6 Must-See Marine Migrations


For us divers, seeing marine animals migrate en masse is one of the most magical things you can witness underwater. From Spider Crabs to Whale Sharks, and Sardines (to name a few), we have compiled a list of 6 migratory marine animals and the best locations where you can witness them around the world!

1. Australian Spider Crab

The Australian Spider Crab is aptly named, as they look like the giant spiders of the sea. For a couple of weeks around May-June, tens of thousands of these Australian Spider Crabs crawl up from the depths of the ocean and line the shallows of the seafloor in Port Philip Bay in Victoria, Australia. They come up to “molt” which is where they shed their old outgrown shells. It is thought that they congregate together to offer protection in numbers during the molting as their new shells are quite soft (making them easy prey for other marine life). If you are lucky enough to visit here, not only will be amazed by the sheer number of crabs and be able to witness their molting, you will have front row seats to a feeding frenzy. And the most surprising thing is the crabs are cannibals and often eat each other!

Best locations to encounter the Australian Spider Crab migration:

  • Blairgowrie Pier and Rye Pier, Port Phillip Bay, Victoria, Australia – May to June. Suitable for snorkelers, freedivers, and scuba divers. 


2. Sardines

If swimming with thousands of fish is your idea of fun, then you will want to book yourself on a Sardine run dive! There are a couple of places in the world to see sardines en masse, but the most impressive is the sardine run in South Africa which goes from Agulhas Bank up to Mozambique and it is one of the largest animal migrations in the world. The exact reason for the migration is not known, with some claiming it is for reproduction while others claim it is due to sea currents. Regardless of the reason, you will be amazed swimming beside a giant bait ball that can be up to 7km long, 1.5km wide and 30m deep!  Not only will the sheer size of the bait ball and synchrony of the fish stun you, but the sardines also create a feeding frenzy, which means you will also get to see sharks, dolphins, seals, and whales! 

Best locations to encounter Sardine migration:

  • Agulhas Bank, South Africa – May to August. Suitable for scuba divers. Book a multi-day scuba tour to increase your chances of seeing the migration. Suitable for snorkelers, scuba divers, and freedivers.
  • Panagsama Beach, Moalboal, Cebu, Philippines – Year-round (but best viewed November to April). While this isn’t technically a migration, you are almost guaranteed to see the sardines year round! Suitable for snorkelers, scuba divers, and free divers.


3. Whale Sharks

If you are looking to swim with the biggest sharks/fish in the ocean then, jump on a Whale Shark snorkeling tour! Whale Sharks like warm tropical seas and migrate for food and reproduction purposes. They can grow between 4m and 12m in length, can live up to 100 years, and have over 300 teeth (even though they are filter feeders), but don’t worry they are very docile! You can tell Whale Sharks apart from the markings on their back which are unique just like a human fingerprint! Snorkeling is the best way to interact with these magnificent creatures, and if you want to know more about how to swim with the whale sharks, then check out our article on the ultimate guide to snorkeling with whale sharks.

Best locations to encounter Whale Shark migration:

All of the below locations are suitable for snorkelers.

  • Donsol Bay, South Luzon, Philippines – December to May. Best sightings are between February and April.
  • Ningaloo Reef, Western Australia, Australia- March to July. Best sightings are between April and July.
  • Sun Island, South Ari Atoll, Maldives -Year-round. Best sightings are between August and November.
  • Tofo Beach, Mozambique – October to March.
  • Utila, Honduras – Year-round. Best sightings are between March and April and October to December.


4. Green Sea Turtles 

If you love Green Sea Turtles, then one of the best places in the world to see them en masse is the Raine Island in Australia, where up to 64,000 turtles migrate for nesting. Green Sea Turtles nesting habits are very interesting, each turtle lays 100 eggs per nest, females return to the same place they were born to nest, and the gender of the hatching turtle depends on the temperature of the nest (hot = female, cool = male). Be aware if you are diving around these waters that nesting turtles attract Tiger Sharks. 

Best locations to encounter Green Sea Turtle migration:

  • Raine Island, Great Barrier Reef, Australia – November. The island itself is off-limits to the public, but you are able to scuba dive in the surrounding waters from a liveaboard.
  • Tortuguero National Park, Costa Rica – July to October. Suitable for snorkelers, scuba divers, and freedivers.


5. Hammerhead Sharks

If you want to see one of the strangest looking fish in the ocean, then book yourself on a Hammerhead Shark dive! Named due to the hammer-like appearance of their head, they have a unique advantage of nearly 360-degree vision (as their eyes are on the side of their head), which gives them a great range to spot food. Growing up to around 4m, seeing Hammerhead Sharks migrate en masse to find cooler water is a pretty spectacular sight. Besides their unique looks, Hammerhead Sharks are also very interesting, as they can give birth from 6 to 50 live pups and they are one of the marine animals that have a tan (because they like to swim close to the surface). 

Best locations to encounter Hammerhead Shark migration:

These locations are suitable for experienced scuba divers only.

  • Cocos Island, Costa Rica – May to November. 
  • Layang Layang, Malaysia – March to May. 
  • Protea Banks, South Africa – November to January.


6. Humpback Whales 

Humpback Whales have one of the longest migrations of any animal in the world and can travel up to 5000km to feed and reproduce. Growing up to 18m long these aren’t the largest whales in the ocean, but the sheer size of them (especially when they are traveling in a pod) can be a bit intimidating. Humpback Whales can be found in all of the world’s oceans and are named after the distinctive hump on their back. Similar to the whale shark, each Humpback Whale can be uniquely identified, but instead of looking at markings on their back, you will need to look at their tail. They also like to sing which helps them locate other whales, and they engage in what is known as bubble net feeding. As a pod they surround prey blow bubbles to get them into a tight space, and then attack them. Typically these whales pose no threat to humans and snorkeling is the best way to interact with these magnificent creatures.

Best locations to encounter Humpback Whale migration:

All of the below locations are suitable for snorkelers.

  • Ningaloo Reef, Western Australia, Australia – June to August.
  • Vava’u Islands, Tonga – July to October.
  • Silverbank, Dominican Republic – January to April.


If you are looking for other exciting marine encounters check out our articles 10 Amazing sharks from around the world and Diving with Schools of Sea Life.

About the Author

Amanda and her husband Dean have been certified divers since 2009. Amanda has her advanced open water and Dean is a dive master. They have travelled the world and dived many sites in Australia, Asia, Central America and the Caribbean.

Amanda and Dean have a travel blog called Scatabout which details the fun and unique experiences they have had on their world travels. You can find them doing something adventurous like scuba diving, hiking or something strange like running down the side of a building.

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