Shark Bay, Australia

All right, ladies and gents, last week we chatted about Shell Beach in Australia. For this week’s adventure, we’re going to pack up our fins and snorkels and head to Shark Bay again, but this time we’ll focus on the area as a whole. And remember, please keep your hands to yourself and watch where you put your feet; we are guests in their environment, and we don’t want to accidentally poke a shark!

Shark Bay is located on the most westerly point of the Australian continent and has been recognized as a UNESCO World Heritage Site since 1991. The protected area covers about 2.2 million hectares. That’s a lot of area, but how do you visualize that?

Well, Shark Bay is about the size of 2.2 million rugby fields, or baseball fields, smashed together in one giant area. If you’re not a sports fan, then visualize Shark Bay as being about the size of New Jersey and roughly half the size of Switzerland. Anyways, that’s a lot of protected area, and 70% of it includes the surrounding marine waters.

Many aspects make this area unique.

It has one of the largest, most diverse seagrass beds in the world with at least 16 different species of seagrass. It’s one of three places in the world where you can look at stromatolites, which I’ll talk about later; for now, I’ll just tell you they are one of the oldest forms of life on Earth—they’re like living fossils!

Shark Bay is home to around 200 species of birds, almost 100 species of reptiles, and several marine species, many of which are threatened or endangered. It has a large population of marine life, including dolphins, dugongs, sharks, rays, two species of endangered sea turtles, and two species of whales, not to mention all of the fish and invertebrates drawn to the seagrass beds.

This area is so important to so very many species living on land and in the water, and it gives you an interesting look at biological and geological evolution overtime. This is the perfect place to go to if you love birds, reptiles, plants, or the ocean—I think I could spend a whole week here and still not do everything I’d like to!

There are all sorts of things to do at Shark Bay! You can dive and snorkel in the waters. There’s a marine park, an aquarium, and a national park to explore. There are guided land tours, boat tours, dive tours, and marine safaris! You can see dolphins, whales, sharks, Manta rays, Green turtles, Loggerhead turtles, and dugongs!

You can explore the seagrass bed or the surrounding land area. There’s Shell Beach to relax at and the Hamelin Pool stromatolites to see! There’s so much, and I’m so ready to pack my bags and go myself—if I ever get the money and the time to go. For those of you who can go, please experience this place and maybe share all your cool stories!

Sources and cool links:


Seagrass Beds

Fun fact: when you search the Internet for general information on seagrass beds, one of the first things to pop up is shopping for “seagrass” beds. No, I’m not spending this time talking to you about beds you can sleep on—I think that would put us both to sleep.

Instead, I’m going to drone talk to you about seagrass bed the habitat.

Seagrass beds are very similar to kelp forests, which I’ve already talked about. They are both habitats that are dominated by a specific plant, and their roles are crucial to the health of the ocean and coastal communities. Seagrass beds are habitats made up of, you guessed it, seagrass.

Seagrass is the only flowering plant that lives its entire life in the sea. I’ll share more cool seagrass facts at another time!

The habitat flourishes in tropical waters, and the beds are most commonly found in shallow, sandy lagoons or enclosed bays. Basically, wherever the water is really clear and calm, that’s where seagrass beds do the best! They can even be found in polar waters too, though they’re more far common in the tropics.

Like kelp forests, seagrass beds function as nurseries and refuges for many fish that will spend their adult lives elsewhere. They also act as nurseries for some commercial invertebrates like shrimp and cuttlefish—and let me tell you, cuttlefish are one of the coolest groups of creatures you will ever see, so if they live in the seagrass, then those habitats are cool places too!

The seagrass itself is really important to green sea turtles, manatees, and dugongs. For green sea turtles it’s one of their primary food sources, but for the other two it’s their only food source. In fact, seagrass is so important that there is a correlation between the decline in seagrass communities and the decline the population numbers of the creatures that eat seagrass.

Green sea turtles and dugongs are endangered, while manatees have just barely—like since 2016—made it off the endangered species list.

Unfortunately, seagrass beds are highly vulnerable to pollution from the mainland. Large amounts of nutrients and sediments that are part of the land runoff oversaturate the water, making the water too murky for the seagrasses to do well. Suffice it to say, these environments are very important to fish, invertebrates, and larger animals and these habitats need to be protected if we want the communities they support to survive.

I’ve yet to dive at a seagrass bed. I’ve seen small patches of seagrass near some of the coral reefs sites that I swam around in Jamaica, but I don’t think they were quite large enough to support much. I think it would be really cool to scuba dive or snorkel in massive seagrass bed areas because of all the life you can see. I would love to play “Where’s Waldo?” with a bunch of the juvenile fish that will be camouflaged to blend in with the seagrass, and if I saw a manatee or a cuttlefish I’d probably squeal!

Sources and cool links with more information:
Ocean: The Definitive Visual Guide made by the American Museum of Natural History

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