean, it separates the upper mixed layer near the surface and the deep, calm water below. Thermoclines exist in the atmosphere as well.

Off the coast of Guinea and Côte d’Ivoire, a seasonal coastal upwelling forms in the gulf. An upwelling occurs when cold, nutrient-rich water from the deep is brought up to the surface water. This nutrient-rich water creates a boom of activity that attracts organisms from every level of the food chain, including fish, birds, and mammals. When the nutrients are depleted, the organisms move on.

The Gulf of Guinea has been nominated as a Hope Spot. The beaches around the gulf contain prime nesting sites for leatherback sea turtles, which are a threatened species. Sea turtles grow for many years before they reach sexual maturity, and the process of reproduction can be fatal to females. Newly hatched sea turtles have a high mortality rate because of predation before they reach the ocean and from human activity. It’s extremely important to protect these nesting sites.

Within the Gulf of Guinea lies the island nation of São Tomé and Príncipe, which contains vital habitat for humpback whales, African manatees, dolphins, and soft corals. Humpback whales are considered endangered by the IUCN Red List their populations are threatened by whalers and by getting struck by cruise liners and cargo ships. African manatees are classified as vulnerable.

The Niger River is being explored for oil and gas mining, which could have a serious impact on the Gulf of Guinea. Luckily, non-government organizations (NGOs) have been working hard with both government and international partners to develop green practices to extract those natural resources. The NGOs have also been developing full-scale wildlife law enforcement programs to protect the gulf and its wildlife.

This is definitely a cool Hope Spot and I wish them the best of luck. If you travel to any of the beaches containing turtle nesting sites, see if there are any volunteer programs you can join. I know in the US there are volunteer programs that help get the baby sea turtles into the water. May not be the ideal vacation plan, but it’ll be something memorable to share with your friends and family!

Sources:
https://mission-blue.org/hope-spots/
https://www.britannica.com/place/Gulf-of-Guinea

Shell Beach, Australia

Not every beach is made of sand.

In fact, there are beaches that are made up of volcanic rocks, pebbles, shells, and coral. I’ve been lucky enough to snorkel from a beach that was made up of dead, broken pieces of coral that were piled up from thousands of years of heavy coastal storms. What materials a beach is comprised of can tell you a lot about the area, including how much energy is involved through wind and wave action, what the waves are like, and the history of the beach—but those are topics for another post!

Today we head over to Australia, the continent of many species that could and will kill you. However, the beach that I’ll be talking about is probably one of the safest places to swim, especially for those who aren’t strong swimmers.

Shell Beach, is found within Western Australia’s Shark Bay, making it an embayed beach. This beach is unique for a few reasons.

The first unique feature is that the immediate water has a salinity that is twice that of the ocean! This occurs because the rate of evaporation is greater than the rate that rain falls, so more water is lost due to the heat than is replaced. When the salt water evaporates, the salt stays behind. Add to this the fact that a massive sea grass bed sits at the mouth of the bay, blocking a lot of tidal flow, and this makes for a super salty environment.

But it’s okay, because this leads into the second unique thing about this place. The salty water conditions have created a safe haven for a specific kind of shelled creature, Fragum erugatum, which is a species of cockle. A cockle is a bivalve—its shell is divided into two halves—and it is very similar to oysters and clams.

The f. erugatum cockle can survive the hypersalinity of the waters of Shell Beach, but its natural predators cannot, meaning that this species thrives in this place. In fact, they’ve survived here in L’Haridon Bight for thousands of years with no decline in their population.

How can we tell? When shelled organisms die, their bodies are consumed or they decay, leaving only their shells behind. So when f. erugatum cockles die, their shells remain in the area, and over thousands of years their shells eventually replaced all the sand and other sediments of the beach.

Today, Shell Beach stretches for about 44 miles and is comprised of only cockle shells, and the shells extend about 26−30ft down below the immediate surface. That’s a lot of shells! The shells even make up the sea bed and stretch quite a ways into the bay. On the back part of the beach there are so many shells that they’ve fused together in places to form large hard shapes, which were mined for a while to make decorative blocks until Shark Bay became a protected site.

I think this beach would be a cool place to go because it is so different. Not a lot of creatures can survive the water, so you don’t have to worry so much about potential animal accidents. And the water is easy to float in, much like the Dead Sea in Jordan, so it’s a great place to relax and float in peace. Also, the beach is a pretty snow-white color and was created in such an inspiring way, at least to someone like me!

Sources and cool links:
Ocean: The Definitive Visual Guide made by the American Museum of Natural History
https://www.australiascoralcoast.com/destination/shell-beach
https://www.atlasobscura.com/places/shell-beach
https://parks.dpaw.wa.gov.au/park/shell-beach